Anatomy Exam 2 (full)
receptor
A _______ refers to any structure capable of detecting a stimulus
Lateral
A brain ventricle located in the cerebrum is the _____ ventricle.
patch of arachnoid mater that pokes up into the sinuses and reabsorbs CSF
Arachnoid villus
Glands, smooth muscle, cardiac muscle Usually involuntary Varicosities Two nerve fibers from CNS to effector; synapse at a ganglion ACh and NE Excitatory or inhibitory
Autonomic Nervous: Effectors: Control: Distal Nerve Endings: Efferent Pathways: Neurotransmitters: Effect on Target Cells:
the presynaptic neuron's axon synapses with the postsynaptic neuron's axon
Axoaxonic synapse
change one form of energy into another form.
By definition, transducers:
forms loose fitting sleeve called the dural sheath around spinal cord; tough collagenous membrane
Dura mater of the spinal cord
kinesin
During axonal transport, which motor protein assists anterograde transport?
The carbohydrate moiety of a glycoprotein hormone is added by the Golgi complex.
During the synthesis of glycoprotein hormones, where in the cell would the carbohydrate be added?
D) granulosa cells of the ovary Theca cells produce androgen, and granulosa cells convert the androgen to estrogen)
Estradiol is produced by which of the following? A) sustentacular cells of the testes B) interstitial cells of Leydig in the testes C) islet cells of the pancreas D) granulosa cells of the ovary
ovaries and adrenal cortex
Estradiol source
Arachidonic acid
Eicosanoids are derived from __________-
gap junctions
Electrical synapses involve coupling of neurons by:
anterior horn
Horn that contains large somas of the somatic motor neurons and the exons from these neurons exit by way of this root of the spinal nerve and goes to skeletal muscles
lateral horn
Horn that sends autonomic efferent signals away
a. free nerve endings.
Hot and cold stimuli are detected by a. free nerve endings. b. proprioceptors. c. end bulbs. d. lamellar corpuscles. e. tactile corpuscles.
Neither FSH nor testosterone alone, for example, stimulates much sperm production. When they act together, however, the testes produce some 300,000 sperm per minute.
How are FSH and testosterone synergists?
from the amino acid tryptophan
How are most monoamines, except TH, synthesized?
synthesized from cholesterol, which is converted as progesterone and then from there they all differ in the functional group attached to the 4-ringed steroid backbone
How are steroids synthesized?
2 (hypophyseal pouch makes up the anterior lobe, and the neurohypophyseal bud makes up the posterior pituitary)
How many different tissues make up the pituitary gland?
6 (in most parts of the brain, it can vary)
How many layers are neurons arranged in in the neocortex?
2
How many nerve fibers connect the CNS with an effector in the ANS?
3; they are all composed of opsin and retinal, but each opsin has a different amino acid sequence that determines which wavelength gets absorbed
How many types of cones are there and how are they different?
500 mL
How much CSF does the brain produce per day?
Such a drug would block leukotriene synthesis and thus inhibit allergic and inflammatory responses, and immune responses
How would the body be affected by a drug that inhibited lipoxygenase?
Oxytocin
Hugging releases
transparent mucous membrane that covers the inner surface of the eyelid and the anterior surface of the eyeball, except the cornea. It secretes mucous film that prevents the eyeball from drying.
Conjunctiva
Both cerebral lobes!
Conscious behavior depends on what side of the brain?
sympathetic, somatic
Consider a basketball player whose heart is racing during the final moments of a game. With seconds on the clock, she makes a jump shot. Her excitement is a function of her ________ nervous system, and her movements are a function of her _______ nervous system.
unmyelinated axons.
Continuous conduction of a nerve impulse occurs only along:
found on the floor of ventricles; spongy mass of capillaries that produces CSF from blood
Choroid plexus
farsightedness; the eyeball is too short snd the retina lies in front of the focal point of the lens and the light rays have not yet come into focus before they reach the retina
Hyperopia
either the entry of an anion or the exit of a cation.
Hyperpolarization of a neuron results from:
convex; converge
Hyperropia can be corrected with a ____________ lens which causes light rays to _____________ before entering the eye
anterior pituitary gland
Hypothalamic inhibiting hormones inhibit the release of hormones from where?
T4
More abundant part of TH
T3
More active part of TH
Diabetes Mellitus
Most common metabolic disease in the world
Type 2
Most common type of Diabetes mellitus
cornea
Most of the refraction happens in the eye in the
carries signals from the CNS to gland and muscle cells to carry out responses; broken down into the somatic and visceral motor divisions
Motor (efferent) division of PNS
reverberating
Motor effects that depend on repetitive output from a neural pool are most likely to use what type of circuit?
somatic
Motor neurons of the _________ nervous system contain more rapidly conducting axons.
in certain situations, the myelin sheath does not form property, and the nerve signals are not able to be transmitted as effectively
Multiple sclerosis
acetylcholine
Muscarinic receptors bind
stapedius and tensor tympani
Muscles of the middle ear
nearsightedness; a condition in which the eyeball is too long. Light rays come into focus before they reach the retina and begin to diverge again by the time they fall on it
Myopia
concave; diverge
Myopia can be corrected with a ________________ lens which causes light rays to ____________ before entering the eye
aspirin, ibuprofen, & celecoxib (Celebrex)
NSAID drugs
the ability of your neurons to process information, store and recall it, and make decisions; based on the post-synaptic potentials produced by neurotransmitters because a neuron has to be depolarized to -55mV to produce action potentials
Neural integration
bundles of actin filaments in the soma
Neurofibrils
Somatic motor
In what nervous system does a myelinated fiber goes all the way from the anterior root to the muscle, where it secretes ACh?
both
Is ADH a neurotransmitter or hormone?
Both
Is oxytocin a neurotransmitter or hormone?
dehydroepiandrosterone
Major androgen that the adrenal cortex secretes
primary motor cortex of the cerebrum
Major site of CNS control over the somatic motor system
Somatostatin of delta cells of pancreatic islets
Modulates digestion, nutrient absorption, and glucagon and insulin secretion
A) Norepinephrine C) Dopamine
Monoamine hormones include catecholamines. What are some examples? A) Norepinephrine B) Insulin C) Dopamine E) Glucagon
Electrical synapse
Of the two types of synapses, based on mode of communication, which is less common but allows faster signal transmission?
pathway in which signals travel over many synapses on their way back to the muscle Some signals follow routes with only a few synapses and return to the flexor muscle quickly, others follow routes with more synapses and return to the flexor muscle more slowly, so the flexor p\muscles receive prolonged output from the spinal cord and not just a sudden stimulus
Polysynaptic reflex arc
contains the somas of sensory neurons going to the spinal cord
Posterior root ganglion
dehydroepiandrosterone
Precursor of testosterone; indirectly promotes growth of bones, pubic and axillary hair, apocrine glands, and fetal male reproductive tract; stimulates libido
acetylcholine.
Preganglionic axons of the ANS release:
androgen
Primary adrenal sex steroid
antidiuretic hormone
Stimulates water retention
facilitation
Summation, either spatial or temporal, leads to
ventricles; CSF
The brain has four chambers called _____ filled with _____
the medulla oblongata, pons, and the midbrain and the diencephalon
The brainstem consists of
gray
The cerebral cortex consists of ______ matter.
40%
The cerebral cortex constitutes about _____ of the mass of the brain
Up-regulation
a cell increases the number of hormone receptors and becomes more sensitive to it
c. its wavelength.
The color of light is determined by a. its velocity. b. its amplitude. c. its wavelength. d. refraction. e. how strongly it stimulates the ro
axon, voltage-
The conductive segment of a neuron is its _______, a region that contains many _______ gated channels.
sympathetic, vasodilation.
The diameter of many blood vessels is controlled exclusively by the ________ nervous system, and decreases in the activity of this system result in _________.
3rd
The diencephalon encloses which ventricle?
enteric
The digestive tract has a semi- independent nervous system called the _____ nervous system.
ducts
The distinction between exocrine and endocrine glands is the presence or absence of
the sympathetic division
The division of the autonomic nervous system that has complete control over the blood vessels is
cortisol
The dominant hormone in the stage of resistance of the stress response is _________.
ADH and OT are made in the hypothalamus neurons and move down the nerve fibers by axoplasmic flow to the posterior pituitary
The hypothalamus controls the posterior pituitary by
Unbound hormone
a hormone not attached to a transport protein; the only type that can leave a blood capillary and enter the target cell
sensation
a subjective awareness of the stimulus; when the receptor sends information to the brain
tunica vasculosa
The iris is part of which tunic?
somatic nervous system.
The knee jerk reflex (when the quadriceps muscles contract after the patellar tendon is tapped) is the work of the:
effectors.
The nervous system controls the activity of muscles and glands. Muscles and glands can generate changes and are therefore called:
enteric
The nervous system that consists entirely of neurons embedded in the walls of the digest tract and does not originate from the brain or spinal cord
3 cell layers (photoreceptor cells, bipolar cells, ganglion cells)
The neural components of the retina consist of what?
CNS (one end expands and becomes the prosencephalon, mesencephalon, and rhombencephalon, and the other end becomes the spinal cord)
The neural tube in the embryo is going to be the
norepinephrine
The neurotransmitter secreted at an adrenergic synapse is
NE
The neurotransmitter that is secreted by almost all sympathetic postganglionic fibers
cerebral cortex
The outer layer of the brain called the __________ is formed by gray matter
somatostatin, glucagon, and insulin
The pancreatic islet cells secrete
sensory (afferent) and motor (efferent)
The peripheral nervous system can be broken down into 2 systems
the primary motor cortex
The precentral gyrus is
Acetylcholine
The preganglionic fiber always releases what neurotransmitter?
spinal cord or brainstem; ganglion
The preganglionic neuron has its cell body in the _________ and its axon terminates in the _________
prevent sweat from dripping into the open eye.
The primary function of eyebrows is to:
Right (there was a decussation)
The primary somatosensory cortex in the left cerebral hemisphere receives signals from what side of the body?
rhombencephalon
The primary vesicle from which the metencephalon arises is the:
the general senses
The receptors for what always decussate?
tunica interna
The retina is part of which tunic?
tumors resulting in overgrowth of functional endocrine tissue or autoimmune disorder
Things that can cause hypersecretion of a hormone
lens
This focuses light on the retina
right
This hemisphere has left hand motor control
right
This hemisphere has memory for shapes
right
This hemisphere has musical ability
left (specialized for spoken and written language)
This hemisphere has superior language comprehension
soma
This is the control center of a neuron
Adrenergic
This type of receptor is found at all target organs that receive NE
type 3
This type of taste cell actives a G protein complex to open the gates and can generate an action potential and it detects sour
rods, cones, ganglion cells
Three photoreceptor cells
-55 mV
Threshold potential for a neuron
glycoproteins
a polypeptide conjugated with a short carbohydrate chain
the brain's 4 connected internal chambers; allow the flow of CSF
Ventricles
fast
Vesicles and glycoproteins required at the synapse are moved down a nerve fiber by _______ axonal transport.
electromagnetic radiation
Vision is the perception of
Sodium, calcium, chloride, glucose, protein
What can be found in CSF?
a ridge of the cerebral cortex
What is a gyrus in the brain?
To equalize air pressure between the atmosphere and the middle ear
What is the function of the auditory tube?
focus light on the retina
What is the function of the lens?
to adjust the response of the cochlea to different frequencies and enable the IHCs to work with greater precision.
What is the function of the outer hair cells?
Astrocyte
What is the most abundant glial cell in the CNS?
the neocortex
What makes up 90% of the cerebral cortex?
Anterior pituitary
What secretes ACTH?
Anterior pituitary
What secretes FSH?
Anterior pituitary
What secretes GH?
Anterior pituitary
What secretes LH?
Anterior pituitary
What secretes TSH?
sclera, cornea
What structures are part of the outer, fibrous layer of the eyeball?
Neurofibrils
What structures extend into the axon and dendrite of a neuron to provide tensile strength?
diameter of the fiber and myelination
What two factors control conduction speed in nerve fibers?
ligand gated
What type of channels do dendrites and the soma have?
A drug that blocked the receptors for substance P might serve as a powerful analgesic because it would block pain signals from reaching the brain.
What would be the benefit of a drug that blocks the receptors for substance P?
c. dehydration (ADH increases water retention in the kidneys, reduces urine volume, and helps prevent dehydration)
What would be the consequence of defective ADH receptors? a. diabetes mellitus b. adrenogenital syndrome c. dehydration d. seasonal affective disorder e. none of these
The lacrimal punctum drains tears into the nasolacrimal duct, so if it was blocked, it would result in watery eyes
What would be the effect of a blockage of the lacrimal punctum?
A) Micturition B) Ejaculation D) Defecation E) Erection (If the brain gets severed from the spinal cord, autonomic spinal reflexes can control the elimination of urine and feces)
Which are autonomic reflexes regulated by the spinal cord? A) Micturition B) Ejaculation C) Vomiting D) Defecation E) Erection
parasympathetic
Which divine of the ANS has long preganglionic fibers and short postganglionic fibers?
Parasympathetic
Which division functions to conserve energy and replenish the supply of nutrients?
PNS
Which division of the nervous system shows a greater capacity for regeneration?
Interneurons
Which functional class of neurons lies entirely within the central nervous system?
thyroid gland
Which gland is located immediately below the larynx and is shaped like a butterfly
GH
Which hormone has the most widespread affect in the body?
a. oxytocin (the hypothalamo-hypophyseal tract is a bundle of nerve fibers from the hypothalamus to the posterior pituitary a the hormones made in the hypothalamic neurons move down the nerve fibers by axoplasmic flow to the posterior pituitary)
Which hormone would no longer be secreted if the hypothalamo-hypophyseal tract were destroyed? a. oxytocin b. follicle-stimulating hormone c. growth hormone d. adrenocorticotropic hormone e. corticosterone
A) Cortisol B) Testosterone
Which hormones are steroid hormones? A) Cortisol B) Testosterone C) Oxytocin D) TH E) Epinephrine
Transmits impulses from the viscera
Which is not a function of the motor division of the nervous system? Conducts impulses from the CNS Transmits impulses to muscles and glands Transmits impulses from the viscera Voluntary control of skeletal muscle Involuntary control of the heart
Transporting materials throughout the body
Which is not a general function of the nervous system? Transporting materials throughout the body Collecting information Processing and evaluating information Responding to information All
Triangular-pre-discharge
Which is not a type of neuronal pool? Converging Triangular-pre-discharge Diverging Parallel-after-discharge Reverberating
D) Skeletal muscle
Which is not an effector innervated by the autonomic nervous system? A) Cardiac muscle B) Smooth muscle C) Glands D) Skeletal muscle E) No exceptions
High mitotic rate
Which is not characteristic of neurons? High mitotic rate High metabolic rate Require continuous supplies of glucose and oxygen Extreme longevity All
E) The SNS is activated by visceral sensory neurons
Which is not true about the somatic nervous system (SNS)? A) The SNS is under voluntary control. B) The SNS uses motor and sensory neurons. C) The SNS innervates skeletal muscle fibers. D) The SNS is part of both the CNS and the PNS. E) The SNS is activated by visceral sensory neurons
B) Oxygen C) Glucose D) Caffeine
Which molecules can pass through the blood-brain barrier? A) Macrophages B) Oxygen C) Glucose D) Caffeine E) Antibodies
Postganglionic nerve fibers of the sympathetic division
Which nerve fibers secrete NE in the ANS?
ANS
Which nervous system controls activity of glands, cardiac muscle, and smooth muscle?
somatic (somatic motor divine of the motor divine of the PNS)
Which nervous system regulates conscious, voluntary movements of the skeletal muscles?
Preganglionioc neurons of both divisions and the postganglionic parasympathetic neurons
Which neurons secrete ACh in the ANS?
B) Reflexes C) Locomotion E) Conduction
Which of the following are functions of the spinal cord? Select all A) Transduction B) Reflexes C) Locomotion D) Cognition E) Conduction
A) They are released in response to stimulation D) They are synthesized by presynaptic neurons D) They bind to receptors and alter the physiology of the postsynaptic cell
Which of the following characterize neurotransmitters? Select all A) They are released in response to stimulation B) They stimulate the opening of voltage regulated gates at the post synaptic neuron C) They are found in the dendrites of the post synaptic neurons D) They are synthesized by presynaptic neurons D) They bind to receptors and alter the physiology of the postsynaptic cell
C) Postganglionic D) Sympathetic E) Unmyelinated
Which of the following describes the axons of the gray communicating ramus? Select all A) Myelinated B) Parasympathetic C) Postganglionic D) Sympathetic E) Unmyelinated F) Preganglionic
d. thyroxine (all the others are secreted by the anterior pituitary)
Which of the following hormones has the least in common with the others? a. adrenocorticotropic hormone b. follicle-stimulating hormone c. thyrotropin d. thyroxine e. prolactin
A) Stretching of the skin B) Vision D) Hearing (Exteroceptors sense signals extenal from the body; vision, hearing, taste, smell, and cutaneous sensations)
Which of the following sensations result from the activation of exteroceptors? A) Stretching of the skin B) Vision C) Bladder pressure D) Hearing E) Visceral pain
The neuroendocrine reflex in ADH secretion is an example of homeostasis. Dehydration triggers a reflex that ultimately promotes water conservation by the kidneys, thus helping to maintain a homeostatic state of water balance.
Which of the unifying themes is best exemplified by the neuroendocrine reflexes that govern ADH secretion?
Cerebellum
Which portion of the brain adjusts skeletal muscle activity to maintain equilibrium and posture?
Medulla oblongata
Which portion of the brain contains the posterior part of the fourth ventricle?
vermis
Which portion of the cerebellum connects the left and right hemispheres?
ganglion cells
Which retinal cells produce action potentials?
B) The SNS does not have ganglia for its motor neurons but the ANS does.
Which statement accurately compares the motor systems of the somatic nervous system (SNS) and autonomic nervous system (ANS)? A) Both the SNS and ANS house their motor neurons in ganglia. B) The SNS does not have ganglia for its motor neurons but the ANS does. C) The ANS does not have ganglia for its motor neurons but the SNS does. D) Neither the SNS nor the ANS house their motor neurons in ganglia
Contains no receptor cells, so it produces a blind spot in the visual field of each eye
Why is the optic disc called the blind spot?
The reason it is so big is because it contributes to immune system and antibodies and once they are formed, it isn't needed much anymore
Why is the thymus so big in infants and so small in adults?
it would oppose the inward movement of the tympanic membrane and reduce the amount of vibration transferred to the inner ear
Why would high air pressure in the middle ear reduce the movements of the basilar membrane of the inner ear?
decreased
With damage to nerve fibers, larger distances between the site of damage and the target structure innervated result in _________ chances of successful regeneration.
supporting cells
Within a taste bud; resemble taste cells but have no synaptic vesicles and no sensory role
optic chiasm; hemidecussation
Within the _____________, half of the nerve fibers from each optic nerve cross over to the other side of the brain, and this is called a ____________
form of STM that allows us to hold an idea in mind long enough to carry out an action such as calling a telephone number we just looked up, working out the steps of a mathematics problem, or searching for a lost set of keys while remembering where we have already looked; based on synaptic facilitation and a circuit of facilitated synapses that can remain quiescent (consuming no energy) most of the time, but be reactivated by a new sensory input.
Working memory
converging
You walk into a restaurant and amidst the sights, sounds, and smells of food preparation, you notice that you have begun to salivate. This is evidence that a particular neuronal circuit has been activated. Which one?
.stress
caused by any situation that upsets homeostasis and threatens one's physical or emotional well-being; injury, surgery, infection, intense exercise, pain, grief, depression, anger, etc
Down-regulation
cell reduces the number of receptors and becomes less sensitive to it; this can happen due to long term exposure to high hormone concentrations
cochlea
coiled tube in the inner ear; organ of hearing in the bony labyrinth
conductive deafness
conditions interfere with transmission of vibrations to inner ear; damaged tympanic membrane, otitis media, blockage of auditory canal, and otosclerosis
Lacrimal apparatus
consists of the lacrimal gland and ducts that drain the tears into the nasal cavity
olfactory mucosa
contains 10 to 20 million olfactory cells, as well as epithelial supporting cells and basal stem cells in the roof of the nasal cavity
spinal cord
cylinder of nervous tissue that arises from the brainstem at the foramen magnum of the skill that passes through the vertebral cavity; gives rise to 31 pairs of spinal nerves; only extends to L3
Unencapsulaed Nerve Endings
dendrites of these receptors are not wrapped in connective tissue
sensory homonucleus
diagram of the primary somesthetic cortex which resembles an upside-down sensory map of the contralateral side of the body and how richly innervated the area is and how sensitive the region is; how much region of the cortex is dediated to their sensation
Fungiform papillae
each has about 3 taste buds; widely distributed, but are especially concentrated at the tip and sides of the tongue
tympanic membrane
eardrum; closes the inner end of the auditory canal and separates it from the middle ear; is suspended in a ring shaped groove in the temporal bone and vibrates freely in response to sound
Leukotrienes
eicosanoids that mediate allergic and inflammatory reactions and are important in the immune system
brain waves
electrical activity in the brain; rhythmic voltage changes resulting mostly from the synchronized postsynaptic potentials in the superficial layers of the cerebral cortex
flow of charged particles from one point to another
electrical current
Eyebrows
enhance facial expressions and nonverbal communication and protect eyes from glare and keep perspiration out of the eyes
adrenal medulla
essentially a sympathetic ganglion consisting of modified neurons without dendrites or axons. Sympathetic preganglionic fibers terminate on these cells and when stimulated they secrete hormones into the bloodstream
hypersecretion
excessive hormone release
an input neuron synapses with other neurons in the pool and it has a vote on what the post synaptic cells do, but it cannot determine alone what they do because it doesn't have enough synapses on the output neuron to reach the threshold
facilitated zone
Myelinated fibers
fast (first) pain; this type of fiber produces the feeling of sharp, localized pain at the time of injury
ultrasonic frequencies
above 20,000 Hz; inaudible vibrations
secreted concurrently with the release of insulin. Inhibits the secretion of stomach
acidsomatostatin of the pancreatic islets (delta cells)
spiral organ
acoustic organ in the cochlear duct; converts vibrations into nerve impulses that is composed of hair cells and supporting cells and has the basilar membrane on the bottom
Enkephalins
analgesic oligopeptides with 200x the potency of morphine secreted by the brain
many dendrites but no axon; help in visual processes. They cannot produce action potentials
anaxonic neuron
PGF
antagonistic of PGE
sound
any audible vibration of molecules
lsensory receptor
any structure specialized to detect a stimulus; can be kinetic (mechanical), electromagnetic (vision, heat through radiation), or chemica
Pupillary dilator
arrangement of contractile myoepithelial cells that when stimulated by the sympathetic nervous system, they contract and widen the pupil
(graves disease) toxic goiter
autoantibodies mimic effect of TSH on the thyroid causing thyroid hypersecretion; caused by autoimmune disorder
Orbit
bony socket in which the eyeball occupies
The majority of our neurons areinterneurons
interneurons
macula utriculi
maculae lie horizontal on the floor; detect head tilt
umami
meaty taste ; produced by the amino acids aspartic and glutamic acid; detected by type 2
.Prostaglandins
most diverse eicosanoids. They have a five-sided carbon ring in their backbone; thought to be produced in most organs of the body
Cortisol
most well known glucocorticoid
Tunica vasculosa
middle layer of the eye
cornea
modified sclera
Adrenal glands
sit on top of the kidney
primary afferent sensory nerve fiber in the muscle spindle
monitor muscle length and how rapidly it changes; very responsive to sudden body movements
zona reticularis
narrow, innermost layer of the adrenal cortex
Stage 1 sleep
one feels drowsy and closes the eyes and begins to relax; accompanied by drifting sensation. One awakens easily when stimulated. Alpha waves dominate EEG
Signal amplification
one hormone molecule can trigger the synthesis of not just one enzyme molecule, but many
Suprachiasmatic nucleus
one of the control centers for sleep; located above the optic chiasm where some nerve fibers enter here instead of the visual cortex of the cerebrum and it uses this input to synchronize multiple body rhythms with the rhythm of day and night. Not just sleep, but body temperature, urine production, hormone secretion, etc.
dermatome
specific area of the skin that sends sensory information to the spinal nerve
emmetropia
state in which the eye is relaxed and focused on an object more than 6m away
in the cerebral cortex; have spheroid somas with dendrites projecting in all directions; receive sensory input and process information on a local level
stellate cells
tunica fibrosa
outer layer of the eye consisting of the cornea and the sclera
tip link
stretchy protein filament that extends from one protein on a stereocilium to the side of the next one
sense organ
structure composed of nervous tissue and other tissues that enhances its response to a certain type of stimulus
sweet
taste that is detected by type 2; produced by many organic compounds, especially sugars
polysynaptic reflex arc
pathway in which signals travel over many synapses on their way back to the muscle
dynamic equilibrium
perception of motion or acceleration
static equilibrium
perception of orientation of the head when the body is stationary
lamellar corpuscles
phasic receptors for deep pressure, stretch, tickle, and vibration
Chromophores
pigmented cells in the iris
Thromboxanes
produced by blood platelets after injury; can they override prostacyclin and stimulate vasoconstriction and clotting
tendon organs
proprioceptors in a tendon near its junction with a muscle has nerve fibers and when it contracts it squeezes the nerve and the nerve fiber sends signals to the spinal cord that provide the CNS with feedback on the degree of muscle tension
reflex
quick, involuntary, stereotyped reactions of glands or muscle to stimulation
Metabolic clearance rate
rate of hormone removal
lacrimal gland
gland above the eye that produces tears
oval window
holds the base of the stapes, where the inner ear begins
cortisol
hormone that helps the body adapt to stress
tactile discs
receptors for light touch and texture
free nerve endings
receptors in the skin and mucous membrane; warm receptors, cold receptors, and nociceptors for pain; they stimulate easily
alpha waves
recorded in the parieto-occipital area; dominate when a person is awake and resting with eyes closed
saccule and utricle
responsible for static equilibrium and the sense of linear acceleration
Suspensory ligament
ring of fibers that attaches to the ciliary body and suspends the lens
thyroid follicles
sacs that compose most of thyroid
signal conduction in myelinated axons; the nerve signal seems to jump from node to node in myelinated fibers
saltatory conduction
Ora serrata
scalloped margin of the retina
cerebrum
seat of sensory perception, memory, thought, judgment, and voluntary motor actions; 5 lobes
basilar membrane
separates cochlear duct from the scala tympani
Aqueous humor
serous fluid secreted by the ciliary body into the posterior chamber between the iris and the lens, then it flows through the pupil into the anterior chamber between the cornea and the iris and it is reabsorbed by the scleral venous sinus
eicosanoids
important family of paracrine secretions, a signaling molecule ; have 20-carbon backbones derived from a polyunsaturated fatty acid called arachidonic acid.
steroidal anti-inflammatory drugs (SAIDs)
inhibit inflammation by blocking release of arachidonic acid from plasma membrane and inhibit synthesis of eicosanoids
Adrenal medulla
inner core of the adrenal gland
tunica interna
inner layer of the eye; retina and beginning of the optic nerve
gamma motor neuron
innervates intrafusal fiber and stimulates its contraction to maintain tension so it stays the same tension as the rest of the muscle
fast (first) pain
sharp, localized pain that occurs at the time of injury
Sensory Projection
the ability of the brain to identify the site of stimulation
receptive field
the area in which a sensory neuron detects stimuli
preganglionic fiber
the first motor neuron that is myelinated and leads from a soma in the brainstem or the spinal cord to the autonomic ganglion and theserelease ACh
Projection pathway
the pathways followed by sensory signals to their destination in the CNS
loudness
the perception of sound energy, intensity, or amplitude of the vibration
Somatotopy
the point-to-point correspondence between an area of the body and an area of the CNS. Precentral gyrus and the postcentral gyrus exhibit this
Thymus
the site of maturation of T cells, which are important in immune defense
taste cells
these cells are within taste bus and have microvilli that serve as receptor surfaces for tastants
Granulosa cells
these cells convert androgen to estrogen
Theca cells
these cells in the ovary synthesize androgen
Peptide and monoamines
these hormones are created from chains of amino acids
Steroids
these hormones re derived from cholesterol
Ciliary body
thick extension of the choroid that forms a muscular ring around the lens to support the iris and lens and it secretes aqueous humor
zona fasciculata
thick middle layer of the adrenal cortex
zona glomerulosa
thin layer located at the adrenal cortex surface
third order
this type of neuron carries the signal from the thalamus to the cerebral cortex
chemoreceptors
this type of receptor responds to chemicals; odors, taste, and body fluid composition
thermoreceptors
this type of receptor responds to heat
mechanoreceptors
this type of receptor responds to physical deformation caused by vibration, touch, pressure, stretch, tension
Conjunctiva
transparent mucous membrane that covers the inner surface of the eyelid and anterior surface of the eyeball except the cornea. It secretes thin mucous film, that prevents the eyeball from drying
Cornea
transparent region of the eye that admits light into the eye
single process leading away from the soma; sensory from skin and organs to spinal cord
unipolar neuron
Referred pain
when pain in the viscera is often mistakenly though to come from superficial sites resulting from the convergence of neural pathways in the CNS
contralateral
when the origin and destination of a tract are on opposite sides of the body; when the decussate
ipsilateral
when the original and destination of a tract are on the same side of the body; does not decussate
decussation
when the tracts cross over from one side of the body to the other as they pass up or down the brainstem and spinal cord, resulting in the left side of the brain receiving sensory information from the side side of the body and sending motor commands to that side
Optic disc
where nerves from all of the regions of the retina converge to form the optic nerve and the optic nerve leaves the rear of the eye
Medial and lateral commissures
where the top and bottom eyelids meet each other
Sclera
white of the eye; covers most of the eye surface; dense collagenous tissue perforated by blood vessels and nerves
one axon and one dendrite extending from the cell body.
A bipolar neurons has:
nodes of Ranvier
A myelinated fiber can only produce action potentials in specialized regions called
E) is a cablelike bundle of parallel axons
A nerve: A) contains a single axon. B) is found only in the CNS. C) carries only sensory information. D) carries information only toward the PNS. E) is a cablelike bundle of parallel axons
autonomic motor
A neuron conducting an impulse from the CNS to the detrusor muscle of the urinary bladder would be classified as a(n) __________ neuron.
Toxic goiter is characterized by thyroid hormone hypersecretion. The calorigenic effect of thyroid hormone elevates the body temperature, and the hypothalamus attempts to compensate for this and thermoregulate by inducing sweating. \
A person with toxic goiter tends to sweat profusely. Explain this in terms of homeostasis.
facilitated zone
A presynaptic nerve fiber cannot cause other neurons in its ____________ to fire but it can make them more sensitive to stimulation from other presynaptic fibers
A) the membrane potential has been reestablished
A second nerve impulse cannot be generated until ________. A) the membrane potential has been reestablished B) the Na ions have been pumped back into the cell C) proteins have been resynthesized D) all sodium gates are closed
hyperpolarization
A shift in the membrane voltage to a value that is more negative than the resting membrane potential
skin, skeletal muscles, bones, and joints
A somatic fiber innervates what?
the fusion of posterior and anterior roots
A spinal nerve is formed from the fusion of what?
A) external acoustic meatus, tympanic membrane, ossicles, and oval window.
After being funneled by the auricle, sound waves pass (in sequence) through the: A) external acoustic meatus, tympanic membrane, ossicles, and oval window. B) external acoustic meatus, oval window, ossicles, and cochlea. C) external acoustic meatus, tympanic membrane, internal acoustic meatus, and oval window. D) internal acoustic meatus, tympanic membrane, oval window, and ossicles. E) internal acoustic meatus, tympanic membrane, ossicles, and round window.
B) incus, stapes, oval window, scala vestibuli perilymph, and cochlear duct endolymph.
After causing vibrations of the maleus, sound waves pass (in sequence) through the: A) stapes, round window, scala externa perilymph, scala media endolymph, and oval window. B) incus, stapes, oval window, scala vestibuli perilymph, and cochlear duct endolymph. C) oval window, scala tympani perilymph, scala vestibuli endolymph, and spiral organ. D) incus, stapes, oval window, scala tympani endolymph, scala vestibuli, and helicotrema. E) stapes, incus, round window, scala media perilymph, and scala vestibuli endolymph.
hyper polarization
An IPSP is the __________ of the postsynaptic neuron
encapsulated
Are lamellar corpuscles encapsulated or unencapsulated?
encapsulated in muscle tissue
Are muscle spindles encapsulated or unencapsulated?
glia and myelinated nerves that connect different regions within the same cerebral hemisphere; link perceptual and memory centers of the brain
Association tracts
A) cochlear nuclei, and they are involved in localizing the source of a sound. They are located in the pons (they function in binaural hearing)
Auditory cells in the superior olivary nucleus receive their input from the and they are located where? A) cochlear nuclei, and they are involved in localizing the source of a sound. B) cochlear nuclei, and they determine the pitch of a sound. C) inferior colliculi, and they are used to relay the information directly to the primary auditory cortex. D) inferior colliculi, and they filter out irrelevant auditory information. E) thalamus, and they allow us to recognize familiar voices.
the presynaptic neuron's axon synapses with the postsynaptic neuron's dendrite
Axodendritic synapse
membrane of axon
Axolemma
nerve fiber that is cylindrical and specialized for rapid conduction of nerve signals to points away from its soma. A lot of microtubules and filaments in the axon to move the materials away from the cell body
Axon
branch that originates from an axon
Axon collateral
mound on one side of the soma from which the axon originates; trigger area because it can generate an action. Most of the neuron cell body cannot support an action potential. The dendrites bring signals into the neuron via a synapse at the end of the dendrite and a signal is transmitted and the receptor proteins on the neurilemma open and we have a local depolarization and we may get a lot of local depolarizations, and those diffuse out of the dendrites into the cell body, and when we get to the axon hillock, we begin to have voltage gated channels here which can generate an action potential. Prior to here, we have ligand or mechanical gated channels which cannot generate an action potential, and when we have voltage gated channels, we can generate an axon potential.
Axon hillock
cytoplasm of the axon
Axoplasm
the presynaptic neuron's axon synapses with the postsynaptic neuron's soma
Axosomatic synapse
Peptide
Chemical classification: Antidiuretic hormone
Peptide
Chemical classification: Calcitonin
Steroid
Chemical classification: Calcitriol
Steroid
Chemical classification: Corticosterone
Peptide
Chemical classification: Corticotropin-releasing hormone
Steroid
Chemical classification: Cortisol
Peptide
Chemical classification: Hormones from the thymus
Peptide
Chemical classification: Inhibin
Peptide
Chemical classification: Insulin
Peptide
Chemical classification: Luteinizing hormone
Monoamine
Chemical classification: Melatonin
Monoamine
Chemical classification: Norepinephrine
Peptide
Chemical classification: Parathyroid hormone
Steroid
Chemical classification: Progesterone
When the ciliary muscle contracts, the diameter of the ciliary body decreases. Thus, the ciliary body as a whole puts less tension on the suspensory ligament on the lens, allowing the lens to relax into a more strongly convex shape.
Contraction of a muscle usually puts more tension on a structure, but contraction of the ciliary muscle puts less tension on the lens. Explain how.
dynenin
During axonal transport, which motor protein assists retrograde transport?
neural plate forms along the embryo and sinks into the tissues to form a neural groove with a raised neural fold on each side and the neural folds roll towards each other (under the influence of the notochord) and fuse and eventually create a hollow region called the neural tube and this neural tube begins to become filled with fluid and becomes the central canal of the spinal cord and the ventricles of the brain and as the neural tube develops some ectodermal cells that lay along the margin of the groove separate from the rest and form a column on each side called the neural crest, and neural crest cells give rise to the two inner meninges, most of the PNS, and other structures of the body
Embryonic development
adrenal medulla
Epinephrine source
Scala vestibuli
Fluid filled chamber in the cochlea that is filled with perilymph; starts at the oval window
ventricles
Fluid filled chambers of the brain are called
Receptor, afferent neuron, interneuron, efferent neuron, effector
From beginning to end, what are the components of a visceral reflex arc?
they are proprioceptors that inform the brain of muscle length and body movements
Function of muscle spindles
There is a lot of convergence and information processing in the retina before the signals are conducted to the brain Convergence occurs when multiple rods or cones synapse with one bipolar cell, and when again many bipolar cells feed into one ganglion cell
How can there be 130 million rods and 6.5 million cones in one retina, but only 1 million nerve fibers in the optic nerve?
Estrogen stimulates the up-regulation of progesterone receptors in the uterus. The uterus would respond poorly to progesterone, if at all, had it not been primed by the first hormone.
How do estrogen and progesterone have permissive effects on each other?
they produce an electrical signal that is conducted to cells at distant locations
How do nerves respond to stimuli?
They are hydrophilic, and cannot penetrate the target cell, so they must stimulate its physiology indirectly and require receptor sites on the cell surface. They bind to specific cell surface receptors, which are linked to second messenger systems on the other side of the membrane
How do peptides and catecholamines affect their target cell?
They are hydrophilic and have no problem mixing with the blood plasma
How do peptides get around the blood?
They are hydrophobic (they have cholesterol as the base, so they are fatty to begin with), so in order to travel through the bloodstream, steroids and TH must bind to hydrophilic transport proteins
How do steroid hormones get around the blood?
all of the ventricles were part of the central canal that were folded over and remodeled, but are still all connected; each time we get an outgrowth of the main part of the brain, the central canals stay confluent with the little areas and the ventricles are derived from the original central canal
How do the cranial ventricles come about?
hypo-hypophyseal tract
How do the posterior pituitary and the hypothalamus connect?
1) Secreted by choroid plexus in each lateral ventricle 2) Interventricular foramina 3) 3rd ventricle where the choroid plexus adds more CSF 4) Cerebral aqueduct 5) 4th ventricle where the chloroid plexus adds more CSF 5) Flows out 2 lateral apertures and one median aperture 7) Fills subarachnoid space and bathes external surfaces of brain and spinal cord 8) At arachnoid villi, CSF reabsorbed into blood of dural venous tissues
How does CSF flow through the brain?
T3 has 3 iodines and T4 has 4
How does T3 differ from T4?
They are hydrophobic (they have cholesterol as the base, so they are fatty to begin with), so in order to travel through the bloodstream, steroids and TH must bind to hydrophilic transport proteins
How does TH get around the blood?
Chickenpox (varicella-voster) is a virus that if a child has it, it remains for life in the posterior root ganglia, but it is kept in check by the immune system. If the immune system becomes compromised, the virus can travel along sensory nerve fibers by fast axonal transport and cause shingles. It will migrate to a dermatome region
How does shingles come about?
Each of the optic nerves in the retina map to a certain area in the brain that allow us to create images that we see. If it was random, all of the light coming in would be scattered all over the place, but the mapping is one-to-one
How is our brain able to make a clear image instead of just a bunch of random everywhere?
Relative to the perilymph, the endolymph has an electrical potential of +80mV because it has an extremely high K+ concentration
How is the endolymph of the cochlear duct different from the perilymph of the scala vestibuli and the scala tympani?
In the dark, rods don't sit quietly doing nothing. They release the neurotransmitter glutamate from the basal end of the cell. When a rod absorbs light, glutamate secretion ceases. Next in line, are sensitive to these on and off pulses of glutamate secretion. Bipolar cells are inhibited by glutamate and excited when its secretion stops; these cells are therefore excited by rising light intensities. As your eye scans a scene, it passes areas of greater and lesser brightness. Their images on the retina cause a rapidly changing pattern of bipolar cell responses as the light intensity on a patch of retina rises and falls. When bipolar cells detect fluctuations in light intensity, they stimulate ganglion cells either by directly synapsing with them, or by indirectly going through amacrine cells Ganglion cells respond to the bipolar cells with rising and falling firing frequencies and via the optic nerve, these changes produce visual signals to the brain
How is the optic nerve signal conducted?
If the thyroid gland is removed, TSH level rises because the hypothalamus and pituitary gland no longer receive negative feedback inhibition from the thyroid.
If the thyroid gland was removed from a cancer patient, would you expect the level of TSH to rise or fall? Why?
A) more negative.
If there were no sodium leak channels, the resting membrane potential of a neuron would be: A) more negative. B) more positive. C) the same. D) 0 mV.
The membrane potential will become lower (more negative).
If we increased the concentration of Cl- ions in the ICF, would the membrane potential become higher or lower?
e, a, c, d, b
If you were to cut a cross section of the retina and examine it under a microscope, what would be the order of features from the choroid to the posterior cavity? a: Rods and cones b: Ganglionic axons progressing to the optic nerve c: Bipolar cells d: Ganglion cells' bodies e: Pigmented retina
undergo adaptation.
In general, you become unaware of the shirt on your back because your touch receptors:
• molecules must be dissolved in the saliva and flood the taste pore
In order to be tasted, what has to happen to food?
E) hypothalamus
In the brain, the ________ is the integration and command center for autonomic functions. A) medulla B) cerebral cortex C) spinal cord D) brainstem E) hypothalamus
gray; white
In the brain, the cortex and nuclei make up ___________ matter and tracts make up _________ matter
Hyeloid canal
In the eye, where an artery used to be to help form the lens when it was growing and it deposited crystals to help make the lens refractory
In the day vision system, there is little neural convergence. In the fovea, each cone has a "private line" to the brain, so each optic nerve fiber represents a tiny area of retina, and vision is relatively sharp. However, the lack of convergence means photopic vision cannot function well in dim light because weakly stimulated cones cannot collaborate to stimulate a ganglion cell.
In the photopic system, is there neural convergence? And what is the consequence or benefit of this.
In the scotopic night vision system, many rods converge on each bipolar cell and many bipolar cells converge on each ganglion cell. This allows rods to combine their effects through spatial summation and stimulate the ganglion cell, generating a nerve signal even in dim light. However, it means that each ganglion cell (and its optic nerve fiber) represents a relatively large area of retina and produces a grainy image.
In the scotopic system, is there neural convergence? And what is the consequence or benefit of this.
Prolactin-inhibiting hormone (PIH)
Inhibits secretion of prolactin (PRL)
pore that connects each lateral ventricle to the third ventricle
Intraventricular foramen
e, c, d, a, b
List these events in the correct order for CSF flow in the CNS. a: CSF flows into the arachnoid villi. b: CSF enters the blood. c: CSF flows through the cerebral aqueduct to the 4th ventricle. d: CSF flows into the subarachnoid space. e: CSF is produced by the choroid plexus
convergence.
Many different sources can stimulate an autonomic ganglion cell simultaneously due to:
pituitary gland
Many of the functions of the hypothalamus are carried out by way of the ___________, which is closely associated with it, anatomically and physiologically
muscle spindles (among the body's proprioceptors)
Many somatic reflexes involved stretch receptors called
pineal gland
Melatonin source
continues into the vertebral canal where it forms the dural sheath around the spinal cord; in some places it folds inward to separate major parts of the brain from each other; dips down into the sulci
Meningeal layer of cranial dura mater
3 fibrous membranes that enclose the brain and spinal cord that separate the soft tissue of the CNS from the bones of the vertebrae and skull; dura mater, arachnoid mater, pia mater. Continuous from the spinal cord into the brain and are continuous around the nerves and is continuous with the connective tissue covering the muscles which is continuous with the connective tissue with the skeleton
Meninges
presynaptic neuron's axon and a postsynaptic neuron's dendrite.
Most commonly, a synapse is made between a:
nervous
Nervous or endocrine: Communicates by means of electrical impulses and neurotransmitters
sendocrine
Nervous or endocrine: May continue responding long after stimulus stop
endocrine
Nervous or endocrine: Reacts more slowly to stimuli (seconds to days)
endocrine
Nervous or endocrine: Releases hormones into the bloodstream for general distribution around the body
nervous
Nervous or endocrine: Releases neurotransmitters at synapses of specific target cells
endocrine
Nervous or endocrine: Sometimes has very general, widespread effects
nervous
Nervous or endocrine: Stops quickly when stimulus stops
BOTH
Nervous or endocrine: Target cell must have receptors
nervous
Nervous or endocrine: Usually has local, specific effects
somatic reflexes
Nervous reflexes in which skeletal muscle is the effector
the way in which the nervous system converts information into meaningful patterns of action potentials
Neural Coding
pathway among neurons in a neural pool that partially determine the function of that pool
Neural circuit
electrophysiology
Neural communication, like muscle excitation, is based on __________
at the end of the neural plate; forms most of the PNS, bones in the head and jaw, adrenal gland, and a source of melanocytes; gives rise to arachnoid mater and pia mater
Neural crest
pools of spinal neurons receive input from multiple sources, integrate information and execute appropriate output and it occurs in the gray matter since the gray matter is the site of synaptic contact and therefore the site of integration
Neural integration function of the spinal cord
made of neural circuits; consists of thousands to millions of interneurons concerned with a particular body function. Information arrives at a neural pool through one or more input neurons, which branch repeatedly and synapse with numerous interneurons in the pool. Some input neurons form multiple synapses with a single postsynaptic cell.
Neural pools
the wrapping of a Schwann cell around an axon; contains the nucleus and cytoplasm of the Schwann cells; in the CNS
Neurilemma
B) acetylcholine and allow sodium ions to enter the cell. (They occur at all synapses in the autonomic ganglia where the preganglionicfibers stimulate the postganglionic cells, on the cells of the adrenal medulla, and at the NMJ in skeletal muscle fibers. The binding of ACh to a nicotonic receptor is ALWAYS EXCITATORY and always produces an EPSP)
Nicotinic receptors bind: A) acetylcholine and allow chloride ions to exit the cell. B) acetylcholine and allow sodium ions to enter the cell. C) muscarine and increase the contractility of intestinal muscle. D) norepinephrine and can either stimulate or inhibit the cell. E) norepinephrine and allow potassium entry, thereby exciting the cell
dark staining regions that represent the rough ER in neurons
Nissil bodies
gaps between the myelin segments; gaps between Schwann Cells because in both the PNS and CNS, a nerve fiber is much longer than the reach of a single glial cell, so it requires many Schwann cells or oligodendrocytes to cover one nerve fiber, so the sheath is segmented
Nodes of Ranvier
deep neuron cell bodies in the CNS (surface layer neuron cell bodies are the cortex)
Nuclei
bipolar
Olfactory receptor cells are _____ neurons.
Paraventricular nucleus of hypothalamus
Part of the hypothalamus that is responsible for making OT
Supraoptic nucleus of hypothalamus
Part of the hypothalamus that is responsible making for ADH
delicate, transparent membrane that follows contours of spinal cord; continues beyond medullary cone as a fibrous strand called the terminal filum within the lumbar cistern; very close to the nerves
Pia mater of the spinal cord
C) gray rami communicantes.
Postganglionic sympathetic axons are carried from the sympathetic trunk to the spinal nerve by the: A) white rami communicantes. B) superior cervical ganglion. C) gray rami communicantes. D) splanchnic nerves. E) pterygopalatine ganglion
the opposite of facilitation; presynaptic neurons suppresses another one and is used to reduce or halt unwanted transmission (different from an IPSP)
Presynaptic inhibition
1) Convergence of the eyes Convergence orients the visual axis of each eye toward the object in order to focus it s image on each fovea 2) Constriction of the pupil Lenses cannot refract light rays at their edges as well as they can at the center, and the image at the edges appears blurry. This can be minimalized by screening out peripheral light rays and looking only at the better focused center, and in the eye, the pupil serves this purpose by constricting as you focus on nearby objects 3) Accommodation of the lens Accommodation is a change in the curvature of the lens that enables you to focus on nearby objects. The ciliary muscle contracts, narrowing the diameter of the ciliary body, relaxing the fibers of the suspensory ligament, and allowing the lens to relax in a more convex shape
Processes of the near response
glia and myelinated nerves that come up from the spinal cord and go up to the various parts of the brain; carry information from the cerebrum to the rest of the body
Projection tracts
Insulin-like growth factor I
Prolongs and mediates action of growth hormone
epinephrine, norepinephrine, dopamine
Promote alertness; mobilize organic fuels; raise metabolic rate; stimulate circulation and respiration; increase blood glucose level; inhibit insulin secretion and glucose uptake by insulin-dependent organs (sparing glucose for brain)
aldosterone
Promotes Na+ and water retention and K+ excretion; maintains blood pressure and volume
Corticotropin-releasing hormone (CRH)
Promotes secretion of adrenocorticotropic hormone (ACTH)
Gonadotropin-releasing hormone (GnRH)
Promotes secretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
Growth hormone−releasing hormone (GHRH)
Promotes secretion of growth hormone (GH)
excitability, conductivity, secretion
Properties of nerve cells
the position or movement of body parts
Proprioceptors respond to stimuli pertaining to
primary ventricle; the forebrain that becomes the telencephalon and the diencephalon
Proscencephalon
e. arachidonic acid.
Prostaglandins are derived from a. phospholipase. b. cyclooxygenase. c. leukotriene. d. lipoxygenase. e. arachidonic acid.
tissue growth requires protein synthesis, and protein synthesis needs two things, amino acids for building material, and messenger RNA for instructions. Within minutes of its secretion, GH boosts the translation of existing mRNA, and within a few hours, it also boosts the transcription of DNA and thus the production of more mRNA. GH also enhances amino acid transport into cells; and to ensure that protein synthesis outpaces breakdown, it suppresses protein catabolism
Protein synthesis function of GH
Age, obesity, sedentary lifestyle, ethnicity (native Americans, Hispanics, Asian)
Risk factors for Type 2 Diabetes
B) defecation
Several regions of the brainstem mediate autonomic responses. Which of the following is not mediated by these areas? A) salivation B) defecation C) pupillary constriction D) blood pressure
carries signals to the skeletal muscle; produces voluntary muscle contractions and involuntary somatic reflexes
Somatic motor division
carries signals from receptors in the skin, muscles, bones, and joints
Somatic sensory division
poor
Some prey animals, such as rabbits, have laterally placed eyes, and the images on their two retinas do not overlap. Such animals would be expected to show _________ depth perception.
1) Opening of calcium gates in the synaptic knob as the nerve signal arrives 2) Exocytosis of ACh and diffusion across the synaptic cleft 3) Binding of Each to receptors on the postsynaptic neuron 4) Opening of Na+ gates on the postsynaptic membrane allowing influx of sodium 5) Depolarization of postsynaptic plasma membrane
Starting with a signal reaching the distal end of the presynaptic axon, indicate the order of events that occur during transmission as a cholinergic excitatory synapse
When the local current arrives at the axon hillock, it depolarizes the membrane at that point. For anything more to happen, this local potential must rise to a critical voltage called the threshold to open the voltage gated channels The neuron now produces an action potential. At threshold, voltage-gated Na+ channels open quickly, while K+ channels open more slowly. The initial effect on membrane potential is therefore due to Na+. Initially, only a few Na+ channels open, but as Na+ enters the cell, it further depolarizes the membrane. This stimulates still more voltage-gated Na+ channels to open and admit even more Na+, creating a positive feedback loop that makes the membrane voltage rise rapidly. As the rising potential passes 0 mV, Na+ channels are inactivated and begin closing. By the time they all close and Na+ inflow ceases, the voltage peaks at approximately +35 mV. The membrane is now positive on the inside and negative on the outside—its polarity is reversed compared to the RMP. By the time the voltage peaks, the slow K+ channels are fully open. Potassium ions, repelled by the positive ICF, now exit the cell. Their outflow repolarizes the membrane—that is, it shifts the voltage back into the negative numbers. The action potential consists of the up-and-down voltage shifts that occur from the time the threshold is reached to the time the voltage returns to the RMP. Potassium channels stay open longer than Na+ channels, so slightly more K+ leaves the cell than the amount of Na+ that entered. Therefore, the membrane voltage drops to 1 or 2 mV more negative than the original RMP, producing a negative overshoot called hyperpolarization Na+ and K+ switch places across the membrane during an action potential. During hyperpolarization, Na+ diffusion into the cell and (in the CNS) the removal of extracellular K+ by astrocytes gradually restore the original RMP. (Local potential increases membrane potential, threshold is reached, depolarization spike, repolarization, hyperpolarization)
Steps of the action potential in nerves
nucleus
Steroid hormones diffuse through the phospholipid regions of the target cell membrane and into the ________ where they bind to a receptor
cortisol and corticosterone
Stimulate fat and protein catabolism, gluconeogenesis, stress resistance, and tissue repair
Estrogen, progesterone
Stimulate fetal development and maternal bodily adaptations to pregnancy; prepare mammary glands for lactation
Adrenocorticotropic hormone (ACTH)
Stimulates growth of adrenal cortex, secretion of glucocorticoids
Growth hormone
Stimulates widespread tissue growth, especially in the liver, bone, cartilage, muscle, fat
Because the Na+-K+ pump removes three positive charges from the cell for every two it brings in, it contributes to the negative membrane potential. If the activity of the Na+-K+ pumps was reduced, ion leakage would make the plasma membrane less polarized and more excitable.
Suppose a poison were to slow down the Na+-K+ pumps of nerve cells. How would this affect the resting membrane potentials of neurons? Would it make neurons more excitable than normal, or make them more difficult to stimulate? Explain.
Assuming that the growling dog instilled fear in you, this would act through the limbic system and hypothalamus to activate the sympathetic fight-or-flight response. The sympathetic nervous system would tend to stimulate epinephrine secretion, dilate your pupils and respiratory passages, dilate your coronary arteries and speed up your heart, cause your hair to stand on end, cause a dry mouth, increase blood flow to your skeletal muscles, promote glycogen breakdown and glucose mobilization, and inhibit digestive and urinary function.
Suppose you are walking alone at night when you hear a dog growling close behind you. Describe the ways your sympathetic nervous system would prepare you to deal with this situation.
vasomotor tone
Sympathetic fibers to blood vessels maintain a state of partial vasoconstriction called _____.
swelling at the end of an axon that form a synapse and contains synaptic vesicles full of neurotransmitters
Synaptic knob
True
T/F: Rods and cones release their neurotransmitter in the dark, not in the light.
False (Some somatic reflexes are mediated primarily through the brainstem and cerebellum)
T/F: Somatic reflexes are those that do not involve the brain.
True
T/F: Some chemoreceptors are interoceptors and some are exteroceptors.
False, all are cholinergic
T/F: Some parasympathetic nerve fibers are adrenergic.
False, all spinal nerves are mixed
T/F: Some spinal nerves are sensory and others are motor.
True
T/F: Some sympathetic postganglionic fibers are cholinergic.
True
T/F: The Broca area is ipsilateral to the Wernicke area.
frequency, intensity
The _______ of a sound stimulus is interpreted as its pitch and measured in hertz, whereas its _______ is referred to as its loudness and is measured in decibels.
anterior pituitary
The _________ develops from a pouch in the pharynx of the embryo.
sympathetic
The _________ division of the ANS and the adrenal medulla developed from the same embryonic tissue and have very related functions
inner; hearing and balance
The __________ ear consists of the cochlea and vestibule, organs that are important for ________________
sclera (when it comes around to the front of the eye, it becomes transparent)
The ___________ is continuous with the cornea on the outside of the eye
posterior root
The ____________ ganglion contains the somas of neurons that carry sensory signals to the spinal cord.
soma; dendrites
The ____________ of a neuron gives rise to __________which are the sites for receiving signals from other neurons
nasolacrimal duct
The ______________ is the most distal portion of the lacrimal apparatus
End bulbs
The battery of your electric toothbrush is running down and so you feel a low frequency vibration in your oral cavity. Which receptors detect this stimulus?
tunica vasculosa
The choroid is part of which tunic?
scala vestibule, cochlear duct, scala tympani
The cochlea has 3 fluid filled chambers that are separated by membranes. What are they?
perineurium
The connective tissue wrapping that surrounds bundles (fascicles) of axons is the:
in the retina
The conversion of light energy into action potentials occurs where
tunica fibrosa
The cornea is part of which tunic?
brain
The eyeball is an extension of the
the high lipid content of the myelin sheath.
The glossy white appearance of most axons is due to:
d. sympathetic postganglionic fibers.
The gray communicating ramus contains a. visceral sensory fibers. b. parasympathetic motor fibers. c. sympathetic preganglionic fibers. d. sympathetic postganglionic fibers. e. somatic motor fibers
sex steroids
The groups of hormones from the adrenal cortex called _______ have various developmental and reproductive functions
nodes of Ranvier on the axon
The highest density of voltage-gated ion channels are found on the _________ of a myelinated axon
20 Hz-20,000 Hz (cycles/sec)
The human hearing range is
open state of voltage-gated potassium channels.
The hyperpolarization that occurs at the end of an action potential is due to the prolonged:
secreting hormones that get picked up in the blood stream and travel down the portal system and into pituitary tissue, inducing it or inhibiting it to secrete something
The hypothalamus controls the anterior pituitary by
lacrimal ducts, lacrimal gland
The lacrimal apparatus consists of what components?
tears
The lacrimal apparatus produces
foliate
The least developed of the papilla types are the ______ papillae, which house only a few taste buds during infancy and early childhood.
vallate
The least numerous but the largest of the papillae are arranged as a V shape on the posterior dorsal surface of the tongue. They contain the majority of taste buds and are called _____ papillae
Both; a lot of decussation
The left primary auditory cortex receives signals from what side of the body?
ciliary muscles relax
The lens of the eye flattens when:
fovea centralis
The most finely detailed vision occurs when an image falls on a pit in the retina called the ______.
B) tactile receptor.
The most numerous type of receptor in the body is the: A) chemoreceptor. B) tactile receptor. C) thermoreceptor. D) nociceptor. E) photoceptor.
the hypothalamus
The most significant autonomic control center within the CNS is
the somatic motor and the visceral motor
The motor division of the PNS can be broken down into two divisions
1) Information received by sensory receptors is transmitted to the CNS 2) Information is processed and an appropriate response is determined 3) A command is issued to effectors such as muscles or glands
The nervous system plays an important role in maintaining homeostasis. List in order the basic steps that describe how it does this.
inner segment
The part of cones and rods that points toward the interior; contains mitochondria and other organelles and gives rise to the cell body which has a nucleus and processes that synapse with retinal neurons in the next layer
primary somatosensory cortex
The postcentral gyrus is the
sensory neurons conducting signals from peripheral sense organs to the spinal cord
The posterior root of a spinal nerve conducts what signals?
GABA.
The primary inhibitory neurotransmitter in the brain is:
absolute; relative
The refractory period has two phases: a(n) __________ refractory period in which no stimulus of any strength will trigger a new action potential and a(n) __________ refractory period in which it is possible to trigger a new action potential, but with an unusually strong stimulus
Converging
The respiratory center of the brain receives input from other parts to set a pattern of breathing. Which type of circuit is this?
left side; right side; hemidecussation at the optic chiasm
The right occipital lobe monitors the _____________ of the visual field, while the left occipital lobe monitors the _________ of the visual field because of _______________
the left side because of decussation
The right post central gyrus receives input from which side of the body?
A) Promote adolescent bone growth C) Regulate menstrual cycle D) Contribute to the development of the reproductive system
The roles of estrogen and progesterone: A) Promote adolescent bone growth B) Maintain blood Na+ levels C) Regulate menstrual cycle D) Contribute to the development of the reproductive system E) Maintain blood glucose levels
a, b, c, d
The route that the sensation of taste follows is: a: Primary axons pass along cranial nerves VII and IX. b: Primary neurons synapse in the nucleus solitarius. c: Secondary neurons synapse in the thalamus. d: Tertiary neurons travel to the primary gustatory cortex.
tunica fibrosa
The sclera is part of which tunic?
taste pores
The taste hairs of taste cells project into small openings in the epithelium of the tongue where they come into contact with saliva mixed with bits of dissolved food. These small pits are called
reverberating
The type of neuronal circuit that uses feedback to produce a repeated, cyclical stimulation of the circuit is a _____________ circuit.
Muscarinic receptors
The type of receptor found at the target organ that binds acetylcholine
lingual papillae (have taste buds in them)
The visible bumps on the tongue are not taste buds, but are
Granulosa cells
These cells line the follicle that the egg cell develops in
ossicles
These connect the tympanic membrane to the inner ear that transmit vibration to sound
stapedius and tensor tympani muscles
These help control the ability of the ossicles to vibrate
can result from tumor or lesion destroying gland or interferes with its ability to receive signals from another gland, autoimmune diseases when the hormone cells are attacked by autoantibodies
Things that can cause hyposecretion of a hormone
motor (efferent) division
This divine of the peripheral nervous system carries signals from the CNS to gland and muscle cells to carry out responses
visceral motor division
This division of the motor division of the PNS carries signals to glands, cardiac muscle, and smooth muscle and we do not have conscious control over it
found in autonomic neurons, beads found along an axon that contains synaptic vesicle and secretes neurotransmitters
Varicosities
Apertures in the 4th ventricle
What allow the CSF to leave the brain and surround it and cushion it?
Astrocytes, oligodenrocytes, ependymal cells, microglia
What are the neuroglia in the CNS?
1) Hormone-receptor binding activates a G protein 2) G protein activates the adenylate cyclase 3) Adenylate cyclase produces cAMP 4) cAMP activates protein kinases 5) Protein kinases phosphorylate enzymes , activating some and deactivating others 6) Activates enzymes catalyze metabolic reactions with a wide range of possible effects
What are the steps of a second messenger system?
a specific protein or glycoprotein embedded in the plasma membrane
What is a hormone receptor?
All proteins needed by the neuron are made in the soma, which has a lot of rough ER and Golgi, yet many of these are also needed in the axon to go down to the synaptic vesicles. There are a lot of microtubules and a lot of microfibrils in the axon that help move the materials down and they back up
What is axonal transport?
In the dark, their retinal has a bent shape called cis-retinal, and when it absorbs light a light photon, it absorbs energy from the photon and this energy causes it to change into a straight form called trans retinal and breaks away from opsin and triggers a G-protein response (cGMP) which allows the cell to respond and the response is to shut down the glutamate production because glutamate inhibits the bipolar cell to trigger further signals Once it interacts with the cGMP, the retinal and opsin separate and go into a dark cycle
What is bleaching in rod cells?
endolymph
What is filling the semicircular canals?
basilar membrane
What is on the bottom of the spiral organ?
brain and spinal cord
What is the central nervous system made of?
a, b, d, c
What is the correct chronological sequence of events for hearing? a: The tympanic membrane vibrates. b: Ossicles vibrate. c: Spiral organ hair cells convert stimulus to nerve impulse. d: Pressure waves from oval window travel through the scala vestibuli.
b, a, e, c, d
What is the correct sequence for lacrimal fluid production and drainage? a: Tears disperse across the surface of the eye. b: Tears are produced by the lacrimal gland. c: Fluid drains through the nasolacrimal duct. d: Fluid enters the nasal cavity. e: Fluid enters the lacrimal canaliculi and collects in the lacrimal sac.
vestibular nerve
What nerve fiber synapses with the hair cells of the macula sacculi, macula utriculi, and the semicircular ducts?
Substance P
What neurotransmitter do nociceptors release?
glutamate
What neurotransmitter do rod cells release?
Optic disc
What part of the retina lacks photoreceptors?
the lacrimal apparatus
What produces tears?
Hypothalamus
What secretes corticotropin-releasing hormone (CRH)?
hypothalamus
What secretes gonadotropin-releasing hormone (GnRH)?
hypothalamus
What secretes growth hormone−releasing hormone (GHRH)?
E) recruitment
What type of neural coding is involved when a quiet sound induces the stimulation of low threshold neurons which in turn induce the stimulation of high threshold fibers? A) quantitative B) tetanic C) posttetanic D) facilitation E) recruitment
EPSP.
When a neurotransmitter opens a chemically gated ion channel that allows sodium to enter the postsynaptic cell, the result is an:
D) immediately following the action potential
When does hyperpolarization occur? A) immediately following threshold B) just prior to depolarization C) at the same time as a membrane repolarizes D) immediately following the action potential
B) epinephrine (Epinephrine is released by the adrenal medulla in response from the sympathetic nervous system and it increases alertness and prepares the body for action. It can boost glucose in the blood)
When it becomes necessary to enlist the fight-or-flight response, a hormone that is released during the alarm phase of the general adaptation syndrome is ________. A) estrogen B) epinephrine C) angiotensinogen D) renin
hyperpolarizes and releases less neurotransmitter
When light strikes a photoreceptor it:
B) from cis to trans, and retinal and opsin disassociate.
When light strikes rhodopsin, the retinal is converted: A) from cis to trans, and retinal and opsin combine. B) from cis to trans, and retinal and opsin disassociate. C) from trans to cis, and retinal and opsin combine. D) from trans to cis, and retinal and opsin disassociate.
spatial summation (leads to facilitation)
When multiple presynaptic neurons release neurotransmitter at various locations onto the postsynaptic neuron at the same time it results in:
near the spinal column
Where are the ganglia of the sympathetic nervous system located?
In the middle ear in the tympanic cavity
Where are the ossicles found?
They are in the anterior horn of the spinal cord (gray matter) and axons of these neurons exit by way of the anterior root of the spinal nerve
Where are the somas of motor neurons located ?
In the middle
Where can the lenses of the eyes refract light rays the best?
In the gray matter
Where in the spinal cord do you find synapses?
in the gray matter of the cerebrum
Where is neural integration carried out?
at the core of the adrenal gland, which is superior to the kidney
Where is the adrenal medulla
In the fovea centralis (The center of the field of vision is focused in this region, where retinal cones are particularly concentrated).
Where is the greatest concentration of cones located?
B) At the apical surface of olfactory neurons
Where would you find olfactory hairs? A) Scattered among the lamina propria B) At the apical surface of olfactory neurons C) Buried within the olfactory glands D) At the surface of supporting cells E) Concentrated along basal cells
In the lens (deposited by the hyeloid canal during development to help make it more refractive)
Where would you find the protein crystallin in the eye?
scala vestibuli and scala tympani
Which 2 fluid filled chambers in the cochlea are continuous?
Oxytocin and ADH
Which 2 hypothalamic hormones are stored in the posterior pituitary and released on demand?
A) Normal body maintenance D) Reducing energy expenditure E) Waste elimination F) Digestion
Which activities are attributed to the parasympathetic nervous system? A) Normal body maintenance B) Increasing blood-glucose levels C) Elevating heart rate D) Reducing energy expenditure E) Waste elimination F) Digestion
C) Epineurium → perineurium→ endoneurium
Which choice correctly orders the connective tissue wrappings of a nerve, beginning at the outermost layer? A) Perineurium → epineurium→ endoneurium B) Perineurium → endoneurium→ epineurium C) Epineurium → perineurium→ endoneurium D) Epineurium → endoneurium→ perineurium E) Endoneurium → perineurium→ epineurium
a) Stimulus strength (intensity of stimulus)
Which choice is not one of the three criteria used to describe receptors? a) Stimulus strength (intensity of stimulus) b) Stimulus origin (location of stimulus) c) Receptor distribution (body location) d) Modality of stimulus (stimulating agent)
scala tympani and scala gestibili
Which cochlear chambers contain perilymph
B) It originates in the CNS and receives input from the cerebral cortex, hypothalamus, and medulla oblongata
Which describes the ANS? A) It acts independently of the CNS B) It originates in the CNS and receives input from the cerebral cortex, hypothalamus, and medulla oblongata
D) Fungiform cell
Which is not a cell type found in the olfactory epithelium? A) Olfactory receptor cell B) Supporting cell C) Basal cell D) Fungiform cell
adrenal cortex
Which is the outer part of the adrenal gland?
A) Requires stimulation D) Involuntary E) Stereotyped (occur the same way every time) F) Quick
Which of the following are properties of a reflex? A) Requires stimulation B) Consciously aware C) Easily suppressible D) Involuntary E) Stereotyped F) Quick
D) enzyme amplification
Which of the following concepts explains the fact that target cells do not have a great number of receptors and normal circulating blood concentrations of hormones are very low? A) hormone specificity B) hormone saturation C) hormone half-life D) enzyme amplification
(FSH leads to sperm production, like testosterone)
Which of the following pituitary hormones stimulates the testes to secrete testosterone? A) FSH B) LH C) TSH D) GH
C) Ketonuria E) Glycosuria
Which of the following would you expect to see in a urinalysis of an untreated diabetic? A) Hematuria B) Oligonuria C) Ketonuria E) Glycosuria
c. digestive secretion
Which of these does not result from sympathetic stimulation? a. dilation of the pupil b. acceleration of the heart c. digestive secretion d. enhanced blood clotting e. piloerection
Anterior pituitary
Which part of the pituitary gland is very metabolically active?
A) Characterized my muscle inactivity B) Occurs in circadian rhythms D) Characterized by a stereotyped posture
Which statements about sleep are true? A) Characterized my muscle inactivity B) Occurs in circadian rhythms C) Defined by the presence of beta waves D) Characterized by a stereotyped posture
A) Scala vestibuli
Which structure is not considered to be part of the membranous labyrinth? A) Scala vestibuli B) Semicircular duct C) Saccule D) Cochlear duct E) Utricle
Sympathetic nervous system
Which system contains short preganglionic axons that branch extensively?
Sympathetic nervous system
Which system engages in mass activation?
B) free nerve endings (Free nerve endings include warm and cold receptors and nociceptors)
You have been cooking on a stove for the last several hours. After turning off the burner, you accidentally place your hand on top of that burner as you reach for something else. What receptors will sense that hot, painful stimulus? A) Merkel disks B) free nerve endings C) Golgi tendon organs D) Meissner corpuscles E) Ruffini corpuscles
descending tracts
conduct motor impulses down the cord
crista ampullaris
mound of hair cells and supporting cells in the ampulla
Antagonistic effects
one hormone opposes the action of another.
Lacrimal punctum
small pore near the medial commissure where tears collect after washing across the eye and opens into the lacrimal canaliculus, which then leads to the lacrimal sac
refraction
the bending of light rays
retina and optic nerve
Neural components of the eye
TSH
Stimulates the growth of the thyroid gland
sulci.
The shallow depressions between folds on the surface of the brain are called:
ascending tracts
carry sensory information up the cord
Glucagon
Antagonist of insulin
stapedius and tensor tympani
Regulate the sensitivity of the tympanic membrane and stapes
Progesterone
Regulates menstrual cycle and pregnancy; prepares mammary glands for lactation
D) first enter into the hypophyseal portal system
Regulating hormones from the hypothalamus ________. A) enter venous circulation and travel to the heart, which pumps the hormone-containing blood to the pituitary B) enter the hepatic portal system, which feeds the pituitary C) travel by arteries to the pituitary D) first enter into the hypophyseal portal system
cerebrum
largest and most conspicuous part of the brain
ganglion cells
largest neurons of the retina and arranged near the vitreous body. The second order neurons of the visual pathway and their axons form the optic nerve
postganglionic fibers
lead from the autonomic ganglion to the target cell and do not end by synapsing with the target cell, but with varicosities that diffuse neurotransmitters into the tissue and may stimulate cells simultaneously
choroid plexus
Cerebrospinal fluid is secreted partly by a mass of blood capillaries called the _____ in each ventricle.
hypoglycemic hormone
lowers blood glucose levels.
dense irregular connective tissue that protects the nerve from stretching and injury that bundles fascicles together
Epineurium
opsin and retinal
2 components of rhodopsin
semicircular ducts
3 ducts that detect rotary movements that are arranged in 90˚ to each other
sensory, interneurons, motor
3 functional classes of neurons
excitable, conductible, secretion
3 properties of a neuron:
gap junctions, neurotransmitters, paracrine, hormones
4 types of communication avenues in the body:
Parathyroid glands
4 glands on the posterior surface of the thyroid
Buoyancy, protection, chemical stability, circulates nutrients
4 proposes of CSF
less negative than
A depolarization is when the inside of a neuron becomes _______________ the resting membrane potential.
ganglion
A knoblike swelling of nerve fibers where cell bodies of neurons are found
hydrocephalus
Abnormal accumulation of cerebrospinal fluid in the ventricles can cause a condition called _____.
excitatory
Acetylcholine is always
glucocorticoids
Adrenal steroids that regulate glucose metabolism are collectively called _________.
cAMP
Adrenergic receptors classified as α1, β1, and β2 act by changing the level of _____ in the target cell.
cholesterol or amino acids
All hormones are made from either _______ or ____________
encapsulated
Are tactile corpuscles encapsulated or unencapsulated?
interneurons.
Based on function, 99 percent of neurons are:
multipolar
Based on structure, the most common type of neuron is the _______ neuron.
thyroid gland's C cells
Calcitonin source
capillaries
Endocrine glands have a high density of _________ to distribute their products
Gametes (egg and sperm)
Exocrine products of the gonads
cochlear duct
Fluid filled chamber in the cochlea that contains the spiral organ; filled with endolymph
scala tympani
Fluid filled chamber in the cochlea that is filled with perilymph; ends at the round window which contains the secondary tympanic membrane
Inside of the white matter; nervous tissue in the spinal cord; neuron cell bodies with little myelin; site of information processing; synaptic integration; contains somas, dendrites and proximal parts of axons and lots of glial cells and composed of posterior and anterior horns
Gray matter in the spinal cord
vibrating air molecules
Hearing is a response to what?
they have different receptors on their surface
How can type 1, 2, and 3 taste cells detect certain compounds?
From the choroid (highly vascular)
How does the retina get oxygen?
Calcitriol
Increases blood calcium level mainly by promoting intestinal absorption of Ca2+
corpus luteum of the ovaries and sustenacular cells of the testes
Inhibin sources
Employs aminobutyric acid (GABA) as its neurotransmitter Same mechanism as ACh synapses, but instead of a sodium channel, the GABA receptor is a Cl- receptor and when chlorine enters, it makes it the ICF more negative than the resting potential, and the neuron is inhibited and less likely to fire
Inhibitory GABA-ergic Synapse
if a neurotransmitter hyperpolarizes the postsynaptic cell and makes it more negative than the RMP, making the postsynaptic cell less likely to fire
Inhibitory post synaptic potential
Inhibin (secreted by the sustenacular cells of the testes and the corpus luteum of the ovaries by negative feedback inhibition because FSH stimulate the ovaries to develop follicles that contain eggs and stimulates the testes to produce sperm)
Inhibits FSH secretion
pancreatic islets (Beta cells)
Insulin source
liver
Insulin-like growth factor I
Pineal gland
It may regulate timing of puberty in humans
dark adaptation (In the light, the rod pigment was bleached into trans-retinal and is non-functional and it has to regenerate)
It may take nearly a half hour for rods of the retina to regenerate a full supply of rhodopsin during the process of:)
the largest which form an arc in each cerebral hemisphere (1st and 2nd ventricles)
Lateral ventricles
primary ventricle; midbrain
Mesencephalon
olfactory cells
Neurons found in the olfactory mucosa
dendrites
Neurons receive incoming signals by way of specialized extensions of the cell called
stimulation
Neurotransmitters are released in response to
neuroglia in the CNS; form myelin in brain and spinal cord that insulates the nerve from the extracellular fluid, speeding up signal conduction; helps form structure in the brain
Oligodendrocytes
pancreatic islets F cells
Pancreatic polypeptide source
calms us; slows heartbeat, stimulates digestion
Parasympathetic divine of the ANS
Melanopsin
Photopigment of ganglion ells
cone cell
Photoreceptor responsible for day and color vision
retinal ganglion cells signal changes in the photoreceptors convert light energy to changes in membrane potential.
Phototransduction is the process in which:
thin membrane that follows the contours of the brain; between the blood vessels and the brain
Pia mater in the brain
on myelinated nerve fibers
Saltatory conduction occurs only
neuroglia in the PNS; envelop nerve fibers of the PNS; produces myelin sheath; assist in the regeneration of damaged fibers
Schwann Cells
ciliary body
Secretes aqueous humor
carries signals from various receptors such as sense organs and sensory nerve endings to the CNS; broken down into the somatic sensory division and the visceral sensory division
Sensory (afferent) division of PNS
Modality, location, intensity, and duration
Sensory receptors transmit what 4 types of information?
Skeletal muscle Usually voluntary NMJ One myelinated nerve fiber from CNS to effector; no ganglia ACh Always excitatory
Somatic Nervous: Effectors: Control: Distal Nerve Endings: Efferent Pathways: Neurotransmitters: Effect on Target Cells:
The body's fat reserves can carry it through months of stress, but when fat is depleted, stress overwhelms homeostasis. The stage of exhaustion sets in, often marked by rapid decline and death.
Stage of Exhaustion of GAS
After a few hours, glycogen reserves are exhausted, but the nervous system continues to demand glucose Stage is dominated by cortisol
Stage of Resistance of GAS
cortex
Surface layer of neuron cell bodies in the CNS
arouses the body for action; increases heartbeat, increasing respiratory flow, inhibits digestion
Sympathetic division of the ANS
True
T/F: Each spinal cord segment has only one pair of spinal nerves.
the neural crest
The PNS developed from which embryonic tissue?
the near response
The adjustment to close-range vision is called
merging of 2 fetal glands with different origins and functions
The adrenal gland is formed by
Acts as an endocrine gland and a ganglion of the sympathetic nervous system
The adrenal medulla can act like 2 things, what are they
nasopharynx
The auditory canal empties into the
2.5 cm
The eye measures about ________ in diameter.
produce faster nerve impulse propagation.
The function of myelin is to:
vasodilation
The lowest rate of sympathetic nerve firing to the smooth muscle cells of the blood vessels causes what?
degradation by an enzyme.
The main way acetylcholine is cleared from a synapse is by:
corpus callosum
The right and left cerebral hemispheres are connected to each other by a thick C-shaped bundle of fibers called the _____.
tectorial membrane.
The stereocilia of cochlear hair cells project into the:
Zona glomerulosa, zona fasciculata, zona reticularis
The zones of the adrenal cortex from most superficial to deep
Chemical and electrical
There are two types of synapses, based on mode of communication. What are they?
.inner hair cells
These are arranged in a row on the medial side of the basilar membrane; has a cluster of 50 to 60 stereocilia, graded from short to tall
nerve cells (neurons)
These carry the communicative properties of the nervous system
When you go to the doctor, they block the cholinergic receptors in the iris and the sympathetic nervous system has complete control and the iris dilates
To dilate your eyes, what does the eye doctor do?
Wrinkling of skin because we are not making the proteins that helps keep our skin toned and reduced muscular mass and strength
Two big impacts that a reduction in GH can have on aging because of a reduction in protein synthesis are
choroid, ciliary body, iris
Which structures are part of the tunica vasculosa?
stereoscopic vision/depth perception
allows you to judge how far away objects are
Adrenal medulla
basically one huge postganglionic mass of 2nd order neurons
infrasonic frequencies
below 20 Hz and not detected by the ear, but we can sense them through vibrations of the skull and skin
otoliths
calcium-carbonate protein deposits in the gelatinous material that rest on top of the stereocilia of the cells that add to the weight and inertia and enhance the sense of gravity and motion
Nasolacrimal duct
carries tears to the nasal cavity
transduction (fundamental purpose of any sensory receptor)
conversion of one form of energy to another; in biological terms it is the conversion of external stimuli to a nerve signal
Nissl bodies
dark staining regions that represent rough ER in the soma
adrenal medulla
dopamine source
the tendon reflex
in response to excessive tension on the tendon organs that inhibits alpha motor neurons to the muscle so the muscle doesn't contract as strongly to moderate muscle contraction before it tears a tendon or pulls it lose from a muscle or bone
Fovea centralis
in the macula lutea; produces the most finely detailed images beasue this is the center of the field of vision where the cones are tightly packed
hyposecretion
inadequate hormone release
stereocilia
long microvilli on the surface of hair cells
hypothalamus
major control center of the endocrine and ANS and plays an important role in homeostatic regulation of all body organs
some association areas receive input from multiple senses and integrate this information into our overall perception of the surroundings
multimodal association area
one axon and multiple dendrites; most common
multipolar neuron
extrafusal fibers
muscle fibers that make up the rest of the muscle and do its work; normal fiber
six layered tissue that constitutes about 90% of the human cerebral cortex; relatively recent in evolutionary origin
neocortex
Filiform papillae
no taste buds, but they are important for food texture and to move food around
somatic pain
pain arising from skin, muscles, and joints
Visceral pain
pain from viscera often resulting from stretch, chemical irritants, and is often accompanied by nausea
nociceptors
pain receptors; nerve ending specialized to respond to tissue injury or situations that threaten to damage tissue
midbrain
part of the brain that helps relay information for vision and hearing
auditory canal
passage leading through the temporal bone to the tympanic membrane and leads to the middle ear
filiform papillae
tiny spikes found mostly in the middle of the tongue
pheochromocytoma
tumor of adrenal medulla secretes excessive epinephrine and norepinephrine
Photopsin
visual pigment in cones
Rhodopsin
visual pigment of the rods; visual purple
e. the higher its pitch.
. The higher the frequency of a sound, a. the louder it sounds. b. the harder it is to hear. c. the more it stimulates the distal end of the spiral organ. d. the faster it travels through air. e. the higher its pitch
Nicotinic receptors and muscarinic receptors
2 cholinergic receptors are
a nerve
A bundle of nerve fibers wrapped in a fibrous connective tissue is called
distant vision.
A flattened lens is necessary for
a hill where the high point approaches the threshold value.
A graph of an EPSP would plot time against a voltage trace that would resemble:
C) can understand the words but cannot follow the lines on the page.
A person with damage to the premotor cortex area that coordinates eye movements: A) can read but cannot understand the words. B) cannot read or understand the words. C) can understand the words but cannot follow the lines on the page. D) can process linguistic information visually but not through auditory inputs.
adaptation.
A reduction in sensitivity to a continually applied stimulus is called:
D) is inhibited by alcohol
ADH ________. A) increases urine production B) promotes dehydration C) is produced in the adenohypophysis D) is inhibited by alcohol
in which no stimulus of any strength will trigger a new action potential; lasts from the start of the action potential until the membrane returns to the resting potential As long as the Na channels are open and then inactivated From the depolarization to the repolarization
Absolute refractory period
E) All choices are correct
Accommodation of the lens occurs when: A) ciliary muscles contract. B) the ciliary body moves closer to the lens. C) parasympathetic axons stimulate the ciliary muscles. D) the lens becomes more spherical. E) All choices are correct
voltage-, axon
Action potentials are generated by the opening of ________ gated channels and they occur on the ________.
identical
Action potentials of a given neuron are
Its conduction speed is relatively slow, but it has a small diameter and contributes relatively little bulk to the nervous tissue.
Advantage and disadvantage of unmyelinated fibers
adrenal cortex's zona glomerulosa
Aldosterone source
sodium; potassium
Aldosterone stimulates the kidneys to retain _________ and excrete ________
B) efferent pathway.
All of the following are anatomical differences between the somatic and autonomic nervous system except the A) type of neurotransmitter used. B) efferent pathway. B) efferent pathway. D) type of effectors.
cholinergic receptors
All receptors that bind ACh are
movement from the soma down the axon
Anterograde transport
transparent membrane over the brain surface that has arachnoid villi that poke through the dura mater into the superior sagittal sinus. A lot of blood vessels in the arachnoid layer that go into the brain and the crevices of the brain
Arachnoid mater of the brain
the arachnoid membrane adhering to side of the dura and loose collagenous and elastic fibers that look like spiders
Arachnoid mater of the spinal cord
encapsulated
Are bulbous corpuscles encapsulated or unencapsulated?
encapsulated
Are end bulbs encapsulated or unencapsulated?
unencapsulated
Are free nerve endings encapsulated or unencapsulated?
unencapsulated
Are hair receptors encapsulated or unencapsulated?
association areas
Areas of cerebral cortex that identify or interpret sensory information are called _____.
c, a, e, d, b
Arrange the five secondary vesicles in the correct anterior to posterior order. a: Diencephalon b: Myelencephalon c: Telencephalon d: Metencephalon e: Mesencephalon
c, b, a
Arrange the primary brain vesicles in the correct anterior to posterior order. a: Rhombencephalon b: Mesencephalon c: Prosencephalon
C) ganglion cell axons from the medial region of each retina cross to the opposite side of the brain. (Ganglion cell axons eventually become the fibers of the optic nerve)
At the optic chiasm: A) all axons from each optic nerve cross to the opposite side of the brain. B) none of the axons actually cross to the opposite side of the brain. C) ganglion cell axons from the medial region of each retina cross to the opposite side of the brain. D) ganglion cell axons from the lateral region of each retina cross to the opposite side of the brain.
presynaptic
At the synapse, the neuron that releases neurotransmitter is the ___________ neuron
the continual activity maintained by the sympathetic and parasympathetic divisions.
Autonomic tone refers to:
pools
Billions of CNS interneurons are grouped in complex patterns called neuronal:
arachnoid mater and pia mater
Blood capillaries in the brain are located between which two meingeal layers?
at the choroid plexuses formed by tight junctions between ependymal cells Tight junctions are absent everywhere else because it is important to allow for exchanges between the brain tissue and the CSF
Blood-CSF barrier
guards blood capillaries by forming tight junctions of the endothelial cells that form the capillary walls. Astrocytes reach out and contact the capillaries with their perivascular feet inducing the endothelial cells to form tight junctions that seal off the gaps between them, ensuring anything that leaves the blood must pass through the cells Everything that goes from the blood to the brain has to go through endothelial cells and then the astrocytes
Blood-brain barrier
corpus callossum
Brain structure that contains most of the commissural tracts
alkaloids.
Caffeine and unsweetened chocolate both taste bitter, as they are:
Yes! But they are not neurons
Can taste cells initiate an action potential?
GH also has a glucose-sparing effect. Its role in mobilizing fatty acids reduces the dependence of most cells on glucose so they will not compete with the brain, which is highly glucose-dependent. GH also stimulates glucose synthesis by the liver
Carbohydrate metabolism function of GH
monoamine
Catecholamines are a subtype of __________ neurotransmitter.
B) dopamine, epinephrine, and norepinephrine. (secreted by the adrenal medulla in response to stimulation by sympathetic fibers and they mobilize the body for action and the fight-or-flight response. They increase alertness, mobilize higher energy fuels, boost glycogenolysis, raise heart rate, blood pressure, stimulate circulation to the muscles, incresae pulmonary airflow, raise metabolic rate, inhibit digestion and urin production)
Catecholamines include: A) acetylcholine, epinephrine, and norepinephrine. B) dopamine, epinephrine, and norepinephrine. C) acetylcholine, epinephrine, and dopamine. D) epinephrine, norepinephrine, serotonin, and all monoamines.
towards the spinal cord; lower
Caudal
Monoamine
Chemical classification: Dopamine
Monoamine
Chemical classification: Epinephrine
Steroid
Chemical classification: Estrogens
Peptide
Chemical classification: Follicle-stimulating hormone
Peptide
Chemical classification: Glucagon
Peptide
Chemical classification: Gonadotropin-releasing hormone
Peptide
Chemical classification: Growth hormone
Peptide
Chemical classification: Growth hormone−releasing hormone
taste hairs
Cilia that are on taste cells where the first tasting occurs and where the receptors for certain compounds are found
cerebral nuclei.
Clusters of gray matter that contain neuron cell bodies and lie within masses of white matter are the:
e. the basilar membrane.
Cochlear hair cells rest on a. the tympanic membrane. b. the secondary tympanic membrane. c. the tectorial membrane. d. the vestibular membrane. e. the basilar membrane.
A) association areas of the cerebrum.
Cognition is generally thought to be governed by: A) association areas of the cerebrum. B) gray matter of the cerebellum. C) the reticular formation of the brainstem. D) primary sensory cortices and projection tracts. E) the corpus callosum.
glia and myelinated nerves that communicate with the brain from the left and right side of the cerebrum through commissures.
Commissural tracts
given off by the anterior ramus, and they connect to the string of sympathetic nerve ganglia alongside the vertebral column
Communicating rami
Lens
Composed of flattened, transparent cells; suspended behind the pupil by a ring of fibers
contains bundles of nerve fibers that conduct information up and down the cord, enabling sensory information to reach the brain, motor commands to reach effectors, and input received at one level to affect output from another level
Conduction function of the spinal cord
adrenal cortex's zona fasciculata and reticularis
Cortisol and corticosterone source
LTM; is the retention of events and facts that you can put into words—numbers, names, dates, and so forth
Declarative memory
MS and Tay Sachs
Diseases associated with myelination
ramus
Distal to the intervertebral foramen, a spinal nerve branches into an anterior and posterior
No, some can act through second messenger systems like the excitatory adrenergic synapse
Do all neurotransmitters open a channel?
changes in states of consciousness
EEG changes are correlated with
some cells do have these, where adjacent cells are joined by gap junctions and ions diffuse directly from one cell into the next Quick transmission Cannot integrate information and make decisions
Electrical synapses
GH promotes Na+, K+, and Cl− retention by the kidneys, enhances Ca2+ absorption by the small intestine, and makes these electrolytes available to the growing tissues.
Electrolyte balance function of GH
Gonadal hormones
Endocrine products of the gonads
inhibit
Endogenous opioids such as endorphins, enkephalins, and dynorphins __________ pain pathways
fibrous connective tissue surrounding the neurilemma of each nerve fiber
Endoneurium
a single NE molecule binding tot the receptor can induce the formation of many cAMPs, each of those can activate many enzyme molecules or induce the transcription of a gene to generate numerous mRNA molecules, and each of those can result in the production of a vast number of metabolic products such as glucose molecules.
Enzyme amplification
above the meninges; between the sheath and vertebral bones; anesthetics inserted here
Epidural fat space
arachnoid villi.
Excess CSF is removed from the subarachnoid space by:
they respond to stimuli
Excitability property of neurons
any voltage change in the direction towards -55 that makes the neuron more likely to fire; EPSPs usually result from Na+ flowing into the cell and neutralizing some of the negative charge on the inside of the membrane.
Excitatory Postsynaptic Potential
help distribute lacrimal fluid to cleanse and lubricate the surface
Eyelids serve two purposes: one is to protect the eye and the other is to:
process in which one neuron enhances the other. Neurons work in groups to modify each others actions
Facilitation
E) active (requires ATP) and can occur in either the anterograde or retrograde direction.
Fast axonal transport is: A) passive and only occurs in the anterograde direction. B) passive and only occurs in the retrograde direction. C) active (requires ATP) and only occurs in the anterograde direction. D) active (requires ATP) and only occurs in the retrograde direction. E) active (requires ATP) and can occur in either the anterograde or retrograde direction.
returns used synaptic vesicles and other materials to the soma and informs to soma of the conditions at the axon terminals. Retrograde transport employs dynein to carry proteins on their back while they reach out to bind repeatedly to the microtubules and walk on them
Fast retrograde transport
hippocampus, association areas of the cerebrum
Formation of new memories involves the ________, and storage of long term memories primarily involves the ________.
ciliary body
Forms a muscular ring around the lens
small triangular chamber between the pons and the cerebellum that narrows and forms the central canal that extends passes through the median aperture which extends out to the spinal cord
Fourth ventricle
Cortisol, epinephrine, aldosterone and glucocorticoids
GAS involves elevated levels of which hormones?
IGF1 secreted by the liver
GH often works in conjunction with
knot like swelling in a nerve where cell bodies of neurons are found
Ganglion
B) are smaller and capable of mitosis.
Glial cells differ from neurons in that they: A) are larger and capable of meiosis. B) are smaller and capable of mitosis. C) are found only in the CNS. D) are found only in the PNS. E) transmit nerve impulses much more slowly
Alpha cells of the pancreatic islets
Glucagon source
acromegaly
Growth hormone hypersecretion in adulthood causes a disease called _________.
7-10 days
Gustatory cells within a taste bud are specialized neuroepithelial cells that have a _________ life span.
near the oval window at the base of the cochlea.
High frequency sounds activate neurons within the cochlea that are:
cortisol
Hormone that has an anti-inflammatory effect
Yes, if they straddle the boundary between 2 receptive fields
If a receptive field is 7 cm in diameter, is it possible for 2 touches that are 1 cm apart to be felt separately?
It would destroy left field vision
If a stroke destroyed the right cerebral hemisphere, how would it affect vision?
glial cells called oligodendrocytes
In the CNS, myelin is produced by
Pancreatic polypeptide
Inhibits release of bile and digestive enzymes; prevent the gallbladder to contract and put bilirubin in the digestive system
liver
Insulin-like growth factor I source
neural coding method; qualitative information and is based on the fact that each nerve fiber to the brain leads from a receptor that specifically recognizes a particular stimulus type. For example, nerve fibers in the optic nerve carry signals only from light receptors in the eye
Labeled line code
categorical hemisphere; specialized for spoken and written language and sequential and analytical reasoning; breaks information down and analyzes it linearly
Left hemisphere
Axons
Long neuronal process that generally conducts impulses from the soma of the nerve cell; nerve fibers
lasts up to a lifetime and it is less limited than STM on what can be stored; some LTM involves physical remodeling of synapses or the formation of new ones through the growth and branching of axon terminal and dendrites
Long-Term Memory
molecular changes that can help ground long term memory; a persistent strengthening of synapses based on recent patterns of activity. These are patterns of synaptic activity that produce a long-lasting increase in signal transmission between two neurons.
Long-term potentiation
norepinephrine
MAO and COMT are enzymes that break down _____ at certain ANS synapses.
sodium-potassium pumps.
Maintenance of appropriate ion concentrations (especially after nerve impulses that involved ion diffusion) is primarily the job of:
Prolactin
Male: Increased LH sensitivity
neural crest
Melanocytes developed from which embryonic tissue?
produces pons and cerebellum; produced from the primary embryonic rhombencephalon (hindbrain)
Metencephalon
neuroglia in the CNS; phagocytize and destroy microorganisms, foreign matter, and dead nervous tissue; synaptic remodeling, changing connections between neurons; modified white blood cells; thought to perform complete clean up everyday
Microglia
most PNS nerves that consist of both afferent and efferent fibers and conduct signals in 2 directions (spinal nerves)
Mixed nerves
intrafusal fibers
Modified muscle fibers serving primarily to detect stretch are called
a. the vallate papillae.
Most taste buds occur in a. the vallate papillae. b. the fungiform papillae. c. the filiform papillae. d. the palate. e. the lips.
The eicosanoids prostacyclin, thromboxanes, and prostaglandins
NSAIDs prevent what from being formed?
bundle of nerve fibers (axon) wrapped in fibrous connective tissue that carry out the communicative properties of the nervous system
Nerve
gamma motor neurons.
Nerve fibers that adjust the tension in a muscle spindle are called
nerve signal is a traveling wave of excitation produced by self propagating action potentials
Nerve signal
nervous
Nervous or endocrine: Adapts quickly to continual stimulation
endocrine
Nervous or endocrine: Adapts relatively slowly
endocrine
Nervous or endocrine: Communicates by hormones
ectoderm.
Neural tissue develops in the embryo from a portion of the:
Adrenal medulla
Norepinephrine source
enteric nervous system, sympathetic nervous system, and sympathetic nervous system
Normal digestive function also requires regulation from
all chordates have notochords that influences the tissues above it and induces them to become the nervous system
Notochord
arbor vitae
On a sagittal plane, the cerebellar white matter exhibits a branching pattern called the _____.
D) follow any of the routes listed.
Once inside the sympathetic trunk, the sympathetic preganglionic axons: A) remain at the level of entry. B) travel superiorly. C) travel inferiorly. D) follow any of the routes listed.
inversely
Our ability to precisely locate a stimulus is ________ proportional to receptive field size.
ganglia
Outside the CNS, the somas of neurons are clustered in swellings called
hydrophilic; cannot; receptors on the cell surface
Peptides and catecholamines are _______________ and (can/cannot) penetrate a target cell. Therefore they bind ______-
wraps nerve fibers into bundles called fascicles
Perineurium
periosteum of the cranial bones
Periosteal layer of cranial dura mater
the rest of the body other than the brain and spinal cord; composed of nerves and ganglia; broken down into sensory and motor division
Peripheral nervous system
dura mater, arachnoid mater, pia mater
Places the meninges in order from superficial to deep
calcium (Post tetanic potentiation is a form of synaptic plasticity in which memories can last longer; the Ca2+ level in the synaptic knob stays elevated for so long that another signal, coming well after the tetanic stimulation has ceased, releases an exceptionally large burst of neurotransmitter. That is, if a synapse has been heavily used in the recent past, a new stimulus can excite the postsynaptic cell more easily. Thus, your memory may need only a slight jog to recall something from several hours earlier)
Posttetanic potentiation of a synapse increases the amount of what in the synaptic knob?
transmitting sound vibrations to the symphonic membrane
Primary function of the outer ear
neurons here send signals to the brainstem and spinal cord, ultimately resulting in muscle contraction; motor homunculus is a drawing of this
Primary motor cortex
receive general sense signals; awareness of stimulation occurs here; drawing of it is the sensory homunculus
Primary somesthetic cortex
proscencephalon, mesencephalon, rhombecephalon
Primary ventricles that appear during the 4th week of development
LTM is the retention of motor skills—how to tie your shoes, play a musical instrument, or type on a keyboard.
Procedural memory
ovaries
Progesterone source
link the cerebral cortex to the caudal brain regions and the spinal cord.
Projection tracts:
When light intensity changes, or when we shift our gaze between distant and nearby objects
Pupillary constriction and dilation occur in 2 situations:
the photo pupillary reflex
Pupillary constriction in response to light is called
tears cleanse, lubricate, deliver oxygen, and nutrients to the conjunctiva
Purpose of the lacrimal gland secreting tears
Parathyroid hormone
Raises blood Ca2+ level by stimulating bone resorption and inhibiting deposition, reducing urinary Ca2+ excretion, and enhancing calcitriol synthesis
branches of spinal nerve
Ramus
collect information.
Receptors are parts of the nervous system that allow it to: initiate responses to information. process information. collect information. conduct impulses to muscles.
X-linked recessive
Red-green colorblindness is what type of trait?
period of resistance to restimulation during an action potential and a few milliseconds after
Refractory period
in which it is possible to trigger a new action potential, but only with an unusually strong stimulus Lasts from repolarization to hyperpolarization During this period, K channels are still open and a new stimulus can allow Na can come in and depolarize the membrane, but K will diffuse out through the open channels as Na comes in and opposes the effect of the stimulus and it requires an especially strong stimulus to override the K outflow and depolarize the cell enough to set off a new action potential
Relative refractory period
difference in the potential inside and outside of the cells; -70 mV in nerves
Resting membrane potential
movement up the axon to the soma
Retrograde transport
hindbrain primary ventricle that forms the metencephalon and the myelencephalon
Rhombecephalon
cortisol and corticosterone
SAID drugs
all eicosanoids
SAIDs prevent what from being formed?
telencephalon, diencephalon, mesencephalon, metencephalon, myelencephalon
Secondary ventricles that develop in the 5th week
gustation
Sense of taste
receptors
Similar to neurotransmitters, hormones exert their action only on cells that have specific _________ that hormones bind to
anterograde process that works in a stop and go fashion. Moves enzymes and cytoskeletal components down the axons, renews work out axoplasmic components and supplies new axoplasm for developing or regenerating neurons. Moves through the cytoplasm
Slow axonal transport
control center of the neuron; neurosome/cell body that has a large nucleus with a large nucleolus and the cytoplasm has mitochondria, lysosomes, Golgi to package neurotransmitters, numerous inclusions, and an extensive rough ER to make the neurotransmitters and cytoskeleton which has a dense mesh of microtubules and neurofibrils. Most of the neuron cell body CANNOT support an action potential
Soma
pancreatic islets Delta cells
Somatostatin source
receptors on the postsynaptic cell
Some neurotransmitters can have either excitatory or inhibitory effects depending on the type of
having two eyes with overlapping visual fields, which allows each eye to look at the same object from a different angle
Stereoscopic vision depends on
Thymopoietin, thymosin, thymulin
Stimulate T lymphocyte development and activity
Follicle-stimulating hormone (FSH)
Stimulates growth of ovarian follicles and secretion of estrogen and sperm production
Thyroid stimulating hormone
Stimulates growth of thyroid, secretion of thyroid hormone
Luteinizing hormone (LH)
Stimulates ovulation, maintenance of corpus luteum and testosterone secretion
cortisol (glucocorticoids)
Stimulates release of fatty acids and glucose into the blood
;aldosterone (secreted by zona glomerulosa of adrenal cortex)
Stimulates the kidneys to retain Na+ and water and excrete K+
filled with CSF in the gap between the arachnoid membrane and pia mater
Subarachnoid space
separates the arachnoid mater from the dura mater
Subdural space
white matter
Substance in the brain that lies deep to the cortical gray matter and comprised of tracts
neuromodulator
Substances released along with a neurotransmitter that body the neurotransmitter's effect
ciliary body
Supports the iris and the lens
slight gap between neurons
Synaptic cleft
True
T/F: A neuron never has more than one axon.
True
T/F: The corticospinal tracts carry motor signals down the spinal cord.
False, ascending
T/F: The gracile fasciculus is a descending spinal tract.
False, adrenal medulla
T/F: The tissue at the center of the adrenal gland is called the zona reticularis.
T3 + T4
TH=
negative-feedback inhibition
Target cells can reduce pituitary secretion by a process called _________.
has a pair of lateral outgrowths that become the cerebral hemispheres; all started out as the tube, and the big telencephalon flips over and encloses everything except the hindbrain
Telencephalon
at the distal end of am axon, extensive complex of fine branches that ends in a synaptic knob
Terminal arborization
interstitial
Testosterone is secreted by the _________ cells of the testis.
testes
Testosterone source
visceral motor system
The ANS is also referred to as the
he initial reaction to stress; mediated by norepinephrine from the sympathetic nervous system and epinephrine from the adrenal medulla to prepare the body to take action. Increases stored glycogen. Aldosterone levels rise
The Alarm Reaction of GAST
REM
The PNS is very active during what sleep stage?
left
The ______ hemisphere is known for its involvement in categorization, symbolization, and analytical reasoning.
stapes
The ______ is a tiny bone that vibrates in the oval window and thereby transfers sound vibrations to the inner ear.
The neural crest
The adrenal medulla developed from which embryonic tissue?
motor signals AWAY from the spinal cord and towards peripheral effectors
The anterior root of a spinal nerve conducts what signals?
neural crest
The arachnoid and pia mater developed from what embryonic tissue?
effector
The axon of the postganglionic nerve synapses with the
brainstem.
The centers for cardiac, digestive, and vasomotor functions are housed within the:
autonomic
The efferent pathway of which nervous system transmits both excitatory and inhibitory signals to its effector cells?
the combination of electrical and chemical gradients between two areas.
The electrochemical gradient refers to:
D) areolar connective tissue.
The endoneurium is composed of: A) dense regular connective tissue. B) simple squamous epithelium. C) dense irregular connective tissue. D) areolar connective tissue. E) pseudostratified nonkeratinized epithelium.
C) dense irregular connective tissue.
The epineurium is composed of: A) dense regular connective tissue. B) simple squamous epithelium. C) dense irregular connective tissue. D) areolar connective tissue. E) pseudostratified nonkeratinized epithelium
amplify sound waves and transmit them to the inner ear.
The function of the ossicles is to:
ependymal cell.
The glial cell that helps to circulate cerebrospinal fluid is the:
astrocyte.
The glial cell that helps to form the blood brain barrier
Schwann cell
The glial cell that myelinates and insulates axons in the peripheral nervous system is the:
oligodendrocyte.
The glial cell that myelinates and insulates axons within the CNS is the:
astrocyte.
The glial cell that provides structural support and organization to the CNS is the:
astrocyte.
The glial cell with perivascular feet that wrap around capillaries in the CNS is the:
astrocyte.
The glial cell with the responsibility of occupying the space left by dead or dying neurons is the:
The production of action potentials involves Na+ inflow into a neuron through these voltage-gated Na+ channels. If these channels were inhibited, then no action potentials and no nerve signals could occur, so tissue damage would not trigger the conduction of pain signals in a nerve.
The local anesthetics lidocaine and procaine prevent voltage-gated Na+ channels from opening. Explain why this would block the conduction of pain signals in a sensory nerve.
cerebrum.
The location of conscious thought processes and the origin of all complex intellectual functions is the:
folia.
The numerous folds of the cerebellar cortex are called:
Mesencephalon
The portion of the adult brain that includes the cerebral peduncles, superior colliculi, and inferior colliculi is derived from which secondary brain vesicle?
Telencephalon
The portion of the adult brain that includes the cerebrum is derived from which secondary brain vesicle?
B) somatic sensory
The portion of the nervous system that conducts impulses from the skin, joints, skeletal muscles, and special senses is the ___________ division. A) autonomic motor B) somatic sensory C) somatic motor D) visceral sensory
somatic motor
The portion of the nervous system that has voluntary control over skeletal muscles is the _____________ division.
C) biofeedback
The possibility of some control over autonomic responses is demonstrated by ________. A) split brain studies B) stress-induced hypertension C) biofeedback D) nightmares
olfaction
The sense of smell
somatic and visceral
The sensory and motor divisions of the peripheral nervous system are further split into which 2 subdivisions?
the somatic sensory division and the visceral sensory division
The sensory division of the nervous system can be broken down into 2 system
pain
The sensory modality mediated by specialized receptors called nociceptors
voltage.
The separation of oppositely charged ionic particles across a resting neuron's membrane results in a potential that is measured as a:
centrioles, this it cannot divide
The soma of a mature neuron lacks
iris
The structure that functions as a diaphragm to control pupil size is the:
antagonistic
The sympathetic and parasympathetic systems have _________ effects on heart rate.
D) somas of ganglionic neurons.
The sympathetic trunk ganglia are primarily composed of: A) axons of preganglionic neurons. B) axons of postganglionic neurons. C) somas of preganglionic neurons. D) somas of ganglionic neurons.
C) immediately lateral to the vertebral column.
The sympathetic trunks are located: A) superior to the brachial plexus. B) inferior to the sacral plexus. C) immediately lateral to the vertebral column. D) lateral to prevertebral ganglia. E) in the craniosacral regions.
adrenal cortex (it stimulates the corte to secrete glucocorticoids which regulate glucose, protein, and fat metabolism, and are important in the body's response to stress)
The target organ for ACTH
channel.
The type of transport protein that moves a substance down its concentration gradient is a:
One reason for unidirectional transmission across synapses is that only the presynaptic neuron has synaptic vesicles and releases neurotransmitters, and another is that only the postsynaptic neuron has neurotransmitter receptors that can produce cellular excitation (discounting receptors in the presynaptic cell for neurotransmitter reuptake). If these structural differences did not exist and signals traveled in both directions, as happens in some simple animals such as hydras, the behavioral responses to stimuli would be much less specific or precise. Signals would spread randomly through the nervous system and effectors everywhere would respond to a sufficiently strong stimulus anywhere.
The unity of form and function is an important concept in understanding synapses. Give two structural reasons why nerve signals cannot travel backward across a chemical synapse. What might be the consequences if signals did travel freely in both directions?
the sympathetic and parasympathetic divisions
The visceral motor division of the nervous system can be broken down into
In pregnancy, the maternal body must mobilize nutrients for the development of the fetus. One of the principal hormones to do this is cortisol, and the rise in cortisol secretion comes about by growth of the zona fasciculata.
The zona fasciculata thickens significantly in pregnant women. What do you think would be the benefit of this phenomenon?
B) Sebaceous filaments
There are three types of unencapsulated tactile receptors. Select the exception. A) Free nerve endings B) Sebaceous filaments C) Root hair plexuses D) Tactile discs
Sensory (afferent) neurons
These are specialized neurons to detect stimuli, such as light, heat, pressure, chemicals, and they transmit information about them to the CNS
amacrine and horizontal cells
These cells enhance perception of contrast, the edges of objects, and changes in light intensity
amacrine and horizontal cells
These cells for horizontal connections between rods, cones, and bipolar cells and intervene in the pathways from receptor cells to ganglion cells
vallate
These papillae are located at the rear of the tongue
fungiform
These papillae are widely distributed, but are concentrated at the tip and sides of the tongue
Baroreceptors
These receptors detect changes in pressure within the body caused by the stretch or distention of internal structures.
Photoreceptors
These receptors detect changes in the color, intensity, and movement of light.
Chemoreceptors
These receptors detect specific molecules in our external and internal environments.
Thermoreceptors
These receptors respond to changes in temperature.
narrow space inferior to the corpus callosum
Third ventricle
somatic motor division
This division of the motor division of the PNS carries signals to skeletal muscle and produces voluntary contractions as well as some involuntary reflexes
sympathetic division
This division of the nervous system increases heartbeat, increases respiratory flow, and inhibits digestion
Sensory (afferent) division
This division of the peripheral nervous system carries signals from receptors to the CNS
the visceral sensory divion
This division of the peripheral nervous system carries signals from the viscera and senses stuff inside of us
sympathetic division
This division of the visceral motor division arouses the body for action
right
This hemisphere feels shapes with the left hand
left
This hemisphere feels shapes with the right hand
right
This hemisphere has an advantage in hearing nonvocal sounds
right
This hemisphere has intuitive, nonverbal thought
left (specialized for spoken and written language)
This hemisphere is specialized for speech
left
This hemisphere is specialized for verbal memory
cerebellum
This part of the brain processes input from the brainstem, cortex, and sensory receptors to provide precise and coordinated movements
peripheral nervous system
This part of the nervous system consists of nerves and ganglia not within the brain and spinal cord
the voltage that the local potential needs to rise to to open voltage gated channels and propagate an action potential (-55mV) at the axon hillock
Threshold
a. nicotinic
Throughout the autonomic nervous system, the neurotransmitter released by the preganglionic fiber binds to _____ receptors on the postganglionic neuron. a. nicotinic b. muscarinic c. adrenergic d. alpha e. beta
thymus
Thymopoietin, thymosin, thymulin source
B) one microelecrode inside the neuron and another in the interstitial fluid.
To measure the resting potential of a neuron, a physiologist would place: A) two electrodes inside the neuron. B) one microelecrode inside the neuron and another in the interstitial fluid. C) one electrode inside the cell and another inside another cell. D) one electrode inside the cell and another outside the body
concave
To see far images, our lens changes to a more ________________ shape
convex
To see near images, our lens changes to a more ____________ shape
tympanic membrane
Transmission of sound vibrations to the auditory ossicles is the function of the
separates cerebellum from cerebrum
Transverse cerebral fissure
endocrine; nervous
Two organ systems are dedicated to internal coordination between other systems to maintain homeostasis of the body. They are ____________ system which communicates by means of hormones and the ___________ which sends quick electrical and chemical messages from cell to cell
A) stimulatory effects.
Typically, alpha adrenergic receptors have: A) stimulatory effects. B) inhibitory effects
melatonin
Uncertain; may influence mood and sexual maturation
sympathetic; ANS
Vasomotor tone is produced by a baseline level of stimulation from the ___________ division of the ___________
autonomic nervous system.
We lack awareness of many of our bodies' systems for maintaining homeostasis. The sensations, movements, and secretions of organs such as the heart and intestines are governed by the:
involved with memory, especially short term memory; sensitive to the effects of alcohol
Wernicke's Area
conjunctiva
What covers the sclera?
hypothalamus
What releases thyrotropin-releasing hormone
An insect crawling in one's hair would trigger the hair receptors; the throb of a patient's pulse is sensed by lamellar corpuscles in one's fingertips; and reading braille presumably stimulates tactile discs and tactile corpuscles.
What type of cutaneous receptor enables you to feel an insect crawling through your hair? What type enables you to palpate a patient's pulse? What type enables a blind person to read braille?
angular acceleration (rotation)
What type of equilibrium do the semicircular ducts detect?
Photoreceptors (they respond to light)
What type of receptor are the receptors in the eye?
chemoreceptors
What type of receptors are the receptors in the mouth?
chemoreceptors
What type of receptors are the receptors in the nose?
vibration, touch, pressure, stretch, tension, balance, hearing,
What type of senses respond to mechanoreceptors?
potassium exits, repolarizing the cell to a negative value.
When voltage gated K+ channels open on the conductive segment of a neuron:
At the end of the terminal arborization
Where are synaptic knobs located?
lateral gray horn
Where are the cell bodies of the sympathetic preganglionic fibers located in the spinal cord?
c. on the target-cell membrane (insulin is a peptide and is hydrophilic and cannot penetrate a target cell)
Where are the receptors for insulin located? a. in the pancreatic beta cells b. in the blood plasma c. on the target-cell membrane d. in the target-cell cytoplasm e. in the target-cell nucleus
Dura mater
Which of the cranial meninges consists of dense irregular connective tissue in two layers (the periosteal layer and the meningeal layer)?
Insula
Which of the five cerebral lobes is the one not visible on the surface of the brain?
C) Reversible, meaning if stimulation stops, cation diffusion out of the cell quickly returns the membrane voltage to resting potential D) Decremental E) Graded meaning they vary in voltage according to stimulus strength. An intense or prolonged stimulus opens more ion channels than a weaker stimulus F) Excitatory or inhibitory
Which of the following are characteristics of local potentials? Select all A) Irreversible B) All-or-none C) Reversible D) Decremental E) Graded F) Excitatory or inhibitory
A) They consist of a complex pattern of interneurons C) They may be concerned with a particular body function
Which of the following are characteristics of neural pools? Select all that apply A) They consist of a complex pattern of interneurons B) They form different types of circuits abased on the shape of the neurons C) They may be concerned with a particular body function
Filiform
Which papillae, distributed on the anterior two thirds of the tongue surface, lack taste buds?
association cortex areas of your cerebrum
Your memories of the sights and sounds of your elementary school are probably stored in:
dual innervation
_____ is a state in which a target organ receives both sympathetic and parasympathetic fibers.
autonomic tone
_____ is a state of continual background activity of the sympathetic and parasympathetic divisions.
b. Enkephalin
______ is a neuromodulator that blocks the conduction of pain signals by second-order spinal neurons. a. Endorphin b. Enkephalin c. Substance P d. Acetylcholine e. Norepinephrine
c. Substance P (released by nociceptor)
______ is a neurotransmitter that transmits pain sensations to second-order spinal neurons. a. Endorphin b. Enkephalin c. Substance P d. Acetylcholine e. Norepinephrine
biofeedback
a process whereby electronic monitoring of a normally automatic bodily function is used to train someone to acquire voluntary control of that function.
hyperglycemic hormone
any hormone that raises blood glucose concentration
Hypophyseal portal system
blood vessels that connect the anterior pituitary to the hypothalamus to deliver hormones to the anterior pituitary
sustenacular cells
cells in the testes that line the seminiferous tubules
sustenacular cells
cells in the testes that produce inhibin
sustenacular cells
cells in the testes that regulate sperm production by inhibiting FSH secretion
neuroendocrine cells
cells that act like neurons in some respects, but like endocrine cells in other respects
Pancreatic islets
cells that control glycemia, the blood glucose concentration
Theca cells
cells that line the granulosa cells and make up a capsule
layer covering the surface of the hemispheres; only 2 - 3 mm thick with 2 main types of neurons, stellate cells and pyramidal cells
cerebral cortex
vestibule
chamber in the inner ear containing the organs of equilibrium
angular acceleration
change in the rate of rotation
linear acceleration
change in velocity in a straight line
is the opposite of a diverging circuit—input from many nerve fibers is funneled to one neuron or neural pool. Such an arrangement allows input from your eyes, inner ears, and stretch receptors in your neck to be directed to an area of the brain concerned with the sense of balance. Also through neural convergence, a respiratory center in your brainstem receives input from other parts of your brain, from receptors for blood chemistry in your arteries, and from stretch receptors in your lungs. The respiratory center can then produce an output that takes all of these factors into account and sets an appropriate pattern of breathing.
converging circuit
Lipoxygenase
converts arachidonic acid to leukotrienes
nerve
cordlike organ composed of numerous nerve fibers (axons bundled into fascicles) bound together by connective tissue
thick bundle of nerve fibers separating the left and right cerebral hemispheres
corpus callosum
secondary tympanic membrane
covers the round window, sealing off one of two openings into the inner ear. It separates the scala tympani of the cochlea from the middle ear. It vibrates with opposite phase to vibrations entering the cochlea through the oval window as the fluid in the cochlea is displaced when pressed by the stapes at the oval window. This ensures that hair cells of the basilar membrane will be stimulated and that audition will occur.
sensorineural (nerve) deafness
death of hair cells or any nervous system elements concerned with hearing; factory workers, musicians and construction workers
Stage 4 sleep
deepest stage and slow-wave sleep; muscles very relaxed and vital signals are very low and one is difficult to awaken. EEG dominated by low frequency, high-amplitude delta waves. A lot of processing happening in this stage
ampulla
dilated sac at the end of the semicircular ducts that houses hair cells and supporting cells
an input neuron can act alone to make post synaptic cells fire
discharge zone
Pain
discomfort caused by tissue injury or noxious stimulation mediated by its own nerve fibers, nociceptors.
Diabetes Mellitus
disruption of metabolism due to hyposecretion or inaction of insulin
one nerve fiber branches and synapses with several postsynaptic cells. Each of those may synapse with several more, so input from just one neuron may produce output through hundreds of neurons. Such a circuit allows one motor neuron of the brain, for example, to ultimately stimulate thousands of muscle fibers.
diverging circuit
NSAIDs
do not affect lipoxygenase function or leukotriene production, but they block prostacyclin, thromboxanes, prostaglandins to mediate inflammation response
Endocrine glands
ductless and release secretions into the bloodstream; traditional sources of hormones
slow (second) pain
dull, diffuse pain the occurs immediately following the injury
difference in the concentration of charged particles between one point and another; form of energy that can produce current; if something has potential, we say it is polarize d
electrical potential
gap junction
enable cells to pass nutrients, electrolytes, and signaling molecules from the cytoplasm of one cell to another; direct communications
Pancreatic islets
endocrine glands that are scattered around the pancreas that secrete hormones
autocrine signaling
form of cell signaling in which a cell secretes a hormone into the ECF that binds to receptors on the same cell and change the physiology in the cell
juxtacrine signaling
form of cell signaling in which a cell secretes a hormone that binds to receptors on the cell right next to it
Retina (the retina is part of the brain)
forms from a cup-shaped outgrowth of the diencephalon called the optic vesicle
cupula
gelatinous cap extending from the crista to the roof of the ampulla in the semicircular ducts the have stereo cilium and kinocilium embedded in them
Pancreas
gland located beneath the stomach; primarily an exocrine digestive gland
Central pattern generators
groups of neurons in the spinal cord that produce rhythmic outputs without rhythmic or sensory input. They produce the sequence of outputs to muscles that cause alternating movements of the lower limbs
eyelashes
guard hairs that keep debris from the eye
thick folds in the brain allowing a greater amount of cortex to fit into the cranial cavity
gyri
When we look directly at a star, we focus this point of light on the fovea centralis. The fovea contains only cone cells, which are not very sensitive to dim light. Therefore, a dim star may not stimulate the receptor cells of the fovea enough to produce an image. When we look slightly away from the star, its image falls on one side of the fovea, in a region with some rod cells. Rods are more sensitive than cones and may therefore respond to the starlight.
if you look directly at a dim star in the night sky, it disappears, and if you look slightly away, it reappears. Why?
ganglion
knot in the middle of a nerve that is a cluster of neurosomas outside the CNS that is enveloped in epineurium continuous with that nerve and bundles of nerve fibers lead into and out of it
Vallate papillae
large papillae arranged in a V at the rear of the tongue; contain half of all of the taste buds
brainstem
large vertical stalk that supports the cerebellum and the two cerebral hemispheres in the brain; consists of the diencephalon, medulla oblongata, pons, and midbrain
Phospholipase A
liberates arachidonic acid from one of the phospholipids of the plasma membrane
macula sacculi
lies vertically on the wall of the; its hair cells therefore respond to vertical acceleration and deceleration.
special senses
limited to head; vision, hearing, equilibrium, taste, and smell
separates the right and left cerebral hemispheres
longitudinal fissure
sympathetic chain ganglia
longitudinal series of ganglia on both sides of the vertebral column
fungiform papillae
mushroom shaped bumps concentrated at the tips and sides of the tongue
protect the neurons and help them function; bind neurons together, provide a supportive framework for the nervous tissue; in the fetus they form a scaffold that guides young neurons to their destination
neuroglia
satellite cells
neuroglia in the PNS; surround somas in the ganglia of the PNS; provide insulation around soma and regulate chemical environment if neurons
reverberating circuit
neurons stimulate each other in a linear sequence from input to output neurons, but some of the neurons late in the path send axon collaterals back to neurons earlier in the path and restimulate them.
Nicotinic receptors
occur at all synapses of autonomic ganglia where the preganglionic fibers stimulate the postganglionic cells
sleep spindles
occur in stage 2 sleep; high spikes on the EEG resulting from interactions between neurons in the thalamus and cerebral cortex
beta waves
occur in the frontal to parietal region and are accentuated during mental activity and sensory stimulation
an input neuron diverges to stimulate several chains of neurons. Each chain has a different number of synapses, but eventually they all reconverge on one or few output neurons. Since the chains differ in total synaptic delay, their signals arrive at the output neurons at different times, and the output neurons may go on firing for some time after input has ceased. Unlike a reverberating circuit, this type has no feedback loop. Once all the neurons in the circuit have fired, the output ceases. Continued firing after the stimulus stops is called after-discharge. It explains why you can stare at a lamp, then close your eyes and continue to see an image of it for a while. Such a circuit is also important in withdrawal reflexes, in which a brief pain produces a longer-lasting output to the limb muscles and causes you to draw back your hand or foot from danger.
parallel after-discharge circuit
Falx cerebri
part of the meningeal layer of the cranial dura mater that extends into the longitudinal fissure as a tough wall between the two cerebral hemispheres
Macula lutea
patch of cells in the retina that surround the fovea
end bulbs
phasic receptors for light touch and texture; found in mucous membrane of lips and tongue and in the eye and epineurium of large nerves
tactile corpuscles
phasic receptors for light touch and texture; in dermal papillae of the skin
DHEA
plays an important role in the prenatal development of the male reproductive tract.
integrating center
point of synaptic contact between neurons in the gray matter of the cord or brainstem usually includes 1+ interneurons, but the more interneurons there are the more complex the processing, but with more synapses, there is more delay between input and output
median and lateral aperture
pores in the 4th ventricle that CSF flows out of and leads to the subarachnoid space in the brain and spinal cord
Prostacyclin
produced by the walls of the blood vessels, where it inhibits blood clotting and vasoconstriction.
sensory adaptation
property all receptors have; if the stimulus is prolonged, the firing of the neuron gets slower and we become less aware of the stimulus
The Flexor (Withdrawal) Reflex
quick contraction of a flexor muscle resulting in the withdrawal of a limb from an injurious stimulus;
reciprocal inhibition
reflex that prevents muscles from working against each other by inhibiting antagonists; stretch reflexes and other muscle contractions depend on this
tectorial membrane
resting on top of the stereocilium in the spiral organ
Endemic goiter
results from a deficiency of iodine, because without iodine, the thyroid gland cannot synthesize TH. Without TH, the pituitary gland receives no feedback and acts as if the thyroid were under stimulated, and it provides extra TSH, stimulating hypertrophy of the thyroid gland
Parafollicular C cells in the thyroid
secrete calcitonin with rising blood calcium; stimulates osteoblast activity and bone formation
when the signal reaches the end of a nerve, the neuron secretes a neurotransmitter that crosses the gap and stimulates the next cell
secretion property of neurons
Pupillary constrictor
smooth muscle cells that encircle the pupil and when stimulated by the parasympathetic nervous system, narrows the pupil and lets in less light
The zona glomerulosa of the cortex
source of aldosterone in the adrenal gland
limited to the head and employ complete sense organs; vision, hearing, equilibrium, taste, smell
special senses
shallow grooves in the brain; some divide the the cerebral hemispheres into five distinct lobes
sulci
bitter
taste associated with spoiled foods and alkaloids such as nicotine, caffeine, quinine, and morphine. Alkaloids are often poisonous and the bitter taste sensation usually induces one to reject food; detected by type 2
salty taste
taste produced by metal ions like sodium and potassium; detected by type 2 taste cells
sour
taste usually associated with acids (H+) in food; detected by type 3
near point of vision
the closest an object can be to the eyes and still be focused
general adaptation syndrome (GAS)
the consistent way body reacts to stress; involves elevated levels of epinephrine and glucocorticoids (especially cortisol, which is there to try to repair damage and give us energy)
Pituitary gland
the master gland of the endocrine system
pigment epithelium
the most posterior part of the retina that is a darkly pigmented layer that absorbs stray light so it does not degrade the visual image
frequency
the number of occurrences of a repeating event per unit time
thyroid stimulating hormone
the pituitary hormone that stimulates secretion of thyroid hormone
interceptors
this type of receptor detect internal stimuli
Encapsulated Nerve Endings
this type of receptor has dendrites wrapped by glial cells or connective tissue
bulbous corpuscles
tonic receptors for heavy touch, pressure, stretching of the skin, and joint movements
Synergistic effects
two or more hormones act together to produce an effect that is greater than the sum of their separate effects.
general (somesthetic) senses
widely distributed; include touch, pressure, heat, cold, pain, blood pressure, etc.
varies in size depending on the magnitude of the stimulus (An intense or prolonged stimulus opens more ion channels than a weaker stimulus, this more Na+ enters the cell and the voltage changes more than it does with a weaker stimulus).
A graded potential is one that:
permissive
A hormone is said to have a/an _________ effect when it stimulates the target cell to develop receptors for other hormones to follow.
polarized
A membrane that has a potential across it is said to be
long term memory
A memory that has lasted over a weekend is described as a:
sensory and motor neurons.
A mixed nerve refers to one that contains both:
visceral sensory
A neuron conducting an impulse from the stomach wall to the CNS would be classified as a(n) __________ neuron.
The cerebral functions essential for survival are duplicated in the right and left hemispheres, so the loss of even an entire hemisphere is not fatal. It will, however, result in such things as visual, motor, language, and cognitive deficits. The hypothalamus, however, is involved in so many basic homeostatic functions that its loss or destruction is not survivable.
A person can survive destruction of an entire cerebral hemisphere but cannot survive destruction of the hypothalamus, which is a much smaller mass of brain tissue. Explain this difference and describe some ways that destruction of a cerebral hemisphere would affect one's quality of life.
A) activation of the parasympathetic system and inhibition of the sympathetic system.
A rise in blood pressure causes a reflexive: A) activation of the parasympathetic system and inhibition of the sympathetic system. B) activation of the sympathetic system and inhibition of the parasympathetic system. C) activation of both the parasympathetic system the sympathetic system. D) inhibition of both the parasympathetic system and the sympathetic system
reciprocal inhibition
A stretch reflex requires the action of to prevent an antagonistic muscle from interfering with the agonist
A) sympathetic trunk.
A structure that is said to resemble a pearl necklace is a: A) sympathetic trunk. B) parasympathetic trunk. C) parasympathetic ganglion. D) splanchnic ganlion.
C) neuromodulator.
A substance which stimulates a postsynaptic neuron to adjust its sensitivity would be a A) neurotransmitter. B) peptide. C) neuromodulator. D) nerve growth factor. E) neural integration factor.
His sphenoid fracture has evidently severed the stalk that connects the hypothalamus to the posterior lobe of the pituitary gland. As a result, the hypothalamus cannot convey antidiuretic hormone to the pituitary or stimulate the pituitary to release ADH into the blood. In the absence of ADH, the kidneys conserve relatively little water, producing a copious output of urine. Excessive water loss from the body, in turn, stimulates intense thirst. The occipital bone does not lie near the pituitary gland, so an occipital bone fracture is unlikely to affect pituitary function. The hormone imbalance resulting from the sphenoid bone fracture is ADH hyposecretion. Diabetes insipidus is not associated with elevated glucose in the urine because ADH is not involved in glucose metabolism. The urine is abundant and dilute, but there is no glycosuria in diabetes insipidus.
A young man is involved in a motorcycle accident that fractures his sphenoid bone. Shortly thereafter, he begins to excrete enormous amounts of urine, up to 30 liters per day, and suffers intense thirst. His neurologist diagnoses the problem as diabetes insipidus. Explain how his head injury resulted in these effects on urinary function and thirst. Why would a sphenoid fracture be more likely than an occipital bone fracture to cause diabetes insipidus? What hormone imbalance resulted from this accident? Would you expect to find elevated glucose in the urine of this diabetic patient? Why or why not?
Cold and warm receptors are phasic receptors, since they quickly adapt to a sustained change in temperature.
Although you may find it difficult to immerse yourself in a tub of hot water or a cold lake, you soon adapt and become more comfortable. In light of this, do you think cold and warm receptors are phasic or tonic? Explain.
tonic receptors because the brain must always be aware of body position, muscle tension, and joint motion
Are proprioceptors phasic or tonic receptors?
No, but they secrete the neurotransmitter, glutamate
Are rods and cones neurons?
rods
Are rods or cones more sensitive to light?
unencapsulated
Are tactile discs encapsulated or unencapsulated?
No, they are epithelial cells, but they synapse with a sensory nerve fiber at their base and release synaptic vesicles to the sensory nerve fibers at their base
Are taste cells neurons?
encapsulated
Are tendon organs encapsulated or unencapsulated?
No, they stimulate each other (i.e. without cortisol, the medulla would shrivel up and go away and the fingers of the medulla go up and stimulate DHEA and sex hormones in the reticularis layer)
Are the adrenal medulla and adrenal cortex functionally independent of each other?
They are not neurons, but synapse with nerve fibers at their base and release neurotransmitters to excite the sensory dendrite at their base
Are the hair cells in the spiral organ neurons?
opening of voltage-gated calcium channels and diffusion of calcium into the synaptic knob.
Arrival of an action potential at the synaptic knob results in:
seeing nearby objects.
As a middle aged person gets older, the lenses of their eyes no longer assume as round of a shape when their ligaments slacken. This results in difficulty in:
their inactivated state to their resting state.
As a neuron's refractory period ends, its sodium channels are changing from:
descending
Ascending or descending tract: Tectospinal tract
ascending
Ascending or descending tract: cuneate fasiculus
ascending
Ascending or descending tract: gracile fasiculus
ascending
Ascending or descending tract: posterior and anterior spinocerebellar tracts
ascending
Ascending or descending tract: spinothalamic tract
descending
Ascending or descending tracts: Lateral and medial reticulospinal tracts
descending
Ascending or descending tracts: Lateral and medial vestibulospinal tracts
descending
Ascending or descending: anterior and lateral corticospinal tracts
areas that are adjacent to primary sensory cortexes where the sensory information received is interpreted and makes cognitive sense of the stimuli
Association areas
connect different regions of the cerebral cortex within the same hemisphere.
Association tracts:
Modality. The brain assumes that if a signal comes from the retina, it must be a visual signal, and if it comes from a taste bud, it must be a taste. This is called the labeled line code
Because all action potentials are identical, how can the brain tell a visual signal from a taste signal?
the same (referred pain)
Because numerous cutaneous and visceral sensory neurons conduct signals on _______ ascending tracts of the spinal cord, the brain sometimes falsely localizes the location of a pain stimulus.
generates a motor program for the muscles of the larynx, tongue, cheeks, and lips to produce speech, as well as hand signaling
Broca area
neurofibrils
Bundles of actin filaments in the soma are called
nonsteroidal anti-inflammatory drugs (NSAIDs)
COX inhibitors; block cyclooxygenase
b. thyroxine. (CRH is secreted by the hypothalamus and promotes secretion of ACTH, which stimulates the adrenal cortex to secrete glycocorticoids, which include cortisol and corticosterone, which releases fatty acids and glucose into the bloodstream)
CRH secretion would not raise the blood concentration of a. ACTH. b. thyroxine. c. cortisol. d. corticosterone. e. glucose.
photoreceptor cells
Cells that absorb light and generate a chemical or electrical signal that are found in the retina
basal cells
Cells within a tastebud; stem cells that multiply and replace taste cells when they die
passes from the core of the midbrain and leads to the fourth ventricle from the 3rd ventricle
Cerebral aqueduct
liquid that bathes the CNS and fills its ventricles
Cerebrospinal fluid
stimuli
Changes in the external and internal environment are ________ that are detected by the sensory system.
unconscious, automatic, stereotyped
Characteristics of a visceral reflex
Local potentials are graded and can vary in magnitude accordingly to the strength of the stimulus. Action potentials are all-or-none Local potentials are decremental, and get weaker as they spread from the point of stimulation. Local potentials are reversible. Local potentials can be excitatory or inhibitory
Characteristics that distinguish local potentials from action potentials:
Peptide
Chemical classification: Adrenocorticotropic hormone
Steroid
Chemical classification: Aldosterone
Steroid
Chemical classification: Androgens
Peptide
Chemical classification: Oxytocin
Peptide
Chemical classification: Pancreatic polypeptide
Peptide
Chemical classification: Prolactin
Peptide
Chemical classification: Somatostatin
Monoamine
Chemical classification: Thyroid hormone
Peptide
Chemical classification: Thyroid-stimulating hormone
Peptide
Chemical classification: Thyrotropin-releasing hormone
peptide
Chemical classification: gastrin
B) receptive
Chemically gated ion channels are mainly found in the ________ segment of a neuron. A) initial B) receptive C) conductive D) transmissive
the chief problem is not lack of insulin, but insulin resistance—unresponsiveness of the target cells to the hormone, either not enough receptors to bind insulin, or faulty receptors
Chief problem with Type 2 diabetes
a, b, d, e, c
Choose the answer that correctly lists, in chronological order, the events involved in synaptic transmission. a: A nerve impulse reaches the synaptic knob. b: Neurotransmitter molecules diffuse across the synaptic cleft. c: A nerve impulse begins in the postsynaptic cell. d: Neurotransmitter molecules bind to receptors in the postsynaptic cell. e: A voltage change occurs in the postsynaptic cell
extend between the right and left cerebral hemispheres.
Commissural tracts:
A) a specific neurotransmitter that either excites or inhibits its target.
Conductive activity in a neuron generally causes it to secrete: A) a specific neurotransmitter that either excites or inhibits its target. B) a specific neurotransmitter that always excites its target. C) several types of neurotransmitter simultaneously, all of which excite the cell's target. D) several types of neurotransmitter simultaneously, that are broadcast to excite and inhibit multiple targets. E) several types of neurotransmitters simultaneously, that all work to prevent another immediate impulse
equilibrium
Coordination, balance, and orientation in a 3D space
most of its input and output travels by way of the spinal cord, but it also communicates through 12 pairs of cranial nerves that arise in the base of the brain and exit the cranium through its foramina and lead to muscles and sense organs mostly located in the head and neck
Cranial nerves
prostacyclin, thromboxane, and prostaglandin
Cyclooxygenase converts arachidonic acid to three other eicosanoids, they are:
adrenal cortex's zona reticularis
Dehydroepiandrosterone source
come off of the soma; thick processes used to receive signals from other neurons; the more dendrites a neuron has, the more information it can receive. Dendrites CANNOT propagate an action potential because they only have ligand gated channels and if they do have voltage gated channels, there are few
Dendrites
2 nerve fibers, Parasympathetic fibers release ACh and stimulate the pupillary constrictor Sympathetic fibers release NE and stimulate the pupillary dilator
Describe dual innervation of the pupils
saltatory conduction; voltage gated channels are scarce, so the action potential can only occur at the nodes of Ranvier. When sodium enters the axon at a node of Ranvier, it diffuses for a short distance and each sodium ion has an electrical fields around it so it pushes the other sodium ions down the membrane. The signal grows weaker with distance. When this signal reaches another node of Ranvier, it is just strong enough to open the sodium channel at the next node, and create a new depolarization and action potential, which is the same strength as the one before it, so each node boosts the signal back to its original strength, and by skipping a whole lot of area, we save time
Describe signal conduction in myelinated fibers
Unmyelinated fibers have voltage gated channels along their length. When an action potential occurs at the trigger zone, sodium enters the axon and diffuses for a short distance beneath the plasma membrane, resultin gin depolarization and exciting the voltage gated channels next to the action potential. Sodium and potassium channels up and a new action potential is produced and a chain reaction occurs until the signal reaches the end of the axon. The nerve signal cannot go backwards because the membrane behind it is still in its refractory period and only the membrane in front of it is sensitive to stimulation
Describe signal conduction in unmyelinated fibers
If you step on glass, this will stimulate pain receptors in your foot, and a sensory neuron will travel to the spinal cord and activate multiple interneurons. One of these will excite ipsilateral flexor nerve to cause your ipsilateral flexor to contract. In addition, contralateral motor neurons will excite the extensor muscle in the other leg causing it to contract to aid in balance when the injured foot is raised
Describe the flexor (withdrawal) reflex and the crossed extension reflex working together
Within the chiasm, half of the nerve fibers from each optic nerve cross over to the other side of the brain, a hemidecussation , thus the right occipital lobe monitors the left side of the visual field, while the left occipital lobe monitors the right side of the visual field
Describe the hemidecussation that occurs with optic nerve fibers
Hypothalamus secretes thyrotropin releasing hormone TRH stimulates anterior pituitary to secrete TSH TSH stimulates the thyroid gland to secrete TH TH stimulates the metabolism of most cells in the body Some TH goes back to the brain and inhibits release of TSH by the pituitary TH also inhibits release of TRH by the hypothalamus
Describe the negative feedback loop function of TH
When the patellar ligament is tapped, this abruptly stretches the quads, stimulating muscle spindles in the quads to send signals to the spinal cord by way of primary afferent fibers (within the intrafusal fibers of the muscle spindle) and in the spinal cord these fibers synapse directly with alpha motor neurons that return to the muscle and excite the quads and cause them to contract to prevent overstretching of the muscle, which could cause damage. This also requires reciprocal inhibition, inhibiting the hamstrings from contracting. Some branches of the sensory fibers from the quad muscle spindles stimulate a spinal interneuron that inhibits the alpha motor neurons of the hamstrings, so the hamstrings, which are the antagonist to the quads, remain relaxed so the quads can extend fully
Describe the patellar (knee-jerk) stretch reflex
Each sound (sound waves are basically air waves) pushes the tympanic membrane, which pushes the middle ear ossicles forward. Then the stapes push on the perilymph in the scala vestibuli. Perilymph cannot be compressed, so it flows away from the stapes footplate and the resulting pressure on the scala vestibule pushes the vestibular membrane downward, pushing on the endolymph in the cochlear duct, which pushes on the basilar membrane, which pushes on the perilymph in the scala tympani and then the secondary tympanic membrane in the tympanic window bulges outward to relieve pressure and as the cycle of vibration continues, the stapes pulls back from the oval window and everything happens in reverse As the stapes goes in and out, the secondary tympanic membrane goes in and out, and the basilar membrane goes up and down The hair cells, which are on the basilar membrane in the spiral organ in the cochlear duct bob up and down as the basilar membrane bobs up and down On each of the inner hair cells, each stereocilium has a single transmembrane protein at its tip that functions as a mechanically gated ion channel and a stretchy protein filament called a tip link extends from one protein on a stereocilium to the side of the next stereocilium. The stereocilium increase progressively in height The tectorial membrane remains still as the hair cells bob up and down and each time the basilar membrane rises up, the hair stereocilia are pushed against the tectorial membrane and bend over towards the tallest one. As each taller stereocilium bends over, it pulls on the tip link, which is connected to the ion gate of the next shortest stereocilium and it pulls the gate open and allows ions to flow in the cell, mainly K+ since it is so highly concentrated and depolarizes the hair cell, creating a local potential, which releases a burst of neurotransmitters, exciting the sensory processes of the cochlear nerve below it, this a signal is generated in the cochlear nerve and transmitted to the brain
Describe the stimulation of the cochlear hair cells
1) Hydrophilic hormone binds to a receptor on the cell surface that is attached to a G protein, and the G protein is activated 2) G protein activates phospholipase enzyme 3) Phospholipase takes a membrane phospholipid and splits it into a phosphate piece (IP3) and a triglyceride piece (DAG) 4) DAG activates protein kinases 5) Kinases then phosphorylate or dephosphorylate certain enzymes and either activate or deactivate them 6) Metabolic effects in the cell
Detail the 2nd messenger system involving DAG that is activated by some hormones
1) Hydrophilic hormone binds to a receptor on the cell surface that is attached to a G protein, and the G protein is activated 2) G protein activates phospholipase enzyme 3) Phospholipase takes a membrane phospholipid and splits it into a phosphate piece (IP3) and a triglyceride piece (DAG) 4) IP3 increases the Ca2+ in the cell by either opening calcium channels in the membrane or by opening calcium channels in the ER. 5) Calcium can bind to calcium dependent molecules in the cell and alter cell metabolism, bind to the calcium receptor calmodulin which can cause smooth muscle to contract or activate kinases and have metabolic effects, or it could bind to membrane channels, changing their permeability and altering the membrane potential of the cell
Detail the 2nd messenger system involving IP3 that is activated by some hormones
1) Hydrophilic hormone binds to a receptor on the cell surface that is attached to a G protein, and the G protein is activated 2) G protein activates adenylate cyclase 3) Adenylate cyclase converts ATP to cAMP + 2P 4) cAMP then is the 2nd messenger and activates protein kinases in the cell 5) Kinases then phosphorylate or dephosphorylate certain enzymes and either activate or deactivate them 6) Metabolic effects in the cell
Detail the 2nd messenger system involving cAMP that is activated by some hormones.
has a pair of cuplike optic vesicles that are an outgrowth of the nerve that become the retinas of the eyes
Diencephalon
firing frequency
Differences in the volume of a sound are likely to be encoded by differences in _________ in the nerve fibers coming from the inner ear
Referred pain results from the fact that cutaneous and visceral sensory pathways converge on the same spinal interneurons, so the brain cannot distinguish the original sources of pain from each other. Scotopic vision is characterized by high light sensitivity, which results from the fact that multiple rods converge on the same bipolar neurons and multiple bipolar neurons converge on the same ganglion cells, thus allowing for spatial summation in the rod pathways.
Discuss the relevance of neural convergence to referred pain and scotopic vision.
NO
Do parasympathetic and sympathetic fibers come off of the same parts of the CNS?
No, they do not, but the ANS just regulates their functioning
Do visceral effectors need the autonomic nervous system to function?
receives input from both the sympathetic and parasympathetic nervous systems.
Dual innervation means that an individual effector:
one of the 3 meninges; pressed tightly against the cranial bone with no intervening epidural space; two layers, periosteal layer and meningeal layer
Dura mater in the brain
in some places, the two layers of the dura are separated by the dural sinuses, which collect CSF and absorb it into the circulatory system; also collect blood and send it back to heart
Dural sinuses
A) the meningeal and periosteal layers separate to form large blood-filled spaces.
Dural venous sinuses are areas where: A) the meningeal and periosteal layers separate to form large blood-filled spaces. B) cerebrospinal fluid is produced. C) cerebrospinal fluid is stored. D) large numbers of nuclei congregate. E) glial cells are formed
REM sleep
EEG resembles waking stage, yet the sleeper is hardest to waken; vital signs increase and the brain consumes a lot of oxygen; sleep paralysis and vivid dreams
anterior and posterior roots; anterior and posterior rami
Each spinal nerve branches win both ends, into ______________ and _______________ approaching the spinal cord, and into ____________ and _____________ leading away from the vertebral column
voluntary muscle contractions and voluntary somatic reflexes
Efferent fibers of the somatic motor division produce what:
Thyroxine (T4) and triiodothyronine (T3)
Elevate metabolic rate and heat production; increase respiratory rate, heart rate, and strength of heartbeat; stimulate appetite and accelerate breakdown of nutrients; promote alertness and quicken reflexes; stimulate growth hormone secretion and growth of skin, hair, nails, teeth, and fetal nervous system
neuroglia in the CNS; line ventricles of the brain and spinal cord; secrete and circulate cerebrospinal fluid; epithelial cells, but no basement membrane, but instead have root like processes that penetrate underlying fluid; have cilia on their apical surfaces that help circulate CSF; slight blood-brain barrier in the choroid plexus
Ependymal cells
C) There are no enzymes to break down epinephrine and norepinephrine in the blood and a few enzymes in peripheral tissues
Epinephrine and norepinephrine released from the adrenal glands affect target organs for a longer period of time than the same substances when released from neurons at their peripheral receptors. Why? A) The adrenal gland releases larger amounts of the neurotransmitters than the neurons B) The hormones released from the adrenal glands bind to different receptors than those released from other neurons C) There are no enzymes to break down epinephrine and norepinephrine in the blood and a few enzymes in peripheral tissues D) The effectors are less sensitive to epinephrine and norepinephrine that are released by the adrenal glands E) The epinephrine and norepinephrine from the adrenal glands are released by sympathetic neurons, whereas parasympathetic neurons released these substances at the effector organs
e. the adrenal medulla (The adrenal medulla secretes epinephrine, norepinephrine, and dopamine into the bloodstream. Parasympathetic fibers ONLY secrete ACh, and sympathetic fibers secrete norepinephrine and ACh. Epinephrins increases alertness, and prepares the body for physical activity. They mobilize high energy fuels)
Epinephrine is secreted by a. sympathetic preganglionic fibers. b. sympathetic postganglionic fibers. c. parasympathetic preganglionic fibers. d. parasympathetic postganglionic fibers. e. the adrenal medulla.
adrenal medulla
Epinephrine, norepinephrine, dopamine source
Broca area and Wernicke area
Except for ____________, the functional regions of the cerebral cortex are found in both hemispheres
uses Norepinephrine. Not all neurotransmitters open a channel, there are a number of neurotransmitters that stimulate a second messenger system NE acts through second messenger Slower to respond than ACh or GABA, but they have the property of enzyme amplification The unstimulated NE receptor is bound to a G protein. Binding of NE to the receptor causes the G protein to dissociate from it. The G protein binds to adenylate cyclase and activates this enzyme, which converts ATP to cAMP. Cyclic AMP can induce several alternative effects in the cell. One effect is to produce an internal chemical that binds to a ligand-gated ion channel from the inside, opening the channel and depolarizing the cell. Another is to activate preexisting cytoplasmic enzymes, which can lead to diverse metabolic changes (for example, inducing a liver cell to break down glycogen and release glucose into the blood). Yet another is for cAMP to induce genetic transcription, so that the cell produces new enzymes leading to diverse metabolic effects.
Excitatory Adrenergic Synapse
•The arrival of a nerve signal at the synaptic knob opens voltage-gated calcium channels. Ca2+ enters the knob and triggers exocytosis of the synaptic vesicles, releasing ACh. Empty vesicles drop back into the cytoplasm to be refilled with ACh, while synaptic vesicles in the reserve pool move to the active sites and release their ACh ACh diffuses across the synaptic cleft and binds to ligand-gated channels on the postsynaptic neuron. These channels open, allowing Na+ to enter the cell and K+ to leave. Na+ and K+ pass in opposite directions through the same gates. As Na+ enters, it spreads out along the inside of the plasma membrane and depolarizes it, producing a local voltage shift called the postsynaptic potential. Like other local potentials, if this is strong and persistent enough (that is, if enough current makes it to the axon hillock), it opens voltage-gated ion channels in the trigger zone and causes the postsynaptic neuron to fire.
Excitatory Cholinergic Synapse
part of the meningeal layer of the cranial dura mater that partially separates the cerebral hemispheres from the inferior side
Falx cerebelli
moves mitochondria, synaptic vesicles, another organelles, components of axolemma, calcium ions, enzymes such as acetylcholinesterase and small molecules such as glucose, amino acids, and nucleotides towards distal end of axon. Employs kinesin to carry proteins on their back while they reach out to bind repeatedly to the microtubules and walk on them
Fast anterograde transport
To transmit the wave-like vibrations to the hairs
Function of the fluid filled chambers in the ear?
to transmit sound vibrations to the auditory ossicles
Function of the tympanic membrane
conduction, neutral integration, locomotion, reflexes
Functions of the spinal cord
Nitric oxide is a gas that is released by the postsynaptic neuron and it is fat soluble and it can diffuse through the cell membrane of the presynaptic neuron, stimulating it to release more neurotransmitter.
GH often works in conjunction with
pancreatic islets
Gastrin source
pancreatic islets G cells
Gastrin sources
seat of neurosomas, dendrites, synapses; forms a surface layer called the cortex over the cerebrum and cerebellum; outside of the brain
Gray matter of the brain
estradiol
Hormone secreted by the adrenal cortex that promotes adolescent skeletal growth and help to sustain adult bone mass.
posterior horn
Horn that carries sensory signals up the spinal cord
Most hormones are taken up and degraded by the kidneys and liver and then excreted in bile or urine, some hormones are degraded by target cells
How are hormones cleared from the body?
the same was as any other protein, the gene for the hormone is transcribed to form an mRNA molecule, and ribosomes translate the mRNA and assemble amino acids to make the peptide. After the peptide is made, the rough ER and Golgi further modify the peptide to form the mature hormone
How are peptide hormones synthesized?
With the head erect, the otolithic membrane bears directly down on the hair cells, and stimulation is minimal. When the head is tilted, however, the heavy otolithic membrane sags and bends the stereocilia, stimulating the hair cells, which synapse with sensory fibers at their base
How can the body sense equilibrium changes?
At the base of the cochlea, the basilar membrane is attached, narrow, and stiff. At its distal end, it is unattached, five times wider, and more flexible. The peak amplitude of this wave is near the distal end in the case of low-frequency sounds and nearer the proximal end with sounds of higher frequencies. When the brain receives signals mainly from inner hair cells at the distal end, it interprets the sound as low-pitched; when signals come mainly from the proximal end, it interprets the sound as high-pitched.
How can the brain distinguish between high pitch and low pitch sounds?
Variations in amplitude cause variations in the intensity of the cochlear vibration because a soft sound produces a slight up and down movement of the basilar membrane and hair cells are stimulated only moderately. Hair cells respond more intensely, generating a higher firing frequency in the cochlear nerve. In addition, for a given frequency, a loud sound vibrates a longer segment of the basilar membrane and thus excites a greater number of hair cells. If the brain detects moderate firing rates associated with hair cells in relatively narrow bands of the cochlea, it interprets this as a soft sound. If it detects a high firing frequency in nerve fibers associated with broader bands, it interprets this as a loud sound.
How can the brain distinguish between loud and soft sounds?
Since nerves do not work in magnitude because action potentials are all-or-nothing, the intensity can be distinguished by which fibers are firing, how many fibers are firing, and how rapid the signals are. Weak stimuli only activate the most sensitive nerve fibers, intense stimuli recruit a greater number of nerves to fire (spatial summation) and as stimulus intensity increases, the firing frequency of sensory nerve fibers increases (temporal summation)
How can the brain distinguish the intensity of a stimulus?
The auditory tubes are continuous between the middle ear and the throat because in children they are relatively short and horizontal, so this allows infections to easily spread to the tympanic cavity of the middle ear
How can throat infections get transferred to the ear?
In response to sound, the OHCs send signals to the brain and the brain immediately sends signals back to the OHCs by way of the motor neurons. In response, the hair cells can shorten. An OHC is anchored to the basilar membrane below and its stereocilia to the tectorial membrane above. Therefore, tensing of an OHC reduces the basilar membrane's mobility. This results in some regions of the cochlea sending fewer signals to the brain than neighboring regions, so the brain can better distinguish between sound frequencies.
How can we tune our cochlea to receive some frequencies better than others?
They are hydrophilic and have no problem mixing with the blood plasma
How do monoamines get around the blood?
When it gets to the cell, it gets released from the transport protein and enter the target cell nucleus and act differently on genes, changing target cell physiology by either activating or inactivating transcription of the gene for a metabolic protein or enzyme. T4 converts to T3 inside of the cell
How do steroids and TH affect their target cells?
myelin presence speeds it up large nerve fibers require large somas and a large energy expenditure, so the evolution of myelin allowed for the evolution of more complex and response nervous systems with smaller, more energy efficient neurons First of all, by wrapping tightly around the axon, it seals the nerve fiber and greatly increases its resistance to the leakage of Na+ out of the axon. Sodium ions therefore maintain a higher density on the inner face of the membrane and transfer energy from one to another more rapidly. Secondly, myelin creates a greater separation between the ICF and ECF. Cations and anions of the ICF and ECF are therefore less attracted to each other—like two magnets now separated by a thick sheet of plastic. Na+ ions can therefore move more freely within the axon, transferring energy from one to another. It allows the action potential to skip
How does myelination speed up conduction speed?
With the semicircular ducts filled with endolymph, when the head turns, the duct rotates, but the endolymph lags behind, pushing the cupula, bending the stereocilia, and stimulating the hair cells and these hair cells also synapse at their base with sensory fibers of the vestibular nerve
How does the body sense angular acceleration?
Location is encoded by which nerve fibers issue the signals to the brain because any neuron only senses stimuli within its receptive field
How does the brain know where a stimulus is coming from?
After ovulation, the mature follicle ruptures and releases the egg, and the remainder of the follicle becomes the corpus luteum
How does the corpus luteum form?
They are first released into the ECF, and then from the ECF they go to the bloodstream and from the bloodstream they go everywhere and as they diffuse out into ECF and if there is a target cell in the ECF, it will pick up the hormone because it has specific receptors
How does the endocrine system communicate with the target organ?
1) A nociceptor stimulates a second order nerve fiber at the spinal interneuron by releasing the neurotransmitter Substance P 2) The second order nerve fiber transmits signals thalamus 3) The thalamus relays the signals through a third-order neuron to the cerebral cortex, where one becomes conscious of pain 4) Signals from the hypothalamus and cerebral cortex feed into the midbrain, allowing both autonomic and conscious influences on pain perception. 5) The midbrain relays signals to certain nuclei in the reticular formation of the medulla oblongata. 6) The medulla issues descending, serotonin-secreting analgesic fibers to the spinal cord two directions: One synapses on this second order neuron's axon and releases enkephalins, which modulate or block the pain signal going up Some fibers also exert presynaptic inhibition, synapsing on the axons of the nociceptors and blocking the release of substance P. This makes the resting potential of the axon even more negative to block the pain signal coming through
How does the pain signal get sent to the brain, and then how does spinal gating happen?
Individual nerve fibers are enclosed in an endoneurium, while muscle fibers are enclosed in an endomysium. Both nerve and muscle fibers are grouped in fascicles. Nerve fascicles are enclosed in perineurium and muscle fascicles in perimysium. Finally, a nerve as a whole is enclosed in epineurium and a muscle in epimysium.
How does the structure of a nerve compare to that of a skeletal muscle?
Cells of the thyroid follicle begin by absorbing I- ions from the blood and at the surface of the cells, they oxidize I- into its reactive form. Then, the follicle cells synthesize the protein thyroglobulin (which is made up of hundreds of tyrosine amino acids). An enzyme of the follicle cell adds either 1 or 2 iodines to the tyrosine (some becoming MIT and some becoming DIT). DIT and MIT or DIT and DIT link up becoming T3 and T4 respectively. One tyrosine then breaks away from its Tg, but remained anchored to Tg through the other tyrosine. The hormone is stored in the thyroid follicles until the thyroid gland gets the signal from the anterior pituitary to release TH. Within the cell, a lysosome hydrolyzes the Tg chain, liberating the thyroid hormone. The released hormone is about 10% T3 and 90% T4
How is TH synthesized?
encoded by changes in firing frequency with the passage of time because all recptors exhibit sensory adaptation, where if the stimulus is prolonged, the firing of the neuron gets slower over time
How is duration encoded in the brain in response to a stimuli?
Insulin begins as a preproinsulin, then we chop it, and it becomes a proinsulin, and then we chop it again and we get insulin and this all happens in the Golgi
How is insulin synthesized?
each oligodendrocyte reaches out to myelinate several nerve fibers in its immediate vicinity. Since it is anchored to multiple fibers, it cannot wrap around them, so it pushes newer layers of myelin around older ones, so myelination spirals inward towards the nerve fibers; no neurilemma or endoneurium
How is myelination accomplished in the CNS?
a Schwann cell spirals repeatedly around a single nerve fiber, laying down compact layers of its own membrane, and these layers make up the myelin sheath and form the neurilemma; forms nodes of Ranvier and internodes
How is myelination accomplished in the PNS?
In neural recruitment, additional neurons are activated as stimulus intensity increases. In motor nerves, this is the basis for multiple motor unit (MMU) summation. When a stronger muscle contraction is needed, more motor nerve fibers fire (neural recruitment), thus activating more motor units in the muscle.
How is neural recruitment related to multiple motor unit summation of muscles?
stereotyped posture and inhibition of muscular activity
How is sleep characterized?
Neither the peptide hormones nor the metabotropic neurotransmitters (such as the catecholamines) can enter their target cells. They bind to surface receptors, which then activate second-messenger systems in the cell.
How is the action of a peptide hormone similar to the action of the neurotransmitter norepinephrine?
:When you fixate on something within 30 m, each eye views it from a slightly different angle and focuses its image on the fovea centralis. The point in space on which the eyes are focused is called the fixation point. Objects farther away than the fixation point cast an image somewhat medial to the foveas, and closer objects cast their images more laterally. The distance of an image from the two foveas provides the brain with information used to judge the position of other points relative to the fixation point.
How the eyes perceive depth
Such a change in the K+ gradient across the plasma membrane results in less net diffusion of K+ out of neurons. The K+ concentration in the cytoplasm increases, partially depolarizing the membrane and making neurons more excitable.
Hyperkalemia is an excess of potassium in the extracellular fluid. What effect would this have on the resting membrane potentials of the nervous system and on neural excitability?
gigantism
Hypesecretion of GH before adolescence results in
pituitary dwarfism
Hyposecretion of GH in childhood results in
D) parasympathetic; increase (The sympathetic will have complete control over the heart)
If the ________ nerves to the heart are cut, the heart rate will ________. A) sympathetic; decrease B) sympathetic; increase C) parasympathetic; decrease D) parasympathetic; increase
spina bifida
If the neural tube does not close all of the way, it leads to
A) the spinal cord may be affectedt
If the posterior portion of the neural tube failed to develop properly ________. A) the spinal cord may be affected B) the cranial nerves would not form C) the hindbrain would not be present D) the telencephalon would cease developmen
B) precision would be greater, but we would need more receptors to monitor the environment for stimuli.
If the receptive fields of the skin's receptors were smaller, then: A) precision would be greater, and we would not need as many receptors to monitor the environment for stimuli. B) precision would be greater, but we would need more receptors to monitor the environment for stimuli. C) precision would be lessened, and we would need more receptors to monitor the environment for stimuli. D) precision would be lessened, but we would not need as many receptors to monitor the environment for stimuli.
cerebral hemispheres
If the telencephalon was removed from a 5-week-old embryo, what structure(s) would fail to develop in the fetus?
the ability to hold something in mind for just a few seconds. By remembering what just happened; may be based on reverberating circuits
Immediate Memory
cortisol
Immunity is depressed by long term exposure to the stress hormone_______
nicotinic
In all cases, the postganglionic fiber has a ________ receptor
androgens
In both sexes, this hormone induces the growth of pubic and axillary hair and their associated apocrine scent glands in puberty, and they stimulate the libido (sex drive) throughout adolescent and adult life
postsynaptic potentials at the initial segment.
In neurophysiology, the term summation refers to the addition of: action potentials at the node of Ranvier. postsynaptic potentials at the initial segment. excitatory neurotransmitter molecules at a receptor. resting membrane potentials in a particular area of the brain. presynaptic hyperpolarizations
inside the cell versus outside the cell, whereas sodium has a higher concentration outside versus inside the cell.
In normal cells, potassium has a higher concentration:
D) Acetylchonine
In the PNS, ptresynaptic fibers release: A) Norepinephrine B) Epinephrine D) Acetylchonine
crossed extension
In the _______________ reflex, contraction of flexor muscles in one limb is accompanied by the contraction of extensor muscles in the contralateral limb.
vertically on the wall of the saccule
In the saccule, how is the macula arranged?
alpha motor fibers that innervate extrafusal muscle fibers and regulate their firing based on the length of the muscle
In the spinal cord, primary afferent neurons of the intrafusal muscle fibers synapse with what?
gray matter
In the spinal cord, what forms horns?
white matter
In the spinal cord, what is formed of tracts?
central canal
In the spinal cord, what is the space within the gray matter that contains CSF and is lined with ependymal cells?
posterior horns, anterior horns, lateral horn
In the spinal cord, which are composed mostly of gray matter?
1) End in the ganglion and immediately synapse with a postganglionic neuron 2) Travel up or down to synapse with ganglion in other levels of the chain 3) Some may pass through without synapsing
In the sympathetic nervous system, the preganglionic fiber enters the sympathetic chain ganglion and has 3 options, they are:
horizontally on the floor of each utricle
In the utricle, how is the macula arranged?
autonomic
In which nervous system are the effectors glands, smooth muscle, and cardiac muscle?
Somatostatin
Inhibits secretion of growth hormone (GH) and thyroid-stimulating hormone (TSH)
most of our neurons and lie entirely within CNS; receive signals from many other neurons and carry out the integrative function of the nervous system (process, store, retrieve, make decisions); association neurons sensory neuron synapses with association neurons which can synapse with a whole bunch of other neurons leading to the brain
Interneurons
association neurons
Interneurons are also called
the myelinated segment from one node of Ranvier to the other
Internodes
B) local and discrete activation.
Limited branching of preganglionic axons allows for: A) mass activation. B) local and discrete activation. C) rapid changes in numerous structures at once
categorical
Linear, analytical, and verbal thinking occurs in the _____ hemisphere of the cerebrum, which is on the left in most people.
to provide energy for growing tissues, GH stimulates adipocytes to catabolize fat and release fatty acids and glycerol into the blood. By providing these fuels, GH makes it unnecessary for cells to consume their own proteins. This is called the protein-sparing effect and it also spares glucose and saves it for the brain
Lipid metabolism function of GH
Alarm reaction, stage of resistance, stage of exhaustion
List in order of occurrence, the stages of the general adaptation syndrome
progesterone, estradiol, inhibin
List the hormones secreted by the ovary
A) Paracrines C) Hormones F) Neurotransmitters G) Gap junctions
List the mechanism by which cell-to-cell communication can be accomplished A) Paracrines B) Desmosomes C) Hormones E) Enzymes F) Neurotransmitters G) Gap junctions
malleus, incus, stapes
List the ossicles of the ear, starting with the one closest to the tympanic membrane
1) Tilt of head 2) Shift of otolithic membrane 3) Bending of stereocilia 4) Depolarization of hair cells
List the steps involved in detecting a change in a static equilibrium
cerebrum.
Lobes of the brain are named for the bones superficial to them and are part of the:
short range change in voltage that does not propagate because the channels that are around there are ligand gated and are not sensitive to voltage changes
Local Potential
pathway through the brain that is the physical basis for memory in which new synapses have formed or existing synapses have been modified to make transmission easier
Memory trance (engram)
Left
Most commonly, which cerebral hemisphere is responsible for controlling speech?
mechanoreceptors
Most encapsulated nerve endings are what
spiral layer of electrical insulation around a nerve fiber, formed by oligodendrocytes in the CNS and Schwann cells in the PNS. Its composition is like that of a plasma membrane sine it consists of the plasma membranes of glial cells; high lipid content
Myelin sheath
)nervous
Nervous or endocrine: Reacts quickly to stimuli (milliseconds
A) Bind neurons together and provide supportive scaffold C) Protect neurons and help them function
Neuroglia are: (select all that apply) A) Bind neurons together and provide supportive scaffold B) Main properties are excitability and conductivity C) Protect neurons and help them function D) Less numerous than neurons
hormones, neuropeptides, and other messengers that modify the effect of a neurotransmitter They modulate the activity in various ways: 1) adjusting the sensitivity of postsynaptic neurons to neurotransmitters 2) may stimulate a neuron to install more receptors in the postsynaptic membrane adjusting its sensitivity to the neurotransmitter 3) may alter the rate of neurotransmitter synthesis, release, reuptake, or breakdown to prolong their effects
Neuromodulators
olfactory bulbs.
Olfactory glomeruli are located in the:
olfactory bulb
Olfactory neurons synapse with mitral cells and tufted cells in the ______, which lies inferior to the frontal lobe.
Terminal ganglia near or within target organs Long preganglionic Short postganglionic Minimal More specific and local Always cholinergic Always cholinergic
Parasympathetic: Location of ganglia: Fiber lengths: Neural Divergence: Effects of system: Neurotransmitter of Preganglionic Fiber: Neurotransmitter of Postganglionic Fiber:
parathyroid glands
Parathyroid hormone (PTH) source
zona fasciculate and reticularis
Part of the adrenal gland that secretes androgens
Zona reticularis and fasciculata
Part of the adrenal gland that secretes estradiol
zona fasciculate and reticularis
Part of the adrenal gland that secretes glucocorticoids
memories lasting for a few hours involve this; the Ca2+ level in the synaptic knob stays elevated for so long that another signal, coming well after the tetanic stimulation has ceased, releases an exceptionally large burst of neurotransmitter. That is, if a synapse has been heavily used in the recent past, a new stimulus can excite the postsynaptic cell more easily. Thus, your memory may need only a slight jog to recall something from several hours earlier.
Post tetanic potentiation
bipolar cells
the first order neurons in the visual pathway; rods and cones synapse with their dendrites, and they turn and synapse with ganglion cells
auricle
the part of the outer ear that is on the side of the head; made of elastic cartilage, except for the earlobe which is adipose tissue and has a specific arrangement of whorls and recesses that direct sound into the auditory channel
hair receptors
these receptors monitor movement of hair; dendrites that wrap around base hair follicle
Vitreous body
transparent jelly that fills the vitreous chamber behind the lens
Electroencephalogram
useful in studying normal brain functions such as sleep and consciousness and diagnosing abnormalities; monitors surface electrical activity of the brain waves
NSAIDs
useful in treatment of fever and thrombosis
sympathetic
what nervous system stimulates the pupillary dilator?
the stretch reflex
when a muscle is suddenly stretched, it fights backs, contracts, increases tone, and feels stiffer than an upstretched muscle; to maintain equilibrium and posture and coordinate movements and smooth out muscle action
1) When a nerve fiber is cut, the fiber distal to the injury cannot survive because it is incapable of protein synthesis. Protein-synthesizing organelles are mostly in the soma. As the distal fiber degenerates, so do its Schwann cells, which depend on it for their maintenance. Macrophages clean up tissue debris at the point of injury and beyond. 2) The soma exhibits a number of abnormalities of its own, probably because it is cut off from the supply of nerve growth factors from the neuron's target cells. The soma swells, the endoplasmic reticulum breaks up (so the Nissl bodies disperse), and the nucleus moves off center. Not all damaged neurons survive; some die at this stage. But often, the axon stump sprouts multiple growth processes as the severed distal end shows continued degeneration of its axon and Schwann cells. Muscle fibers deprived of their nerve supply exhibit a shrinkage called denervation atrophy. 3) Near the injury, Schwann cells, the basal lamina, and the neurilemma form a regeneration tube. The Schwann cells produce cell-adhesion molecules and nerve growth factors that enable a neuron to regrow to its original destination. When one growth process finds its way into the tube, it grows rapidly (3-5 mm/day), and the other growth processes are retracted. 4) The regeneration tube guides the growing sprout back to the original target cells, reestablishing synaptic contact. 5) When contact is established, the soma shrinks and returns to its original appearance, and the reinnervated muscle fibers regrow.
Process of nerve fiber regeneration
Thyrotropin-releasing hormone
Promotes secretion of thyroid-stimulating hormone (TSH) and prolactin (PRL)
One way depends on the fact that different neurons have different thresholds of excitation. A weak stimulus excites neurons with the lowest thresholds, while a strong stimulus excites less sensitive high-threshold neurons. Bringing additional neurons into play as the stimulus becomes stronger is called recruitment. It enables the nervous system to judge stimulus strength by which neurons, and how many of them, are firing. Another way of encoding stimulus strength depends on the fact that the more strongly a neuron is stimulated, the more frequently it fires. A weak stimulus may cause a neuron to generate 6 action potentials per second, and a strong stimulus, 600 per second. Thus, the central nervous system can judge stimulus strength from the firing frequency of afferent neurons because rthere is a limit on how often a neuron can fire based on its refractory period
Quantitative information is encoded by neurons in 2 ways
representational hemisphere; perceives information; imagination and insight, musical and artistic skills
Right hemisphere
towards the forehead; higher
Rostral
specialized to detect stimuli such as light, heat, pressure, and chemicals and transit information about them to the CNS; begin in almost all organs in the body and end in the CNS
Sensory (afferent) neurons
lasts from a few seconds to a few hours. Information stored in STM may be quickly forgotten if we stop mentally reciting it, we are distracted, or we have to remember something new.
Short-Term Memory
it will be faster
Signal conduction through a neuron with a large diameter and a myelinated axon will compare to signal conduction through a neuron with a small diameter and unmyelinated axon how?
This occurs when EPSPs from several synapses add up to threshold at the axon hillock. Any one synapse may admit only a moderate amount of Na+ into the cell, but several synapses acting together admit enough Na+ to reach threshold. The presynaptic neurons collaborate to induce the postsynaptic neuron to fire.
Spatial summation
An odorant molecule must bind to a receptor on one of the olfactory hairs by diffusing through the mucous layer. Hydrophilic odorants diffuse freely through the mucous of the olfactory epithelium, but hydrophobic odorants are transported to the receptors by an odorant-binding protein in the mucous When the receptor binds an odorant, it activates a G protein and through it, the cAMP 2nd messenger system. The cAMP system ultimately opens ion channels in the plasma membrane admitting cations into the cell, depolarizing it, creating a receptor potential, triggering an action potential in the axon of the olfactory cell. When olfactory fibers pass through the roof of the nose through the ethmoid bone, they enter a pair of olfactory bulbs. Here they synapse with the dendrites of neurons called mitral cells and tufted cells. Olfactory axons reach up and mitral and tufted cell dendrites reach down to meet each other in spherical clusters called glomeruli. The tufted and mitral cells carry output from the glomeruli and their axosn form bundles called olfactory tracts which go to the brain
Steps of smelling and the projection pathway
genes
Steroid hormones enter the target cell nucleus and act directly on the ______ changing target cell physiology by either activating or inhibiting transcription
cortisol from adrenal cortex
Stimulated in response to ACTH from the anterior pituitary
Glucagon
Stimulates amino acid absorption, gluconeogenesis, glycogen and fat breakdown; raises blood glucose and fatty acid levels
Estradiol
Stimulates female reproductive development and adolescent growth; regulates menstrual cycle and pregnancy; prepares mammary glands for lactation
Testosterone
Stimulates fetal and adolescent reproductive development, musculoskeletal growth, sperm production, and libido
Insulin
Stimulates glucose and amino acid uptake; lowers blood glucose level; promotes glycogen, fat, and protein synthesis
is the process of adding up postsynaptic potentials and responding to their net effect. It occurs in the trigger zone. A single action potential in a synaptic knob does not produce enough activity to make a postsynaptic cell fire. An EPSP may be produced, but it fades before reaching threshold. A typical EPSP is a voltage change of only 0.5 mV and lasts only 15 to 20 ms. If a neuron has an RMP of -70 mV and a threshold of -55 mV, it needs at least 30 EPSPs to reach threshold and fire. There are two ways in which EPSPs can add up to do this, and both may occur simultaneously.
Summation
First of all, of course, the claim would be almost certainly false. But even if it were true, the whole principle behind it would be misguided. Cholesterol is the precursor of all our steroid hormones, so if the body were totally purged of cholesterol, we also would have no sex steroids, aldosterone, or glucocorticoids, and one's metabolism would be seriously and fatally deranged. Not that this would matter much, because one would probably die even more quickly of widespread hemorrhaging and other cellular and tissue breakdown as a result of weakened plasma membranes, which depend on cholesterol as a structural entity.
Suppose you were browsing in a health-food store and saw a product advertised: "Put an end to heart disease. This herbal medicine will rid your body of cholesterol!" Would you buy it? Why or why not? If the product were as effective as claimed, what are some other effects it would produce?
B) only by the sympathetic nervous system.
Sweat glands and arrector pili muscles are controlled: A) only by the parasympathetic nervous system. B) only by the sympathetic nervous system. C) by both the sympathetic and parasympathetic nervous systems. D) by both the autonomic and somatic nervous systems
Paravertebral ganglia adjacent to spinal column and prevertebral ganglia anterior to it Short preganglionic Long postganglionic Extensive Often widespread and general Always cholinergic Mostly adrenergic, a few cholinergic
Sympathetic: Location of ganglia: Fiber lengths: Neural Divergence: Effects of system: Neurotransmitter of Preganglionic Fiber: Neurotransmitter of Postganglionic Fiber:
can be induced by tetanic stimulation, the rapid arrival of repetitive signals at a synapse. Each signal causes a certain amount of Ca2+ to enter the synaptic knob. If signals arrive very rapidly, the neuron cannot pump out all the Ca2+ admitted by one action potential before the next action potential occurs. More and more Ca2+ accumulates in the knob. Since Ca2+ is what triggers the release of neurotransmitter, each new signal releases more neurotransmitter than the one before. With more neurotransmitter, the EPSPs in the postsynaptic cell become stronger and stronger, and that cell is more likely to fire; can cause memory to last longer
Synaptic facilitation
synapses are not fixed for life; in response to experience, they can be added, taken away, or modified to make transmission easier or harder. Indeed, synapses can be created or deleted in as little as 1 or 2 hours.
Synaptic plasticity
the process of making transmission easier by modifying certain pathways
Synaptic potentiation
False (norepinephrine, cholecystokinin, thyrotropin-releasing hormone, dopamine and antidiuretic hormone are all both. Norepinephrine is a neurotransmitter, but it is also a hormone released by the adrenal gland)
T/F: A chemical can either act as a neurotransmitter, or a hormone. It cannot be both
False, without iodine, there is no thyroid hormone (TH) and without TH, there can be no negative feedback inhibition
T/F: A deficiency of dietary iodine would lead to negative feedback inhibition of TSH synthesis.
False (The effect of a neurotransmitter varies from place to place depending on the type of receptor present)
T/F: A given neurotransmitter has the same effect no matter where in the body it is secreted.
False, multiple receptor types exist for a particular neurotransmitter and can act in different ways for the same neurotransmitter and the receptor governs the effect the neurotransmitter has on the target cell
T/F: A neurotransmitter has the same effect everywhere
True
T/F: A resting neuron has a higher concentration of K+ in its cytoplasm than in the extracellular fluid surrounding it.
False. There are no voltage gated channels there, and even if there were, myelin would not allow the ions in
T/F: Action potentials can occur at the internodes
False (hormones can also be secreted by the heart, liver, kidneys, and other organs)
T/F: All hormones are secreted by endocrine glands.
True (If the blood flow in the hypophyseal portal system was blocked, the hypothalamus could secrete gonadotropin-releasing hormone GnRH, but it would not be able to get to the anterior pituitary to stimulate it to release FSH and LH which are needed for normal functioning of the testes and ovaries because FSH stimlates the secretion of ovarian sex hormones and the development of the follicles that contain egggs and in the testes it stimulates sperm production, and LH is needed becasue in females it stimulates ovulation and in males it stimulates the testes to secrete testosterone)
T/F: An atherosclerotic deposit that blocked blood flow in the hypophyseal portal system would cause the testes and ovaries to malfunction.
True
T/F: Blood vessels of the skin receive no parasympathetic innervation.
True (If there are no gonad cells to bind to, it would just keep circulating the blood after being secreted by the anterior pituitary)
T/F: Castration would raise a man's blood gonadotropin concentration.
True
T/F: Cells are exposed to many hormones in the bloodstream, but only respond to the ones that they have receptors for
False, they block signals that have already reached the spinal cord
T/F: Descending analgesic fibers prevent pain signals from reaching the spinal cord.
False (only a small fraction of the neuron's Na+ and K+ exchange places across the plasma membrane)
T/F: During an action potential, most of the Na+ and K+ exchange places across the plasma membrane.
True
T/F: Epinephrine and thyroid hormone have the same effects on metabolic rate and blood pressure.
False (The threshold stays the same but an EPSP brings the membrane potential closer to the threshold.)
T/F: Excitatory postsynaptic potentials lower the threshold of a neuron and thus make it easier to stimulate.
False (Hearing is a temporal lobe function; vision resides in the occipital lobe)
T/F: Hearing is a function of the occipital lobe.
False (interactive effects of hormones include permissive, antagonistic, and synergistic interactions)
T/F: Hormones always function independently of other hormones
False (Both norepinephrine and glucagon cause glycogen hydrolysis (breakdown) in liver)
T/F: Hormones and neurotransmitters have antagonistic effects on the same organ
False (hormones are released into blood fluid, neurotransmitters are released at synapses at target organs)
T/F: Hormones are released into the synaptic cleft
True
T/F: Hormones in the glycoprotein class cannot have cytoplasmic or nuclear receptors in their target cells.
False (Learning involves modification of the synapses of existing neurons, not an increase in the neuron population; synaptic potentiation and synaptic plasticity)
T/F: Learning occurs by increasing the number of neurons in the brain tissue.
True
T/F: Mature neurons are incapable of mitosis.
True, and these hormones can have interactive effects
T/F: Most cells are sensitive to more than 1 hormone
False (The cerebellum contains more than half of all brain neurons.)
T/F: Most of the brain's neurons are found in the cerebral cortex.
False (The choroid plexuses produce only 30% of the CSF; the ependymal cells IN the choroid plexus add)
T/F: Most of the cerebrospinal fluid is produced by the choroid plexuses.
False (some do not require conscious awareness like pH and body temperature)
T/F: Most sensory signals sent to the central nervous system produce a conscious sensation
False (The signals travel rapidly through the internodes and slow down at each node of Ranvier.)
T/F: Myelinated nerve fibers conduct signals more rapidly than unmyelinated ones because they have nodes of Ranvier.
False, there are 2 testes, 2 ovaries, and 4 parathyroid glands
T/F: Of the endocrine organs, only the adrenal glands are paired; the rest are single.
True
T/F: Oligodendrocytes perform the same function in the brain as Schwann cells do in the peripheral nerves.
True
T/F: Parasympathetic effects are more localized and specific than sympathetic effects.
True
T/F: The absolute refractory period sets an upper limit on how often a neuron can fire.
True
T/F: The anterior and posterior horns of the spinal cord are composed of gray matter.
False (The cerebral hemispheres do not develop from neural crest tissue, they develop from the telencephalon which is from the neural tube becasue the neural tube is going to develop into the CNS.)
T/F: The cerebral hemispheres would fail to develop if the neural crests of the embryo were destroyed.
False (they overlap as much as 50%)
T/F: The dermatomes are nonoverlapping regions of skin innervated by different spinal nerves.
The dura is separated from the bone by a fat-filled epidural space.
T/F: The dura mater adheres tightly to the bone of the vertebral canal
True
T/F: The midbrain is caudal to the thalamus.
True (The autonomic ganglion for parasympathetic fibers is within the target organ)
T/F: The parasympathetic division shows less neural divergence than the sympathetic division does.
False, both systems are always simultaneously active
T/F: The parasympathetic nervous system shuts down when the sympathetic nervous system is active, and vice versa.
False, they go involution with age
T/F: The pineal gland and thymus are larger in adults than in children.
False (it is not strictly a spinal reflex since it is mediated in part by the brain)
T/F: The stretch reflex is mediated solely by the spinal cord
False, it inhibits digestion
T/F: The sympathetic nervous system stimulates digestion.
True (it prevents the muscle from contracting anymore and tearing the tendon or the muscle itself by inhibiting alpha motor neurons)
T/F: The tendon reflex acts to inhibit muscle contraction.
True
T/F: The two divisions of the ANS have antagonistic effects on the iris.
False (This fissure separates the cerebral hemispheres, not the cerebellar hemispheres)
T/F: The two hemispheres of the cerebellum are separated by the longitudinal fissure.
True
T/F: The tympanic cavity is filled with air, but the membranous labyrinth is filled with liquid.
False, the posterior chamber is the area between the iris and the lens and is filled with aqueous humor
T/F: The vitreous body occupies the posterior chamber of the eye.
False, because of hemidecussation, each hemisphere receives signals from both eyes
T/F: Things we see with the left eye are perceived only in the right cerebral hemisphere.
True
T/F: Things we touch with the left hand are perceived only in the right cerebral hemisphere.
True
T/F: Tumors can lead to either hyposecretion or hypersecretion of various hormones.
False (waste elimination can occur by autonomic spinal reflexes without involving the brain)
T/F: Urination and defecation cannot occur without signals from the brain to the bladder and rectum.
False, limited
T/F: Voluntary control of the ANS is not possible.
TSH
TH is secreted in response to _________
This occurs when a single synapse generates EPSPs so quickly that each is generated before the previous one fades. This allows the EPSPs to add up over time to a threshold voltage that triggers an action potential. Temporal summation can occur if even one presynaptic neuron stimulates the postsynaptic neuron at a fast enough rate.
Temporal summation
C) The presence of the appropriate receptors on the cells of the target tissue or organ
The ability of a specific tissue or organ to respond to the presence of a hormone is dependent on: A) The location of the tissue or organ with respect to the circulatory path B) The membrane potential of the cells of the target organ C) The presence of the appropriate receptors on the cells of the target tissue or organ D) Nothing
d. the macula sacculi.
The acceleration you feel when an elevator begins to rise is sensed by a. the anterior semicircular duct. b. the spiral organ. c. the crista ampullaris. d. the macula sacculi. e. the macula utriculi.
sympathetic
The adrenal medulla consists of modified postganglionic neurons of the _____ nervous system.
postganglionic sympathetic
The adrenal medulla consists of what type of modified neurons?
an increase in total brain size and complexity.
The advances in higher order brain functioning that happen from birth to age five correlate with:
sensory
The afferent division of the nervous system is also known as the _____ division.
130 ml.
The amount of CSF within the brain at any given moment is approximately:
Cerumen because it is hydrophobic and repels water
The auditory canal secretes what and why?
b. skeletal muscle.
The autonomic nervous system innervates all of these except a. cardiac muscle. b. skeletal muscle. c. smooth muscle. d. salivary glands. e. blood vessels.
sympathetic; parasympathetic
The autonomic nervous system is subdivided into the ______ division which arouses the body for action and the ________ division which calms the body
The cytoskeleton stiffens and strengthens the nerve fiber, protecting what might otherwise be a very delicate and vulnerable structure from physical injury. Microtubules of the cytoskeleton also provide trackways for the axonal transport of organelles and chemicals up and down the axon.
The axon of a neuron has a dense cytoskeleton, why is this important to neuron structure and function?
ganglion cells
The axons of these cells form the fibers of the optic nerve
astrocyte perivascular feet and capillary endothelial cells.
The blood-brain barrier is made up of
central; peripheral
The brain and spinal cord are components of the _______ nervous system while the nerves and ganglia are components of the _______ nervous system
hypothalamus.
The brain region that exerts significant control over the endocrine system is the:
fourth
The brain ventricle located between the pons and the cerebellum is the _____ ventricle.
cerebrospinal fluid and ependymal cells
The central canal of the spinal cord contains
provides the retina with oxygen, and it also absorbs stray light that would potentially result in the perception of confusing images
The choroid behind the retina has 2 functions:
tunica vasculosa
The ciliary body is part of which tunic?
divergence.
The circuitry of the autonomic system allows for control in activation. The characteristic that allows a small number of preganglionic cells to stimulate a large number of postganglionic cells is:
B) the modality of the stimulus it perceives.
The classification of a receptor as a photoreceptor or a mechanoreceptor depends on: A) the location of origin of the stimulus it perceives. B) the modality of the stimulus it perceives. C) its location in the body. D) whether it is a somatic or visceral receptor
preganglionic
The first of the two ANS motor neurons is the ______ neuron.
C) both olfaction and gustation.
The flavor of food depends upon: A) olfaction. B) gustation. C) both olfaction and gustation. D) neither olfaction nor gustation
B) much smaller than the tympanic membrane and the ossicles therefore amplify sound waves.
The footplate of the stapes is: A) much larger than the tympanic membrane and the ossicles therefore amplify sound waves. B) much smaller than the tympanic membrane and the ossicles therefore amplify sound waves. C) much larger than the tympanic membrane and the ossicles therefore dampen sound waves. D) much smaller than the tympanic membrane and the ossicles therefore dampen sound waves.
the optic nerve
The ganglion cells' fibers form
vitreous humor.
The gelatinous mass inside of the eye is called the:
otoliths (otoliths add weight and inertia and enhance the sense of gravity and motion in the otolithic membrane)
The gelatinous membranes of the macula sacculi and macula utriculi are weighted by protein-calcium carbonate granules called ______.
pineal gland
The gland that is attached to the roof of the 3rd ventricle of the brain, beneath the posterior end of the corpus callosum is the
pituitary gland
The gland that is suspended from the floor of the hypothalamus by a stall and house in a depression of the sphenoid bone, the sella turcica
microglial cell
The glial cell that defends the body against pathogens is the:
arachnoid mater.
The meninx composed of a delicate web of collagen and elastic fibers is the:
pia mater
The meninx composed of a thin layer of delicate areolar connective tissue that follows every contour of the brain surface is the:
temporal
The middle and inner ear are housed within the _____ bone.
Negative feedback loop
The most common way that target organs regulate the pituitary and hypothalamus is through a
A) potassium out of the cell through leak channels. (plasma membrane is more permeable to K)
The most crucial factor determining the resting potential of a neuron is the diffusion of: A) potassium out of the cell through leak channels. B) potassium into the cell through gated channels. C) sodium out of the cell through leak channels. D) sodium into the cell through gated channels
Broca area
The motor pattern for speech is generated in an area of cortex called the _____ and then transmitted to the primary motor cortex to be carried out.
proprioception
The nonvisual awareness of the body's position and movements is called (information about joint angle, muscle length, muscle tension all give information about how we are oriented in space)
the adrenal medulla
The only nerve that leads straight from the sympathetic nervous system to its target organ is the nerve leading to
olfactory cells
The only neurons from the CNS in the body that are directly exposed to the external environment
in the tympanic cavity
The ossicles are where?
A) maculae of the inner ear.
The otolithic membrane is part of the: A) maculae of the inner ear. B) tympanic cavity of the middle ear. C) semicircular canals of the inner ear. D) cochlea of the inner ear.
a funnel for conducting airborne vibrations to the tympanic membrane
The outer ear serves as what?
spinal cord.
The parasympathetic autonomic responses associated with defecation and urination are processed and controlled at the level of the:
outer segment
The part of cones and rods that points towards the wall of the eye; highly modified cilium to absorb light; where the photo pigments are stacked up
spiral organ.
The part of the cochlea that converts pressure waves (from sounds) into changes in membrane potentials is the:
ganglion cells
The photopigment melanopsin is produced by what retinal cell?
cones
The photopigment photopsin is produced by what retinal cell?
rods
The photopigment rhodopsin is produced by what retinal cell?
hypothalamus; infundiubulum stalk
The pituitary gland is attached to the ____________ by ____________
luteinizing hormone
The pituitary hormone that stimulates the testes to secrete testosterone
d, c, a
The proper sequence of eye layers from the outermost to the innermost layer is: a: Neural tunic b: Fatty tunic c: Vascular tunic d: Fibrous tunic
c. the choroid.
The retina receives its oxygen supply from a. the hyaloid artery. b. the vitreous body. c. the choroid. d. the pigment epithelium. e. the scleral venous sinus.
Bitter-acids such as those in toxins or poisons
There are five basic taste sensations. Select the one mismatched with its causative agent. Sweet-organic compounds such as sugar Sour-hydrogen ions from acids such as those in lemons Salty-metal ions such as potassium or sodium Bitter-acids such as those in toxins or poisons Umami-amino acids such as glutamate or aspartate found in chicken soup
follicular cells of the thyroid; thyroglobulin
These cells grab iodine out of the blood, and pump it into the follicle where it meets _____________
interneurons
These neurons receive signals from other neurons and carry out the integrative functions of the nervous system, such as processing, storing, retrieving, and making decisions
motor (efferent) neurons
These neurons send signals out from the CNS to muscles and glands
parasympathetic division
This division of the nervous system calms us, slows our heartbeat, an d stimulates digestion
right
This hemisphere has limited language comprehension
right
This hemisphere has superior recognition of faces and spatial relationships
left (specialized for spoken and written language)
This hemisphere hears vocal sounds
left
This hemisphere is has right hand motor control
left
This hemisphere is specialized for rational, symbolic thought
right
This hemisphere receives olfactory senses from the left nasal cavity
left
This hemisphere receives olfactory senses from the right nasal cavity
right
This hemisphere sees left field vision
left
This hemisphere sees vision in the right field
GH
This hormone has a big impact on carbohydrate metabolism
GH
This hormone has a big impact on electrolyte balance in the body
GH
This hormone has a big impact on lipid metabolism
GH
This hormone has a big impact on protein synthesis
insulin
This hormone lowers blood glucose levels
calcitonin
This hormone stimulates osteoblast activity, preventing an increase in blood calcium levels
Enteric nervous system
This nervous system does not arise from the brain or spinal cord
Enteric nervous system
This nervous system has no CNS components
enteric nervous system
This nervous system innervates smooth muscles and glands to help regulates motility of esophagus, stomach, and intestines and secretion of digestive enzymes and acid
enteric nervous system
This nervous system is composed of 100 million neurons found in the walls of the digestive tract
nervous system
This organ system communicates by chemical messengers and electrical messengers
hypothalamus
This part of the brain closely regulates pituitary functioning
cerebellum
This part of the brain fine tunes motor activity by integrating information from a lot of different places
central nervous system
This part of the nervous system processes information coming into it, and determines what response, if any, is necessary
somatic sensory division
This part of the sensory division carries signals from receptors in the skin, muscles, bones, and joints
Gonadotropes in the anterior pituitary
This pituitary cell produces the hormone FSH
Somatotropes in the anterior pituitary
This pituitary cell produces the hormone GH
corticotropes in the anterior pituitary
This pituitary cell produces the hormone adrenocorticotropic hormone
lactotropes in the anterior pituitary
This pituitary cell produces the hormone prolactin
Pineal gland
This portion of the brain secretes the hormone melatonin, which helps to regulate the body's circadian rhythm.
corpus luteum
This produces progesterone and inhibin in the ovary
second order
This type of neuron carries the signal from the spinal cord or brainstem to the thalamus
first order
This type of neuron detects stimulus and transmits a signal to the spinal cord or brainstem
tonic receptor
This type of receptor adapts more slowly and generates steady signals
phasic receptor
This type of receptor generates a burst of action potentials when first stimulated, then quickly adapt and sharply reduce or stop signaling even if the stimulus continues and may fire again when the stimulus ceases
itype 2
This type of taste cell actives a G protein complex to open the gates and can generate an action potential and it detects bitter, sweet, salty and umam
type 1
This type of taste cell has no action potential and doesn't do anything
outer hair cilia
Three rows of ______ in the cochlea have V-shaped arrays of stereocilia and tune the frequency sensitivity of the cochlea.
the protein rich colloid of Tg
Thyroid follicles contain what?
carbohydrates, fats, and proteins
Thyroid hormone accelerates the breakdown of
thyroid gland
Thyroxine (T4) and triiodothyronine (T3) source
tyrosine
Thyroxine (T4) is synthesized by combining two iodinated molecules of the amino acid _________.
denervation hypersensitivity
Visceral effectors exhibit ___________ when their nerves are severed, which is when they exhibit exaggerated responses
carries signals to glands, cardiac muscle, and smooth muscle; do not have voluntary control; broken down into the parasympathetic and sympathetic divines (autonomic nervous system)
Visceral motor division
carries signals mainly from the viscera of the thoracic and abdominal cavities, such as the heart, lungs, stomach, and urinary bladder; senses stuff within us and we typically are not aware of it
Visceral sensory division
ramus (rami)
What are branches of the spinal cord called?
Stimulation of orgasms, smooth muscle contraction during labor
What are sympathetic effects of the reproductive system?
taste cells, supporting cells, and basal cells
What are taste buds made of?
photoreceptor cells, bipolar cells, ganglion cells
What are the 3 cells in the retina from the rear of the eye forward?
1) You can sense small objects, small pressures, and small textures 2) The finer your level of sense is, the greater your level of dexterity is
What are the advantages for having a small receptive field?
A) Dopamine B) Epinephrine D) Norepinephrine
What are the catecholamines secreted by the adrenal medulla? A) Dopamine B) Epinephrine C) Melatonin D) Norepinephrine E) Serotonine
glands, smooth muscle, cardiac muscle
What are the effectors in the autonomic nervous system?
skeletal muscles
What are the effectors in the somatic nervous system?
1) Oval window vibrates 2) Pressure wave travels through the perilymph of the Scala vestivuli 3) Basilar membrane moves up and down 4) Inner hair cells pushed against tectorial membrane 5) Stereocilia bend 6) Tip-link proteins open K+ channels 7) K+ enter hair cell, depolarizing them 8) Hair cell releases neurotransmitter from its base 9) Sensory dendrite that the hair cell synapses with gets excited and a signal is sent via the cochlear nerve
What are the events, starting with the vibration of the oval window, that lead to the stimulus transmitted to the brain
cranial nerves
What are the nerves that arise from the base of the brain, exit the cranium through its foramina, and lead to muscles and sense organs?
Satellite cells, Schwann cells
What are the neuroglia in the PNS?
cornea, aqueous humor, lens, vitreous body
What are the optical components of the eye?
Malleus Incus Stapes
What are the ossicles in order from tympanic membrane to oval window?
taste, equilibrium, hearing, smell, vision
What are the special senses?
1) Light strikes the retina 2) Rhodopsin absorbs light 3) Cis-retinal isomerizes to trans-retinal 4) Opsin triggers signaling cascade in outer segment of rod cells 5) glutamate release from rod cell decreases 6) Bipolar cells detect changes in glutamate release and when glutamate release stops, they release a neurotransmitter that acts on the ganglion cells 7) The ganglion cells respond with action potentials that get sent up to the optic nerve and nto the brain
What are the steps involved in generating visual signals?
B) Liver C) Skeletal muscle D) Adipose
What are the target cells of insulin? A) Brain B) Liver C) Skeletal muscle D) Adipose E) RBCs
Nerve cells and muscle fibers share the properties of excitability and conductivity, but neurons also carry out secretion and muscle fibers undergo contraction.
What basic properties do a nerve and muscle cell have in common, and how are they different?
they can integrate information and make decisions
What can chemical synapses do that electrical synapses cannot do?
he body produces autoantibodies that destroy pancreatic beta cells, and when beta cells are gone, insulin falls to a low level that it can no longer regulate the blood glucose level.
What causes Type 1 diabetes?t
a person lacks either L (red) or M cones (green) so they cannot distinguish red and green from each other
What causes red-green color blindness?
endoneurium
What covers the myelin sheath in a nerve?
movement of ions through channels
What creates electrical currents in neurons?
D) A wave of depolarization open more voltage-gated channels immediately distal to the action potential
What describes signal conduction in unmyelinated axons? A) A local potential is passively conducted down the entire length of the axon B) The entire axon depolarizes at the same time C) The signal is transmitted from one node of Ranvier to the next D) A wave of depolarization open more voltage-gated channels immediately distal to the action potential
longitudinal fissure
What divides the cerebrum into right and left hemispheres?
They assist neurons in their respective functions.
What do all glial cells have in common?
They divide and form olfactory cells since olfactory cells have a short lifespan because they are exposed to the outside environment
What do the basal cells in the olfactory mucosa?
?hold things upright and form rings with tight junctions and the hairs can come between the cells, so the only things that stick out are the hairs and nothing can slip between the cells
What do the supporting cells do in the olfactory mucosa and the taste buds
The lacrimal gland right above the eye and the ducts that drain tears into the nasal cavity
What does the lacrimal apparatus consist of?
the vestibular apparatus (the 3 semicircular ducts) and a saccule and a utricle
What does the receptor for equilibrium consist of?
Cornea and sclera
What does the tunica fibrosa consist of?
the start of the optic nerve and the retina
What does the tunica intern contain?
retina and beginning of the optic nerve
What does the tunica interna consist of?
Thromboxane
What eicosanoid can override prostacyclin?
mesencephalon
What embryonic structure becomes the midbrain?
metencephalon
What embryonic structure develops into the cerebellum?
metencephalon
What embryonic structure develops the pons?
diencephalon
What embryonic structure does the thalamus come from?
telencephalon
What embryonic structure forms the cerebrum?
myelencephalon
What embryonic structure forms the medulla oblongata?
Hypophyseal pouch from near the roof of the mouth
What forms the anterior lobe of the pituitary gland?
Neurohypophyseal bud from the brain
What forms the posterior lobe of the pituitary gland?
exocrine
What glands secrete their product by way of a duct onto an epithelial surface?
If an excitatory or inhibitory potential hit at the same time, nothing happens because they balance each other out
What happens if an excitatory or inhibitory potential hit at the same time?
A) How rapidly sensory neurons fire B) How many sensory neurons respond E) Which sensory neurons respond
What information does the brain use to determine the intensity of a stimulus? A) How rapidly sensory neurons fire B) How many sensory neurons respond C) Which receptive fields are stimulated D) How long the stimulus lasts E) Which sensory neurons respond
C) Maculae (macula utriculi and the macula sacculi)
What inner ear structure detects acceleration and deceleration movements of the head? A) Tensor tympani and stapedius B) Spiral organ C) Maculae D) Ossicles E) Scala vestibule
diagram of the primary somesthetic and motor cortex which resembles an upside-down sensory map of the contralateral side of the body and how richly innervated the area is and how sensitive the region is; how much region of the cortex is dedicated to their sensation. Shows the neurons in the cortex that are involved in whatever parts of the body. Somatopy allows for this
What is a homunculus?
a patch of hair cells and supporting cells in the saccule and utricle
What is a macula?
olfactory hairs that are nonmotile cilia but have binding sites for odor molecules
What is on the head of an olfactory cell?
The protein opsin and retinal Opsin and retinal come together to form the pigment
What is rhodopsin composed of?
connective tissue enhances sensitivity and it makes it more selective with respect to the modality that it responds to
What is the advantage to having an encapsulated nerve ending?
somatic motor pathway
What is the efferent pathway that lacks a ganglion and has a single nerve fiber extending from the CNS to the effector?
sclera
What is the posterior, white portion of the tunica fibrosa?
It can open and allow air to enter or leave the tympanic cavity, equalizing air on both sides of the tympanic membrane allowing it to vibrate freely
What is the purpose of the auditory tube?
mechanoreceptors (respond to physical deformation)
What kind of receptors are the organs for equilibrium?
Mechanoreceptors (respond to physical deformation by vibration)
What kind of receptors are the organs for hearing?
follicular cells
What lines the thyroid follicles?
NaK pump
What maintains the RMP?
3 semicircular ducts arranged at 90˚ angles to each other
What makes up the vestibular apparatus?
Odorant-binding proteins
What molecules help concentrate odorants at the olfactory receptor cells?
Gustatory nerve fiber
What nerve fiber do taste cells synapse with?
the cochlear nerve
What nerve fiber leads away from the cochlea?
parasympathetic
What nervous system stimulates the pupillary constrictor?
Posterior pituitary
What secretes antidiuretic hormone?
posterior pituitary
What secretes oxytocin?
hypothalamus
What secretes prolactin-inhibiting hormone (PIH)?
Anterior pituitary
What secretes prolactin?
Hypothalamus
What secretes somatostatin?
diverging (a diverging circut allows one motor neuron of the brain to ultimately stimulate thousands of muscle fibers)
What type of circuit is used to maintain body posture while walking?
parallel-after-discharge
What type of circuit would you use to solve a higher order mathematical problem?
The stapedius and tensor tympani muscles are fast glycolytic muscles. The ability to respond quickly to loud noises is more important in these muscles than fatigue resistance, a characteristic of slow oxidative muscles.
What type of muscle fibers—slow oxidative or fast glycolytic do you think constitute the stapedius and tensor tympani? That is, which type would best suit the purpose of these muscles?
preganglionic neuron (in ANS)
What type of neuron has its cell body in the spinal cord or brainstem and its axons terminate in a ganglion?
A) always produces an excitatory response. (ACh is always excitatory no matter what)
When ACh binds to nicotinic receptors it: A) always produces an excitatory response. B) always produces an inhibitory response. C) sometimes excites and sometimes inhibits the target cell depending on the subtype of receptor. D) sometimes excites and sometimes inhibits the target cell E) depending on the extracellular fluid surrounding the cell.
facilitation (facilitation is a process in which one neuron enhances the effect of another)
When a neuromodulator slows the reuptake of a neurotransmitter or causes expression of an increased number of receptors on postsynaptic neurons, the effect is called:
IPSP, which is a hyperpolarization (K+ will rush out of the cell via diffusion from higher to lower, leaving more negative ions inside of the cell)
When a neurotransmitter causes the opening of chemically gated potassium channels on the postsynaptic cell, the postsynaptic potential that results is an:
motility increases. (EXCITATORY ALWAYS)
When neurotransmitter binds to muscarinic receptors on smooth muscle cells in the gastrointestinal tract:
A) adrenergic receptors on effectors such as smooth muscle.
When norepinephrine is released from varicosities of postganglionic neurons, its targets are: A) adrenergic receptors on effectors such as smooth muscle. B) adrenergic receptors on preganglionic sympathetic neurons. C) cholinergic receptors on effectors such as cardiac muscle. D) cholinergic receptors on preganglionic sympathetic neurons.
depth perception.
When our brains process visual information about objects directly in front of us, they are able to use information that compares signals from the two eyes (steroscopic vision) in order to provide:
exocrine
When they secrete eggs and sperm, the gonads are considered what type of glands ?
the presynaptic neuron's synaptic knob into the synaptic cleft.
When transmission occurs at a synapse, neurotransmitter is released by:
C) in the ampullae of our semicircular ducts. (semicircular ducts only detect angular acceleration, while utricle and saccule detect static equilibrium and linear acceleration)
When we initiate a rapid rotation of our head, it results in bending of cilia on hair cells A) in the utricle of our cochleas. B) in the maculae of our semicircular ducts. C) in the ampullae of our semicircular ducts. D) in the maculae of our vestibules. E) in the ampullae of our vestibules.
No, they have to bind to the receptors on the olfactory cell hairs
When you sense something in the air, do you immediately smell it?
C) utricle and saccule. (static equilibrium)
When you travel on a moving walkway or an elevator the acceleration of your body in a straight line is sensed by the: A) cochlea. B) semiciercular canals. C) utricle and saccule. D) ossicles.
In the PNS
Where are ganglia found?
within the target organ
Where are ganglia located in the parasympathetic nervous system?
by the areas nearest to the oval window
Where are high frequency sounds picked up?
bloodsteam
Where are hormones released?
by areas farther away from the oval window
Where are low frequency sounds picked up?
Gray matter
Where are neuron cell bodies, dendrites, and synapses found in the CNS?
in the presynaptic neuron
Where are neurotransmitters synthesized?
In the pigment epithelium
Where is the outer segment of the rods and cones embedded?
in the outer segment which is embedded in the pigment epithelium
Where is the photopigment located in cones and rods?
Within the vestibule
Where is the saccule located?
skeletal muscles and things that need to move fast
Where would myelinated fibers be employed to?
structures that we do not need very fast such as stomach or dilation of pupils
Where would unmyelinated fibers be employed to?
Sympathetic
Which division functions to increase alertness and direct bodily responses in stressful situations?
sympathetic
Which division of the ANS has general, widespread effects?
parasympathetic
Which division of the ANS is the rest and digest division?
Pigmented layer of the retina
Which eye feature provides vitamin A for photoreceptor cells?
testosterone
Which hormone is responsible for the development and general health of the male reproductive tract?
D) Increased ATP production
Which is a response that occurs during the fight-or-flight response? A) Increased bronchoconstriction B) Increased urine formation C) Increased pupillary constriction D) Increased ATP production E) Increased glycogen production in the liver
D) CSF helps to promote mitosis within neuronal tissue.
Which is not a function of cerebrospinal fluid? A) CSF helps to remove waste products from the brain. B) CSF helps to reduce the effective weight of the brain. C) CSF transports nutrients and chemicals to the brain. D) CSF helps to promote mitosis within neuronal tissue. E) CSF provides a liquid cushion to protect the brain from sudden movements
A) Long postganglionic axons (The parasympathetic division has long preganglionic fibers that almost reach the target organ before they diverge, thus the parasympathetic division is more specific in stimulating its target organ)
Which is not characteristic of the parasympathetic division of the ANS? A) Long postganglionic axons B) Long preganglionic axons C) No rami communicantes D) Terminal ganglia close to the target organ E) Craniosacral preganglionic neuron cell bodies
D) Each Schwann cell can wrap only a 1 mm portion of a single axon.
Which is true regarding the action of a Schwann cells? A) Each Schwann cell can form a myelin sheath around many axons simultaneously. B) A Schwann cell is responsible for forming part of the blood-brain barrier. C) Schwann cells function only within the CNS. D) Each Schwann cell can wrap only a 1 mm portion of a single axon. E) A Schwann cell attacks pathogens
filiform and foliate
Which lingual papillae have no taste buds in adults?
fungiform and vallate
Which lingual papillae have taste buds in adults?
D) All of the choices are correct
Which may be involved in an autonomic reflex? A) Cardiac muscle contraction B) Smooth muscle contraction C) Secretion by glands D) All of the choices are correct E) None of the choices is correct
Absolute refractory period
Which occurs first, the absolute or relative refectory period?
cerebellum
Which of the areas of the brain is responsible for equilibrium, motor coordination, and memory of learned motor skills?
A) Touch D) Stretch E) Pressure F) Pain
Which of the following are examples of somatosensory senses? A) Touch B) Equilibrium C) Vision D) Stretch E) Pressure F) Pain
A) The sympathetic speeds up heart rate while the parasympathetic slows it down B) The sympathetic induces dilation of the pupil while the parasympathetic induces pupil to constrict
Which of the following are examples off the antagonistic effects of the sympathetic and parasympathetic divisions? A) The sympathetic speeds up heart rate while the parasympathetic slows it down B) The sympathetic induces dilation of the pupil while the parasympathetic induces pupil to constrict C) Salivary glands secrete saliva in response to parasympathetic stimulation while sympathetic stimulation induces them to secrete mucous
A) Epinephrine C) Glucagon D) Cortisol
Which of the following are hyperglycemic hormones> A) Epinephrine B) Insulin C) Glucagon D) Cortisol E) Thyroxine
A) Insulin B) Oxytocin D) FSH
Which of the following are peptide hormones? A) Insulin B) Oxytocin C) Calcitriol D) FSH E) Aldoesterone
A) Ions can only be exchanged with the ECF at the nodes of Ranvier C) Action potentials occur only at the nodes of Ranvier D) There are few voltage-gated ions channels at the myelin covered internodes and multiple channels at the nodes of Ranvier
Which of the following are true about signal conduction along myelinated axons? A) Ions can only be exchanged with the ECF at the nodes of Ranvier B) No nerve signal conduction occurs at the internodes C) Action potentials occur only at the nodes of Ranvier D) There are few voltage-gated ions channels at the myelin covered internodes and multiple channels at the nodes of Ranvier
C) Unmyelinated fibers have voltage-gated channels across their entire length D) A zone of depolarization excites voltage gated channels immediately distal to the action potential
Which of the following are true about signal conduction along unmyelinated fibers? (select all that apply) A) The signal conduction is saltatory B) The area in front of the action potential is the refractory period C) Unmyelinated fibers have voltage-gated channels across their entire length D) A zone of depolarization excites voltage gated channels immediately distal to the action potential
B) Bidirectional C) Involves transport proteins within the axon
Which of the following describe axonal transport? Select all A) A type of transport that occurs only in anaxonic neurons B) Bidirectional C) Involves transport proteins within the axon
E) All of these are correct
Which of the following is correct about the autonomic nervous system (ANS)? A) The ANS is part of both the CNS and the PNS. B) ANS functions are involuntary. C) ANS motor neurons innervate cardiac muscle fibers, smooth muscle fibers, and glands. D) ANS motor pathways always include two neurons. E) All of these are correct
c. thyroxine-binding globulin (binds to thyroid hormone to transport it around the blood since it is hydrophobic and needs a transport protein)
Which of the following is not a hormone? a. prolactin b. prolactin-inhibiting hormone c. thyroxine-binding globulin d. atrial natriuretic peptide e. cortisol
b. It has a low threshold. (it has a high threshold since there is very little convergence of the cones on the bipolar cells and ganglion cells, so a weakly stimulated cone cannot collaborate to stimulate a ganglion cell)
Which of the following statements about photopic vision is false? a. It is mediated by the cones. b. It has a low threshold. c. It produces fine resolution. d. It does not function in starlight. e. It does not employ rhodopsin.
D) The blood-brain barrier is impermeable to water, and prevents dehydration from affecting the brain.
Which of the following statements concerning the blood-brain barrier is false? A) The blood-brain barrier is formed by the basement membrane and tight junctions between endothelial cells of capillaries. B) The blood-brain barrier is permeable to glucose, alcohol, caffeine, nicotine, and anesthetics. C) Where the blood-brain barrier is absent, HIV can enter the brain. D) The blood-brain barrier is impermeable to water, and prevents dehydration from affecting the brain.
A) Reuptake of neurotransmitter into the presynaptic knob B) Enzymatic degradation of neurotransmitter in the synaptic cleft C) Cessation of signals in the presynaptic nerve fiber D) Diffusion of neurotransmitter from the synaptic cleft into the ECF
Which of the following would cause postsynaptic stimulation to end? Select all A) Reuptake of neurotransmitter into the presynaptic knob B) Enzymatic degradation of neurotransmitter in the synaptic cleft C) Cessation of signals in the presynaptic nerve fiber D) Diffusion of neurotransmitter from the synaptic cleft into the ECF E) Removal of receptors from the presynaptic membrane
B) red blood cells
Which of the following would you not find in normal cerebrospinal fluid? A) glucose B) red blood cells C) potassium D) protein
c. C cells (C cells in the thyroid secrete calcitonin)
Which of these cells stimulate bone deposition? a. alpha cells b. beta cells c. C cells d. G cells e. T cells
E) Only A and B can trigger this reflex.
Which of these could trigger the Golgi tendon reflex? A) excessive stretching of a muscle or tendon B) when some parts of a muscle contract more than others C) when a muscle become flaccid due to spinal shock D) All of the above can trigger this reflex. E) Only A and B can trigger this reflex.
d. the pancreas (the pancreas is mostly an exocrine digestive gland, but scattered throughout the exocrine tissue are endocrine cell clusters called pancreatic islets)
Which of these has more exocrine than endocrine tissue? a. the pineal gland b. the adenohypophysis c. the thyroid gland d. the pancreas e. the adrenal gland
a. ACTH (the rest are either steroids or thyroid hormones that are hydrophobic)
Which of these hormones relies on cAMP as a second messenger? a. ACTH b. progesterone c. thyroxine d. testosterone e. estrogen
retina
Which part of the eye forms from a cup-shaped outgrowth of the diencephalon and is actually part of the brain?
Soma
Which part of the neuron contains the nucleus?
Anterior pituitary
Which part of the pituitary gland is connected to the hypothalamus via blood vessels?
Posterior pituitary, which came from the neurohypophyseal bud
Which part of the pituitary gland is nervous tissue from the brain?
Rods (130 million rods and 6.5 million cones)
Which photoreceptor cells are more numerous?
Rods
Which photoreceptor cells function in dim light?
adrenal medulla
Which portion of the adrenal gland secretes epinephrine, norepinephrine, and dopamine?
Rods, cones, and bipolar cells
Which retinal cells produce local potentials?
Diencephalon
Which secondary brain vesicle forms the portion of the adult brain that includes the epithalamus, thalamus, and hypothalamus?
taste & smell
Which sensory modalities depend on the activity of chemoreceptors?
a, b, d, c
Which sequence correctly traces the pathway of aqueous humor in the eye? a: Aqueous humor is secreted by epithelial ciliary cells. b: Aqueous humor is released into the posterior chamber. c: Aqueous humor is drained into the scleral venous sinus. d: Aqueous humor washes over the lens and then passes through the pupil into the anterior chamber.
C) Visuospatial skills and music
Which skills are associated with the right hemisphere for most individuals? A) Language and task sequencing B) Categorization and symbolization C) Visuospatial skills and music D) Mathematics and the partitioning of information into small fragments
A) The gustatory microvillus of a gustatory cell extends through the taste pore of a taste bud.
Which statement accurately describes structures at a taste bud? A) The gustatory microvillus of a gustatory cell extends through the taste pore of a taste bud. B) The gustatory villi of basal cells project through the taste bud to the surface of the epithelium. C) The gustatory microvilus of a papilla projects through the gustatory pore to the gustatory glomerulus. D) Basal cells contain villi that project through the pore of a papilla to make a taste bud
A) Having small receptive fields allow for more precision, but since more receptors are needed it increases overall energy costs.
Which statement accurately describes the merits of different receptive field properties? A) Having small receptive fields allow for more precision, but since more receptors are needed it increases overall energy costs. B) Having large receptive fields allow for more precision, but since since the area of responsiveness is larger, it increases the body's energy costs. C) Having small receptive fields allows for more precision, smaller body surfaces, and decreased energy costs overall. D) Having large receptive fields allows for more precision, larger body surfaces, and decreased energy costs overall.
B) Most neurons formed in fetal development last a lifetime, but some brain regions in adults can generate new neurons.
Which statement is consistent with the current understanding of neural tissue? A) A person is born with all of the neurons they will ever have. B) Most neurons formed in fetal development last a lifetime, but some brain regions in adults can generate new neurons. C) Neurons are constantly dying and being replaced throughout all regions of the brain. D) Stem cells in the brain become glia, which can later become neurons if there is a need for them to do so.
A) Each oligodendrocyte can form a myelin sheath around many axons simultaneously.
Which statement is true regarding the action of an oligodendrocyte? A) Each oligodendrocyte can form a myelin sheath around many axons simultaneously. B) An oligodendrocyte is responsible for forming part of the blood-brain barrier. C) Oligodendrocytes function only within the PNS. D) Each oligodendrocyte can wrap only a 1 mm portion of a single axon.
B) Adrenal medulla pathway
Which sympathetic pathway involves only a preganglionic axon going to the effector organ? A) Splanchnic nerve pathway B) Adrenal medulla pathway C) Postganglionic sympathetic nerve pathway D) Spinal nerve pathway E) None of these answers involve only a sympathetic preganglionic axon
Parasympathetic nervous system
Which system has long preganglionic axons and therefore ganglia that are relatively far from the central nervous system?
Sympathetic division
Which system has more divergence of preganglionic axons?
Interoceptors
Which term best describes receptors that detect stimuli from internal organs?
Exteroceptors
Which term best describes receptors that detect stimuli from the external environment?
efferent
Which term is used to describe motor neurons which travel away from the CNS and send signals to muscles and glands?
the stretch and the tendon reflex (the proprioceptors give us information about length and tension)
Which two reflexes use proprioceptors?
Sympathetic
Which type of innervation causes pupil dilation?
Sympathetic
Which type of innervation causes reduced blood flow to the digestive tract?
Sympathetic
Which type of innervation causes the heart rate to increase?
A reverberating circuit, because a neuron early in the circuit is continually restimulated
Which type of neural circuits is likely to fire the longest after a stimulus ceases and why?
D) lamellated corpuscles
Which type of receptor responds to vibration? A) Ruffini corpuscles B) Krause-end bulbs C) tactile corpuscles D) lamellated corpuscles
nervous tissue in the spinal cord outside of the gray matter; abundantly myelinated axons that carry signals up and down the cord to provide communication between the different levels of the CNS; usually tracts
White matter in the spinal cord
lies deep to the cortical gray matter; composed of tracts which connect one part of brain to the other and to the spinal cord
White matter of the brain
Most of the volume in the cerebrum is white matter composed of glia and myelinated nerve fibers that transmit information from one region of the cerebrum to another and between the cerebrum and other brain centers. These fibers form three tracts, the projection, commissural, and association tracts.
White matter of the cerebrum
The midportion of an intrafusal fiber lacks sarcomeres and cannot contract, but is supplied with primary afferent and secondary afferent sensory nerve fibers that enter the posterior horn of the spinal cord, synapse on alpha motor neurons and regulate their firing and also send branches up to the spinal cord and brain so the brain can constantly monitor the length and tension of every skeletal muscle important for maintaining posture, fine movement control, and corrective reflexes
Why do we have primary and secondary afferent sensory nerve fibers?
One EPSP is a voltage change of only 0.5 mV or so. A change of about 15 mV is required to reach threshold and make a neuron fire.
Why is a single EPSP insufficient to make a neuron fire?
they are hydrophobic, so they must bind to a hydrophilic transport protein
Why is it difficult for steroids and TH to travel through the blood?
Slower, because they are unmyelinated fibers. This assumes the two fibers are of equal diameter.
Would autonomic postganglionic fibers have faster or slower conduction than somatic motor fibers?
color blindness
a hereditary x-linked disorder in which people lack on type of photopsin or another
Bound hormone
a hormone attached to a transport protein
cortisol
a potent glucocorticoid that stimulates fat and protein catabolism, gluconogenesis and the release of fatty acids into the blood
one axon and one dendrite
bipolar neuron
Eyelids
block foreign objects from entering the eye, prevent visual stimuli from disturbing sleep, moisten the eye, sweep debris from the eye surface
spinal tracts
bundles of axons that carry signals from one level of the CNS to another within the CNS that have a similar origin, destination, and function
Pupil
central opening of the iris
Hormones
chemical messengers that are transported by the bloodstream and stimulate physiological responses in cells of another tissue or organ, often a considerable distance away
paracrine messengers
chemical signals released into the tissue fluid and not into the blood and diffuse only to nearby cells in the same tissue
diabetes insipidus
chronic polyuria
neurons respond to stimuli by producing electrical signals that are conducted to cells at distant locations
conductivity property fo neurons
epineurium
connective tissue that wraps around fascicles of nerves
unaware of objects on opposite side of their body
contralateral neglect syndrome
Neuroendocrine reflexes
control of the pituitary by the brain; the release of hormones in response to nerve signals from the CNS
Palpebral fissure
fissure that separates the eyelids from each other
otosclerosis
fusion of auditory ossicles that prevents their free vibration
band of nerve tissue that connects the right and left sides of the gray matter in the spinal cord; punctured by a central canal lined with ependymal cells and filled with CSF
gray commissure
cerebellum and cerebrum
has left and right hemispheres
Deafness
hearing loss
PGE
help relax smooth muscle
Choroid
highly vascular and pigmented region of the eye; behind the retina
Spinal gating
mechanisms in which pain signals can be stopped at the posterior horn
Pineal gland
might have an affect on Seasonal Depressive Order because it responds to sunlight
Stage 3 sleep
moderate to deep sleep and begins 20 minutes after stage 1; muscles relax and vital signs fall. Theta and delta waves dominate EEG
secondary afferent sensory nerve fiber in the muscle spindle
monitor only muscle length
send signals predominately to muscle and gland cells
motor (efferent) neurons
theta waves
normal in children or drowsy or sleepy adults, but the predominance of these waves suggests an adult with emotional stress or brain disorders
Stage 2 sleep
one passes into light sleep. EEG declines in frequency but increases in amplitude. Sleep spindles occur here
monosynaptic reflex arc
only one synapse between the afferent and efferent neuron so there is little synaptic delay
tarsal glands
open along the edge of the eyelid and secrete oil that coats the eye and reduces tear evaporation
Thymus
organ that plays a role in the endocrine, lymphatic, and immune systems
Arachidonic acid
originally a phosopholipid of the plasma membrane, and then converted into this after a peptide hormone acted on it
pitch
our sense of whether a sound is 'high' or 'low'; determined by the frequency at which the sound source, eardrum, and other parts of the ear vibrate
Adrenal cortex
outer part of the adrenal gland
in the cerebral cortex tall, and conical, with apex toward the brain surface; a thick dendrite with many branches with small, knobby dendritic spines; include the output neurons of the cerebrum; only neurons that leave the cortex and connect with other parts of the CNS
pyramidal cells
contralateral reflex arc
reflex arc in which the input and output are on opposite side; crossed extension reflex
ipsilateral reflex arc
reflex arc in which the sensory input and the motor output are on the same sides of the spinal cord; flexor reflex
intersegmental reflex
reflex in which the input and output occur at different levels (segments) of the spinal cord
vestibular membrane
separates the cochlear duct from the scala vestibule; helps separate endolymph from perilymph and maintain chemical differences between them
circadian cycles
sleep occurs in these; marked by events that occur in 24-hour intervals
inhibition of muscular activity
sleep paralysis
Unmyelinated pain fibers
slow (second) pain; this type of fiber produces the longer-lasting dull, diffusive pain
delta waves
slow EEG waves; adults exhibit when sleeping. A predominance of these waves in an awake adult means brain damage
receptor potential
small, local electrical change that is generated when a receptor responds to the stimulus
The zona glomerulosa of the cortex
source of mineralocorticoids in the adrenal gland
alpha motor neuron
spinal motor neurons that supply the extrafusal muscle fibers; normal fiber that goes to the muscle and causes it to contract
gastrin
stimulates acid secretion and gastric motility
oxytocin
stimulates labor contractions, milk release; possibly involved in ejaculation, sperm transport, sexual affection, and mother−infant bonding
muscle spindle
stretch receptors embedded in the muscle to inform the brain of the muscle length and body movements, enabling the brain to send motor commands back to the muscle that control tone, posture, coordinated movement, and corrective reflexes; made of intrafusal fibers
a chain of ganglia along the vertebral column; neurosomas of the preganglionic fibers come here after they exit the spinal cord
sympathetic chain ganglia
sleep
temporary state of unconsciousness from which one can awaken when stimulated
preganglionic; postganglionic
The sympathetic nervous system has short _____ and long _____ nerve fibers.
Thyroxine (T4) and triiodothyronine (T3)
The thyroid gland produces what hormones?
the gelatinous otolithic membrane
The tips of the stereocilia and kinocilium of the macula are embedded in what?
B) contain autonomic ganglia to house ganglionic neurons.
The two divisions of the autonomic nervous system: A) use preganglionic and postganglionic neurons to innervate skeletal muscle. B) contain autonomic ganglia to house ganglionic neurons. C) are voluntary. D) are composed of PNS structures only. E) function only during sleep.
converging
The type of neuronal circuit in which several nerve impulses come together at a single postsynaptic neuron is a _____________ circuit.
parallel-after-discharge
The type of neuronal circuit in which several neurons process the same information at one time is a _____________ circuit.
reverberating
The type of neuronal circuit that ensures that we continue to breathe while asleep is a _____________ circuit.
diverging
The type of neuronal circuit that spreads information from one presynaptic neuron to several postsynaptic neurons is a _____________ circuit.
c, a, b
The vascular tunic of the eye has three distinct regions. From anterior to posterior what are they? a: Ciliary body b: Choroid c: Iris
blood pressure, medulla oblongata.
The vasomotor center is an important regulator of ________ and is located in the ________.
