Anatomy 430 Unit 5 Exam
sympathetic
During physical or emotional stress, the sympathetic division dominates the parasympathetic division. High sympathetic tone favors body functions that can support vigorous physical activity and rapid production of ATP. At the same time, the sympathetic division reduces body functions that favor the storage of energy. Besides physical exertion, various emotions—such as fear, embarrassment, or rage—stimulate the ______________ division
choroid, ciliary body, iris
Of the 3 parts of the vascular (middle) tunic the __________ forms the major vascular portion that lines the internal surface of the sclera. The ___________ consists of two parts: The ciliary processes that secrete aqueous humor The ciliary muscle that changes the shape of the lens to adapt to near and far vision. The _______ is the colored portion of the eyeball consisting of circular and radial smooth muscle fibers.
Contraction or relaxation of smooth muscle, increased or decreased rate and force of contraction of cardiac muscle, increased or decreased secretions of glands.
What are the responses of the autonomic nervous system?
optic nerve, optic chiasm, optic tract, lateral geniculate nucleus of the thalamus, optic radiations, primary visual area
Name the structures that are passed in the visual pathway
ceruminous glands, cerumen
Near the exterior opening, the external auditory canal contains a few hairs and specialized sweat glands called _____________ that secrete earwax or __________. The combination of hairs and earwax helps prevent dust and foreign objects from entering the ear.
gray ramus, gray rami communicantes
Recall that some of the incoming sympathetic preganglionic neurons synapse with postganglionic neurons in the sympathetic trunk, either in the ganglion at the level of entry or in a ganglion farther up or down the sympathetic trunk. The axons of some of these postganglionic neurons leave the sympathetic trunk by entering a short pathway called a ___________ and then merge with the anterior ramus of a spinal nerve. Therefore, ________________ are structures containing sympathetic postganglionic axons that connect the ganglia of the sympathetic trunk to spinal nerves. The "gray" in their name indicates that they contain unmyelinated axons.
contraction of skeletal muscle
What are the responses of the somatic nervous system?
accommodation by the lens 25%, pupillary constriction, refraction by the cornea 75%
What are the three steps of refraction?
semicircular canals
What are these
bipolar neurons
What are these cells?
ciliary processes, production of aqueous humor
What are these structures on the iris called? What is one of the main functions of these?
ossicles
What are these structures?
tarsal plates
What are these structures?
ossicles
What are these:
sympathetic ganglia, parasympathetic ganglia
What are two major groups of autonomic ganglia?
hypothalamus, limbic system, brain stem, spinal cord, little bit from cerebral cortex
What controls the motor output of the autonomic nervous system?
stapes
What inner ear bone is shown?
incus
What inner ear bone is this
malleus
What inner ear bone is this
stapes
What inner ear bone is this
internal auditory meatus
What is the bone feature?
vitreous humor
What is the fluid/material found in this space?
transmitting vibrations
What is the function of inner ear bones?
anterior chamber of the anterior segment
What is the name of this lumen?
posterior chamber of the anterior segment
What is the name of this lumen?
palpebral fissure
What is the opening of the eyelid called?
basilar membrane
What is the structure at the tip of the pointer.
osseous spiral lamina
What is this bony shelf called?
vitreous body, vitreous humor
What is this clear structure? What fluid is inside this?
fovea centralis, point of sharpest vision
What is this depression? What is the significance of this?
cochlea
What is this inner ear structure?
scala tympani
What is this known as?
scala vestibuli, perilymph
What is this known as? What fluid is it filled with?
membranous labyrinth
What is this labyrinth called?
posterior segment
What is this lumen?
anterior chamber of the anterior cavity, aqueous humor
What is this lumen? Identify the fluid filling this
basilar membrane
What is this membrane called?
caruncle
What is this mound called?
tensor tympani
What is this muscle?
external auditory canal
What is this passageway?
osseous labyrinth
What is this set of channels within the temporal bone?
cupula
What is this structure
spiral organ
What is this structure
optic disc, blood vessels
What is this structure in the back of the retina? what are radiating out from this?
oval window
What is this structure?
tectorial membrane
What is this structure?
spiral ganglion
What is this?
tympanic membrane
What membrane is this?
tensor tympani
What muscle is this?
ciliary muscles
What muscles control the accommodation of the lens? When they contract and pull on the lens, the lens is in its normal state, when they relax, the lens becomes more ball-like
acetylcholine
What neurotransmitter(s) are released by somatic motor neurons?
acetylcholine, norepinephrine
all somatic motor neurons release only acetyl- choline (ACh) as their neurotransmitter, but autonomic motor neurons release either what two neurotransmitters?
primary gustatory area
Taste is perceived consciously as signals from the thalamus arrive at the ______________________ at the base of the somatosensory cortex in the parietal lobe.
perforated eardrum
Tearing of the tympanic membrane is called a _______________. It may be due to pressure from a cotton swab, trauma, or a middle ear infection, and usually heals within a month.
Smooth muscle fibers in blood vessels that serve salivary glands, skin, mucosal membranes, kidneys, and abdominal viscera; radial muscle in iris of eye; sphincter muscles of stomach and urinary bladder, salivary gland cells, sweat glands on palms and soles
What are the major locations of α1 receptors?
smooth muscle fibers in some blood vessels, cells of pancreatic islets that secrete the hormone insulin (beta cells), pancreatic acinar cells, platelets in blood.
What are the major locations of α2 receptors?
Cardiac muscle fibers, juxtaglomerular cells of kidneys, posterior pituitary, adipose cells
What are the major locations of β1 receptors?
smooth muscle in walls of airways, in blood vessels that serve heart, skeletal muscle, adipose tissue, and liver, walls of visceral organs, such as urinary bladder, ciliary muscle in eye, hepatocytes in liver
What are the major locations of β2 receptors?
brown adipose tissue
What are the major locations of β3 receptors?
ciliary ganglion, pterygopalatine ganglion, submandibular ganglion, otic ganglion
What are the named terminal ganglia?
ganglion cells, optic nerve II
What are the nuclei at the tip of the arrow? The axons of these cells form what structure?
Plasma membrane of postganglionic sympathetic and parasympathetic neurons, chromaffin cells of adrenal medullae, sarcolemma of skeletal muscle fibers
What are the major locations of nicotinic receptors?
sympathetic
_____________ stimulation leads to secretion of norepinephrine by the adrenal glands, an increase in the rate and strength of the heartbeat, constriction of blood vessels of non-essential organs, dilation of vessels of essential organs (skeletal muscle and the cerebral cortex), an increase in the rate and depth of breathing, hepatic conversion of glycogen to glucose, and decrease in GI activity.
basal cells
_____________ located near the CT base multiply and differentiate, first to become the supporting cells around the taste bud, then the gustatory receptor cells inside the taste bud
no effect
effect of parasympathetic stimulation of adipose tissue
no effect
effect of parasympathetic stimulation of the adrenal medullae
decreased heart rate, decreased force of atrial contraction
effect of parasympathetic stimulation of the cardiac muscle
contraction for close vision
effect of parasympathetic stimulation of the ciliary muscle of the eye
Contraction leads to constriction of pupil
effect of parasympathetic stimulation of the circular muscle of iris
release of bile into small intestine
effect of parasympathetic stimulation of the gallbladder and ducts
secretion of gastric juice
effect of parasympathetic stimulation of the gastric gland arterioles
airway constriction
effect of parasympathetic stimulation of the lungs
secretion of digestive enzymes and the hormone insulin
effect of parasympathetic stimulation of the pancreas
no effect
effect of parasympathetic stimulation of the pineal gland
no effect
effect of parasympathetic stimulation of the posterior pituitary gland
no effect
effect of parasympathetic stimulation of the radial muscle of iris
vasodilation, which increases the secretion of saliva
effect of parasympathetic stimulation of the salivary gland arterioles
erection in males
effect of parasympathetic stimulation of the sex organs
increased motility and tone
effect of parasympathetic stimulation of the stomach and intestines
no effect
effect of parasympathetic stimulation of the sweat glands
Contraction of muscular wall, relaxation of internal urethral sphincter
effect of parasympathetic stimulation of the urinary bladder
no effect
effect of parasympathetic stimulation of the uterus
lipolysis
effect of sympathetic stimulation of adipose tissue
secretion of epinephrine and norepinephrine
effect of sympathetic stimulation of the adrenal medullae
increased heart rate and force of contractions
effect of sympathetic stimulation of the cardiac muscle
Relaxation to adjust shape of lens for distant vision
effect of sympathetic stimulation of the ciliary muscle of the eye
no effect
effect of sympathetic stimulation of the circular muscle of iris
storage of bile in the gallbladder
effect of sympathetic stimulation of the gallbladder and ducts
vasoconstriction which inhibits gastric secretion
effect of sympathetic stimulation of the gastric gland arterioles
erection of hairs which leads to goosebumps
effect of sympathetic stimulation of the hair follicles, arrector pili muscles
vasoconstriction which inhibits intestinal secretion
effect of sympathetic stimulation of the intestinal gland arterioles
secretion of renin
effect of sympathetic stimulation of the kidneys
slight secretion of tears
effect of sympathetic stimulation of the lacrimal glands
glycogenolysis, gluconeogenesis, decreased bile secretion
effect of sympathetic stimulation of the liver
airway dilation
effect of sympathetic stimulation of the lungs
inhibits secretion of digestive enzymes and the hormone insulin, promotes secretion of the hormone glucagon
effect of sympathetic stimulation of the pancreas
secretion of melatonin
effect of sympathetic stimulation of the pineal gland
secretion of antidiuretic hormone
effect of sympathetic stimulation of the posterior pituitary gland
contraction of iris leads to dilation of pupil
effect of sympathetic stimulation of the radial muscle of iris
vasoconstriction which decreases the secretion of saliva
effect of sympathetic stimulation of the salivary gland arterioles
ejaculation in males
effect of sympathetic stimulation of the sex organs
discharge of stored blood into circulation
effect of sympathetic stimulation of the spleen
decreased motility and tone
effect of sympathetic stimulation of the stomach and intestines
Relaxation of muscular wall, contraction of internal urethral sphincter
effect of sympathetic stimulation of the urinary bladder
Inhibits contraction in nonpregnant women, promotes contraction in pregnant women
effect of sympathetic stimulation of the uterus
Preganglionic neurons release ACh, which is excitatory and stimulates postganglionic neurons; postganglionic neurons release ACh.
neurotransmitters of parasympathetic nervous system?
Preganglionic neurons release acetylcholine (ACh), which is excitatory and stimulates postganglionic neurons; most postganglionic neurons release norepinephrine (NE); postganglionic neurons that innervate most sweat glands and some blood vessels in skeletal muscle release ACh.
neurotransmitters of sympathetic nervous system?
emmetropic
normal eyes are called ______________
Preganglionic neurons with long axons usually synapse with four to five postganglionic neurons with short axons that pass to single visceral effector
axon length and divergence of parasympathetic nervous system
preganglionic neurons with short axons synapse with many postganglionic neurons with long axons that pass to many visceral effectors
axon length and divergence of sympathetic nervous system
interoreceptors, some from somatic senses and special senses
from where does the autonomic nervous system get its sensory input?
cardiac plexus, pulmonary plexus
The major plexuses in the thorax are the
incus
The malleus goes up and attaches to the second bone, which is called what?
cochlea
What is this entire structure known as?
ciliary body
structure?
lacrimal glands
what is this?
malleus
what is this?
osseous labyrinth
what is this?
accommodation
An increase in the curvature of the lens for near vision is called _______________.
They can enter and travel with spinal nerves, They can form fine networks of periarterial preganglionic traveling cephalad to synapse in the cervical ganglia, Postganglionic axons exiting the sympathetic trunk can form sympathetic nerves to the heart and lungs. Preganglionic axons can leave the sympathetic trunk without synapsing and form splanchnic nerves.
Axons leave the sympathetic trunk in four possible ways:
acetylcholinesterase
Because acetylcholine is quickly inactivated by the enzyme _______________, effects triggered by cholinergic neurons are brief.
Nuclei of cranial nerves III, VII, IX, X and lateral gray matter of the second through fourth sacral segments of the spinal cord, craniosacral division, craniosacral outflow
Cell bodies of preganglionic neurons of the parasympathetic division are located in the ________________. Hence, the parasympathetic division is also known as the ___________, and the axons of the parasympathetic preganglionic neurons are known as ____________
odorants
Chemicals that have an odor and can therefore stimulate the olfactory hairs are called ____________.
tastants, gustatory hairs
Chemicals that stimulate gustatory receptor cells are known as ___________. Once they are dissolved in saliva, they can make contact with the plasma membrane of the _______________, which are the sites of taste transduction. The result is a receptor potential that stimulates exocytosis of synaptic vesicles from the gustatory receptor cell. In turn, the liberated neurotransmitter molecules trigger nerve impulses in the first-order sensory neurons that synapse with gustatory receptor cells.
supporting cells, gustatory receptor cells, and basal cells
Each taste bud is an oval body consisting of three kinds of epithelial cells:
gustatory receptor cells
Each taste bud is composed of about 50 _______________, surrounded by a number of supporting cells.
vestibular apparatus
Equilibrium is another function of the inner ear - controlled by the ________________ (the saccule and utricle of the vestibule, and the 3 semicircular canals)
nasal lacrimal duct
From the canaliculi, tears flow into the
norepinephrine
In the ANS, adrenergic neurons release _______________, also known as noradrenalin
utricle, saccule
Inside the vestibule are two cavities:
dynamic equilibrium
Involves the maintenance of balance during sudden movements.
Nuclei of cranial nerves III, VII, IX, and X and lateral gray matter of spinal cord segments S2-S4. Axons of preganglionic neurons constitute craniosacral outflow
Location of preganglionic neuron cell bodies and site of outflow of the parasympathetic division
myenteric plexus, submucosal plexus
Most of the nerve fibers that innervate the digestive organs arise from two plexuses within the enteric system:
tectorial membrane
Movements of the hair cells in contact with the tectorial membrane transduce mechanical vibrations into electrical signals which generate nerve impulses along the cochlear branch of CN VIII (vestibulocochlear nerve).
nervous tunic, vascular tunic, fibrous tunic
Name in sequence, from left to right, the tunics seen in this view
terminal ganglia
Preganglionic axons of the parasympathetic division synapse with postganglionic neurons in ______________.
taste aversion
Probably because of taste projections to the hypothalamus and limbic system, there is a strong link between taste and pleasant or unpleasant emotions. Sweet foods evoke reactions of pleasure while bitter ones cause expressions of disgust even in newborn babies. This phenomenon is the basis for ____________, in which people and animals quickly learn to avoid a food if it upsets the digestive system. The advantage of avoiding foods that cause such illness is longer survival. However, the drugs and radiation treatments used to combat cancer often cause nausea and gastrointestinal upset regardless of what foods are consumed. Thus, cancer patients may lose their appetite because they develop ___(same as previous)____ for most foods.
sympathetic trunk ganglia, prevertebral ganglia, celiac ganglia, superior mesenteric ganglia, inferior mesenteric ganglia, aorticorenal ganglia, renal ganglia
Some of the major groups of sympathetic ganglia include:
macula
Static equilibrium is controlled by the sensory hairs within the ___________ of the utricle and saccule.
vascular tunic, choroid, ciliary body, iris
The ____________ or uvea (U ̄ -ve-a) is the middle layer of the eyeball. It is composed of three parts:
vagus nerve
The _____________ (CN X) carries nearly 80% of the total parasympathetic flow to the organs of the thorax and upper abdomen. Lower abdominal and pelvic organs are innervated by the sacral output.
macula lutae
The _____________ is in the exact center of the posterior portion of the retina, at the visual axis of the eye
optic disc
The _____________ is where the optic nerve and retinal vessels enter and exit the eyeball. Its existence creates a necessary defect on the retina - an area where there are no cones or rods. Bilateral vision, and saccade (involuntary, quick) muscle movements allow our brain to correct for this "blind spot", and most are not even aware they have one.
spiral ganglia
The cell bodies of the sensory neurons are located in the _____________. Nerve impulses pass along the axons of these neurons, which form the cochlear branch of the vestibulocochlear (VIII) nerve.
superior cervical ganglion, middle cervical ganglion, inferior cervical ganglion
The cervical portion of each sympathetic trunk is located in the neck and is subdivided into superior, middle, and inferior ganglia. Postganglionic neurons leaving the ______________ serve the head and heart. They are distributed to the sweat glands, smooth muscle of the eye, blood vessels of the face, lacrimal glands, pineal gland, nasal mucosa, salivary glands (which include the submandibular, sublingual, and parotid glands), and heart. Postganglionic neurons leaving the _______________ and the ___________ innervate the heart.
air
The middle ear: What is this cavity filled with?
superior olivary nuclei
The nerve impulses follow CN VIII (vestibulocochlear) en route to the medulla, pons, midbrain, and thalamus, and finally to the primary auditory cortex in the temporal lobe. Slight differences in the timing of nerve impulses arriving from the two ears at the _______________ in the pons allow us to locate the source of a sound.
acetylcholine
The neurotransmitter used at all parasympathetic postganglionic synapses is _____________.
ophthalmoscope
The retina can be viewed through the pupil using an _________________, allowing direct inspection of the retinal vessels for any pathological changes. This is the only place in the body where arterial vessels can be so viewed (without opening the body).
cochlea, scala vestibuli, scala tympani, scala media
The snail shaped ___________ contains the hearing apparatus. Two types of fluid, perilymph and endolymph, fill its 3 different internal channels: The ___________, ___________, and ____________ (cochlear duct)
fibrous tunic, vascular tunic, nervous tunic
The wall of the eyeball consists of three layers or tunics: The _______________ is the outer layer and is composed of the sclera ("white" of the eye) and the cornea (the transparent epithelium the protects the front of the eye). The _______________ or uvea is the middle layer and is composed of the choroid, the ciliary body and the iris. The _______________ is the inner retinal layer.
sclera
This white part is the what?
facial nerve VII, glossopharyngeal nerve IX, Vagus Nerve X
Three cranial nerves contain axons of the first-order gustatory neurons that innervate the taste buds. The ______________ serves taste buds in the anterior 2/3 of the tongue. The ______________ serves taste buds in the posterior 1/3 of the tongue. The ______________ serves taste buds in the throat and epiglottis.
photoreceptor layer, bipolar cell layer, ganglion cell layer
Three distinct layers of retinal neurons—the __________, the _______________, and the _______________—are separated by two zones, the outer and inner synaptic layers, where synaptic contacts are made. Note that light passes through the ganglion and bipolar cell layers and both synaptic layers before it reaches the photoreceptor layer.
circularvallate papillae, fungiform papillae, foliate papillae, filiform papillae
Three types of papillae contain taste buds: About 12 very large, _________________ form an inverted V-shaped row at the back of the tongue. Each of these papillae houses 100-300 taste buds. ________________ are mushroom-shaped elevations scattered over the entire surface of the tongue that contain about five taste buds each. ________________ are located in small trenches on the lateral margins of the tongue, but most of their taste buds degenerate in early childhood. In addition, the entire surface of the tongue has _______________. These pointed, threadlike structures contain tactile receptors but no taste buds. They increase friction between the tongue and food, making it easier for the tongue to move food in the oral cavity.
false
True or False: During periods of rest and recovery, the sympathetic activity to glands and smooth muscles predominates over parasympathetic activity.
true
True or False: The primary reason that the sympathetic division of the ANS produces immediate responses within the body is based on the concept of divergence.
true
True or False: The sympathetic division is associated with excitement or embarrassment
photoreceptors
Vision is possible because of _______________ that are able to "catch" photons of EM radiation in the 400-700 nm wavelengths - what we perceive as visual light
taste buds
We have nearly 10,000 ___________ located on the tongue, soft palate, pharynx, and larynx. The number decreases with age.
vestibular membrane
What is this membrane
pupil
What is this opening?
One-neuron pathway: Somatic motor neurons extending from CNS synapse directly with effector
What type of motor neuron pathway is found in the somatic nervous system?
sclera
What's the structure? (white of the eye)
ciliary muscle
What's this red tissue?
odorant
When an __________ binds to the receptor of an olfactory hair it initiates a cascade of intracellular events through a G-protein and a 2nd messenger (--> production of cAMP --> opening of Na+ channels --> inflow of Na+ --> generator potentials)
to absorb the light
Why is this layer of simple cuboidal epithelium so heavily pigmented? What is the function of that pigment?
olfactory glands
Within the connective tissue that supports the olfactory epithelium are ______________, which produce mucus that is carried to the surface of the epithelium by ducts. The secretion moistens the surface of the olfactory epithelium and dissolves odorants so that transduction can occur. Both supporting cells of the nasal epithelium and olfactory glands are innervated by autonomic neurons within branches of the facial (VII) nerve, which can be stimulated by certain chemicals. Impulses in these nerves in turn stimulate the lacrimal glands in the eyes and nasal mucous glands. The result is tears and a runny nose after inhaling substances such as pepper or the vapors of household ammonia.
otitis externa
_____________ (commonly called "swimmer's ear") is a dermatitis of the epithelium of the outer ear (infectious and noninfectious). The chlorine, water, and ear plugs associated with swimming can result in irritated, inflamed tissues of the outer ear and ear canal.
myringitis
_____________ is an inflammation of the ear drum Infections of the middle ear cavity (otitis media) are common in children between 6 mo. - 5 yrs. old, and usually presents with a crying child and a TM (viewed through an otoscope), that looks angry, red, and bulging.
sympathetic trunk ganglia
______________ (also called vertebral chain ganglia or paravertebral ganglia) lie in a vertical row on either side of the vertebral column. These ganglia extend from the base of the skull to the coccyx. Postganglionic axons from sympathetic trunk ganglia primarily innervate organs above the diaphragm, such as the head, neck, shoulders, and heart.
convergence
______________ is the inward movement of the eyes so that both are directed at the object being viewed - becoming a little cross-eyed when viewing things close up The nearer the object, the greater the degree of convergence needed to maintain binocular vision the coordinated action of the extrinsic eye muscles brings about convergence. It allows us to have binocular vision and to see in three dimensions.
basal cells
______________, stem cells found at the periphery of the taste bud near the connective tissue layer, produce supporting cells, which then develop into gustatory receptor cells.
meniere's disease
__________________ is a disorder of the inner ear that can affect hearing and balance, and is thought to be due to increased pressure in the cochlea and semicircular canals (extra endolymph) Episodes of vertigo (the room spinning) and ringing in the ears (tinnitus) can be a mild annoyance, or a chronic, disabling disability.
no effect
effect of parasympathetic stimulation of the hair follicles, arrector pili muscles
secretion of intestinal juice
effect of parasympathetic stimulation of the intestinal gland arterioles
no effect
effect of parasympathetic stimulation of the kidneys
secretion of tears
effect of parasympathetic stimulation of the lacrimal glands
glycogen synthesis, increased bile secretion
effect of parasympathetic stimulation of the liver
no effect
effect of parasympathetic stimulation of the spleen
increased sweating
effect of sympathetic stimulation of the sweat glands
palpabrae
eyelids are known as what?
canaliculi
from the puncta, tears flow through the
puncta
little dots where tears leave
olfactory receptors, supporting cells, basal cells
olfactory epithelium consists of three kinds of cells:
limited mainly to head and to viscera of thorax, abdomen and pelvis, some blood vessels
where is the parasympathetic division of the ANS found?
skin, sweat glands, arrector pili muscles of hair follicles, adipose tissue, smooth muscle of blood vessels
where is the sympathetic division of the ANS found?
no
white and gray rami communicantes in parasympathetic division?
cataract
A __________ is an opaque defect in the cornea or lens of the eye - most of these are in the lens. These are causes by injury, medications, and diseases like diabetes. They are common in old age.
detached retina
A _______________ may occur due to trauma, such as a blow to the head, in various eye disorders, or as a result of age-related degeneration. The detachment occurs between the neural portion of the retina and the pigmented epithelium. Fluid accumulates between these layers, forcing the thin, pliable retina to billow outward. The result is distorted vision and blindness in the corresponding field of vision. The retina may be reattached by laser surgery or cryosurgery (localized application of extreme cold), and reattachment must be accomplished quickly to avoid permanent damage to the retina.
agonist
A large variety of drugs and natural products can selectively activate or block specific cholinergic or adrenergic receptors. An __________ is a substance that binds to and activates a receptor, in the process mimicking the effect of a natural neurotransmitter or hormone. Phenylephrine, an adrenergic agonist at α1 receptors, is a common ingredient in cold and sinus medications. Because it constricts blood vessels in the nasal mucosa, phenylephrine reduces production of mucus, thus relieving nasal congestion.
pupil
A principal function of the iris is to regulate the amount of light entering the eyeball through the _________, the hole in the center of the iris. The pupil appears black because, as you look through the lens, you see the heavily pigmented back of the eye (choroid and retina). However, if bright light is directed into the pupil, the reflected light is red because of the blood vessels on the surface of the retina. It is for this reason that a person's eyes appear red in a photograph ("red eye") when the flash is directed into the pupil.
sympathetic, divergence
A single ____________ preganglionic fiber has many axon collaterals (branches) and may synapse with 20 or more postganglionic neurons. This pattern of projection is an example of ___________ and helps explain why many sympathetic responses affect almost the entire body simultaneously.
diverging
A truism of the sympathetic division is that a single sympathetic preganglionic fiber synapses with many postganglionic branches (with 20 or more) to create a _____________ circuit.
they can enter spinal nerves, they can form cephalic periarterial nerves, they can form sympathetic nerves, they can form splanchnic nerves.
Axons leave the sympathetic trunk in four possible ways:
parasympathetic
Axons of preganglionic neurons of the ________ division pass to terminal ganglia near or within a visceral effector. In the ganglion, the presynaptic neuron usually synapses with only four or five postsynaptic neurons, all of which supply a single visceral effector, allowing parasympathetic responses to be localized to a single effector.
cholinergic receptors, nicotinic receptors, muscarinic receptors
ACh is stored in synaptic vesicles and released by exocytosis. It then diffuses across the synaptic cleft and binds with specific _________________, integral membrane proteins in the postsynaptic plasma membrane. The two types of cholinergic receptors, both of which bind ACh, are _______________ and _______________.
fight or flight
Activation of the sympathetic division and release of hormones by the adrenal medullae set in motion a series of physiological responses collectively called the _______________ response, which includes the following effects: • The pupils of the eyes dilate. • Heart rate, force of heart contraction, and blood pressure increase. • The airways dilate, allowing faster movement of air into and out of the lungs. • The blood vessels that supply the kidneys and gastrointestinal tract constrict, which decreases blood flow through these tissues. The result is a slowing of urine formation and digestive activities, which are not essential during exercise. • Blood vessels that supply organs involved in exercise or fight- ing off danger—skeletal muscles, cardiac muscle, liver, and adipose tissue—dilate, allowing greater blood flow through these tissues. • Liver cells perform glycogenolysis (breakdown of glycogen to glucose), and adipose tissue cells perform lipolysis (break- down of triglycerides to fatty acids and glycerol). • Release of glucose by the liver increases blood glucose level. • Processes that are not essential for meeting the stressful situation are inhibited. For example, muscular movements of the gastrointestinal tract and digestive secretions slow down or even stop.
opsin, retinal
All photopigments associated with vision contain two parts: a glycoprotein known as _________ and a derivative of vitamin A called ___________. Vitamin A derivatives are formed from carotene, the plant pigment that gives carrots their orange color. Good vision depends on adequate dietary intake of carotene-rich vegetables such as carrots, spinach, broccoli, and yellow squash, or foods that contain vitamin A, such as liver. ______(same as blank 2)______ is the light-absorbing part of all visual photopigments.
somatic
Although we are generally not conscious of breathing, the muscles that generate respiratory movements are skeletal muscles controlled by __________ motor neurons
antagonist
An _____________ is a substance that binds to and blocks a receptor, thereby preventing a natural neurotransmitter or hormone from exerting its effect. For example, atropine blocks muscarinic ACh receptors, dilates the pupils, reduces glandular secretions, and relaxes smooth muscle in the gastrointestinal tract. As a result, it is used to dilate the pupils during eye examinations, in the treatment of smooth muscle disorders such as iritis and intestinal hypermotility, and as an antidote for chemical warfare agents that inactivate acetylcholinesterase. Propranolol (Inderal®) often is prescribed for patients with hypertension (high blood pressure). It is a nonselective beta blocker, meaning it binds to all types of beta receptors and prevents their activation by epinephrine and norepinephrine. The desired effects of propranolol are due to its blockade of β1 receptors—namely, decreased heart rate and force of contraction and a consequent decrease in blood pressure. Undesired effects due to blockade of β2 receptors may include hypoglycemia (low blood glucose), resulting from decreased glycogen breakdown and decreased gluconeogenesis (the conversion of a noncarbohydrate into glucose in the liver), and mild bronchoconstriction (narrow- ing of the airways). If these side effects pose a threat to the patient, a selective β1 blocker (which binds only to specific beta receptors) such as metoprolol (Lopressor®) can be prescribed instead of propranolol.
otolithic membrane
An _______________, studded with dense calcium carbonate crystals (otoliths), responds to gravity when head position is changed. This movement opens transduction channels in the hair cells, producing local potentials which summate to form nerve action potentials.
dacryocystitis
An infection of the lacrimal sacs is called ____________. It is usually caused by a bacterial infection and results in blockage of the nasolacrimal ducts.
cochlea
Anterior to the vestibule is the __________, a bony spiral canal that resembles a snail's shell and makes almost three turns around a central bony core called the modiolus.
glaucoma
Any sort of blockage to aqueous humor flow, or overproduction at the ciliary body may result in an increase of pressure inside the eye - a condition called, which if not treated, can lead to a degeneration of eye function.
autonomic tone
As noted earlier, most body organs receive innervation from both divisions of the ANS, which typically work in opposition to one another. The balance between sympathetic and parasympathetic activity, called ______________, is regulated by the hypothalamus. Typically, the hypothalamus turns up sympathetic tone at the same time it turns down parasympathetic tone, and vice versa. The two divisions can affect body organs differently because their postganglionic neurons release different neurotransmitters and because the effector organs possess different adrenergic and cholinergic receptors. A few structures receive only sympathetic innervation—sweat glands, arrector pili muscles attached to hair follicles in the skin, the kidneys, the spleen, most blood vessels, and the adrenal medullae. In these structures there is no opposition from the parasympathetic division. Still, an increase in sympathetic tone has one effect, and a decrease in sympathetic tone produces the opposite effect.
circular muscles, radial muscles
Autonomic reflexes regulate pupil diameter in response to light levels. When bright light stimulates the eye, parasympathetic fibers of the oculomotor (III) nerve stimulate the ________________ or sphincter pupillae of the iris to contract, causing a decrease in the size of the pupil (constriction). In dim light, sympathetic neurons stimulate the _______________ or dilator pupillae of the iris to contract, causing an increase in the pupil's size (dilation).
hypogastric plexus, renal plexus
Axons of some sympathetic postganglionic neurons from the inferior mesenteric ganglion also extend through the______________, which is anterior to the fifth lumbar vertebra, to supply the pelvic viscera. The ____________ contains the renal ganglion and supplies the renal arteries within the kidneys and ureters.
lens, crystallins
Behind the pupil and iris, within the cavity of the eyeball, is the ________. Within the cells of the __(same____, proteins called _____________, arranged like the layers of an onion, make up the refractive media of the lens, which normally is perfectly transparent and lacks blood vessels. It is enclosed by a clear connective tissue capsule and held in position by encircling zonular fibers, which attach to the ciliary processes. This structure helps focus images on the retina to facilitate clear vision.
hair bundles of hair cells
Bending of _______________ in the semicircular ducts, utricle, or saccule causes the release of a neurotransmitter (probably glutamate), which generates nerve impulses in the sensory neurons that innervate the hair cells. The cell bodies of sensory neurons are located in the vestibular ganglia. Nerve im- pulses pass along the axons of these neurons, which form the vestibular branch of the vestibulocochlear (VIII) nerve. Most of these axons synapse with sensory neurons in vestibular nuclei, the major integrating centers for equilibrium, in the medulla oblongata and pons. The vestibular nuclei also receive input from the eyes and proprioceptors, especially proprioceptors in the neck and limb muscles that indicate the position of the head and limbs. The remaining axons enter the cerebellum through the inferior cerebellar peduncles.
decreased heart rate, bronchoconstriction, pupil constriction
Besides the increasing SLUDD responses, other important parasympathetic responses are "three decreases":
tensor tympani muscle, stapedius, hyperacusia
Besides the ligaments, two tiny skeletal muscles also attach to the ossicles (Figure 17.19). The ______________, which is supplied by the mandibular branch of the trigeminal (V) nerve, limits movement and increases tension on the eardrum to prevent damage to the inner ear from loud noises. The _____________muscle, which is supplied by the facial (VII) nerve, is the smallest skeletal muscle in the human body. By dampening large vibrations of the stapes due to loud noises, it protects the oval window, but it also decreases the sensitivity of hearing. For this reason, paralysis of the stapedius muscle is associated with _______________,which is abnormally sensitive hearing. Because it takes a fraction of a second for the tensor tympani and stapedius muscles to contract, they can protect the inner ear from prolonged loud noises but not from brief ones such as a gunshot.
white ramus, white rami communicantes
Cell bodies of sympathetic preganglionic neurons are part of the lateral gray horns of all thoracic segments and of the first two lumbar segments of the spinal cord. -The preganglionic axons leave the spinal cord along with the somatic motor neurons at the same segmental level. After exiting through the intervertebral foramina, the myelinated preganglionic sympathetic axons pass into the anterior root of a spinal nerve and enter a short pathway called a ___________ before passing to the nearest sympathetic trunk ganglion on the same side. Collectively, these are called the __________. Thus, these are structures containing sympathetic preganglionic axons that connect the anterior ramus of the spinal nerve with the ganglia of the sympathetic trunk. The "white" in their name indicates that they contain myelinated axons. Only the thoracic and first two or three lumbar nerves have these.
vestibular apparatus
Collectively, the receptor organs for equilibrium are called the __________________; these include the saccule, utricle, and semicircular ducts.
ampulla, crista, cupula
Dynamic equilibrium is controlled by the sensory hairs within the ________ of the semicircular canals. Within each ampulla is a small elevation called the _________. Each crista contains hair cells and supporting cells covered by gelatinous material called the ________. With movement, the endolymph within the ampulla lags behind the moving cupola, causing a difference in the inertial forces - the hair bundle of the cupula bends and nerve impulses are generated.
preganglionic neuron, postganglionic neuron
Each division of the ANS has two motor neurons. The first of the two motor neurons in any autonomic motor pathway is called a _____________. Its cell body is in the brain or spinal cord; its axon exits the CNS as part of a cranial or spinal nerve. The axon of this neuron is a small-diameter, myelinated type B fiber that usually extends to an autonomic ganglion, where it synapses with a _________, the second neuron in the autonomic motor pathway. Note that the this second neuron lies entirely outside the CNS in the PNS. Its cell body and dendrites are located in an autonomic ganglion, where it forms synapses with one or more preganglionic axons. The axon of this second neuron is a small-diameter, unmyeli- nated type C fiber that terminates in a visceral effector.
cornea, sclera
Even though you can't easily see it, the _________ is a very important structure in the outer avascular fibrous tunic. It's composed of a transparent epithelium that covers the anterior eye and helps focus light onto the retina LASIK is a common visual corrective procedure that is performed on the cornea of the eye Because of the amount of collagen fibers in the ________ it forms the tough, white part of the eye The sclera gives the eye it's shape and protects the inner anatomical parts.
chemoreceptors, mechanoreceptors
Examples of interoceptors are __________ that monitor blood CO2 level and __________ that detect the degree of stretch in the walls of organs or blood vessels. Unlike those triggered by a flower's perfume, a beautiful painting, or a delicious meal, these sensory signals are not consciously perceived most of the time, although intense activation of interoceptors may produce conscious sensations.
ciliary ganglia, pterygopalatine ganglia, submandibular ganglia, otic ganglia.
Four pairs of cranial parasympathetic ganglia innervate structures in the head:
blind spot
From photoreceptors, information flows through the outer synaptic layer to bipolar cells and then from bipolar cells through the inner synaptic layer to ganglion cells. The axons of ganglion cells extend posteriorly to the optic disc and exit the eyeball as the optic (II) nerve. The optic disc is also called the ______________. Because it contains no rods or cones, we cannot see images that strike this area.
temporal bone
Identify the bone represented by this model
suspensory ligaments, change the shape of the lens
Identify the fibrous structures in this area: what is their function?
posterior cavity, vitreous humor
Identify the lumen. Identify the material filling this lumen
facial nerve, vestibulocochlear nerve
Identify the nerves
eye, cornea
Identify the organ in the field of view. Identify the structure in the field of view.
eye
Identify the organ in the field of view:
fungiform papillae
Identify the organ, and the structures:
eye
Identify the organ:
cochlea
Identify the structure in the field of view
cupula
Identify the structure indicated by the pointer: it is in the circular canal, structure of the crista ampularis.
macula
Identify the structure occupied by the pointer and facing the lumen:
lens, refraction of 25% of light
Identify the structure: Give its function
nonkeratinized stratified squamous epithelial tissue
Identify the tissue occupied by the arrow
spiral organ
Identify the transducer in the field of view
vascular tunic
Identify the tunic occupied by the arrow
auditory hair cells
Identify these cells
ceruminous glands, cerumen
Identify these glands. What do they produce?
scala vestibuli, perilymph
Identify this cavity. Identify the fluid inside this cavity.
scala tympani, perilymph
Identify this cavity. Identify the fluid within this cavity.
scala media, endolymph
Identify this cavity. What fluid is contained here?
tympanic membrane, external ear from middle ear
Identify this structure: It divides what two sections of the ear?
Horner's Syndrome
In _______________, the sympathetic innervation to one side of the face is lost due to an inherited mutation, an injury, or a disease that affects sympathetic outflow through the superior cervical ganglion. Symptoms occur on the affected side and include ptosis (drooping of the upper eyelid), miosis (constricted pupil), and anhidrosis (lack of sweating).
Raynaud's Disease
In _______________________ the digits (fingers and toes) become ischemic (lack blood) after exposure to cold or with emotional stress. The condition is due to excessive sympathetic stimulation of smooth muscle in the arterioles of the digits and a heightened response to stimuli that cause vasoconstriction. When arterioles in the digits vasoconstrict in response to sympathetic stimulation, blood flow is greatly diminished. As a result, the digits may blanch (look white due to blockage of blood flow) or become cyanotic (look blue due to deoxygenated blood in capillaries). In extreme cases, the dig- its may become necrotic from lack of oxygen and nutrients. With rewarming after cold exposure, the arterioles may dilate, causing the fingers and toes to look red. Many patients with Raynaud phenomenon have low blood pressure. Some have increased numbers of alpha adrenergic receptors. Raynaud is most common in young women and occurs more often in cold climates. Patients with Raynaud phenomenon should avoid exposure to cold, wear warm clothing, and keep the hands and feet warm. Drugs used to treat Raynaud include nifedipine, a calcium channel blocker that relaxes vascular smooth muscle, and prazosin, which relaxes smooth muscle by blocking alpha receptors. Smoking and the use of alcohol or illicit drugs can exacerbate the symptoms of this condition.
rest and digest
In contrast to the fight-or-flight activities of the sympathetic division, the parasympathetic division enhances _____________ activities. Parasympathetic responses support body functions that conserve and restore body energy during times of rest and recovery. In the quiet intervals between periods of exercise, parasympathetic impulses to the digestive glands and the smooth muscle of the gastrointestinal tract predominate over sympathetic impulses. This allows energy-supplying food to be digested and absorbed. At the same time, parasympathetic responses reduce body functions that support physical activity.
true
In contrast to the sympathetic system, the parasympathetic response is more controlled. true or false?
cyclic GMP, glutamate
In darkness, sodium ions (Na+) flow into photoreceptor outer segments through ligand-gated Na+ channels. The ligand that holds these channels open is _____________. The inflow of Na+, called the "dark current," partially depolarizes the photoreceptor. As a result, in darkness the membrane potential of a photoreceptor is about -30 mV. This is much closer to zero than a typical neuron's resting membrane potential of -70 mV. The partial depolarization during darkness triggers continual release of neurotransmitter at the synaptic terminals. The neurotransmitter in rods, and perhaps in cones, is the amino acid ____________. At synapses between rods and some bipolar cells, glutamate is an inhibitory neurotransmitter: It triggers inhibitory postsynaptic potentials (IPSPs) that hyperpolarize the bipolar cells and prevent them from sending signals on to the ganglion cells. When light strikes the retina and cis-retinal undergoes isomerization, enzymes are activated that break down ___(same as blank 1)___. As a result, some Na+ channels close, Na+ inflow decreases, and the membrane potential becomes more negative, approaching -70 mV. This sequence of events produces a hyperpolarizing receptor potential that decreases the release of __(same as blank 2)__. Dim lights cause small and brief receptor potentials that partially turn off glutamate release; brighter lights elicit larger and longer receptor potentials that more completely shut down neurotransmitter release. Thus, light excites the bipolar cells that synapse with rods by turning off the release of an inhibitory neurotransmitter. The excited bipolar cells subsequently stimulate the ganglion cells to form action potentials in their axons.
light adaptation, dark adaptation
In daylight, regeneration of rhodopsin cannot keep up with the bleaching process, so rods contribute little to daylight vision. In contrast, cone photopigments regenerate rapidly enough that some of the cis form is always present, even in very bright light As a consequence, ______________ (from dark conditions to light conditions) happens in seconds; ______________ (from light to dark) takes minutes to occur (up to 40 minutes to fully adapt).
binocular vision, convergence
In humans, both eyes focus on only one set of objects—a characteristic called _______________. This feature of our visual system allows the perception of depth and an appreciation of the three-dimensional nature of objects. It occurs when light rays from an object strike corresponding points on the two retinas. When we stare straight ahead at a distant object, the incoming light rays are aimed directly at both pupils and are refracted to comparable spots on the retinas of both eyes. As we move closer to an object, however, the eyes must rotate medially if the light rays from the object are to strike the same points on both retinas. The term _____________ refers to this medial movement of the two eyeballs so that both are directed toward the object being viewed, for example, tracking a pencil moving toward your eyes. The nearer the object, the greater the degree of convergence needed to maintain binocular vision. The coordinated action of the extrinsic eye muscles brings about ___(same as second blank)___.
somatic nervous system
In the ______________, feedback via tactile, thermal, pain, and proprioceptive sensations are consciously perceived, and skeletal muscle is the main tool used to provide reflexive and voluntary movement.
ciliary body
In the anterior portion of the vascular tunic, the choroid becomes the ___________. It extends from the ora serrata, the jagged anterior margin of the retina, to a point just posterior to the junction of the sclera and cornea.
lateral horns of the gray matter in T1-T12 and L1-L3, thoracolumbar division, thoracolumbar outflow
In the sympathetic division, the preganglionic neurons have their cell bodies in the ________. For this reason, the sympathetic division is also called the ___________, and the axons of the sympathetic preganglionic neurons are known as the ______________.
autonomic plexuses
In the thorax, abdomen, and pelvis, axons of both sympathetic and parasympathetic neurons form tangled networks called ___________, many of which lie along major arteries. These also may contain sympathetic ganglia and axons of autonomic sensory neurons.
Lateral gray horns of spinal cord segments T1-L2. Axons of preganglionic neurons constitute thoracolumbar outflow
Location of preganglionic neuron cell bodies and site of outflow of the sympathetic division
sympathetic, parasympathetic
Most body organs have dual ANS innervation; that is, they receive impulses from both ____________ and ______________ neurons. Usually the nerve impulses from one division stimulate an organ, while impulses from the other division decrease activity.
color blindness, nyctalopia
Most forms of ________________, an inherited inability to distinguish between certain colors, result from the absence or deficiency of one of the three types of cones. The most common type is red-green color blindness, in which red cones or green cones are missing. As a result, the person cannot distinguish between red and green. Prolonged vitamin A deficiency and the resulting below-normal amount of rhodopsin may cause night blindness or ______________, an inability to see well at low light levels.
taste buds
Most of the nearly 10,000 ____________ of a young adult are on the tongue, but some are found on the soft palate (posterior portion of the roof of the mouth), pharynx (throat), and epiglottis (cartilage lid over voice box). The number present declines with age.
dual innervation
Most organs have ____________; that is, they receive impulses from both sympathetic and parasympathetic neurons. In some organs, nerve impulses from one division of the ANS stimulate the organ to increase its activity (excitation), and impulses from the other division decrease the organ's activity (inhibition). For example, an increased rate of nerve impulses from the sympathetic division increases heart rate, and an increased rate of nerve impulses from the parasympathetic division decreases heart rate.
gustatory
Olfactory and _____________ (taste) impulses travel not only to the cerebral cortex, but also to the limbic system this is why we can have emotional responses and trigger strong memories to certain smells and tastes gustation and olfaction work together but olfaction is much stronger/more sensitive (when someone has a cold it is difficult to taste food)
olfactory nerves I, olfactory bulbs, olfactory tract, primary olfactory area, orbitofrontal area
On each side of the nose, about 40 bundles of the slender, un- myelinated axons of olfactory receptors extend through about 20 olfactory foramina in the cribriform plate of the ethmoid bone. These 40 or so bundles of axons collectively form the right and left ___________________, which terminate in the brain in paired masses of gray matter called ______________. Axons of olfactory bulb neurons extend posteriorly and form the _________________. Some of the axons of the olfactory tract project to the __________________ of the cerebral cortex; located at the inferior and medial surface of the temporal lobe, the primary olfactory area is where conscious awareness of smell begins. From this area, pathways also extend to the frontal lobe. An important region for odor identification and discrimination is the ________________.
●1 An axon may synapse with postganglionic neurons in the ganglion it first reaches. ●2 An axon may ascend or descend to a higher or lower ganglion before synapsing with postganglionic neurons. The axons of incoming sympathetic preganglionic neurons that pass up or down the sympathetic trunk collectively form the sympa- thetic chains, the fibers on which the ganglia are strung. ●3 An axon may continue, without synapsing, through the sym- pathetic trunk ganglion to end at a prevertebral ganglion and synapse with postganglionic neurons there. ●4 An axon may also pass, without synapsing, through the sym- pathetic trunk ganglion and a prevertebral ganglion and then extend to chromaffin cells of the adrenal medullae that are functionally similar to sympathetic postganglionic neurons.
Once axons of sympathetic preganglionic neurons pass to sympathetic trunk ganglia, they may connect with postganglionic neurons in one of the following ways
primary olfactory area
Once generated, nerve impulses travel through the two olfactory nerves to the olfactory bulbs to the olfactory tract to the _______________ in the temporal lobe of the cortex.
terminal
Parasympathetic ganglia are called __________ ganglia because they are located far from their origin at the "terminal" ends of the pathways (near the target organs).
isomerization, bleaching, retinal isomerase, regeneration
Photopigments respond to light in the following cyclical process: ●1: In darkness, retinal has a bent shape, called cis-retinal, which fits snugly into the opsin portion of the photopigment. When cis-retinal absorbs a photon of light, it straightens out to a shape called trans-retinal. This cis-to-trans conversion is called ______________ and is the first step in visual transduction. After retinal isomerizes, several unstable chemical intermediates form and disappear. These chemical changes lead to production of a receptor potential. ●2: In about a minute, trans-retinal completely separates from opsin. The final products look colorless, so this part of the cycle is termed ___________ of photopigment. 3: An enzyme called _____________ converts trans-retinal back to cis-retinal. 4: 4 The cis-retinal then can bind to opsin, reforming a functional photopigment. This part of the cycle—resynthesis of a photopigment—is called _____________.
rod cells, cone cells
Photoreceptors are specialized cells that begin the process by which light rays are ultimately converted to nerve impulses. There are two types of photoreceptors: __________ allow us to see in dim light, such as moonlight. Because rods do not provide color vision, in dim light we can see only black, white, and all shades of gray in between. Brighter lights stimulate __________, which produce color vision. Three types of cones are present in the retina: (1) blue cones, which are sensitive to blue light, (2) green cones, which are sensitive to green light, and (3) red cones, which are sensitive to red light. Color vision results from the stimulation of various com- binations of these three types of cones. Most of our experiences are mediated by the cone system, the loss of which produces legal blindness. A person who loses rod vision mainly has difficulty seeing in dim light and thus should not drive at night.
greater splanchnic nerve, lesser splanchnic nerve, celiac ganglion, least splanchnic nerve, lumbar splanchnic nerve, inferior mesenteric ganglion
Preganglionic axons from the fifth through ninth or tenth thoracic ganglia (T5-T9 or T10) form the _______________. It pierces the diaphragm and enters the ______________ of the celiac plexus. From there, postganglionic neurons follow and innervate blood vessels to the stomach, spleen, liver, kidneys, and small intestine. Preganglionic axons from the tenth and eleventh thoracic ganglia (T10-T11) form the _______________. It pierces the diaphragm and passes through the celiac plexus to enter the aorticorenal ganglion and superior mesenteric ganglion of the superior mesenteric plexus. Postganglionic neurons from the superior mesenteric ganglion follow and innervate blood vessels of the small intestine and proximal colon. The _________________, which is not always present, is formed by preganglionic axons from the twelfth thoracic ganglia (T12) or a branch of the lesser splanchnic nerve. It pierces the diaphragm and enters the renal plexus near the kidney. Postganglionic neurons from the renal plexus supply kidney arterioles and the ureters. Preganglionic axons that form the ____________________ from the first through fourth lumbar ganglia (L1-L4) enter the inferior mesenteric plexus and terminate in the ___________________, where they synapse with postganglionic neurons. Axons of postganglionic neurons extend through the inferior mesenteric plexus to supply the distal colon and rectum; they also extend through the hypogastric plexus to supply blood vessels of the distal colon, rectum, urinary bladder, and genital organs. Postganglionic axons leaving the prevertebral ganglia follow the course of various arteries to abdominal and pelvic visceral effectors.
scala media, scala vestibuli, scala tympani
Sections through the cochlea reveal that it is divided into three channels: The _______________ (cochlear duct) is a continuation of the membranous labyrinth into the cochlea; it is filled with endolymph. The channel above the cochlear duct is the ________________, which ends at the oval window. The channel below is the _________________, which ends at the round window.
optic disc, central retinal artery
Several landmarks are visible through an ophthalmoscope. The _____________ is the site where the optic (II) nerve exits the eyeball. Bundled together with the optic nerve are the ________________, a branch of the ophthalmic artery, and the central retinal vein. Branches of the _______(same as blank 2)____ fan out to nourish the anterior surface of the retina; the central retinal vein drains blood from the retina through the optic disc.
superior rectus, inferior rectus, lateral rectus, medial rectus, superior oblique, inferior oblique
Six extrinsic eye muscles move each eye: They are supplied by cranial nerves III, IV, or VI
sympathetic nerves
Some of the incoming sympathetic preganglionic neurons synapse with postganglionic neurons in one or more ganglia of the sympathetic trunk. Then, the axons of the postganglionic neurons leave the trunk by forming _____________ that extend to visceral effectors in the thoracic cavity. These nerves provide sympathetic innervation to the heart and the lungs.
chromaffin cells
Some sympathetic preganglionic axons pass, without synapsing, through the sympathetic trunk, greater splanchnic nerves, and celiac ganglion, and then extend to ________________ in the adrenal medullae of the adrenal glands. These cells release hormones into the blood. Upon stimulation by sympathetic preganglionic neurons, these cells release a mixture of catecholamine hormones—about 80% epinephrine, 20% norepinephrine, and a trace amount of dopamine. These hormones circulate throughout the body and intensify responses elicited by sympathetic postganglionic neurons.
cephalic periarterial nerves
Some sympathetic preganglionic neurons that enter the sympathetic trunk ascend to the superior cervical ganglion, where they synapse with postganglionic neurons. The axons of some of these postganglionic neurons leave the sympathetic trunk by forming ____________, nerves that extend to the head by wrapping around and following the course of various arteries (such as the carotid arteries) that pass from the neck to the head. These nerves provide sympathetic innervation to visceral effectors in the skin of the face (sweat glands, smooth muscle of blood vessels, and arrector pili muscles of hair follicles), as well as other visceral effectors of the head (smooth muscle of the eye, lacrimal glands, pineal gland, nasal mucosa, and salivary glands).
papillae
Taste buds are found in elevations on the tongue called ______________, which increase the surface area and provide a rough texture to the upper surface of the tongue
autonomic nervous system
Structurally, the _________ includes autonomic sensory neurons, integrating centers in the central nervous system (CNS), autonomic motor neurons, and the enteric division. This system also operates via reflex arcs.
superior cervical ganglia, middle cervical ganglia, inferior cervical ganglia
Sympa- thetic trunk ganglia in the neck have specific names. They are the ____________. The remaining sympathetic trunk ganglia do not have individual names.
excretory lacrimal ducts, lacrimal puncta, nasolacrimal duct
Tears (lacrimal fluid) run from the lacrimal glands, into the ___________________, onto the surface of the conjunctiva, over the surface of the eyeball some lacrimal fluid also evaporates. Tears drain into the _____________, which are two openings on the nasal side of the extreme edge of the eyeball. Superior and inferior lacrimal canals empty the tears into the nasolacrimal sac and _________________. The right and left sided nasolacrimal ducts empty into each side of the nose.
lens
The ________ is an avascular refractory structure situated posterior to the pupil and iris. It consists of a capsule with crystallin proteins arranged in layers, and like the cornea, the lens is transparent It attaches to the ciliary muscle of the ciliary body by suspensory ligaments that fine tune the focusing of light on the retina.
iris
The __________ , the colored portion of the eyeball, is shaped like a flattened donut. It is suspended between the cornea and the lens and is attached at its outer margin to the ciliary processes. It consists of melanocytes and circular and radial smooth muscle fibers. The amount of melanin in the iris determines the eye color. The eyes appear brown to black when the iris contains a large amount of melanin, blue when its melanin concentration is very low, and green when its melanin concentration is moderate.
sclera, scleral venous sinus, aqueous humor
The __________, the "white" of the eye, is a layer of dense connective tissue made up mostly of collagen fibers and fibroblasts. It covers the entire eyeball except the cornea; it gives shape to the eyeball, makes it more rigid, protects its inner parts, and serves as a site of attachment for the extrinsic eye muscles. At the junction of the sclera and cornea is an opening known as the ____________ (canal of Schlemm). A fluid called _____________, which will be described later, drains into this sinus.
conjunctiva, palpebral conjunctiva, bulbar conjunctiva
The ___________ is a thin, protective mucous membrane composed of nonkeratinized stratified squamous epithelium with numerous goblet cells that is supported by areolar connective tissue. The _____________ lines the inner aspect of the eyelids, and the _____________ passes from the eyelids onto the surface of the eyeball, where it covers the sclera (the "white" of the eye) but not the cornea, which is a transparent region that forms the outer anterior surface of the eyeball. Over the sclera, the conjunctiva is vascular.
vestibule, utricle, saccule, cochlea
The ___________ is the middle part of the bony labyrinth The membranous labyrinth in the vestibule consists of two sacs called the __________ and the __________ (both contain rc for static equilibrium) The ___________ , located anterior to the vestibule, contains rc for hearing The three semicircular canals are above the vestibule, each ending in a swollen enlargement called the ampulla (for dynamic equilibrium).
fibrous tunic, cornea
The ___________ is the superficial layer of the eyeball and consists of the anterior cornea and posterior sclera. The ___________ is a transparent coat that covers the colored iris. Because it is curved, it helps focus light onto the retina. Its outer surface consists of nonkeratinized stratified squamous epithelium. The middle coat of this structure consists of collagen fibers and fibroblasts, and the inner surface is simple squamous epithelium. Since the central part of the cornea receives oxygen from the outside air, contact lenses that are worn for long periods of time must be permeable to permit oxygen to pass through them.
middle ear, oval window, round window, auditory ossicles, malleus, incus, stapes
The ____________ is a small, air-filled cavity in the petrous portion of the temporal bone that is lined by epithelium. It is separated from the external ear by the tympanic membrane and from the internal ear by a thin bony partition that contains two small membrane-covered openings: the _______________ and the ______________. Extending across the middle ear and attached to it by ligaments are the three smallest bones in the body, the ______________, which are connected by synovial joints. The bones, named for their shapes, are commonly called the hammer, anvil, and stirrup, respectively. The "handle" of the __________ attaches to the internal surface of the tympanic membrane. The head of this hammer like bone articulates with the body of the ________. This anvil like bone, the middle bone in the series, articulates with the head of the ________. The base or footplate of this stirrup like bone fits into the oval window. Directly below the oval window is another opening, the round window, which is enclosed by a membrane called the secondary tympanic membrane.
external ear, pinna, helix, lobule, external auditory canal, tympanic membrane, simple cuboidal,
The _______________ consists of the auricle, external auditory canal, and eardrum (Figure 17.18). The auricle or ________ is a flap of elastic cartilage shaped like the flared end of a trumpet and covered by skin. The rim of the auricle is the _______; the inferior portion is the ________. Ligaments and muscles attach the auricle to the head. The _______________ is a curved tube about 2.5 cm (1 in.) long that lies in the temporal bone and leads to the eardrum. The _______________ is a thin, semi transparent partition between the external auditory canal and middle ear. This is covered by epidermis and lined by ______________ epithelium. Between the epithelial layers is connective tissue composed of collagen, elastic fibers, and fibroblasts.
tarsal plate, tarsal, chalazion
The _______________ is a thick fold of connective tissue that gives form and support to the eyelids. Embedded in each tarsal plate is a row of elongated modified sebaceous glands, known as _________ or Meibomian glands, that secrete a fluid that helps keep the eyelids from adhering to each other. Infection of the tarsal glands produces a tumor or cyst on the eyelid called a ____________.
eustachian tube
The ________________ (auditory tube) connects the middle ear with the nasopharynx (upper portion of the throat). It consists of bone and hyaline cartilage and is normally passively collapsed. It opens to equalize pressures on each side of the tympanic membrane, allowing it to freely vibrate.
inner ear, semicircular canals, vestibule, cochlea, epithelial membranous labyrinth, ampulla, semicircular ducts
The ____________ is also called the labyrinth because of its complicated series of canals. structurally, it consists of two main divisions: The bony labyrinth is a series of cavities in the petrous portion of the temporal bone divided into three areas: the ______________, the ____________ , and the _____________. The bony labyrinth is lined with periosteum and contains perilymph. This fluid, which is chemically similar to cerebrospinal fluid, surrounds the membranous labyrinth, a series of epithelial sacs and tubes inside the bony labyrinth that have the same general form as the bony labyrinth and house the receptors for hearing and equilibrium. The ________________________ contains endolymph. The level of potassium ions (K+) in endolymph is unusually high for an extracellular fluid, and potassium ions play a role in the generation of auditory signals. The vestibule is the oval central portion of the bony labyrinth. The membranous labyrinth in the vestibule consists of two sacs called the utricle and the saccule, which are connected by a small duct. Projecting superiorly and posteriorly from the vestibule are the three bony semicircular canals, each of which lies at approximately right angles to the other two. Based on their positions they are named the anterior, posterior, and lateral semicircular canals. The anterior and posterior semicircular canals are vertically oriented; the lateral one is horizontally oriented. At one end of each canal is a swollen enlargement called the _____________. The portions of the membranous labyrinth that lie inside the bony semicircular canals are called the ___________________. These structures connect with the utricle of the vestibule.
middle ear, stapes, incus, malleus
The ____________ is an air-filled cavity in the temporal bone. It is lined with epithelium and contains 3 auditory ossicles (bones): The _________ (stirrup) The _________(anvil) The handle of the __________ (hammer) attaches to the Tympanic Membrane.
superior mesenteric plexus, inferior mesenteric plexus
The _____________ contains the superior mesenteric ganglion and supplies the small and large intestines. The ____________ contains the inferior mesenteric ganglion, which innervates the large intestine.
lacrimal apparatus, lacrimal fluid, lacrimal glands, excretory lacrimal ducts, lacrimal puncta, lacrimal canals, lacrimal sac, nasolacrimal duct
The _____________ is a group of structures that produces and drains _____________ or tears. The _____________, each about the size and shape of an almond, secrete lacrimal fluid, which drains into 6-12 _____________ that empty tears onto the surface of the conjunctiva of the upper lid. From here the tears pass medially over the anterior surface of the eyeball to enter two small openings called ____________. Tears then pass into two ducts, the ______________, which lead into the ______________ and then into the _____________. This duct carries the lacrimal fluid into the nasal cavity just inferior to the inferior nasal concha.
accessory structures
The _____________ of the eye include the eyelids, eyelashes, eyebrows, the lacrimal (tear-producing) apparatus, and extrinsic eye muscles.
pigmented layer, neural layer
The _____________ of the retina is a sheet of melanin-containing epithelial cells located between the choroid and the neural part of the retina. The melanin in the pigmented layer of the retina, as in the choroid, also helps to absorb stray light rays. The ____________ of the retina is a multilayered outgrowth of the brain that processes visual data extensively before sending nerve impulses into axons that form the optic nerve.
eyelashes, eyebrows, sebaceous ciliary glands, sty
The _____________, which project from the border of each eyelid, and the _____________, which arch transversely above the upper eyelids, help protect the eyeballs from foreign objects, perspiration, and the direct rays of the sun. Sebaceous glands at the base of the hair follicles of the eyelashes, called ________________, release a lubricating fluid into the follicles. Infection of these glands, usually by bacteria, causes a painful, pus-filled swelling called a _____________.
internal ear, bony labyrinth, membranous labyrinth, semicircular canals, vestibule, cochlea
The ______________ (inner ear) is also called the labyrinth because of its complicated series of canals Structurally, it consists of two main divisions: an outer ______________ that encloses an inner ______________. the bony labyrinth is sculpted out of the petrous part of the temporal bone, and divided into three areas: the ______________, _______________, and the ____________.
ciliary processes, zonular fibers, ciliary muscle
The ______________ are protrusions or folds on the internal surface of the ciliary body. They contain blood capillaries that secrete aqueous humor. Extending from the ciliary process are ______________ (suspensory ligaments) that attach to the lens. The fibers consist of thin, hollow fibrils that resemble elastic connective tissue fibers. The ____________ is a circular band of smooth muscle. Contraction or relaxation of the ciliary muscle changes the tightness of the zonular fibers, which alters the shape of the lens, adapting it for near or far vision.
cranial parasympathetic outflow, sacral parasympathetic outflow
The ______________ consists of preganglionic axons that extend from the brain stem in four cranial nerves. The _________________ consists of preganglionic axons in anterior roots of the second through fourth sacral spinal nerves. The preganglionic axons of both of these end in terminal ganglia, where they synapse with postganglionic neurons.
celiac plexus
The ______________ is the largest autonomic plexus and surrounds the celiac trunk. It contains two large celiac ganglia, two aorticorenal ganglia, and a dense network of autonomic axons and is distributed to the stomach, spleen, pancreas, liver, gallbladder, kidneys, adrenal medullae, testes, and ovaries.
tectorial membrane
The ______________, a flexible gelatinous membrane, covers the hair cells of the spiral organ
fovea centralis
The ______________, a small depression in the center of the macula lutea, contains only cones. In addition, the layers of bipolar and ganglion cells, which scatter light to some extent, do not cover the cones here; these layers are displaced to the periphery of the fovea centralis. As a result, the fovea centralis is the area of highest visual acuity or resolution (sharpness of vision).
hypothalamus
The ________________ is the major control and integration center of the ANS. It receives sensory input related to visceral functions, olfaction (smell), and gustation (taste), as well as changes in temperature, osmolarity, and levels of various substances in blood. It also receives input relating to emotions from the limbic system. Output from the this part of the brain influences autonomic centers in both the brain stem (such as the cardiovascular, salivation, swallowing, and vomiting centers) and the spinal cord (such as the defecation and urination reflex centers in the sacral spinal cord). Anatomically, it is connected to both the sympathetic and parasympathetic divisions of the ANS by axons of neurons with dendrites and cell bodies in various nuclei. The axons form tracts from this brain structure to parasympathetic and sympathetic nuclei in the brain stem and spinal cord. through relays in the reticular formation. The posterior and lateral parts of this structure control the sympathetic division. Stimulation of these areas produces an increase in heart rate and force of contraction, a rise in blood pressure due to constriction of blood vessels, an increase in body temperature, dilation of the pupils, and inhibition of the gastrointestinal tract. In contrast, the anterior and medial parts of this structure control the parasympathetic division. Stimulation of these areas results in a decrease in heart rate, lowering of blood pressure, constriction of the pupils, and increased secretion and motility of the gastrointestinal tract.
vestibular membrane, basilar membrane, spiral organ, hair cells
The __________________ separates the cochlear duct (scala media) from the scala vestibuli, and the ______________, separates the cochlear duct from the scala tympani. Resting on the basilar membrane is the ____________ or organ of Corti. This is a coiled sheet of epithelial cells, including supporting cells and about 16,000 __________, which are the receptors for hearing. There are two groups of thees cells: The inner hair cells are arranged in a single row, whereas the outer hair cells are arranged in three rows. At the apical tip of each hair cell are 40-80 stereocilia that extend into the endolymph of the cochlear duct. Despite their name, stereocilia are actually long, hairlike microvilli arranged in several rows of graded height.
autonomic nervous system
The ____________________ contributes to homeostasis by responding to subconscious visceral sensations and exciting or inhibiting smooth muscle, cardiac muscle, and many glands.
salivation, lacrimation, urination, defecation, digestion
The acronym SLUDD can be helpful in remembering five parasympathetic responses. It stands for:
COMT, MAO
The activity of norepinephrine at a synapse is terminated either when the NE is taken up by the axon that released it or when the NE is enzymatically inactivated by either __________ or __________. Compared to ACh, norepinephrine lingers in the synaptic cleft for a longer time. Thus, effects triggered by adrenergic neurons typically are longer lasting than those triggered by cholinergic neurons. Most sympathetic postganglionic neurons are adrenergic.
fibrous tunic, vascular tunic, nervous tunic
The adult eyeball measures about 2.5 cm (1 in.) in diameter. Of its total surface area, only the anterior one-sixth is exposed; the remainder is recessed and protected by the orbit, into which it fits. Anatomically, the wall of the eyeball consists of three layers:
preganglionic, postganglionic
The anatomy of all autonomic pathways can best be understood by picturing a double-barrelled neuronal construct consisting of a ____________ neuron leading to an intermediate ganglion that contains the cell bodies of ____________ neurons
pinna, ceruminous glands, external auditory canal, tympanic membrane
The anatomy of the external ear includes: The ___________, a flap of elastic cartilage covered by skin and containing ______________________ A curved 1" long ____________________ situated in the temporal bone leading from the meatus to the _________________, which separates the external ear from the middle ear.
auditory tube
The anterior wall of the middle ear contains an opening that leads directly into the ______________, commonly known as the eustachian tube. It consists of both bone and elastic cartilage, connects the middle ear with the nasopharynx (superior portion of the throat). It is normally closed at its medial end. During swallowing and yawning, it opens, allowing air to enter or leave the middle ear until the pressure in the middle ear equals the atmospheric pressure. Most of us have experienced our ears popping as the pressures equalize. When the pressures are balanced, the tympanic membrane vibrates freely as sound waves strike it. If the pressure is not equalized, intense pain, hearing impairment, ringing in the ears, and vertigo could develop. The eustachian tube also is a route for pathogens to travel from the nose and throat to the middle ear, causing the most common type of ear infection.
external ear, middle ear, internal ear
The ear is divided into three main regions: (1) the _____________, which collects sound waves and channels them inward; (2) the _____________, which conveys sound vibrations to the oval window; and (3) the _____________, which houses the receptors for hearing and equilibrium.
retina
The inner nervous tunic lines the posterior 2/3 of the eye. The ________ consist of a layer of melanin pigmented epithelium that allows light to be absorbed rather than scattered. Without the melanin, scattered light in our eye would cause us to always be squinting, even in a moderately lit room.
optic chiasm, optic tract, lateral geniculate nucleus, optic radiations, superior colliculi, pretectal nuclei, nasal half, temporal half
The axons within the optic (II) nerve pass through the _______________, a crossing point of the optic nerves. Some axons cross to the opposite side, but others remain uncrossed. After passing through the optic chiasm, the axons, now part of the ____________, enter the brain and most of them terminate in the ________________________ of the thalamus. Here they synapse with neurons whose axons form the ________________, which project to the primary visual areas in the occipital lobes of the cerebral cortex, and visual perception begins. Some of the fibers in the optic tracts terminate in the _______________, which control the extrinsic eye muscles, and the ___________, which control pupillary and accommodation reflexes. Everything that can be seen by one eye is that eye's visual field. As noted earlier, because our eyes are located anteriorly in our heads, the visual fields overlap considerably. We have binocular vision due to the large region where the visual fields of the two eyes overlap—the binocular visual field. The visual field of each eye is divided into two regions: ____________ and the _____________.
receptor, sensory neuron, integrating center, motor neurons, effector
The components of an autonomic reflex arc are as follows:
ciliary ganglia- Preganglionic axons pass with the oculomotor nerve III to the ciliary ganglia and innervate smooth muscle fibers in the eyeball , pterygopalatine ganglia- receive preganglionic axons from the facial nerve VII and send postganglionic axons to the nasal mucosa, palate, pharynx, and lacrimal glands, submandibular ganglia- receive preganglionic axons from the facial nerves and send postganglionic axons to the submandibular and sublingual salivary glands. otic ganglia- They receive preganglionic axons from the glossopharyngeal nerve IX and send postganglionic axons to the parotid salivary glands.
The cranial outflow has four pairs of ganglia and the ganglia associated with the vagus (X) nerve. The four pairs of cranial parasympathetic ganglia innervate structures in the head and are located close to the organs they innervate. What are they?
b
The definition of autonomic tone is: a) The communication between the autonomic nervous system and the somatic nervous system b) The balance between sympathetic and parasympathetic activity c) the constant slight contraction seen in skeletal muscles d) the canceling out effects of adrenergic and cholinergic responses to a stimulus
external ear, middle ear, internal ear
The ear has 3 principle regions: The ____________, which uses air to collect and channel sound waves The ____________, which uses a bony system to amplify sound vibrations. The ____________, which generates action potentials to transmit sound and balance information to the brain.
1. Sympathetic postganglionic axons diverge more extensively; as a result, many tissues are activated simultaneously, 2. Acetylcholinesterase quickly inactivates acetylcholine, but norepinephrine lingers in the synaptic cleft for a longer period, 3. epinephrine and norepinephrine secreted into the blood from the adrenal medullae intensify and prolong the responses caused by norepinephrine liberated from sympathetic postganglionic axons
The effects of sympathetic stimulation are longer lasting and more widespread than the effects of parasympathetic stimulation for three reasons:
fovea centralis
The exact center of the retina is called the macula lutea, and in its center is a small depression called the ______________.
periorbital fat
The extrinsic eye muscles extend from the walls of the bony orbit to the sclera (white) of the eye and are surrounded in the orbit by a significant quantity of ________________.
visible light
The eyes are responsible for the detection of _____________, the part of the electromagnetic spectrum with wavelengths ranging from about 400 to 700 nm.
photopigment, rhodopsin
The first step in visual transduction is absorption of light by a _________________, a colored protein that undergoes structural changes when it absorbs light, in the outer segment of a photoreceptor. Light absorption initiates the events that lead to the pro- duction of a receptor potential. The single type of this protein in rods is ________________. Three different cone photopigments are present in the retina, one in each of the three types of cones.
●1 The auricle directs sound waves into the external auditory canal. ●2 When sound waves strike the tympanic membrane, the alter- nating waves of high and low pressure in the air cause the tympanic membrane to vibrate back and forth. The tympanic membrane vibrates slowly in response to low-frequency (low-pitched) sounds and rapidly in response to high- frequency (high-pitched) sounds. ●3 The central area of the tympanic membrane connects to the malleus, which vibrates along with the tympanic membrane. This vibration is transmitted from the malleus to the incus and then to the stapes. ●4 As the stapes moves back and forth, its oval-shaped footplate, which is attached via a ligament to the circumference of the oval window, vibrates in the oval window. The vibrations at the oval window are about 20 times more vigorous than the tym- panic membrane because the auditory ossicles efficiently transmit small vibrations spread over a large surface area (the tympanic membrane) into larger vibrations at a smaller surface (the oval window). ●5 The movement of the stapes at the oval window sets up fluid pressure waves in the perilymph of the cochlea. As the oval window bulges inward, it pushes on the perilymph of the scala vestibuli. ●6 Pressure waves are transmitted from the scala vestibuli to the scala tympani and eventually to the round window, causing it to bulge outward into the middle ear. (See ●9 in the figure.) ●7 The pressure waves travel through the perilymph of the scala vestibuli, then the vestibular membrane, and then move into the endolymph inside the cochlear duct. ●8 The pressure waves in the endolymph cause the basilar membrane to vibrate, which moves the hair cells of the spiral organ against the tectorial membrane. This leads to bending of the stereocilia and ultimately to the generation of nerve impulses in first-order neurons in cochlear nerve fibers. ●9 Sound waves of various frequencies cause certain regions of the basilar membrane to vibrate more intensely than other regions. Each segment of the basilar membrane is "tuned" for a particular pitch. Because the membrane is narrower and stiffer at the base of the cochlea (closer to the oval window), high-frequency (high-pitched) sounds induce maximal vibra- tions in this region. Toward the apex of the cochlea, the basilar membrane is wider and more flexible; low-frequency (low-pitched) sounds cause maximal vibration of the basilar membrane there. Loudness is determined by the intensity of sound waves. High-intensity sound waves cause larger vibrations of the basilar membrane, which leads to a higher frequency of nerve impulses reaching the brain. Louder sounds also may stimulate a larger number of hair cells.
The following events are involved in hearing:
transduction channel
The hair cells transduce mechanical vibrations into electrical signals. As the basilar membrane vibrates, the hair bundles at the apex of the hair cell bend back and forth and slide against one an- other. A tip link protein connects the tip of each stereocilium to a mechanically gated ion channel called the _________________ in its taller stereocilium neighbor. As the stereocilia bend in the direction of the taller stereocilia, the tip links tug on the transduction channels and open them. These channels allow cations in the endolymph, primarily K, to enter the hair cell cytosol. As cations enter, they produce a depolarizing receptor potential. De- polarization quickly spreads along the plasma membrane and opens voltage-gated Ca2+ channels in the base of the hair cell. The resulting inflow of Ca2+ triggers exocytosis of synaptic vesicles containing a neurotransmitter, which is probably glutamate. As more neurotransmitter is released, the frequency of nerve impulses in the first-order sensory neurons that synapse with the base of the hair cell increases. Bending of the stereocilia in the opposite direction closes the transduction channels, allows hyper- polarization to occur, and reduces neurotransmitter release from the hair cells. This decreases the frequency of nerve impulses in the sensory neurons.
choroid
The highly vascularized ___________, which is the posterior portion of the vascular tunic, lines most of the internal surface of the sclera. Its numerous blood vessels provide nutrients to the posterior surface of the retina. It also contains melanocytes that produce the pigment melanin, which causes this layer to appear dark brown in color. Melanin in the choroid absorbs stray light rays, which prevents reflection and scattering of light within the eyeball.
stapes
The incus attaches to this third inner ear bone, called what?
vitreous chamber, vitreous body, hyaloid canal
The larger posterior cavity of the eyeball is the ______________, which lies between the lens and the retina. Within this chamber is the _______________, a transparent jelly-like substance that holds the retina flush against the choroid, giving the retina an even surface for the reception of clear images. The ____________ is a narrow channel that is inconspicuous in adults and runs through the vitreous body from the optic disc to the posterior aspect of the lens. In the fetus, it is occupied by the hyaloid artery.
anterior cavity, posterior cavity
The lens divides the eyeball into two cavities: An ________________ anterior to the lens, and a ________________ (vitreous chamber) behind the lens. The ____(blank one)_____ is further divided at the level of the iris into anterior and posterior chambers (both filled with aqueous humor). The much larger ____(blank 2)____ of the eyeball (vitreous chamber) lies between the lens and the retina Within the vitreous chamber is the vitreous body, a transparent jellylike substance that holds the retina flush against the choroid, giving the retina an even surface for the reception of clear images occasionally, collections of debris called vitreal floaters cast shadows on the retina and create a spot in our field of vision (they are usually harmless and do not require treatment)
anterior cavity, vitreous chamber, anterior chamber, posterior chamber, aqueous humor
The lens divides the interior of the eyeball into two cavities: the ___________ and _____________. The anterior cavity—the space anterior to the lens—consists of two chambers. The _____________ lies between the cornea and the iris. The _______________ lies behind the iris and in front of the zonular fibers and lens. Both chambers of the anterior cavity are filled with _____________.
otolithic membrane
The maculae consist of two kinds of cells: hair cells, which are the sensory receptors, and supporting cells. Hair cells have on their surface 40-80 stereocilia (which are actually microvilli) of graduated height, plus one kinocilium, a conventional cilium anchored firmly to its basal body and extending beyond the longest stereocilium. As in the cochlea, the stereocilia are connected by tip links. Collectively, the stereocilia and kinocilium are called a hair bundle. Scattered among the hair cells are columnar supporting cells that probably secrete the thick, gelatinous, glycoprotein layer, called the __________________, that rests on the hair cells. A layer of dense calcium carbonate crystals, called otoliths, extends over the entire surface of the otolithic membrane. Because the otolithic membrane sits on top of the macula, if you tilt your head forward, the otolithic membrane (along with the otoliths as well) is pulled by gravity. It slides "downhill" over the hair cells in the direction of the tilt, bending the hair bundles. However, if you are sitting upright in a car that suddenly jerks for- ward, the otolithic membrane lags behind the head movement, pulls on the hair bundles, and makes them bend in the other direction. Bending of the hair bundles in one direction stretches the tip links, which pull open transduction channels, producing depolarizing receptor potentials; bending in the opposite direction closes the transduction channels and produces hyperpolarization. As the hair cells depolarize and repolarize, they release neurotransmitter at a faster or slower rate. The hair cells synapse with first-order sensory neurons in the vestibular branch of the vestibulocochlear (VIII) nerve. These neurons fire impulses at a slow or rapid pace depending on the amount of neurotransmitter present. Motor neurons also synapse with the hair cells and sensory neurons. Evidently, the motor neurons regulate the sensitivity of the hair cells and sensory neurons.
autonomic sensory neurons, interoreceptors
The main input to the ANS comes from ___________. Mostly, these neurons are associated with ____________, which are sensory receptors located in blood vessels, visceral organs, muscles, and the nervous system that monitor conditions in the internal environment.
norepinpehrine
The neurotransmitter used at most sympathetic postganglionic synapses is ______________.The exception to this rule is that ACh is used at sympathetic postganglionic synapses for sweat glands.
acetylcholine, nicotinic receptors, muscarinic receptors
The neurotransmitter used in all of the synapses of sympathetic and parasympathetic ganglia (between the synapses of the preganglionic and postganglionic fibers) is _______________. Receptors that respond to ACh released by these cholinergic neurons are called cholinergic receptors and there are 2 subtypes: _____________________ (found in the ganglia) and __________________ (found in the synapses with the effector organs).
myopia, hyperopia, astigmatism
The normal eye, known as an emmetropic eye, can sufficiently refract light rays from an object 6 m (20 ft) away so that a clear image is focused on the retina. Many people, however, lack this ability because of refraction abnormalities. Among these abnormalities are _________, or nearsightedness, which occurs when the eyeball is too long relative to the focusing power of the cornea and lens, or when the lens is thicker than normal, so an image converges in front of the retina. Myopic individuals can see close objects clearly, but not distant objects. In _____________or farsightedness, also known as hyper- metropia, the eyeball length is short relative to the focusing power of the cornea and lens, or the lens is thinner than normal, so an image converges behind the retina. Hyperopic individuals can see distant objects clearly, but not close ones. Another refraction abnormality is ____________, in which either the cornea or the lens has an irregular curvature. As a result, parts of the image are out of focus, and thus vision is blurred or distorted.
olfactory receptor, supporting cells, basal cells
The olfactory epithelium consists of 3 kinds of cells:
coccygeal ganglia
The paired sympathetic trunk ganglia are arranged anterior and lateral to the vertebral column, one on either side. Typically, there are 3 cervical, 11 or 12 thoracic, 4 or 5 lumbar, 4 or 5 sacral, and 1 coccygeal ganglion. The right and left _____________ are fused together and usually lie at the midline. Although these ganglia extend inferiorly from the neck, chest, and abdomen to the coccyx, they receive preganglionic axons only from the thoracic and lumbar segments of the spinal cord.
rest and digest
The parasympathetic division is often referred to as the _____________ division because its activities conserve and restore body energy during times of rest or digesting a meal; the majority of its output is directed to the smooth muscle and glandular tissue of the output is directed to the smooth muscle and glandular tissue of the gastrointestinal and respiratory tracts. The parasympathetic division conserves energy and replenishes nutrient stores.
intraocular pressure
The pressure in the eye, called __________________, is produced mainly by the aqueous humor and partly by the vitreous body; normally it is about 16 mmHg (millimeters of mercury). It maintains the shape of the eyeball and prevents it from collapsing.
pelvic splanchnic nerves
The sacral parasympathetic outflow consists of preganglionic axons from the anterior roots of the second through fourth sacral spinal nerves (S2-S4). As the preganglionic axons course through the sacral spinal nerves, they branch off these nerves to form ______________. These nerves synapse with parasympathetic postganglionic neurons located in terminal ganglia in the walls of the innervated viscera. From the terminal ganglia, parasympathetic postganglionic axons innervate smooth muscle and glands in the walls of the colon, ureters, urinary bladder, and reproductive organs.
pelvic splanchnic nerves
The sacral preganglionic axons branch off of sacral spinal nerves to form _________________ which synapse with parasympathetic postganglionic neurons located in terminal ganglia in the walls of the innervated viscera. From the terminal ganglia, postganglionic axons innervate smooth muscle and glands in the walls of the colon, ureters, urinary bladder, and reproductive organs
prevertebral ganglia
The second group of sympathetic ganglia, the _______________, lies anterior to the vertebral column and close to the large abdominal arteries. In general, postganglionic axons from prevertebral ganglia innervate organs below the diaphragm. There are five major prevertebral ganglia: (1) The celiac ganglion is on either side of the celiac trunk, an artery that is just inferior to the diaphragm. (2) The superior mesenteric ganglion is near the beginning of the superior mesenteric artery in the upper abdomen. (3) The inferior mesenteric ganglion is near the beginning of the inferior mesenteric artery in the middle of the abdomen. (4) The aorticorenal ganglion and (5) the renal ganglion are near the renal artery of each kidney.
palpebral fissure, lateral commissure, medial commissure, lacrimal caruncle
The space between the upper and lower eyelids that exposes the eyeball is the _____________. Its angles are known as the ________________, which is narrower and closer to the temporal bone, and the _____________, which is broader and nearer the nasal bone. In the medial commissure is a small, reddish elevation, the ______________, which contains sebaceous (oil) glands and sudoriferous (sweat) glands. The whitish material that sometimes collects in the medial commissure comes from these glands.
gustatory receptor cells, gustatory hair
The supporting cells sur- round about 50 ______________ in each taste bud. A single, long microvillus, called a _______________, projects from each receptor cell to the external surface through the taste pore, an opening in the taste bud. each of these cells has a lifespan of about 10 days
fight or flight
The sympathetic division is often called the _________ division. Sympathetic activities result in increased alertness and metabolic activities in order to prepare the body for an emergency situation. Responses to such situations, which may occur during physical activity or emotional stress, include a rapid heart rate, faster breathing rate, dilation of the pupils, dry mouth, sweaty but cool skin, dilation of blood vessels to organs involved in combating stress (such as the heart and skeletal muscles), constriction of blood vessels to organs not involved in combating stress (for example, the gastrointestinal tract and kidneys), and release of glucose from the liver.
sympathetic trunk ganglia, prevertebral ganglia
The sympathetic ganglia are the sites of synapses between sympathetic preganglionic and postganglionic neurons. There are two major types of sympathetic ganglia: sympathetic trunk ganglia and prevertebral ganglia.
retina
The third and inner layer of the eyeball, the __________, lines the posterior three-quarters of the eyeball and is the beginning of the visual pathway. This layer's anatomy can be viewed with an ophthalmoscope, an instrument that shines light into the eye and allows an observer to peer through the pupil, providing a magnified image of the retina and its blood vessels as well as the optic (II) nerve. The surface of the ___ (same as prior)____ is the only place in the body where blood vessels can be viewed directly and examined for pathological changes, such as those that occur with hypertension, diabetes mellitus, cataracts, and age-related macular disease.
thoracic sympathetic trunk
The thoracic portion of each sympathetic trunk lies anterior to the necks of the corresponding ribs. This region of the sympathetic trunk receives most of the sympathetic preganglionic axons. Postganglionic neurons from the _____________ innervate the heart, lungs, bronchi, and other thoracic viscera. In the skin, these neurons also innervate sweat glands, blood vessels, and arrector pili muscles of hair follicles. The lumbar portion of each sympathetic trunk lies lateral to the corresponding lumbar vertebrae. The sacral region of the sympathetic trunk lies in the pelvic cavity on the medial side of the anterior sacral foramina.
semicircular ducts, ampulla, crista, cupula
The three _____________ function in dynamic equilibrium. The ducts lie at right angles to one another in three planes. The two vertical ducts are the anterior and posterior semicircular ducts, and the horizontal one is the lateral semicircular duct. This positioning permits detection of rotational acceleration or deceleration. In the __________, the dilated portion of each duct, is a small elevation called the ___________. This contains a group of hair cells and supporting cells. Covering the this is a mass of gelatinous material called the ___________. When you move your head, the attached semicircular ducts and hair cells move with it. The endolymph within the ampulla, however, is not attached and lags behind. As the moving hair cells drag along the stationary endolymph, the hair bundles bend. Bending of the hair bundles produces receptor potentials. In turn, the receptor potentials lead to nerve impulses that pass along the vestibular branch of the vestibulocochlear (VIII) nerve.
palpebrae
The upper and lower ___________ are the eyelids, with the fissure being the space between them.
eyelids
The upper and lower ___________, or palpebrae, shade the eyes during sleep, protect the eyes from excessive light and foreign objects, and spread lubricating secretions over the eyeballs
levator palpebrae superioris muscle
The upper eyelid is more movable than the lower and contains in its superior region the _____________
vestibular ganglia
The vestibular branch of the vestibulocochlear (VIII) nerve consists of ampullary, utricular, and saccular nerves. These nerves contain both first-order sensory neurons and motor neurons that synapse with receptors for equilibrium. The first-order sensory neurons carry sensory information from the receptors, and the motor neurons carry feedback signals to the receptors, apparently to modify their sensitivity. Cell bodies of the sensory neurons are located in the ________________.
static equilibrium, dynamic equilibrium
There are two types of equilibrium or balance. __________________ refers to the maintenance of the position of the body (mainly the head) relative to the force of gravity. Body movements that stimulate the receptors for this equilibrium include tilting the head and linear acceleration or deceleration, such as when the body is being moved in an elevator or in a car that is speeding up or slowing down. __________________ is the maintenance of body position (mainly the head) in response to sudden movements such as rotational acceleration or deceleration.
nicotinic receptors
These receptors are present in the plasma membrane of dendrites and cell bodies of both sympathetic and parasympathetic postganglionic neurons, the plasma membranes of chromaffin cells of the adrenal medul- lae, and in the motor end plate at the neuromuscular junction. They are so named because nicotine mimics the action of ACh by binding to these receptors.
cholinergic neurons
These release the neurotransmitter acetylcholine (ACh). In the ANS, these neurons include all sympathetic and parasympathetic preganglionic neurons, sympathetic postganglionic neurons that innervate most sweat glands, and all parasympathetic postganglionic neurons.
cornea
This clear part is the
spiral organ
This is known as what?
true
True or False: The primary difference between an autonomic reflex arc and a somatic reflex arc is that the former has two motor neurons connecting the CNS to an effector.
horizontal cells, amacrine cells
Two other types of cells present in the bipolar cell layer of the retina are called ______________ and _____________. These cells form laterally directed neural circuits that modify the signals being transmitted along the pathway from photoreceptors to bipolar cells to ganglion cells.
tensor tympani, stapedius
Two small skeletal muscles, the _____________ and ___________ attach to the ossicle and dampen vibrations to prevent damage from sudden, loud sounds.
sympathetic division, parasympathetic division
Unlike somatic output (motor), the output part of the ANS has two divisions. What are they?
●1: The axons of all retinal ganglion cells in one eye exit the eyeball at the optic disc and form the optic nerve on that side. ●2: At the optic chiasm, axons from the temporal half of each retina do not cross but continue directly to the lateral geniculate nucleus of the thalamus on the same side. ●3: In contrast, axons from the nasal half of each retina cross the optic chiasm and continue to the opposite thalamus. ●4: Each optic tract consists of crossed and uncrossed axons that project from the optic chiasm to the thalamus on one side. ●5: Axon collaterals (branches) of the retinal ganglion cells project to the midbrain, where they participate in neural circuits that govern constriction of the pupils in response to light and coordination of head and eye movements. Collaterals also extend to the suprachiasmatic nucleus of the hypothalamus, which establishes patterns of sleep and other activities that occur on a circadian or daily schedule in response to intervals of light and darkness. ●6: The axons of thalamic neurons form the optic radiations as they project from the thalamus to the primary visual area of the cortex on the same side.
Visual information from the right half of each visual field is con- veyed to the left side of the brain, and visual information from the left half of each visual field is conveyed to the right side of the brain, as follows:
optic nerve II
Visual signals in the retina undergo considerable processing at synapses among the various types of neurons in the retina (horizontal cells, bipolar cells, and amacrine cells; see Figure 17.10). Then, the axons of retinal ganglion cells provide output from the retina to the brain, exiting the eyeball as the ____________.
sympathetic
Visualizing body changes that occur during "E situations" such as exercise, emergency, excitement, and embarrassment will help you remember most of the ____________ responses
changes in pupil size, dilation and constriction of blood vessels, adjustment of the rate and force of the heartbeat
What are examples of some autonomic motor responses?
terminal ganglia
What are the associated ganglia of the parasympathetic division?
Sympathetic trunk ganglia, prevertebral ganglia
What are the associated ganglia of the sympathetic division?
smooth muscle, cardiac muscle, glands
What are the effectors of the autonomic nervous system?
skeletal muscles
What are the effectors of the somatic nervous system?
excitation in some receptors and inhibition in others, increased sweating, Inhibition leads to relaxation leads to vasodilation
What are the effects of receptor activation for muscarinic receptors?
excitation leads to impulses in postganglionic neurons, epinephrine and norepinephrine secretion, excitation leads to contraction
What are the effects of receptor activation for nicotinic receptors?
Excitation leads to contraction, which causes vasoconstriction, dilation of pupil, and closing of sphincters, Secretion of K+ and water, Increased sweating
What are the effects of receptor activation for α1 receptors?
Inhibition leads to relaxation leads to vasodilation, decreased insulin secretion, inhibition of digestive enzyme secretion, aggregation to form platelet plug
What are the effects of receptor activation for α2 receptors?
excitation leads to increased force and rate of contraction, renin secretion, antidiuretic hormone secretion, breakdown of triglycerides leads to release of fatty acids into blood
What are the effects of receptor activation for β1 receptors?
inhibition leads to relaxation which causes dilation of airways, vasodilation, and relaxation of organ walls, inhibition leads to relaxation, glycogenolysis
What are the effects of receptor activation for β2 receptors?
thermogenesis
What are the effects of receptor activation for β3 receptors?
celiac ganglion, superior mesenteric ganglion, inferior mesenteric ganglion, aorticorenal ganglion, renal ganglion
What are the five major prevertebral ganglia?
Integral proteins in postsynaptic plasma membranes; activated by the neurotransmitter norepinephrine and the hormones norepinephrine and epinephrine.
What are the major locations of adrenergic receptors?
Integral proteins in postsynaptic plasma membranes
What are the major locations of cholinergic receptors?
Effectors innervated by parasympathetic postganglionic neurons, Sweat glands innervated by cholinergic sympathetic postganglionic neurons, Skeletal muscle blood vessels innervated by cholinergic sympathetic postganglionic neurons
What are the major locations of muscarinic receptors?
All sympathetic and parasympathetic preganglionic neurons release ACh. Most sympathetic postganglionic neurons release NE; those to most sweat glands release ACh. All parasympathetic postganglionic neurons release ACh. Chromaffin cells of adrenal medullae release epinephrine and norepinephrine.
What neurotransmitters are released by the autonomic nervous system?
tongue, taste bud, microvilli, increasing surface area
What organ? What is this cell? What is the organelle of the cell being pointed out? what is the function of this organelle?
posterior surface, simple cuboidal epithelial tissue
What surface of the cornea is indicated? What is the tissue? What is the crucial mechanism of this tissue?
vascular tunic
What tunic does this represent
fibrous tunic
What tunic is this representing?
nervous tunic
What tunic is this?
fibrous tunic, sclera
What tunic is this? What is the name for this tunic?
refraction
When light rays traveling through a transparent substance (such as air) pass into a second transparent substance with a different density (such as water), they bend at the junction between the two substances. This bending is called ___________. When light rays enter the eye, they are refracted at the anterior and posterior surfaces of the cornea. Both surfaces of the lens of the eye further refract the light rays so they come into exact focus on the retina.
light adaptation, dark adaptation
When you emerge from dark surroundings (say, a tunnel) into the sunshine, _____________ occurs—your visual system adjusts in seconds to the brighter environment by decreasing its sensitivity. On the other hand, when you enter a darkened room such as a theater, your visual system undergoes _____________—its sensitivity increases slowly over many minutes. The difference in the rates of bleaching and regeneration of the photopigments in the rods and cones accounts for some (but not all) of the sensitivity changes during these adaptations.
cerebral cortex, basal ganglia, cerebellum, brainstem, spinal cord
Where does the control of motor output of the somatic nervous system come from?
somatic senses and special senses
Where does the sensory input of the somatic nervous system come from?
a
Which of the following does not describe the autonomic nervous system? a) The effectors are primarily skeletal muscle b) the sympathetic division generally stimulates an organ c) preganglionic axons release ACh d) the parasympathetic division decreases heart rate
a
Which of the following effects does not occur during fight or flight response? a) The pupils constrict b) The airways increase in diameter c) Blood vessels to skeletal muscles dilate d) heart rate speeds up e) blood pressure increases
b
Which of the following sympathetic responses is mismatched with its body part? a) iris of eye- dilation of pupil b) liver- increased glycogen synthesis c) stomach- decreased motility d) hair follicles- contraction of arrector pili muscles e) adipose tissue- increased lipolysis
myopia, hyperopia
With _______________, only close objects can be seen clearly: Light rays coming in from distant objects are naturally focused in front of the retina and appear blurry Correction involves the use of a concave (negative) lens With _______________, only distant objects can be seen clearly: Light rays coming in from nearer objects are naturally focused behind the retina Correction involves the use of a convex (positive) lens
olfactory epithelium
With a total area of 5 cm2 (a little less than 1 in.2), the ________________ occupies the superior part of the nasal cavity, covering the inferior surface of the cribriform plate and extending along the superior nasal concha
presbyopia
With aging, the lens loses elasticity and thus its ability to curve to focus on objects that are close. Therefore, older people cannot read print at the same close range as can younger people. This condition is called ______________. By age 40 the near point of vision may have increased to 20 cm (8 in.), and at age 60 it may be as much as 80 cm (31 in.). This condition usually begins in the mid-forties. At about that age, people who have not previously worn glasses begin to need them for reading. Those who already wear glasses typically start to need bifocals, lenses that can focus for both distant and close vision.
biofeedback
__________, in which monitoring devices display information about a body function such as heart rate or blood pressure, enhances the ability to learn such conscious control of autonomic motor responses.
hearing, equilibrium
___________ is the ability to perceive sounds. The ear is an engineering marvel because its sensory receptors can transduce sound vibrations with amplitudes as small as the diameter of an atom of gold (0.3 nm) into electrical signals 1000 times faster than photoreceptors can respond to light. The ear also contains receptors for ____________, the sense that helps you maintain your balance and be aware of your orientation in space.
vision
___________, the act of seeing, is extremely important to human survival. More than half the sensory receptors in the human body are located in the eyes, and a large part of the cerebral cortex is devoted to processing visual information. In this section, we examine electromagnetic radiation, the accessory structures of the eye, the eyeball itself, the formation of visual images, the physiology of vision, and the visual pathway from the eye to the brain.
preganglionic neurons, postganglionic neurons
____________ convey nerve impulses from the CNS to autonomic ganglia, and _____________ relay the impulses from autonomic ganglia to visceral effectors.
autonomic
____________ motor neurons regulate visceral activities by either increasing (exciting) or decreasing (inhibiting) ongoing activities in their effector tissues.
audition
____________, the process of hearing, is accomplished by the organs of the ear. The ear is an engineering marvel because its sensory receptors can transduce sound vibrations with amplitudes as small as the diameter of an atom of gold into electrical signals 1000 times faster than the eye can respond to light.
Sound waves
_____________ are alternating high and low pressure regions traveling in the same direction through some medium (such as air). They originate from a vibrating object in much the same way that ripples arise and travel over the surface of a pond when you toss a stone into it. The frequency of a sound vibration is its pitch. The higher the frequency of vibration, the higher is the pitch. The sounds heard most acutely by the human ear are those from sources that vibrate at frequencies between 500 and 5000 hertz. The entire audible range extends from 20 to 20,000 Hz. Sounds of speech primarily contain frequencies between 100 and 3000 Hz, and the "high C" sung by a soprano has a dominant frequency at 1048 Hz. The sounds from a jet plane several miles away range from 20 to 100 Hz. The larger the intensity (size or amplitude) of the vibration, the louder is the sound. Sound intensity is measured in units called decibels (dB). An increase of one decibel represents a tenfold in- crease in sound intensity. The hearing threshold—the point at which an average young adult can just distinguish sound from silence—is defined as 0 dB at 1000 Hz. Rustling leaves have a decibel level of 15; whispered speech, 30; normal conversation, 60; a vacuum cleaner, 75; shouting, 80; and a nearby motorcycle or jackhammer, 90. Sound becomes uncomfortable to a normal ear at about 120 dB, and painful above 140 dB.
supporting cells
_______________ are columnar epithelial cells of the mucous membrane lining the nose. They provide physical support, nourishment, and electrical insulation for the olfactory receptors, and they help detoxify chemicals that come in contact with the olfactory epithelium.
basal cells
_______________ are stem cells located between the bases of the supporting cells. They continually undergo cell division to produce new olfactory receptors, which live for only a month or so before being replaced. This process is remarkable considering that olfactory receptors are neurons, and as you have already learned, mature neurons are generally not replaced.
aqueous humor, scleral venous sinus
_______________ is produced at the ciliary body and flows first through the posterior chamber (of the anterior cavity of the eye). Traveling along the posterior surface of the iris it passes through the pupil to enter the anterior chamber. It proceeds along the anterior surface of the iris until it is reabsorbed into the _________________ (canal of Schlemm) and returned to the venous system.
olfaction
_______________ is the process of perceiving smells. Smell and taste are brought about through the interpretation of chemicals present in the environment
Adrenergic receptors
________________ bind both norepinephrine and epinephrine. The norepinephrine can be either released as a neurotransmitter by sympathetic postganglionic neurons or released as a hormone into the blood by chromaffin cells of the adrenal medullae; epinephrine is released as a hormone. The two main types of adrenergic receptors are alpha (α) receptors and beta (β) receptors, which are found on visceral effectors innervated by most sympathetic postganglionic axons. These receptors are further classified into subtypes—α1, α2, β1, β2, and β3—based on the specific responses they elicit and by their selective binding of drugs that activate or block them. Although there are some exceptions, activation of α1 and β1 receptors generally produces excitation, and activation of α2 and β2 receptors causes inhibition of effector tissues. β3 receptors are present only on cells of brown adipose tissue, where their activation causes thermogenesis (heat production).
electromagnetic radiation, electromagnetic spectrum
________________ is energy in the form of waves that radiates from the sun. There are many types of electromagnetic radiation, including gamma rays, x-rays, UV rays, visible light, infrared radiation, microwaves, and radio waves. This range of __(previous)__ is known as the _________________
autonomic motor neurons
________________ regulate visceral activities by either increasing (exciting) or decreasing (inhibiting) ongoing activities in their effector tissues (cardiac muscle, smooth muscle, and glands).
autonomic reflexes
_________________ are responses that occur when nerve impulses pass through an autonomic reflex arc. These reflexes play a key role in regulating controlled conditions in the body, such as blood pressure, by adjusting heart rate, force of ventricular contraction, and blood vessel diameter; digestion, by adjusting the motility (movement) and muscle tone of the gastrointestinal tract; and defecation and urination, by regulating the opening and closing of sphincters.
olfactory receptors, olfactory hairs
___________________ are the first-order neurons of the olfactory pathway. Each olfactory receptor is a bipolar neuron with an exposed knob-shaped dendrite and an axon projecting through the cribriform plate and ending in the olfactory bulb. The parts of the olfactory receptors that respond to inhaled chemicals are the ______________, cilia that project from the dendrite.
age-related macular disease
____________________, is a degenerative disorder of the retina in persons 50 years of age and older. In this condition, abnormalities occur in the region of the macula lutea, which is ordinarily the area of most acute vision. Victims of advanced stages retain their peripheral vision but lose the ability to see straight ahead. For instance, they cannot see facial features to identify a person in front of them. This condition is the leading cause of blindness in those over age 75, afflicting 13 million Americans, and is 2.5 times more common in pack-a-day smokers than in nonsmokers. Initially, a person may experience blurring and distortion at the center of the visual field. In "dry" ______(same as previous blank)______, central vision gradually diminishes because the pigmented layer atrophies and degenerates. There is no effective treatment. In about 10% of cases, dry _____(same as previous)_____ progresses to "wet" _____(same as previous)_____, in which new blood vessels form in the choroid and leak plasma or blood under the retina. Vision loss can be slowed by using laser surgery to destroy the leaking blood vessels.
conjunctivitis
conjunctivitis is an inflammation of the conjunctival membrane which covers part of the front of the eye Conjunctivitis is caused most frequently by viral infections (pink eye) and allergy. It can also result from bacterial infections and many other irritants.
hyperopic, convex, converging
farsighted eyes are __________. In this condition, the individuals cannot see things that are close very easily. This condition is corrected with the use of __________ lenses . Are these diverging or converging as light passes through them?
myopic, concave, diverging
nearsighted eyes are __________. In this condition, the individuals cannot see things that are far away easily. This condition is corrected with the use of __________ lenses. Are these diverging or converging as light passes through them?
static equilibrium
refers to a state of balance relative to the force of gravity.
macular degeneration
results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It is a major cause of visual impairment in older adults (>50 years) It can become impossible to recognize faces, yet enough peripheral vision remains to allow other activities of daily life.
cornea, refracts 75% of light
structure? function?
iris, constricts and dilates pupil
structure? function?
enteric nervous system
the gastrointestinal tract has its own nervous system with intrinsic input, processing, and output that functions independently from the central nervous system activity but also can receive controlling input from the central nervous system. This is the specialized collection of nerves and ganglia forming a complex, integrated neuronal network within the wall of the gastrointestinal tract, pancreas, and gallbladder. This incredible nerve network contains in the neighborhood of 100 million neurons, approximately the same number as the spinal cord, and is capable of continued function without input from the central nervous system. This network of nerves and ganglia contains sensory neurons capable of monitoring tension in the intestinal wall and accessing the composition of the intestinal contents. These sensory neurons relay their input signals to interneurons within the enteric ganglia. The interneurons establish an integrative network that processes the incoming signals and generates regulatory output signals to motor neurons throughout plexuses within the wall of the digestive organs. The motor neurons carry the output signals to the smooth muscle and glands of the gastrointestinal tract to exert control over its motility and secretory activities.
photoreceptors
these are the cell bodies of the?
muscarinic receptors
these receptors are present in the plasma membranes of all effectors (smooth muscle, cardiac muscle, and glands) innervated by parasympathetic postganglionic axons. In addition, most sweat glands receive their innervation from cholinergic sympathetic postganglionic neurons and possess these receptors, which are so named because a mushroom poison called muscarine mimics the actions of ACh by binding to them.
true
true or false: Activation of nicotinic receptors by ACh causes depolarization and thus excitation of the postsynaptic cell, which can be a post- ganglionic neuron, an autonomic effector, or a skeletal muscle fiber. Activation of muscarinic receptors by ACh sometimes causes depolarization (excitation) and sometimes causes hyper- polarization (inhibition), depending on which particular cell bears the muscarinic receptors.
true
true or false: Most of the parasympathetic ganglia are located very close to the organs or intended action.
true
true or false: Most sympathetic postganglionic neurons are adrenergic.
true
true or false: The postganglionic axons typically terminate in several different visceral effectors, making the effects of sympathetic stimulation a widespread massive response. This is why anger can be hard to control - it is such a diffuse response.
true
true or false: most autonomic motor pathways consist of two motor neurons in series, that is, one following the other (Figure 15.1b). The first neuron (preganglionic neuron) has its cell body in the CNS; its myelinated axon extends from the CNS to an autonomic ganglion. The cell body of the second neuron (postganglionic neuron) is also in that same autonomic gan- glion; its unmyelinated axon extends directly from the ganglion to the effector (smooth muscle, cardiac muscle, or a gland). Alterna- tively, in some autonomic pathways, the first motor neuron extends to specialized cells called chromaffin cells in the adrenal medullae (inner portions of the adrenal glands) rather than an autonomic ganglion.
Typically near or within wall of visceral effectors
what are the ganglia locations of the parasympathetic nervous system?
Close to CNS and distant from visceral effectors
what are the ganglia locations of the sympathetic nervous system?
Usually two neuron pathway: Preganglionic neurons extending from CNS synapse with postganglionic neurons in autonomic ganglion, and postganglionic neurons extending from ganglion synapse with visceral effector. Alternatively, preganglionic neurons may extend from CNS to synapse with chromaffin cells of adrenal medullae.
what is the motor neuron pathway of the autonomic nervous system?
Both present; white rami communicantes contain myelinated preganglionic axons; gray rami communicantes contain unmyelinated postganglionic axons
white and gray rami communicantes in sympathetic division?
