Bio 318 Exam 1
o What are two ways tumors can result in anosmia?
Block nasal passage (nasal polyps) Disrupt neural pathway (brain tumor)
o What is the purpose of gamma motor nerve fibers?
Contract intrafusal fibers Keep fibers taught to perceive stretching
o Why do some reflexes exist only in infants and not in healthy adults?
Development and myelination of NS takes time Reflexes are beneficial to survival during infancy Evolutionary adaptations for infant success Nervous system takes time to develop, unmyelinated axons and incompletely integrated synapses
o How do allergies and the common cold cause anosmia?
Excess mucus covers/blocks sensory receptors
What are two main differences between graded and action potentials?
Graded = short distance; has to come first • Ligand-gated • Signal decreases in strength Action potential = long distance • Voltage gated • Constant strength in signal Ion channel type and strength over distance
o What is an example of a physiological process under sympathetic ( fight or flight ) control?
Increasing heart rate, breathing rate, etc.
o A patient has been experiencing hearing-related issues. The patient can hear fine, but is not physically responding to loud, unexpected, directional sounds when tested by the doctor. What structure could be damaged?
Inferior colliculus = auditory reflexes
o What tract carries motor information to your hand after holding it over a flame?
Lateral corticospinal tract
o A patient was recently involved in a car accident on the safest road in Lafayette, Pinhook Rd. The patient received a blow to the upper back region during the accident and is unable to feel positional sensation in his left arm & hand. What is a plausible structure that may have been damaged? What part of the brain would you expect is not receiving normal signals?
Left cuneate fasciculus, right cerebral cortex (motor & somatosensory)
o What type of receptor is a hair cell?
Mechanoreceptor • Bent, physically open up the channel
o A patient has accidentally been injected with curare (blocks Ach receptors on skeletal muscle). Why is the patient still able to move his/her eyes?
Motor neurons to eye muscles have electrical synapses Doesn't need ACH
o What would be an effect of a blocked neurotransmitter transport protein?
NT could remain in synaptic cleft - overstimulation of postsynaptic cell
o What neuroglial cell forms the myelin sheath in the PNS and CNS?
PNS= Schwann cells CNS= oligodendrocytes
o What taste sensations rely on concentration gradients of stimuli?
Salty, Sour
o What are different ways graded potentials can be strengthened?
Spatial summation, temporal summation, or both
o What tract relays temperature information from the skin through the CNS?
Spinothalamic tract
o A patient is having issues perceiving and adjusting to the day's 24-hour cycle. What region of the hypothalamus could most likely be damaged?
Suprachiasmatic nucleus
o What part of a neuron interprets graded potential summation in the initiation of a potential impulse?
Trigger zone (axon hillock)
o What type of muscle fiber would a neuron innervating a quadriceps muscle be classified as?
Type A: efferent signals to skeletal muscles
o Does multiple sclerosis have a wide range of effects/symptoms or narrow range? Why?
Wide range; depends on myelination of axon of which it affects; not specific to exact location of a neuron, specific to myelination; depends on what part of CNS is affected
RMP is ___mV
-70
what is RMP
-70mV
hyperpolarization is ___mV. during this __ channels are open ___ than needed because they take longer to open or close. the Na+K+ pumps begin again and take it up to ___
-90 K+ longer resting
if K+ was the only ion affecting the RMP, it would give the membrane a potential of ___mV. the RMP is much less permeable to __ than K+, but __ does diffuse __ its concentration gradient into the cell, attracted by the __ charge in the ICF. the Na+ leak is only a trickle, but it is enough to cancel some of the ___ charge and reduce the ___ across the membrane
-90 Na+ Na+ down negative negative voltage
with monoamines, ____ is removed from amino acids. 2 examples of monoamines. these involve a ___ _____ ____
-COOH epinephrine, dopamine second messenger system
as complex as synaptic events may seem, they typically require only ___ ms or so-an interval called ___ ____. this is the time from the arrival of a signal at the axon terminal a presynaptic cell to the beginning of an action potential in the postsynaptic cell.
0.5 synaptic delay
How long is the synaptic delay?
0.5 msec
the average neuron has ___-____ synapses
1,000-10,000
Nerve fibers leave sympathetic chain by 3 routes
1. spinal nerve route 2. sympathetic nerve route 3. splanchnic nerve route
how many cerebral peduncles are there and what do they surround
2 corpora quadragenita
the ANS output pathways, there are __ fibers that go to the target organ. where they synapse is called _____ which is a group of cell bodies. the preganglionic fiber is ____, but the postsynaptic fiber is ______. when you look at axon terminal, these systems implement _____ which are systems that have bulbs that are synaptic vesicles that contain NT. these release their content right over the muscle which allows effective cmcn between alot of cells in one region.
2 ganglion myelinated unmyelinated variscosities
neuropeptides are chains of __-___ AAs some are _____ 4 examples
2-40 hormones CCK (digestive system), substance P, endorphins, enkelphins
the blood brain barrier is __% of oxygen and glucose
20
what 2 things create differences in permeability
25x more K+ leak channels
the Na+ K+ pump pumps __ Na+ for every __ K+ and requires ___ because they are moving from a ___ to ___ concentration
3 2 ATP low high
the cord gives rise to ___ pairs of spinal nerves
31
what is the range we can see light
380-720 nm
about ___% of our neurons are interneurons
90%
formed by acetate and choline
ACh
muscarinic receptors bind to
ACh
6 types of neurotransmitters
ACh amino acid monoamines purines gases neuropeptides
the supraoptic secretes _____ which regulates the body's ___ content and is sent to the ___ pituitary
ADH water posterior
a motor NS that controls glands, cardiac muscle, and smooth muscle
ANS
neurons have a high demand for ____ and therefore ____ and ____. the constancy of blood supply is essentially critical to the NS because it uses ___% of glucose and oxygen. blood is also a source of ___ and _____ and damaged brain tissue is ______. to protect the brain, there is a ____ ____ ____ that strictly regulates what can get from the bloodstream into the tissue fluid of the brain. there are 2 points of entry that must be guarded: the blood ____ in brain tissue and capillaries of the ____ ___. the brain is protected by the BBB in the blood capillaries of the tissues due to ___ junctions between ____ cells. at the choroid plexuses, the brain is protected by the ___-___ barrier formed by ____ junctions between ___ cells. the BBB is highly permeable to water, glucose, and lipid-soluble substances. it is slightly permeable to sodium, potassium, chloride, urea and creatinine. the BBB is an obstacle to the delivery of _____ such as antibiotics and cancer drugs
ATP glucose oxygen 20 toxins macrophages blood brain barrier capillaries choroid plexus tight endothelial blood-CSF tight ependymal medications
What intrinsic property limits the rate at which neurons can initiate an impulse?
Absolute refractory period - Na+ channels inactivated
PNS is outside the ___
CNS
consists of the brain and spinal cord, which are enclosed and protected by the cranium and vertebral column
CNS
2 major anatomical subdivisions of nervous system
CNS and PNS
a clear, colorless liquid that fills the ventricles and canals of the CNS and bathes its external surface
CSF
the action potential goes in and activated the ____ channels, this enters, ___ form then fuse to the ____, ___ occurs, there is ___ potential in the postsynaptic neuron, the _____ binds to a specific ____ which opens ___-gated ___ channels, which creates a postsynaptic ___ which creates a ____ impulse
Ca++ vesicles membrane exocytosis graded neurotransmitter receptor ligand Na+ potential nerve
3 points of regulation of the BBB
Capillaries of brain tissue --> tight endothelial cells Choroid plexuses --> tight junctions of ependymal cells Large molecules --> transcytosis
The vagus nerve releases ACh on cardiac muscle. What is the effect and what type of receptor does it bind to?
Decrease HR, muscarinic receptor
if excitatory effects are greater than inhibitory, ____ occurs and the membrane is ___ threshold
EPSP below
2 types of postsynaptic potential
EPSP and IPSP
with sweet taste, there a ___ ____ receptors. sugar binds to the receptor which activates the ___ ____. this creates a ___ ____ cascade which ____ the cell.there are __ second messengers. ___ channel activated causes the release of the ____.
G protein G protein second messenger depolarizes 2 Ca++ NTs
the taste umami uses the ___ ____ mechanism. the chemical that binds to the receptor is __-______. this taste signifies that you are eating ___-rich foods
G protein L-glutamate protein
with bitter taste, there are also ___ ____ receptors. ____ occurs activating ______. ____ and ____ are also released. the membrane can _____ or ______. the taste buds for this is near the _____ tongue
G protein cAMP adenolcyclase IP3 DAG depolarize hyperpolarize posterior
photoreceptors work by ___ ____ activation. they absorb light which triggers a cascade and _____ photoreceptors
G protein depolarizes
with olfaction, bipolar neurons use the __ ___ mechanism to activate cells. this uses ___ potentials. axons synapse with ___ cells and they go to the ____ ___.
G protein graded mitral olfactory tract
sweet and bitter tastes rely on a ___ ___, ___ ___ system
G protein second messenger
Sugars, alkaloids, and glutamate stimulate taste cells by binding to receotors that activate ___ ___ and ___ ___ ____. Na+ and acids penetrate into the cell and ___ it directly. taste cells then release ____ that stimulate sensory dendrites at their base
G proteins second messenger systems depolarize NT
synapses that employ GABA as their neurotransmitter are called _____-___ synapses. amino acid neurotransmitters such as GABA work by the same mechanism as ACh; they bind to ion channels and cause immediate changes to its membrane potential. the GABA receptor, however, is a ___ channel. when it opens, ___ enters the cell and makes the inside even more ___ than the RMP. the neuron is therefore ____.
GABA-ergic chlorine Cl- negative inhibited
• Leg/trunk sensation and position
Gracile fasciculus
3 ascending tracts
Gracile fasciculus spinocerebellar Anterolateral
with sour taste, ___ concentration is higher outside the cell and can__ into the cell. this involves the same mechanism as in salty taste. the membrane ____ and __ are released
H+ diffuse depolarizes NTs
4 examples of neural pools
Heart rate, breathing rate, limb movement, smell
if inhibitory effects are greater than excitatory, ____ occurs and the membrane ____
IPSP hyperpolarizes
inhibitory NTs that bind to metabotropic receptors are linked to opening ___ or ___ channels. ___ goes in and hyperpolarizes. ___ goes in and _____.
K+ Cl- Cl- K+
___ ions have the greatest influence on the RMP because the membrane is more permeable to __ than any other ion. also in the ICF are a number of cytoplasmic anions that cannot escape from the cell because of their size or charge-____, _____, small ___ ___, ____, ____, and ____. K+ ions diffuse freely through ___ channels in the membrane, down their ____ ____ and out of the cell, leaving these cytoplasmic anions behind. As a result, the ICF becomes more and more _____ charged and exerts a stronger attraction for the ___ ions and attracts them back in the cell. eventually an _____ is reached in which K+ is moving ___ of the cell down its concentration gradient and __ the cell by electrical ____ at ___ rates. there is no further ___ diffusion of K+. At the point of equilibrium, K+ is about __ times as concentrated in the ICF as in the ECF.
K+ K+ phosphates sulfates organic acids proteins ATP RNA negatively K+ equilibrium out into attraction equal 40
o Gate o Delayed opening triggered at threshold
K+ channels
___ is secreted by nearly all sympathetic postganglionic fibers. nerve fibers that secrete it are called ____ fibers and the receptors are called ____ receptors. there are 2 types of receptors: __-_____ and __-____
NE adrenergic adrenergic alpha-adrenergic beta-adrenergic
___ leaks into the cell and ___ leaks out, but the ___ ___ ___ compensates for this leakage. it pumps __Na+ out of the cell for every __ K+ it brings in, consuming __ ATP for each exchange cycle. the RMP of __mV is the net effect of all these ion movements-__ diffusion out of the cell, ___ diffusion inward, and the ___ ___ ___ continually offsetting this ion leakage. the Na+ K+ pump accounts for about ___% of the ATP requirement of the NS. every signal generated by a neuron slightly upsets the distribution of Na+ and K+, so the pump must work ____ to restore equilibrium. this is why nervous tissue has one of the highest rates of ___ consumption of any tissue in the body and why it demands so much glucose and oxygen
Na+ K+ Na+ K+ pump 3 2 1 -70 K+ Na+ Na+ K+ pump 70 continuously ATP
salty is produced by metal ions such as ___ and ___. since their salts are vital ____, there is obvious value in our ability to taste them and in having an appetite for salt. electrolyte intake is also important in the ____ regulation of the body's fluid balance
Na+ K+ electrolytes osmotic
with salty taste, there is high ____ outside receptor cells. ___ diffuses into cells which causes the membrane to _____. after, ___ are released and the neuron is stimulated
Na+ Na+ depolarize NTs
physical deformation of cell membrane triggers ___ channels to open. something must _____ open them
Na+ physically
during repolarization, ___ channels are inactivated, ___-gated ___ channels open, ___ moves out of axon, away from the neuron which causes the charge inside to be more _____
Na+ voltage K+ K+ negative
in saltatory conduction, ___ rushes in and pushes ions towards the next node causing the __-gated channel to ___. this process then ___ all the way down the axon. ____ blocks ___ attraction across the membrane
Na+ voltage open repeats myelin charge
what 3 types of channels are the most important
Na+ and K+ leak
more complicated due to refractory period activation and inactivation gates
Na+ channels
How is the resting membrane potential achieved following an action potential?
Na+/K+ pump, leak channels (K+ is most important)
consists of all the rest; it is composed of nerves and ganglia
PNS
• Limbs, posture control
Reticulospinal
____ and ___ are proteins that are located inside photoreceptors that are pigmented
Rhodopsin & opsins
3 general classes of neurons
Sensory (afferent) neurons Interneurons Motor (efferent) neurons
• Turing head reflex
Tectospinal
• Respond to tilt, keep balance
Vestibulospinal tract
Damage to the _____ nerve could result in defects of eye movement.
abducens
o No neuron can fire another axon potential, cannot be generated o No continuous AP all the time, have to have gaps o After half a ms, Na+ inactivation gates are shut
absolute refractory period
the ______ is a period of time in which a neuron is producing an AP and cannot respond to another stimulus of any strength
absolute refractory period
ACh is ___ + ____ commonly observed at the _____ junction
acetate choline neuromuscular
enzyme that breaks down ACh
acetylcholinesterase
how does enzyme degradation break down ACh
acetylcholinesterase (present near postsynaptic cell) and breaks down ACH into choline and acetate
graded potentials have to be strong enough if they want to trigger a(n) ____ potential
action
in audition, sound waves are transmitted into ____ potentials
action
If graded potential is "strong" enough, it will trigger a(n)
action potential
• Long distance signaling • Constant strength
action potential
an ___ ___ is a more dramatic change produced by voltage-gated ion channels in the plasma membrane. they only occur when there is a high enough ____ of voltage-gated channels. if an excitatory local potential spreads all the way to the trigger zone and is still strong enough when it arrives, it can __ these channels and generate an ___ potential. they are produced by ___-gated channels on the trigger zone and axon, always begins with ____, is ___ or ____: either does not occur at all or exhibits the same voltage regardless of stimulus strength, is ___: goes to completion once it begins, is self-_______: has effects a great distance from point of origin, and the signal maintains the same ____ regardless of distance
action potential density open action voltage depolarization all or none irreversible propagating strength
epsp encourages ___ ___. the neurotransmitter causes the membrane to ___. you typically need more than one/one epsp for an action potential to occur
action potential depolarize more than one
ipsp prevent ___ ___. the neurotransmitter causes the membrane to ______. usually, ___ channels open and ___ flows into the neuron making it more ____
action potentials hyperpolarize Cl- Cl- negative
normally, both systems are ___. they exhibit a background rate of activity called ____ ____ and the balance between sympathetic tone and parasympathetic tone shifts in accordance with the body's changing needs. parasympathetic tone maintains ___ muscle tone in the intestines and holds the resting ___ ___ down to about 70-80 bpm. if the parasympathetic vagus nerves to the heart are cut, the heart beats at its own intrinsic rate of about ___ bpm. sympathetic tone keeps most BV partially ____ and thus maintains ____ ____. a loss of sympathetic tone can cause such a rapid drop in BP that a person goes into ____ and may ____. neither division has universally excitatory nor inhibitory effects. the sympathetic excites the ____, but inhibits ____ and ____ functions, whereas the parasympathetic has the ____ effects.
active autonomic tone smooth HR 100 constricted blood pressure shock faint heart digestive urinary opposite
2 examples of purines
adenosine ATP
epinephrine is secreted by
adrenal medulla
the ___ ___ is a sympathetic ganglion. it consists of modified ____ neurons without dendrites or axons. sympathetic preganglionic fibers penetrate through the cortex and ____ on these cells. when stimulated, it secretes a mixture of hormones into the blood such as _____ and ____. these hormones together are called ____
adrenal medulla postganglionic terminate epinephrine norepinephrine catecholamines
the ____ ____, ____ ___, and many ___ ___ receive only S fibers. the most significant example of control without dual innervation is regulation of _____ ____ and routes of ____ ____. an increase in firing rate constricts a vessel by increasing ____ muscle contraction and vice versa. the blood pressure in the vessel, pushing ___ on its wall, then ___ the vessel. the S alone exerts ___ effects on the vessels. S control of vasomotor tone can shift blood flow from one organ to another according to ___ needs of the body. in times of emergency, stress, or exercise, the __ muscles and ___ receive a high priority and the S ___ the arteries that supply them. processes such as ______, ____ absorption, and __ formation can wait; thus the S constricts arteries to the ___ tract and ____. it also reduces blood flow through the ____, which may help minimize bleeding in the event that the stress-producing situation leads to injury. since there is not enough blood in the body to supply all the organ systems equally, it is necessary to divert blood away from some organs in order to supply an adequate amount to the muscular system.
adrenal medulla sweat glands blood vessels blood pressure blood flow smooth pressure dilates opposite changing skeletal heart dilates digestion nutrient urine GI kidneys skin
Certain nerve fibers are called _____ fibers because they secrete norepinephrine.
adrenergic
an _____ synapse employs the neurotransmitter norepinephrine (NE), also called noradrenaline. NE, other monoamines, and neuropeptides act through ____-messenger systems such as _____. the receptor is not an ion channel but a transmembrane protein associated with a __ ____ on the inner face of the membrane. the unstimulated NE receptor is bound to a __ ____. binding of NE to the receptor causes the __ ____ to ____ from it. the __ ____ binds to adenylate cyclase and activates this enzyme, which converts ATP to ____. ____ can induce several alternative effects in the cell. one effect is to produce an internal chemical that binds to a ___ -gated ion channel from the inside, opening the channel and ___ the cell. another is to activate preexisting cytoplasmic enzymes which can lead to diverse _____ changes. yet another is for cAMP to induce genetic ___, so that the cell produces new enzymes leading to diverse metabolic effects
adrenergic second cAMP G protein G protein G protein dissociate G protein cAMP cAMP ligand depolarizing metabolic transcription
Norepinephrine is considered ______. it is released at the _____ _____. its 2 receptors are ____-adrenergic receptors and ____-adrenergic receptors.
adrenergic sympathetic postganglion alpha beta
Neurons that convey information to the CNS are called sensory, or ______, neurons.
afferent
the sensory input is sensed by a receptor and the signal is brought to the brain by an _____ neuron
afferent
towards CNS
afferent
the RF helps regulate _____. it has projections into the _____ and controls signals reaching the _____. if you damage your RF, you can go into a ___
alertness thalamus cerebrum coma
bitter taste comes from ____. examples are bitter plant products such as ___ and ____. bitter plants are ___ to some organisms, but can also be _____.
alkaloids coffee hops toxic antibacterial
where is the conduction zone? what affects the rate of conduction?
along the rest of the axon size and myelination
recorded in the parito-occipital area awake and resting, with the eyes closed and mind wandering
alpha
4 waves in an EEG
alpha beta theta delta
in the spinal cord, these fibers synapse directly with the ___ motor neurons that return to the muscle thus forming _____ reflex arcs. thats is, there is only one synapse between the afferent and efferent neuron so there is little synaptic delay and a very prompt response. the alpha motor neurons excite the quads, making it ___ and creating the knee ___
alpha monosynaptic contract jerk
extrafusal fibers involved in a muscle spindle are called ___ ___ fibers
alpha motor
o Relayed back to muscles; tell fibers to contract or relax o Contract actual muscle
alpha motor neurons
glutamate, GABA
amino acids
our ability to distinguish differences in loudness and pitch stems from the fact that the cochlea responds differently to sounds of different ____ and ____. a loud sound vibrates a longer segment of the ___ ___ and thus excites a greater number of ___ ___
amplitude frequency basilar membrane hair cells
Anger, fear Primal reactions
amygdala
inhibitory NTs binding to ionotropic receptors have ___ channels because they want to ____ the membrane
anion hyperpolarize
common diagnosis of damage to olfactory membrane the loss of smell mostly temporary, but can be permanent
anosmia
• One muscle does the opposite of the other • Ex: bicep and triceps
antagonist
____ effects oppose each other. for example, the sympathetic speeds ___ the heart and the parasympathetic speeds it ___. the S ____ digestion and P ___ it. S ___ the pupil and P ___ it. in some cases, these effects are exerted through dual innervation of the same effector cells, as in the ____, where nerve fibers of both divisions terminate on the same ___ cells. in other cases, antagonistic effects arise because each division innervates different effector cells with ____ effects on organ function. in the iris of the eye, S fibers innervate pupillary ___ cells and P fibers innervate ___ cells.
antagonistic up down inhibits stimulates dilates constricts heart muscle opposite dilator constrictor
lesions on the hippocampus create ___ ___ where you dont lose memory, but one is unable to form new memories moving forward
anterograde amnesia
lesions of the hippocampus can cause profound ____ ____. experiments that show the removal of the hippocampus showed no effects on ____ or _____ memory, but left him with the inability to form ____ ___. he could still learn new ____ skills which show that ____ and ____ memory involve separate brain regions. other parts of the brain involved in memory include the ____, with a role in learning motor skills, and the _____, with a role in emotional memory
anterograde amnesia intelligence explicit new memories motor explicit implicit cerebellum amygdala
• Spinothalmic and spinoreticular tracts o Spinal cord thalamus cortex o Spinal cord reticular formation • Sensation (light touch, pain, temperature, pressure)
anterolateral
on a sagittal plane, the cerebellar white matter exhibits a branching pattern called
arbor vitae
what is the white matter of the cerebellum
arbor vitae
Spatial and temporal summation are/are not mutually exclusive. can they happen at the same time?
are not yes
areas of cortex that ID or interpret sensory info
association
how is bitter taste an evolutionary adaptation
association of bitter taste with a bad taste body's way of preventing us from digesting something toxic
connect different regions within the same hemisphere link perceptual and memory centers of the brain
association tracts
o Connect regions in same hemisphere
association tracts
cover brain surface and nonsynaptic regions of neurons; form supportive framework in CNS; induce formation of BBB; nourish neurons; produce growth factors that stimulate neurons; communicate electrically with neurons and may influence synaptic signaling; remove K+ and some neurotransmitters from ECF of brain and spinal cord; help to regulate composition of ECF; form scar tissue to replace damaged nervous tissue
astrocytes
___ binds only to muscarinic receptors and ___ to only nicotinic receptors
atropine curare
hearing
audition
Integrate auditory stimuli
auditory association
audition begins at the ____ which is the cartilage external ear and sound waves enter the ear through the ___ ___ which funnels sound into the ear. the sound waves then vibrates the ____ ____ also known as the eardrum in the middle ear. this then vibrates 3 bones in the middle ear: ____, ____, and ______. the function of these bones is to pick up sound waves and ____ them and continue the vibration into the inner ear. next, the sound waves hits the _____ in which the stapes is in contact with in the inner ear. the soundwave becomes a ____ wave. the waves goes up to the ____ and excite the ___ receptor cells
auricle ear canal tympanic membrane malleus, incus, stapes amplify vestibule fluid cochlea hair
____ NS carries signals to gland, cardiac muscle, and smooth muscle. we have no voluntary control over these effectors and it operates at an unconscious level
autonomic
_____ ____ is a state of continual background activity of the S and P divisions
autonomic tone
alpha waves show when one is ___, but _____ with your eyes ____, not concentrating on any one subject or task. which 2 lobes are involved?
awake resting closed parietal occipital
specialized for rapid conduction of nerve signals to points remote from the soma
axon
the place where the axon originates; trigger zone
axon hillock
where is the trigger zone? at this point, ___ potentials are summed up. if the stimulus is strong enough, a(n) ____ potential is produced
axon hillock graded action
the trigger zone of a neuron consists of its ______ and ________
axon hillock, initial segment
at the end of the axon, there are ___ ___ which forms a ____ with the next cell and contains ____ _____ full of neurotransmitter
axon terminals synapse synaptic vesicles
the white matter surrounds the grey matter. it consists of bundles of ____ that course up and down the cord and provide avenues of ______ between different levels of the CNS. these bundles are called ____.
axons communication columns
the medial aperatures are located at the ___ of the brain. the lateral aperatures are located on the sides of the ___ ventricle
back 4th
where are photoreceptors located
back of the retina
the CSF protects the brain from ____. buoyancy makes the brain _____ and without this the brain would ___ itself. CSF also inhibits various ___ from entering brain
bacteria float crush chemicals
meningitis is the ___ or ___ invasion of the CNS and can come through the ___ and ____ due to them being connected to the ____ nerve and tract to the brain. ___ and ____ mater most affected. it can spread to brain ____ just below the layers. it is diagnosed by drawing ___ in a ___ ____
bacteria viral nose throat olfactory pia arachnoid tissue CSF spinal tap
meningitis is caused by a variety of ____ and ____ that invade the CNS by way of the ___ and ____, often following respiratory, throat, or ear infections. the ___ and ___ mater are most affected and from here the infection can spread to ____ ____. signs and symptoms include high fever, stiff neck, drowsiness, intense headache, and vomiting. it is diagnosed by examining ____ for bacteria and WBC. the CSF is obtained by ____ puncture
bacteria viruses nose throat pia arachnoid nervous tissue CSF lumbar
cochlear hair cells rest on the
basilar membrane
each upward movement of the _____ ____ pushes the inner hair cells closer to the stationary ____ ____. this forces the stereocilia to bend in the direction of the ____ one. each stereocilia has a tip link connecting it to an ____ ____ at the top of the next shorter stereocilia. when the taller one bends over, it pulls the channel ____. ____ ions flow into the cell and ___ it. the hair cell releases a burst of ____, exciting the sensory processes of the ___ ____ cells below it. thus a signal is generated in the ____ ____ and transmitted to the brain.
basilar membrane tectorial membrane tallest ion channel open K+ depolarize NTs cochlear nerve cochlear nerve
frontal-parietal area mental activity and sensory stimulation
beta
the suprachiasmatic deals with the ____ ___ or the day/night cycle. it also regulates ____ cycles and communicates with the ___ nucleus
biological clock reproductive preoptic
2 projections coming off the cell body
bipolar
one axon and one dendrite olfactory cells, retina, and inner ear
bipolar
the retinal ganglion cells' dendrites and cell bodies pick up signal from ___ neurons. the axons of ganglion cells travel to get to ___ nerve and this depends on where they are ____. these pass through the ___ ____, to the ____ ___, then to the ____ ____ where the nerves cross, and then become ___ ____. these go to the ___ ____ nucleus to the ___ ___ in the occipital lobe where you receive visual info
bipolar optic located optic disk optic nerve optic chiasma optic tracts lateral geniculate striate cortex
• Photoreceptors communicate with these neurons • Relay info between 2 different cells o Classified as interneurons
bipolar neurons
the red nucleus contains ___ ____ and has tracts with the ____. it is involved with ___ motor control
blood vessels cerebellum fine
the autonomic effects on glandular secretion are often the indirect results of action on ___ ___. many glandular secretions begin as a ___ of the blood, which is then modified by the gland cells. increasing blood flow through a gland such as a ___ or ___ gland tends to increase _____ and vice versa. sympathetic effects tend to last ____ than parasympathetic effects. after a parasympathetic secretes ACh into a synapse, it is quickly broken down by ______ and its effects only last a few ___. some parasympathetic fibers relax BV by stimulating endothelial cells to release ___ ____, which inhibits ___ muscle tone in the vessel wall, thus allowing the vessel to dilate. this increases blood flow through the vessel.
blood vessels filtrate salivary sweat secretion longer acetylcholinesterase seconds nitric oxide smooth
in dual innervation, an organ receives nerve fibers from one/both divisions. this has more of a _____ effect such as in heart muscle cells, but can also be ______ such as in eye muscle cells.
both antagonistic cooperative
the parasympathetic's nerve fibers arise from the ____ and ___ region. somas of the preganglionic fibers are located in the ____, ____, ___, and in the ____ region. this division has ____ preganglionic fibers, reaching almost all the way to the target cells, and ___ postganglionic fibers that cover the rest of the distance. this division has _____ postganglionic than preganglionic. this division is ____ in its stimulation of target organs.
brain sacral midbrain pons medulla sacral long short fewer selective
in the parasympathetic, neurons leave near ____ or ____ region. they have ganglia near ___ ____ and have long _____ fibers. there is ____ of neurons closer to the organ and there are fewer ___ fibers which cause more ____ stimulation control. fibers are shorter/longer than in sympathetic. this targets the ___, ____, ___, and ___ system.
brain sacral target organs preganglionic divergence postganglionic specific shorter eye heart lungs digestive
a stretch reflex is mediated primarily by the ___ and is not strictly a spinal reflex, but a weak component of it is ___ and occurs even if the SC is severed from the brain. the spinal component can be more pronounced if a muscle is stretched very suddenly. this occurs in the reflexive contraction of a muscle when its tendon is tapped as in the ___ reflex.
brain spinal patellar
the stretch reflex is mediated by _____ but has a ____ ___ component. this depends on _____ _____
brain spinal cord reciprocal inhibition
2 parts of the CNS
brain and spinal cord
for research and clinical purposes, it is common to monitor electrical activity called ______ _____. these are rhythmic ___ changes resulting from synchronized ___ potentials in the superficial layers of the cortex. the recording, called the ________ is useful in studying normal brain functions such as sleep and consciousness, and in diagnosing degenerative brain diseases, metabolic abnormalities, brain tumors, trauma, etc. the complete and persistent absence of brain waves is a common clinical and legal criterion of ___ ___. there are 4 types of brain waves which are ___, ___, ___ and ____. they are distinguished by differences in ___ and ____.
brain waves voltage postsynaptic electroencephalogram brain death alpha beta theta delta amplitude frequency
the reticular formation is found in the ____ and is made up of the ____, ___, and ____
brainstem midbrain pons medulla
the motor pattern for speech is generated in an area of cortex called the _____ and then transmitted to the primary motor cortex to be carried out
broca
Motor part of speech
broca area
due to ___ of the CSF, the brain never sinks nor floats because the brain and CSF are similar in density.
buoyancy
3 functions of CSF
buoyancy, protection, chemical stability
3 purposes of CSF
buoyancy, protection, chemical stability
adregenic receptors classified by A1, B1, and B2 act by changing the level of ____ in the target cell
cAMP
Posttetanic potentiation of a synapse increases the amount of ________ in the axon terminal
calcium
o How can one neurotransmitter have opposite (ultimate) functions?
can bind to different receptor types
____ binds to temperature sensitive ion channels. it only binds to ion channels that are sensitive to temps over ____/____. it is bound for a ____ time and competes for temp ____ which can block _____ stimuli.
capsaicin 37C/98.6F long signal pain
___ muscle has a very strong ARP
cardiac
in the medulla the RF includes a ____ center which regulates heart beat, a ___ center which regulates BP and flow by dilating and constricting BV, and 2 ____ centers which regulate the rhythm and depth of breathing
cardiac vasomotor respiratory
excitatory NTs binding to ionotropic receptors have ____ channels because they want to ____ the membrane
cation depolarize
chemical synapses have no ___ to ___ contact. neurotransmitters have to be released through the ____ ___ which is a physical space. here, there is no conduction of impulses/conduction of impulses. an _____ signal causes a chemical signal and happens at a _____.
cell to cell synaptic cleft no conduction of impulses electrical synapse
with electrical synapses, impulses travel between adjacent ___. with electrical synapses, there is no physical ___, cells are connected through ___ junctions. their cytosols are also connected through the protein of gap junctions called _____ and the entire entity called _____ which is the direct connection between ____
cells gaps gap connexin connexons cytoplasm
____ ____is between premotor and primary motor
central sulcus
the soma of a mature neuron lacks a
centrioles
Signals from the inner ear for equilibrium project mainly to the __________ and several _________ nuclei concerned with head and eye movements and visceral functions. Some fibers of this system, however, are routed through the _________ to areas of association. this is the seat of _____ of our body movements and ____ in space
cerebellum brainstem thalamus consciousness orientation
the coordination of all these muscles and maintenance of equilibrium are mediated by the ______ and ____ _____
cerebellum cerebral cortex
the ____ is the largest part of the hindbrain and second-largest part of the brain as a whole. it consists of left and right _____ ____ that are connected. it has a surface cortex of ___ matter and a deep layer of ___ matter. this deep layer exhibits a branching, fernlike pattern called the ____ ____. each hemisphere has 4 masses of grey matter called ___ ____ embedded in the white matter. all input goes to the ___ and all output comes from the ___ ___. the cerebellum is connected to the brainstem by 2 pairs of stalks called ____ _____ that connects it to the ____, ____, and ____. it appears that its general role is in the evaluation of certain kinds of ___ input and monitoring muscle ______. the cerebellum is highly active when a person explores objects with the ____, such as when comparing the textures of 2 objects when looking at them. it is much more active when a person is required to solve a pegboard puzzle than when moving pegs randomly around the same puzzle board. people with lesions also have difficulty identifying different views of a ___ object as belonging to the same object. it is also a ____.
cerebellum cerebral hemispheres grey matter arbor vitae deep nuclei cortex deep nuclei cerebellar peduncles medulla, pons, midbrain sensory movement fingers 3D timekeeper
5 targets of the auditory pathway:
cerebellum (head/eye movement, muscle tone, posture) nuclei of oculomotor, trochlear, and abducens nerves (eye movements) reticular formation (adjusts breathing and blood circulation to changes in posture) spinal cord (vestibulospinal tracts; quick movements and balance) thalamus (body position and movement; motor control of head and body)
connects 3rd and 4th ventricles midbrain
cerebral aqueduct
what is caudal to the hypothalamus
cerebral aqueduct
Surface layer of brain grey matter
cerebral cortex
the olfactory tract is located in the ___ ___ and is involved in the ____ ____. sensory neurons for smell do not synapse in the ___ before it gets to the cortex, rather it goes straight up to the cortex. ___ chemicals can damage the ____ _____. neurons can be _____. axons form right next to/far away from the others.
cerebral cortex limbic system thalamus toxic olfactory membrane regenerated right next to the others
Bundle of nerve fibers that connect cerebrum to pons Carries corticospinal tracts moving limbs
cerebral crus
If the telencephalon was removed from a 5-week-old embryo, which of the following structures would fail to develop in the fetus?
cerebral hemispheres
two bulging structures that contain descending pyramidal motor tracts; midbrain
cerebral peduncles
the ____ is the largest and most conspicuous part of the human brain. it is the seat of ___ motor control and our most distinctly human mental process. it is composed of two ____ ____ separated by the ____ ____ but connected to the ____ ____. it consists of 4 lobes which are ____, ____, ___ and ___.
cerebrum voluntary cerebral hemispheres longitudinal fissure corpus callosum frontal parietal temporal occipital
how are charges separated
channels
ACh is a ____ neurotransmitter that uses a ___ synapse
chemical chemical
graded potentials are driven by ____ or ____ signals such as ____-____ channels, _______, or _____-____ channels
chemical mechanical ligand-gated neurotransmitters mechanical-gated
5 types of transduction receptors
chemical pressure vibration stretch photoreceptors
olfaction uses ___ stimuli. this is located in the ___ nasal cavity and involves the ___ ___. axons feed though the ____ bone of the ____ ____.
chemical superior olfactory bulb ethmoid cribriform plate
2 types of synapses
chemical and electrical
theta waves are only seen in ____ and very ___ adults. if there are abnormal amounts in adults, then they may be under ___ or have a ____
children tired stress disorder
a ___ synapse employs ACh as its neurotransmitter. ACh excites some postsynaptic cells such as ____ muscle and inhibits others such as ____ muscle. the arrival of a nerve signal at the axon terminal open ___-gated ___ channels. ___ enters the terminal and triggers ___ of the synaptic vesicles, releasing __. empty vesicles drop back into the cytoplasm to refilled with ___, while synaptic vesicles in the reserve pool move to the ___ sites and release their ____. ACh diffuses across the ___ ___ and binds to ___-gated channels on the postsynaptic neuron. these channels open, allowing __ to enter the cell and __ to leave. As Na+ enters, it spreads out along the inside of the membrane and _____ it, producing a local voltage shift called the ____ _____. if this is strong and persistent enough, it opens ___-gated ion channels in the trigger zone and causes the ____ neuron to fire.
cholinergic skeletal cardiac voltage Ca++ Ca++ exocytosis ACh ACh active ACh synaptic cleft ligand Na+ K+ depolarizes postsynaptic potential voltage postsynaptic
ACh has _____ receptors. which fibers secrete ACh? what 2 receptors are associated with ACh?
cholinergic preganglionic fibers in both ANS and postganglionic fibers in parasympathetic muscarinic nicotinic
the retina receives its oxygen supply from
choroid
trace the flow of CSF: 1. CSF produced and secreted by ___ ____ in the ____ ____ 2. CSF passes through the ____ ____ and goes to the ____ ____ 3. Choroid plexus in 3rd ventricle adds ___ 4. CSF goes through the ___ ___ and goes to the ___ ___ 5. Choroid plexus in 4th ventricle adds ____ 6. CSF leaves through the ____ and ____ ____ (hole/tunnel) or down ____ ____ of SC 7. CSF fills _____ _____, covers brain and SC surface 8. CSF enters _____ _____ through ___ ____ 9. CSF reabsorbed into ___ blood in ___ sinus
choroid plexus lateral ventricle interventricular foramen 3rd ventricle CSF cerebral aqueduct 4th ventricle CSF medial and lateral apertures central canal subarachnoid space arachnoid granulations arachnoid villi venous dural
the cochlear nerve leads away from the ____. this nerve joins the ___ nerve and the two together become the _____ nerve. each ear sends fibers to both sides of the ____. there they end in the cochlear nuclei that synapse with another neuron that ascends to the ___ ____ ____ of the pons. by way of the vestibulocochlear nerve, this issues the ___ fibers back to the cochlea that are involved in cochlear tuning. the ___ ____ help to locate the origin of a sound in space, process fluctuations in pitch that are important for such purposes as understanding another person's speech, and mediate the startle response and rapid head turning that occur in reaction to loud or sudden noises. the other neurons lead to the ____ and then to the ___ ___ ___ then to the ___ lobe which is the site of conscious perception of sound, and it completes the info processing. because of the extensive ____ in the auditory pathway, damage to the right or left auditory cortex does not cause a unilateral loss of hearing.
cochlea vestibular vestibulocochlear medulla superior olivary nucleus efferent inferior colliculi thalamus primary auditory cortex temporal decussation
cones sense
colors
injury to the RF can result in a __
coma
cross from one cerebral hemisphere to the other through bridges called commissures
commissural tract
o Bridges b/t hemispheres o Corpus callosum
commisural tracts
each paraventricular ganglion is connected to a spinal nerve by two branches called _____ ____. the preganglionic fibers are small myelinated fibers that travel from the spinal nerve to the ganglion by way of the ____ _____ which gets its color and name from myelin. unmyelinated postganglionic fibers leave the ganglion by way of the ____ _____, named for its lack of myelin. this ramus returns to the _______ ___. postganglionics that are ____ than preganglionics extend the rest of the way to the target
communicating rami white ramus grey ramus spinal nerve longer
the protective function of the flexor reflex requires more than a quick jerk like a tendon reflex, so it involves more ____ neural pathways. sustained contraction of the flexors is produced by a ____ ____-____ circuit in the spinal cord. this circuit is part of a _____ reflex arc-a pathway in which signals travel over many synapses on their way back to the muscle. some signals follow route with only a few synapses and return to the flexor muscles quickly. others follow routes with more synapses and therefore more ____, so they reach muscles later. the flexor muscles receive prolonged output from the spinal cord and not just one sudden stimulus as in a stretch reflex.
complex parallel after discharge polysynaptic delay
beta waves show when one is engaged in ____ mental activity and ___ stimulation. which 2 lobes are involved
concentrated sensory frontal parietal
• Determines which way ions flow • High to low without using energy
concentration gradients
the reason a cell has a RMP is that the ___ are unequally distributed between the ECF on the outside of the plasma membrane and the ICF on the inside. The RMP results from the combined effect of 3 factors: the diffusion of ions down their ___ ____ through the membrane; ____ ____ of the membrane, allowing some ions to pass more easily than others; and the electrical ___ of cations and anions to each other
concentration gradients selective permeability attraction
what is the key to understanding action potentials (2)
concentration gradients and ion channels
the spinal cord contains bundles of nerve fibers that ____ info up and down the cord, connecting different levels of the trunk with each other and with the brain. this enables sensory info to reach the ____, motor commands to reach the ____, and input received at one level of the cord to affect ___ from another level
conduct brain effectors output
if the graded potential reaches trigger zone and is strong enough, it will go down the _____ zone
conduction
neurons respond to stimuli by producing electrical signals that are quickly conducted to other cells at distant locations
conductivity
to perform their role, neurons must have the properties of excitability, secretion, and _____
conductivity
postsynaptic cells receive many signals and some can be ___
conflicting
protein found in gap junction
connexins
the parasympathetic division ____ the walls of the bladder but ____ the male internal urethral sphincter. it employs _____ for both purposes. the sympathetic division ____ most BV but _____ the bronchioles of the lungs and achieves both effects with ____.
contracts relaxes ACh constricts dilates norepinephrine
when a muscle is suddenly stretched, it "fights back" meaning it ____, increases ____, and feels ____. this response called the ____ ____ helps to maintain equilibrium and posture. when you tip your head forward, this stretches muscles at the back of your neck. this stimulates their ____ ____ which send signals to the cerebellum by way of the brainstem. the cerebellum integrates this info and ____ it to the cerebral cortex and the cortex sends signals back, via the brainstem to the ____. the muscles ___ and raise your head.
contracts tone stiff stretch reflex muscle spindles relays muscles contract
spinal nerve systems are _____ meaning the signal is interpreted on different sides
contralateral
input from many nerve fibers or neural pools is funneled to fewer intermediate or output pathways. for example, you have a brain stem respiratory center that receives info from other parts of your brain, blood chemistry sensors in your arteries, and stretch receptors in your lungs. the respiratory center can then produce an output that takes all of these factors into account and sets appropriate pattern of breathing
converging
o The medulla oblongata receives information from blood and blood vessels and integrates the information to determine how to alter breathing patterns. What type of neural pool is mostly involved with relaying this information?
converging - integrating
• Many neuron fewer neurons (as low as one) o Start with a bunch of neurons then go down to fewer
converging circuit
____ effects are seen when the 2 divisions act on different effectors to produce a unified overall effect. ___ is an example because the P stimulates ____ cells of the salivary glands to secret a watery. enzyme-rich secretion, while the S stimulates ___ cells of the same glands to secrete mucous. even when both divisions innervate a single organ, they do not always innervate it ____. for example, the P forms an extensive plexus in the wall of the ___ tract and exerts much ___ influence over it than the S does. in the ventricles of the heart, there is much ___ P than S innervation.
cooperative salivation serous mucous equally digestive more less
located in the midbrain; contains reflex centers for vision and auditory reflexes.
corpora quadrigemina
the midbrain contains the ____ ____ which splits into the ___ colliculi for visual reflexes such as visual attention and visually tracking moving objects and ___ colliculi for auditory reflexes such as turning the head in response to a sound and jumping when startled by a noise. the midbrain also consists of the ___ ___ - the two stalks that anchor the cerebrum to the brainstem. it also contains the ____ ____ which is named for its pink color from high density of BV. the cerebral aqueduct is encircled by the central grey matter that is involved with the _____ tract in controlling awareness of pain
corpora quadrigemina superior inferior cerebral peduncles red nucleus reticulospinal
the right and left cerebral hemispheres are connected to each other by a thick C-shaped bundle of fibers called
corpus callosum
the greatest majority of commissural tracts pass through the ____ ____. these tracts allow the two sides of the cerebrum to ____ with each other
corpus callosum communicate
the cerebellum and cerebrum both have their own ___ regions
cortex
• Fine limb movement • Cortex spinal cord
corticospinal
4 descending tracts
corticospinal reticulospinal tectospinal vestibulospinal
the largest group of descending fibers in the medulla is the ____ tracts. these carry motor signals from the cortex to the SC to stimulate skeletal muscles. a smaller ___ tract controls the neck muscles.
corticospinal tectospinal
the _______ sense fine motor control of limbs. the lateral decussates in the ___ and anterior decussates in the ___ ____
corticospinal medulla SC
an example of a projection tract
corticospinal tract
sensory pathway that innervates the brain
cranial nerve systems
trauma to the brain makes it move and can sever the _____ ____ which can damage the _____ ____. also, damage to the ___ lobe and ___ bone can cause anosmia to occur.
cribriform plate olfactory nerve frontal ethmoid
in the ____ reflex, contraction of flexor muscles in one limb is accompanied by the contraction of extensor muscles in the contralateral limb
crossed extension
the ____ ____ reflex is the contraction of extensor muscles in the limb opposite from the one that is withdrawn. to produce this reflex, branches of the ___ nerve fibers cross from the stimulated side of the body to the contralateral side of the SC. there, they synapse with _____ which excite or inhibit ___ motor neurons to the muscles of the contralateral limb
crossed extension afferent interneurons alpha
a flow of charged particles from one point to another
current
• Flow of charge between points • Flow down concentration gradient
current
the crossing of a nerve fiber or tract from one side to another
decussation
• Crossing of neurons to the opposite side in the CNS
decussation
several of the tracts undergo _____ as they pass up or down the SC meaning they cross over from the left to the right side. as a result, the left side of the brain receives ___ info from the right side of the body and sends ____ commands to that side while the right side of the brain senses and controls the ___ side of the body. a stroke that damages motor centers of the right side can cause paralysis of the ___ limbs. when the origin and destination of a tract are on the opposite side of the body, we say they are _____. when a tract does not decussate, its origin and destination are on the same side of the body and we call that ____
decussation sensory motor left left contralateral ipsilateral
adults in a deep sleep if in awake adults, there is serious brain damage
delta
typically neuronal response begins at a ____, spreads through the ___, travels down the ___, and ends at the ___ ____. the chemical (ligand) binds to ___ on a neuron. This opens ___-gated __ channels that allow ___ to flow into the cell. this inflow cancels some of the internal __ charge, so the voltage across the membrane at that point drifts towards ___. any such case in which the voltage shifts to a less negative value is called ______. the incoming Na+ diffuses for ___ distances along the inside of the membrane, creating a wave of ____ that spreads out from the point of stimulation. this short range change in voltage is called a ___ ____
dendrite soma axon axon terminal receptors ligand Na+ Na+ negative 0 depolarization short excitation local potential
Neurons recieve incoming signals by way of specialized extensions of the cell called.......
dendrites
primary site for receiving signals from other neurons
dendrites
where is the input zone for graded potentials
dendrites
name the 5 parts of a neuron
dendrites cell body axon hillock axon axon terminals
where is the reception zone? what senses the signal?
dendrites dendrites
Membrane potential closer to 0 from -70 mV
depolarization
Depolarization causes the membrane next to it to then ______ also Signal does not go backwards, because __+ channels are ____
depolarize Na inactivated
local (graded) currents _____. _____ helps to reach threshold.
depolarize summation
after the binding to a receptor, the cell _____ and ___ are released to ___ neurons. this produces a ___ potential on sensory neurons. if the graded potential is strong enough, an ____ potential is fired. the ___ cranial nerve controls the anterior __/3, the _____ cranial nerve controls the posterior __/___, and the ____ nerve which causes our gag reflex is in the most ___ region of the tongue
depolarizes NTs sensory graded action facial 1/3 glossopharyngeal 2/3 vagus posterior
The pyramids of the medulla contain
descending corticospinal tracts
in MS, the oligodendrocytes and myelin sheaths of the CNS _____ and are replaced by hardened ___ tissue. nerve ___ is disrupted and there is/is no cure.
deteriorate scar conduction is no
the speed at which a nerve signal travels along a nerve fiber depends on two factors: the ___ of the fiber and the presence or absence of ____. signal conduction occurs along the ___ of a fiber. large fibers have more ____ ____ and conduct signals more ____ than small fibers. myelin further _____ signal conduction.
diameter myelin surface surface area rapidly increases
How can different autonomic neurons have different effects?
different NTs different receptors
how do we have different effects of NTs and receptors?
different NTs have different end results different receptor types
• Allows flexibility in integrating input --> "decision"
differential regulation
simple ____ of a neurotransmitter takes it away from the gap/synaptic cleft
diffusion
neurotransmitters or their breakdown products simply diffuse away from the synpase into the nearby ECF ex: acetate CNS: ___ absorb NTs PNS: ____ ___ absorb NTs
diffusion astrocytes satellite cells
3 ways to remove NTs
diffusion enzyme degradation uptake by cells
____ of the pupil, ___ of the heart, enhanced ___ ___, and _____ result from sympathetic stimulation
dilation acceleration blood clotting piloerection
• Synapses where input neuron can cause AP in a neural pool • More synapses per postsynaptic cell
discharge zone
an individual neuron sends signals to multiple downstream neurons, or one neural pool may send output to multiple downstream neural pools. each of those neurons or neural pools many communicate with several more, so input from just one pathway may produce output through hundreds of others. such a circuit allows signals from one motor neuron of the brain, for example, to ultimately stimulate thousands of muscle fibers
diverging
• One neuron many downstream neurons o Diverging into more and more neurons
diverging circuit
4 types of neural circuits
diverging, converging, reverberating, parallel after discharge
neurotransmitters and receptors have different ____ and contrasting ____. this can occur ____ and ____ which can cause ___ or ___ effects.
divisions effects between within excitatory inhibitory
cocaine blocks _____ reuptake proteins. this is not ____ and stays _____, this stimulates the postsynaptic neuron _____. repeated doses makes the body release ___ which causes ______.
dopamine recycled longer longer less withdrawals
sensory nerve fibers carry info from somatic receptors to the ____ horn of the SC or brainstem. it then goes to the integrating center which is a point of synaptic contact between neurons in the ___ matter of the cord or brainstem. motor nerve fibers carry __ impulses to the muscles and then to the effector that carry out the ____
dorsal grey motor response
the core of the spinal cord consists mainly of two ____ ____, which extend towards the postereolateral surfaces of the cord, and two ____ ____ which extend toward the antereolateral surfaces. the right and left sides of the grey matter are connected by a median bridge called the ___ _____. in the middle of the commissure is the ____ ____, which is collapsed in most areas of the adult spinal cord, but some places remain open, lined with ependymal cells, and filled with CSF. the posterior horn receives ___ nerve fibers from the spinal nerves which usually synapse with networks of ____ in the horn. the anterior horn contains large ____ of ___ neurons whose axons lead out to the ___ muscles. an additional ___ ____ is visible on each side of the grey matter. it contains neurons of the ____ NS, which send their axons out of the cord by way of the anterior root along with somatic efferent fibers
dorsal horns ventral horns grey commissure central canal sensory interneurons somas motor skeletal lateral horn sympathetic
the ___ ganglion contains the somas of neurons that carry sensory signals to the SC
dorsal root
the signal must be propagated ___ the axon
down
2 types of innervation of the ANS
dual single
_____ _____ is a state in which a target organ receives both S and P fibers
dual innervation
Most of the viscera receive nerve fibers from both the sympathetic and parasympathetic divisions and thus are said to have ___ ____. in such cases, the 2 divisions may have either _____ or ____ effects on the same organ.
dual innervation antagonistic cooperative
3 meninges
dura mater, arachnoid mater, pia mater
motor output has ___ organs involved and produces a response with ____ neurons
effector efferent
Cells and organs that respond to commands from the nervous system are called...?
effectors
away from CNS
efferent
a difference in the concentration of charged particles between one point and another
electrical potential
if a neuron is to communicate with another cell, a signal has to travel to the __ of an axon. an unmyelinated fiber has ___-gated channels along its entire length. when an AP occurs at the trigger zone, __ enters the axon and diffuses for a __ distance just beneath the membrane. the resulting depolarization excites voltage-gated channels immediately distal to the AP. Na+ and K+ channels open and close just as they did at the trigger zone, and a new ___ potential is produced. by repetition, this excites the membrane distal to that. this chain reaction continues until the traveling signal reaches the end of the axon. because this produces an uninterrupted wave of electrical excitation all along the fiber, this mechanism is called ____ _____. note that an AP itself does not travel along an axon; rather, it stimulates the production of a new ___ ___ in the membrane just ahead of it. the ____ ____ is a traveling wave of excitation produced by self-propagating AP. No one AP travels to the end of the axon; the nerve signal is a ___ of AP, each triggering the next one ahead of it. if one AP stimulates the production of a new one next to it, you might think that the signal could also start traveling backward and return to the soma. this does not, however, because the membrane immediately behind the nerve signal is still in its ____ ____ and cannot be restimulated. the refractory period thus ensures that nerve signals are conducted in the proper direction, from the ___ to the ___ ____.
end voltage Na+ short action continuous conduction action potential nerve signal chain refractory period soma axon terminals
saltatory conduction is ____ efficient because it helps send a lot ___ signals in a __ amount of time
energy more short
Need ____ to separate charges; separated charges produces ____ energy
energy potential
is a neuromodulator that blocks the conduction of pain signals by second-order spinal neurons
enkephalin
the digestive tract has a semi-independent NS called the ____ NS
enteric
in the ANS, there is another division called the ____ NS which corresponds with the system that innervates the ____ tract. this system is _____ from the CNS because it has its own network of neurons. however, it has regulation by ____ and ____ fibers. it involves ____ muscle and ____ in the digestive tract. it has about ___ million neurons which makes it more complex/less complex than the CNS. it deals with 2 things: 1. ______ of the ___, _____, and _____ 2. secretion of digestive ____ and _____. there are 2 major types of intrinsic fibers involved: _____ nerve plexus and ____ nerve plexus.
enteric digestive independent PSNS SNS smooth glands 500 more complex movement esophagus stomach intestines enzymes acid submucosal myenteric
the digestive tract has a NS of its own called the ___ NS. it does not arise from brainstem or SC, but it innervates ____ muscle and ___. there are ____ million neurons in this system and it has its own ___ ___. the entire NS regulates the motility of the ____, ____, and ____ and the secretion of ___ ___ and ___. to function normally, these activities require regulation by the ____ and ___ systems
enteric smooth glands 500 reflex arc esophagus stomach intestines digestive enzymes acid sympathetic parasympathetic
Line cavities of the brain and spinal cord; secrete and circulate CSF
ependymal cells
The blood-CSF barrier is formed by
ependymal cells
the cerebellum deals with ____ and _____. it is very active in ____ exploration and in the __ aspect of objects. it also functions in ___ coordination. Helps provide ____ and ____ body movement
equilibrium balance tactile 3D time smooth, coordinated
all cells, especially neurons, are able to respond to stimuli/environmental changes
excitability
3 fundamental physiological properties that enable neurons to communicate with other cells
excitability conductivity secretion
some neurotransmitters are _____, some are ____, and for some the effect depends on what kind of ____ the postsynaptic cell has
excitatory inhibitory receptor
the same neurotransmitter can be ___ or ___ because it depends on the ____ structure
excitatory inhibitory receptor
alpha-adrengeric usually have ___ effects. the binding of NE to this receptor promotes ___ ___ and ____ dermal BV which works through _____ as a ____ ____, yet inhibits ____ motility which inhibits the synthesis of _____.
excitatory labor contractions constricts Ca++ second messenger intestinal cAMP
extend muscle
extensors
a presynaptic nerve fiber cannot cause other neurons in its _____ to fire, but it can make them more sensitive to stimulations from other presynaptic fibers
facilitated zone
• Input neuron needs help for AP
facilitated zone
spinal reflexes are ___ and require few ____. they are voluntary/involuntary and require _____. they are very ______. we test them to test the functionality of the _____.
fast neurons involuntary stimulation predictable CNS
electrical synapses are slower/faster?
faster
saltatory conduction is much ___ than unmyelinated transmission because myelin separates the ____
faster attraction
EPSP and IPSP do not determine whether or not a neuron ____, but only change the ___ of firing by stimulating or inhibiting the production of more APs.
fires rate
Differences in the volume of a sound are likely to be encoded by differences in _____ ______ in nerve fibers from the inner ear.
firing frequency
flex muscles
flexor
a ____ ____ is the quick contraction of flexor muscles resulting in the withdrawl of a limb from an injurious stimulus
flexor reflex
• Contraction of a flexor muscle
flexor reflex
the inner ear is ___ filled. the waves go into the _____ ____ and then the ____ _____ the fluid waves bend the ____ membrane and the location of where it hits is based on _____. ___ bend towards the longest and open ___ channels. this ____ the hair cell. this then triggers the ___ nerve and goes to the ____ to synapse. this is then sent to the ___ lobe for ____.
fluid scala vestibuli scala tympani basilar membrane frequency cilia ion depolarizes cochlear thalamus temporal interpretation
toxic chemicals such as ____ can block chemicals and cause anosmia
formalin
nerves emerge from the CNS through ___ of the skull and vertebral column and carry ___ to and from other organs of the body
formina signals
the most finely detailed vision occurs when an image falls on a pit in the retina called the
fovea centralis
Bare dendrites that associate pain, temperature, tickle, itch, and some touch sensations are: pain, heat, cold
free nerve endings
dendrites that pick up on stimuli
free nerve endings
hot and cold stimuli are detected by
free nerve endings
the key of stimulus encoding is the ___ of ___ potentials.
frequency action
A lesion in which lobe of the cerebrum is most likely to cause a radical alteration of the personality?
frontal
conscious, abstract thought; explicit or declarative memory; cognitive and emotional processes such as mood, motivation, foresight, planning, decision making, emotional control, and judging socially appropriate behavior; speech production; voluntary motor control
frontal lobe
the ___ does not receive input from the eyes
frontal lobe
developmentally dynamic reflexes in adults are called ___ ___ ___. it is called this because the pathways integrate with ___ region of brain
frontal release signs frontal
Different thicknesses of cortex is based on ____ of area. ex: 4 th layer receives a lot of ___ info so it is thicker
function sensory
sarcomere distribution depends on ____ ____ fibers which are ___ fibers
gamma motor intrafusal
a stretch reflex requires the action of ____ to prevent an antagonistic muscle from interfering with the agonist
gamma motor neurons
nerve fibers that adjust the tension in a muscle spindle
gamma motor neurons
o Collections of cell bodies of neurons (somas)
ganglia
outside the cns somas of neurons are clustered in swellings called
ganglia
a cluster of neurosomas outside the CNS
ganglion
a knotlike swelling in a nerve where the cell bodies of peripheral neurons are concentrated
ganglion
the only cells of the retina that generate AP
ganglion cells
motor neuron goes to ____ ____. the white rami is ______ and the gray rami is _____. which can ____ with each other.
ganglion chain white rami gray rami communicate
nitric oxide (NO) and carbon monoxide inorganic synthesized as needed rather than stored in synaptic vesicles; they simply diffuse out of the axon terminal rather than being released by exocytosis; and they diffuse into the postsynaptic neuron rather than bind to a surface receptor
gases
the thalamus is the ___ to the cerebral cortex. Input to ______ passes through here such as ____, ____, ____, ____, ____, _____. it is a ____ and ____ relay center. it has ___ control pathways and also has a ____ function.
gateway cerebrum Smell, vision, taste, touch, pressure , temp. afferent efferent motor memory
receptors throughout the body
general receptors
employ widely distributed receptors in the skin, muscles, tendons, joints, and viscera
general senses
amino acid NTs include ____ and ___. these bind to ____
glutamate GABA channels
the ___ ___ carries signals from the midthoracic and lower parts of the body. it carries sensations of limb and trunk ___ and ____. it decussates in the ____. this is the same for the ____ ____
gracile fasciculus position movement cuneate fasciculus
local potentials are ___, meaning they vary in voltage according to the strength of the stimulus. local potentials get ____ as they spread from the point of origin. local potentials are ___, meaning that if stimulation ceases, cation diffusion out of the cell quickly returns the membrane voltage to its resting potential. local potentials can be ___ or ____. local potentials are produced by ___ channels on the dendrites and soma.
graded weaker reversible excitatory inhibitory gated
• Done through neurotransmitters • Chemical process through ligand-gated channels • Short distance signaling • Variable strength • Small region of membrane
graded potentials
what are failed initiations
graded potentials that were not strong enough to trigger a response
neural integration is carried out in the ___ matter of the cerebrum, which is found in 3 places: the ____, ___ ___, and ____ ____. the ____ ___ is a layer of grey matter covering the surface of the hemispheres. it possesses two types of neurons: ____ cells and ____ cells.
grey cortex basal nuclei limbic system cerebral cortex stellate pyramidal
the spinal cord consists of ___ and ___ matter. ___ matter lacks myelin and contains the somas, dendrites, and proximal parts of the axons of neurons. it is the site of ____ contact between neurons and the site of all neural ____ in the spinal cord. ___ matter has myelin and is composed of bundles of axons called ___ that carry signals from one level of the CNS to another
grey white grey synaptic integration white tracts
Unmyelinated Integration center to elicit a response
grey matter
by taking the spinal nerve route, postganglionic fibers exit a ganglion by way of the ____ ____, return to the ____ ___ and travel to ____ organ. this is the route most ____ glands and ____ ____ of the skin and skeletal muscles
grey ramus spinal nerve target sweat blood vessels
the sympathetic ganglion taking the spinal nerve route goes from the ____ ____ then returns to the ____ ____ then to the ___ ____. this includes ___ glands and ___ ___ near skin
grey ramus spinal nerve target organ sweat blood vessels
taste
gustation
__ begins with the chemical stimulation of sensory cells clustered in ____ ___. the visible bumps on the tongue are called ___. to be tasted, molecules must dissolve in the ___ and flood the taste poor
gustation taste buds papillae saliva
on the tongue, there are ____ receptor cells. we taste due to ____ chemicals
gustatory saliva
a process in which the brain learns to ignore repetitive inconsequential stimuli while remaining sensitive to others
habituation
learning what signals are important or not
habituation
nerve endings involve ____ ___ movement. when it bends, it activates the _____
hair follicle mechanoreceptors
dendrites that coil around a hair follicle and respond to movements of the hair light touch
hair receptors
___ is a response to vibrating air molecules and ____ is the sense of body orientation, movement, and balance
hearing equilibrium
by taking the sympathetic nerve route, postganglionic fibers exit by way of sympathetic nerves that lead to the ____, ____, ____, and ____ ____ ____. this tracts includes ____, ____, and ____ glands; ___ ___; and ____ of the iris.
heart esophagus thoracic blood vessels sweat salivary nasal blood vessels dilators
the limbic system is paired between the 2 ___ meaning there are __ of them. the circular shape makes a ___ of fiber tracts so it is a ____ ___ with itself. it regulates ___, ___, and _____
hemispheres 2 loop feedback loop emotion learning memory
the higher frquency of a sound, the
higher its pitch
the medulla is in the _____ and has ______ on the ventral side. the ____ and ____ fasciculi decussate here carrying ___ info. it then goes to the ____ ____, synapses in the ____, finally to the cortex. the motor ____ tract decussates here, go to the inferior ____ nucleus out of the brain and to the ____ to cerebellum
hindbrain pyramids • Gracile & cuneate sensory medial lemniscus thalamus corticospinal olivary spinal cord
Primary memory
hippocampus
the ______ of the limbic system is an important memory forming center. it does not ___ memories, but ____ sensory and cognitive experiences into a unified long-term memory. it learns from sensory input while an experience is happening, but it has ___ memory. later, perhaps when one is sleeping, it plays this memory repeatedly to the _____ which is a slow learner but forms ___-lasting memories. this process of teaching the cortex until a long-term memory is established is called _____ _____. ones vocab and memory of faces reside in the _____ _____ lobe and memories of one's plans and social roles are in the ____ cortex
hippocampus stores organizes short cortex longer memory consolidation superior temporal prefrontal
parts of the limbic system
hippocampus, amygdala
the ANS is a division of the NS responsible for _____, acting through mostly ____ and ____ control of ____, ____ muscle, and ___ muscle. it acts through motor pathways that involve 2 nerve fibers, ______ and ______, reaching from CNS to effector.
homeostasis unconscious involuntary glands smooth cardiac preganglionic postganglionic
in the hypothalamus, the endocrine control center does 6 things. 1. _____ regulation of organs 2. secretes _____ which is control of the ___ ____ 3. integrates with _____ regions 4. _____ 5. regulates ____ and _____ 6. part of ______ pathways between hippocampus and thalamus
homeostatic hormones anterior pituitary autonomic thermoregulation hunger thirst memory
the hypothalamus has nuclei that are concerned with _____ secretion, ____ effects, _____, ___ and ___ intake, ____ and rhythms, ____, and ___ behavior and ____ response.
hormone autonomic thermoregulation food water sleep cardiac memory emotional sexual
the hypothalamus secretes ____ that control the ___ pituitary gland which regulate growth, metabolism, reproduction, and stress responses. it also produces 2 others that are stored in the ___ pituitary gland that are concerned with labor contractions, lactation, and water conservation.
hormones anterior posterior
the ventromedial regulates ____, but is ____ or makes you feel ____
hunger supresses full
abnormal accumulation of CSF in the ventricles can cause
hydrocephalus
accumulation of CSF in the brain
hydrocephalus
An IPSP is _____ of the postsynaptic neuron.
hyperpolarization
Functions associated with the endocrine system Release hormones
hypothalamus
Because of a brain lesion, a certain patient never feels full, but eats so excessively that she now weighs nearly 270 kg (600 lb). The lesion is most likely in her
hypothalamus
the most significant autonomic control center within the CNS is
hypothalamus
the ___ forms the floor and part of the walls of the 3rd ventricle. it extends anteriorly to the ___ ____, where the optic nerves meet, and posteriorly to a pair of humps called the ___ ____ which relays signals from limbic system to thalamus. the ____ ____ is attached to the hypothalamus by a stalk called the _____ between the optic chiasm and mammillary bodies. the hypothalamus is the major control center of the ____ and ___ NS. it plays a role in the ____ regulation of nearly all organs of the body.
hypothalamus optic chiasm mammillary bodies pituitary gland infundibulum endocrine autonomic homeostatic
• What symptom would not be a result of a damaged reticular formation? o Reduction of motor reflexes o Increased PA o Reduction in pain signals o Altered breathing o Inability to "phase out" repeated stimuli
increased PA
metabotropic receptors have ____ connection to ion channels. the NT binds to ___ which activates a ___ ____. the __ ____ mechanism occurs. (over __%-__% responsible for interacting with this mechanism). there is __ ___ direct activation or ____ ____.
indirect receptor G protein G protein 60-70 G protein second messenger
parts of the midbrain
inferior and superior colliculi
auditory reflex
inferior colliculi
receives auditory input and triggers head-turning auditory relfex
inferior colliculi
what is an example of a converging circuit? what 3 things does it involve? signals are ____ in the ____ center = output ____ pattern. these circuits are typically ____
influence of signals on respiration Brain, blood chemistry, vessel stretch receptors integrated respiratory sensory
the more dendrites a neuron has, the more ____ it can receive and incorporate into its decision making
info
beta-adrenergic receptors are usually ______ such as when it dilates the brochioles causing them to relax during exercise so more air can get into the lungs. however, it can also be ______ such as when it excites cardiac muscle to increase HR during exercise
inhibitory excitatory
beta-adrenergic are usually ____ effects. NE ___ and ___ the bronchioles (thus enhancing respiratory airflow) when it binds to these receptors of the ____ muscle. yet when it binds to these receptors of cardiac muscle, it has a ___ effect. such contrasting effects are appropriate to a state of ____. both types act through ____ as a ___ ___.
inhibitory relaxes dialates smooth excitatory exercise cAMP second messenger
the flexor reflex is initiated by a ___ stimulus and is ______. it depends on ____ ____ systems and can be ____ or _____. this is involved in the ____ ____ relfex
injurious polysynaptic weight bearing ipsilateral contralateral crossed extensor
the ___ ear is housed in a maze of temporal bone passages. the ____ contains organs of equilibrium. the organ of hearing is the _____. the cochlea has 3 fluid-filled chambers separated by membranes. the superior chamber is the ___ ___ and the inferior is ___ ____. these are filled with fluid and communicate with each other through a narrow channel at the apex of the cochlea. the ____ ____ begins near the oval window and spirals to the apex; from there, the ___ ____ spirals back down to the base and ends at the ___ _____. the middle chamber is the ___ ____. it is separated from the scala vestibuli above by the ____ ____ and from the scala tympani below by the ____ _____. within the cochlear duct, supported on the basilar membrane is the ___ __ ____. this converts vibrations into nerve impulses. the organ of corti is composed of ___ cells that have stereocilia. resting on top of the stereocilia is the ___ _____
inner vestibule scala vestibuli scala tympani scala vestibuli scala tympani round window cochlear duct vestibular membrane basilar membrane organ of corti hair tectorial membrane
the negative value of RMP means there are more negatively charged particles on the ___ of the membrane than on the ____
inside outside
what is an example of a reverberating circuit? this circuit continues for ___ seconds
inspiration (activation of diaphragm) 2
the hypothalamus is a major ____ center for the ____ NS. it regulates HR, BP, GI secretion and motility, and pupil diameter. it also controls _____ which consists of a collection of neurons that monitor body temperature in the ___ nucleus. it also regulates sensations of ___ and ____. the hormone ____ conserves water by reducing urine output. the hypothalamus is also part of the ___ ___. it controls ____. the ___ nucleus controls our biological clock. the ___ nuclei lie in the pathway of signals traveling from the hippocampus, an important ___ center of the brain, to the thalamus. it is also involved in several ___ responses such as anger, aggression, fear, pleasure, and contentment, and in ___ drive, copulation, and orgasm
integrating autonomic thermoregulation preoptic hunger thirst ADH reticular formation sleep suprachiasmatic mammillary memory emotional sexual
Thoughts, memories, decisions, sensation Where message is received Brain processes
integration
• Summation of postsynaptic potentials • Add all together to get the final signal
integration
interneurons help with ____, are typically ____ neurons, make up __% of neurons, and are found mostly in the ____
integration multipolar 99% brain
experiments where the hippocampus was removed showed that it had no effect on ____ or ____ memory, but people could not form new ____ of people and experiences, but could form new ___ skills. this shows that memory for motor skills is stored in the same/different part of the brain
intelligence retrograde memories motor different
lie entirely within the CNS receive signals from many other neurons and carry out the integrative function of the NS-that is they processes, store, and retrieve info and make decisions that determine how the body responds to stimuli
interneurons
the integrative functions of the NS are preformed by
interneurons
in most reflex arcs, the integrating center includes one or more _____. synaptic events in the integrating center determine whether the efferent neurons issue signals to the muscles. the more interneurons there are, the more complex the integrating process may be, but with more synapses, there is a longer ____ between input and output
interneurons delay
hydrocephalus occurs due to blockage in CSF flow route in the ______ _____, ______, and _______. it expands ____ and compresses ____ tissue. Typically, it can be seen in ____. their head can ____ because their bones are not ___, which pushes bones apart
interventricular foramen, aqueduct, apertures ventricles nervous infants expand fused
the modified muscle fibers within the spindle are called _____ fibers and those that make up the rest of the muscle and do its work are called ____ fibers. each end of an intafusal fiber has a few _____. a ___ ___ neuron of the SC innervates each end and stimulates its contraction. this maintains tension and sensitivity of the intrafusal fiber, preventing it from going slack like an unstretched rubber band when a muscle shortens. spinal motor neurons that supply the extrafusal muscle fibers are called ____ ____ neurons. __/3 of all spinal motor neurons are the gamma type.
intrafusal extrafusal gamma motor alpha motor 1
Modified muscle fibers serving primarily to detect stretch are called
intrafusal fibers
the ANS is under ____ control. it controls ____ motor output such as ____, ____ muscle, and ____ muscle. it regulates _____, which is based on sensory info, such as ____ ____, ____ ____, ____ ____, _____, ____ ____, _____, and ____ ____
involuntary visceral glands cardiac smooth homeostasis heart rate blood pressure respiration rate digestion pupil diameter metabolism sexual functions
• Generate or reduce gradient
ion channels
explain how ACh can be excitatory and inhibitory. excitatory ACh bind to ____ receptor --> ___ receptors open --> ___ inhibitory ACh binds to ____ receptor --> ___ channels open --> ____
ionotropic cation EPSP metabotropic K+ IPSP
2 types of neurotransmitter receptors
ionotropic and metabotropic
Contains NT binding site & ion channel • Same protein Ligand-gated channel
ionotropic receptors
electrical currents in the body are created by the flow of ___ through ___ channels in the plasma membrane. These channels can be opened and closed by various ___ which enables cells to turn electrical currents __ and __
ions gated stimuli on off
the flexor reflex employs an _____ reflex arc one in which the sensory input and motor input are. on the same side of the SC. the crossed extension reflex employs a _____ reflex arc in which the input and output are on opposite sides
ipsilateral contralateral
cranial nerve systems are _____ meaning the signal is interpreted on the same side of the brain. one exception of this is the ___ pathway due to the ___ ___. this is considered a partial ____ system
ipsilateral optic optic chiasma contralateral
brain tissue is largely ____
irreplaceable
testing somatic reflexes is valuable in diagnosing many diseases that cause exaggeration, inhibition, or absence of reflexes
know
Certain stimulus for certain neuron Ex: rubbing eyes; tricking brain that you are seeing light
labeled line code
the most important mechanism for transmitting qualitative info is the ___ ____ ____. this code is based on the fact that each nerve fiber to the brain leads from a _____ that specifically recognizes a particular stimulus type. nerve fibers in the optic nerve, for example, carry signals only from ___ receptors in the eye. the brain therefore interprets any signals in those fibers in terms of light-even if the signals result from artificial stimulation of the nerve. this effect is seen when you rub your eyelids and see flashes of light as the pressure on the eyeball mechanically stimulates optic nerve fibers. thus, each nerve fiber to the brain is a line of communication ____ by the brain as representing a particular stimulus quality.
labeled line code receptor light labeled
phasic receptors chiefly for vibration; deep pressure deep in the dermis
lamellar corpuscles
deep pressure receptors involve _____ ____ in the ____
lamellated corpuscles dermis
o Cerebral White Matter is the ____ volume and is ___% of the brain's volume. ____ cells and ____ fibers support the white matter. they transmit signal ____ and ____ areas
largest 60 glia myelinated between within
most of the axons of the optic tracts end in the ___ ___ ___ of the thalamus. other neurons arise here and form the ___ ____ of fibers in the white matter of the cerebrum. these project to the ___ ___ cortex of the ___ lobe, where conscious visual sensation occurs. a lesion of the occipital lobe can cause ___ even if the eyes are fully functional.
lateral geniculate nucleus optic radiation primary visual occipital blindness
the _____ _______ controls balance and posture and decussates _____. the ____ _____ controls head position and decussates in the ____
lateral vestibulospinal no where medial vestibulospinal medulla
4 types of ion channels
leak ligand-gated mechanically-gated voltage-gated
• Not always open • Ions can pass right through them
leak channels
information management by the brain entails ____ (acquiring new info), memory ____ (info storage and retrieval), and ______ (eliminating trivial info). brain-injured people are sometimes unable to recall things they once knew, or ____ ____, or unable to store new info, or _____ _____. amnesia refers to defects in ___ memory such as the ability to describe past events
learning proper forgetting retrograde amnesia anterograde amnesia explicit
secondary sensory fibers are based on ____
length
sensory input depends on muscle ____ and ____. motor output is _______, coordinates _____, and regulates _____
length movement contractions movement posture
primary sensory fibers are based on ___ and ___
length rate
neurons can differ on axon ___/___ and can have different ____ and ____ patterns
length/size diameter myelination
nicotinic receptors have ____-gated channels. they are found in _____ synapses, the ____ ____, and ____ muscle. these are almost always _____.
ligand ganglia adrenal medulla skeletal excitatory
• Open when chemically bound to a ligand • Ex: AcH
ligand gated
rods sense
light intensity
an important center of emotion and learning encircles corpus callosum and thalamus hippocampus + amygdala
limbic system
the mammillary deals with ____ ____ ____
long term memory
limbic system components are interconnected through a complex ___ of fiber tracts allowing for circular patterns of ___. the parts of the limbic system include the ____ and ____ which are ___ paired. it plays a significant role in ____ and ____. most limbic systems have structures have centers for both ___ and ____. stimulation of a gratification center produces a sense of pleasure or reward; stimulation of an aversion center produces unpleasant sensations such as fear or sorrow. gratification centers dominate some limbic stractures such as the ____ ____, while aversion centers dominate other such as the ____
loop feedback hippocampus amygdala bilaterally emotion memory gratification aversion nucleus accumbens amygdala
4 types of mechanoreceptors
low pressure deep pressure nerve endings physical deformation of cell membrane
blood can contain ___ and ____
macrophages toxins
• Physically gets pulled open or closed
mechanically gated
respond to physical deformation of a cell or tissue caused by vibration, touch, pressure, stretch, or tension
mechanoreceptor
pressure, vibration, and stretch receptors are considered _____
mechanoreceptors
Swallowing, respiration, heart rate, blood pressure, GI tract control Equilibrium, touch, pressure, pain, temp
medulla
All nerve fibers connecting the brain to the spinal cord pass through the?
medulla
hearing, equilibrium, touch, pressure, temperature, taste, pain chewing, salivation, swallowing, gagging, vomiting, respiration, speech, coughing, sneezing, sweating, cardiovascular and gastrointestinal control, head, neck and shoulder movements
medulla
where do the following decussate? Fasciculi: Spinothalamic: Spinoreticular: Ant. spinocerebellar: Post. Spinocerebellar:
medulla SC SC SC none
where do the following decussate? Lat. corticospinal: Ant. corticospinal: Tectospinal: Reticulospinal: Lat. vestibulospinal: Med. vestibulospinal:
medulla SC midbrain none none medulla
parts of the hindbrain
medulla, pons, cerebellum, reticular formation
in meningocele, the ____ of spinal cord protrude through opening of vertebrae. these are ____ filled. there are no spinal ____ or ____ in sac
meninges fluid nerves or tissues
the spinal cord and brain are enclosed in 3 fibrous membranes called ____. they are the ____ ___, ____ ___, and ____ ___
meningies dura matter arachnoid matter pia matter
the brain is enveloped. in 3 membranes, the _____, which lie between the nervous tissue and bone. they ___ the brain and provide a structural framework for its ____ and ____. the dura mater continues into the vertebral canal, where it forms the ___ ___ around the spinal cord. in some places, two layers of dura are separated by ___ ___, spaces that collect blood that has circulated through the brain. these sinuses meet like an inverted T at the back of the brain and ultimately empty into ___ of the neck. the ____ mater is a transparent membrane over the brain's surface. a _____ _____ separates it from the pia below and a _____ _____ separates it from the dura above. the subarachnoid space contains the largest ____ ____ of the cerebral surface. the ____ mater is a very thin, delicate membrane
meningies protect arteries veins dural shealth dural sinuses veins arachnoid subarachnoid space subdural space blood vessels pia
inflammation of the meningies seen in children
meningitis
low pressure receptors involve ___ cells in the ___ ___ layer of skin
merkel stratum basale
NT binding site, no ion channel
metabotropic receptor
Phagocytize and destroy microorganisms, foreign matter, and dead nervous tissue
microglia
the glial cells that fight infections in the CNS
microglia
short segment of brainstem that connects hindbrain and forebrain contains the cerebral aqueduct, medial lemniscus and RF, and oculomotor nerve and trochlear nerve
midbrain
the ____ ear is located in the tympanic cavity of the temporal bone. the ear drum is called the ____ ____. it closes the inner end of the auditory canal and separates it from the middle ear. it vibrates in response to sound. the ___ connect the tympanic membrane to the inner ear. they are the ____, ____, and ____. the base of the stapes is held by the ___ ____ where the inner ear begins.
middle tympanic membrane ossicles malleus incus stapes oval window
the sympathetic division prepares the body to be _____
mobile
each sense is considered a ___
modality
o Drugs of abuse most commonly mimic or inhibit the reuptake of what type of neurotransmitter?
monoamine - dopamine
synthesized from amino acids by removal of the -COOH group. they retain the -NH2 epinephrine, dopamine
monoamines
All somatic reflexes share all of the following properties except
monosynaptic
synapse is only between the sensory and motor neurons
monosynaptic
• Until ~3-4 months • Sudden stress, moved suddenly they flare arms out
moro reflex
sensory fibers in the spinal cord synapse with ___ neurons, mainly ____ motor fibers
motor alpha
example of a diverging circuit in the brain: ___ output from brain = thousands of ___ fibers. these circuits are usually ____
motor muscle motor
efferent neurons carry ____ info and activate ___ and ____
motor muscles glands
the somatic system uses ___ nerve fibers such as ___ muscle and has ____ control
motor skeletal voluntary
send signals predominately to muscle and gland cells, the effectors most lead to muscle cells signal conduction away from the CNS
motor (efferent) neurons
a multipolar neuron is usually which two types of neurons
motor or interneuron
carries signals from the CNS mainly to gland and muscle cells that carry out the body's responses
motor/efferent division
with olfaction, molecules dissolve in the ___ layer and bind to ____. these help the ____ to the receptor dendrites of ______ neurons.
mucus proteins transport bipolar
neuron with several projections
multipolar
one axon with multiple dendrites most common type neurons of the brain and spinal cord
multipolar
neurons are structurally classified in 3 ways according to the number of processes extending from the soma
multipolar bipolar unipolar
proprioception/muscle stretch skeletal muscles near tendon
muscle spindles
many somatic reflexes involve stretch receptors called _____ ___ embedded in the muscles. these among the body's _____ sense organs sepcialized to monitor the position and movement of body parts. the finction of muscle spindles is to inform the brain of muscle ___ and body _____. this enables the brain to send ___ commands back to the muscles that control muscle tone, posture, coordinated movement, and corrective reflexes. spindles are especially abundant in muscles that require ___ control
muscle spindles proprioceptors length movement motor fine
a spiral layer of insulation around a nerve fiber, formed by oligodendrocytes in the CNS and schwann cells in the PNS
myelin sheath
____ axons are faster
myelinated
MS is caused by damage to ___ neurons. some patients experience decreased neural activity die to the loss of ____
myelinated myelination
the autonomic motor pathway to a target organ differs significantly from somatic. in somatic, a motor neuron in the brainstem or SC issue a ____ axon that reaches all the way down to a ___ muscle. in autonomic, the signal must travel across __ nerve fibers to get to the ___ and it must cross a ____ where these neurons meet in an autonomic _____. the first fiber called the _____ ____ is myelinated and leads from a soma in the _____ or ____ ____ to the autonomic ganglion. it synapses there with a neuron that issues an unmyelinated ______ ____ to the target cells. in contrast to somatic, postganglionic fibers of the ANS do not end by synapsing with a target cell, but with a chain of ____ that diffusely release NT into the tissue and may stimulate many cells simultaneously.
myelinated skeletal 2 target synapse ganglion preganglionic fiber brainstem SC postganglionic fiber variscosities
saltatory conduction occurs only in
myelinated nerve fibers
production of the myelin sheath
myelination
Inside of neuron more ____ at rest than outside
negative
the leak channels creates the ___ charge inside
negative
a cordlike organ composed of numerous nerve fibers (axons) bound together by connective tissue
nerve
if EPSP is greater than threshold, a ___ ___ occurs
nerve impulse
a bundle of fibers (axons) wrapped in fibrous connective tissue
nerves
what are axon bundles called in the PNS
nerves
employs electrical and chemical means to send messages from cell to cell
nervous system
one neuron may receive input from thousands of other neurons. some incoming nerve fibers may produce EPSPs while others produce IPSPs. the neuron's response depends on whether the __ input is excitatory or inhibitory. if epsps override ipsps, ____ may be reached and set off an AP. if ipsps prevail, they ___ the neuron from firing. ____ is the process of adding up postsynaptic potentials and responding to their net effect. it occurs in the ___ zone. it is fundamentally a balance between epsps and ipsps that enables the NS to make ___. if a neuron has a RMP of -70mV and a threshold of -55mV, it needs at least ___ EPSPs to reach threshold and fire.
net threshold inhibit summation trigger decisions 30
the functions of a neural pool are partly determined by its ___ ___- the pathways among its neurons
neural circuit
neural pathways are also known as
neural circuits
the way in which the NS converts info to a meaningfu pattern of APs
neural coding
pools of spinal neurons receive input from multiple sources, integrate the information, and execute an appropriate output.
neural integration
Large groups of neurons associated with a particular function
neural pools
neurons function in larger ensembles called ____ ____, each of which may consist of thousands of interneurons concerned with a particular body function. info arrives at a neural pool through one or more ____ neurons, which branch repeatedly and synapse with interneurons in the pool. some input neurons form multiple synapses with a single postsynaptic cell. they can produce EPSPs at all points of contact with that cell and, through ___ summation, make it fire more easily than if they synapsed with it at only one point. within the ____ ____ of an input neuron, that neuron acting alone can make the postsynaptic cell fire. but in a broader ____ ____, it synapses with still other neurons in the pool, with fewer synapses on each of them. it can stimulate those neurons to fire only with the assistance of other input neurons; that is, it facilitates the others. it "has a __" on what the postsynaptic cells in the facilitated zone will do, but it cannot determine the outcome by itself. such arrangements, repeated thousands of times throughout the CNS, give neural pools great flexibility in integrating input from several sources ___ on an appropriate outcome.
neural pools input spatial discharge zone facilitated zone vote deciding
the lumen of the ___ ___ becomes a fluid filled space that later constitutes the central canal of the SC and ventricles of the brain
neural tube
spina bifida is a ___ ___ defect and results from the tube not _____. 3 types of spina bifida
neural tube closing spina bifida occulta meningocele myelomeningocele
cells that protect the neurons and help them function; help bind neurons together and provide a supportive framework for the nervous tissue
neuroglia cells
__________ are substances released along with a neurotransmitter that modify the neurotransmitter's effect
neuromodulators
neurons sometimes secrete chemical signals that have long term effects on entire groups of neurons instead of brief, quick effects at an individual synapse. some call these _____. they adjust the activity of neuron groups in various ways: increase the release of ____ by presynaptic neurons, adjust the ____ of postsynaptic neurons to NTs, or alter the rate of NT ____ or ____ to prolong their effects
neuromodulators neurotransmitter sensitivity reuptake breakdown
chemical synapses use the _____ ____
neuromuscular junction
the communciative role of the NS is carried out by ____
neurons
• Excitable and designed to receive stimuli • One way body communicates with itself
neurons
chains of 2-40 AA CCK and endorphins some function as hormones
neuropeptides
molecules that are synthesized by a neuron, released when a nerve signal reaches an axon terminal or variscosity of the nerve fiber, and have a specific effect on a receiving cell's physiology
neurotransmitter
when a nerve signal reaches the end of an axon, it triggers the release of a _____ that stimulates a new wave of electrical activity in the next cell across the synapse. signals arrive at the synapse by way of the _____ neuron, which releases a neurotransmitter. the next neuron, which responds to it, is called the ___ neuron. the presynaptic neuron may synapse with a ____, the ____, or the ____ of the postsynaptic neuron.
neurotransmitter presynaptic postsynaptic dendrite soma axon
the presynaptic neuron releases _____ which is before the _____ ___
neurotransmitter synaptic cleft
an enzyme in the synaptic cleft breaks the neurotransmitter down into fragments that have no stimulatory effects on the postsynaptic cell ex: ACh broken into choline and acetate
neurotransmitter degradation
3 ways to stop the signal
neurotransmitter degradation reuptake diffusion
Throughout the autonomic nervous system, the neurotransmitter released by the preganglionic fiber binds to _____ receptors on the postganglionic neuron.
nicotinic
the simplest neuromodulator is the gas ___ ____. it diffuses readily into a postsynaptic cell and activates ___ messenger pathways with such effects as relaxing smooth muscle
nitric oxide second
are all neurons at -70mV? more sensitive neurons have a more ___ threshold
no postive
pain is also called _____ which describes stimuli beyond ____. ____ released by cells when they are damaged is picked up by _____
nociception threshold chemicals dendrites
pain receptors
nociceptors
ion channels are only active at the ___
nodes
Gaps between myelin sheaths
nodes of ranvier
The highest density of voltage-gated ion channels is found on the ______ of a neuron.
nodes of ranvier
a myelinated nerve fiber can produce APs only in specialized regions called
nodes of ranvier
anions are bound to _____ molecules
nondiffusable
the neurotransmitter secreted at an adrenergic synapse is __________
norepinephrine
inside CNS; same as ganglia
nucleus
Pleasure, gratification Ex: rat experiment
nucleus accumbens
parallel series have different ___ of neurons. signals arrive at the end at the same/different times. the signal ____ after the stimulus stops. this is not a ____ ____.
number different propagates feedback loop
How are stimuli of differing intensities detected? (2)
number of neurons more excitatory potentials
why do pons and medulla have so many functions
o Pons and medulla have so many functions because they are close to the spinal cord, nerve tracts have to go through them to get to the spinal cord
visual center of the brain, where we first become aware of visual stimuli and process them to identify what we see
occipital lobe
olfactory neurons synapse with mitral cells in the ____ ____
olfactory bulb
When olfactory fibers pass through the roof of the nose, they enter a pair of _____ ____ beneath the frontal lobes of the brain. here they synapse with the dendrites of neurons called ___ cells. olfactory cells' axons form bundles called ____ ____, which course along the underside of the frontal lobes. most fibers of the olfactory tracts end in various regions of the inferior surface of the temporal lobe called the ___ ___ ___. olfactory signals can reach the cerebral cortex directly without first passing through the ____; except for the ____ ___ pathway.
olfactory bulbs mitral olfactory tracts primary olfactory cortex thalamus spinoreticular pain
forms the myelin sheath in the CNS; insulates the nerve fiber from extracellular fluid and speeds up signal conduction in the nerve fiber
oligodendrocytes
in the CNS, myelin is produced by glial cells called
oligodendrocytes
in single innervation, one neuron/many neurons produce opposite effects when needed such as looking at blood routes during emergencies/stress. during this, ____ fibers decrease firing rate, ____ muscles relax. the blood puts pressure on the walls which causes _____ so vessels leading to vital organs get more blood such as the brain, heart, and skeletal muscle. this is ____ summation.
one sympathetic smooth dialation temporal
o The direction of light towards photoreceptors is ___ to that of the signal transduced away from the photoreceptors
opposite
protein of rhodopsin
opsin
ganglion cells form the ___ ___
optic nerve
most neurotransmitters are small ___ molecules that are released by ___ and bind to specific ___ on the receiving cell, but there are exceptions.
organic exocytosis receptors
the ___ ear is essentially a funnel for conducting airborne vibrations to the ___ membrane. it begins with the fleshy ___ shaped and supported by elastic cartilage except for the earlobe which is adipose. this directs sound into the ___ ____ ____ which is the passage leading through the temporal bone to the tympanic membrane.
outer tympanic auricle external acoustic meatus
Na+ is higher ___ K+ is higher ____ __ is the most important
outside inside K+
the paraventricular produces ____ which is associated with the body's reward system and is released in the ____ pituitary
oxytocin posterior
the RF deals with ___ control. these signals and inhibitory neurons run through this area. if you damage you RF, you may have difficulty sensing ___
pain pain
some receptors are themselves neurons, such as those for ___ and ___. in other cases, the receptor is a separate cell that communicates directly with a sensory neuron such as ___ and ___
pain smell taste hearing
free nerve endings sense ____ and ____.
pain temp
type C fibers sense other ___, ___, ___, and ___ branches from ____ centers. they also stimulate ___, ___ muscle, and ____
pain touch heat autonomic relay heart smooth glands
• Until 5-6 months • Something comes in contact with hand, infant reacts by grabbing it
palmar grasp reflex
bumps on the tongue
papillae
• Begins 6-7 months • Child falls, arms reach out in front them
parachute reflex
an input neuron diverges to stimulate several chains of neurons. each chain has a different number of synapses, but eventually they all reconverge on one or a few output neurons. since the chains differ in total synaptic delay, their signals arrive at the output neurons at different times, and the output neurons may go on firing for some time after input has ceased. this has no feedback loop. once all neurons in the circuit have fired, the output ceases. continued firing after the stimulus stops is called after discharge. it explains why you can stare at a lamp then close your eyes and continue to see that image for awhile. such a circuit is also important in withdrawal reflexes, in which a brief pain produces a longer lasting output to the limb muscles and causes you to draw back your hand or foot from danger
parallel after-discharge
• One neuron parallel series of neurons one output o All neurons going in one direction; no feedback loop; different numbers of neurons being branched out; generates an imbalance with the number of neurons on either side o More neurons = longer signal takes to transmit o Signals reach output at different times o Allows signal to prolong
parallel after-discharge circuit
has a calming effect on many body functions associated with reduced energy expenditure and normal bodily maintenance, including such functions as digestion and waste elimination
parasympathetic
rest and digest
parasympathetic
tends to have a calming effect rest and digest
parasympathetic
while taking notes, the ____ division is more active.
parasympathetic
• Reduced energy usage • Body maintenance (digestion, waste removal) rest and digest
parasympathetic
list the 7 nuclei of the hypothalamus
paraventricular supraoptic anterior ventromedial preoptic suprachiasmatic mammillary
taste, somatic sensation, visual processing, multisensory integration such as correlating sights and sounds to hollistically comprehend our sensory world.; spatial perception and awareness of body orientation; language processing, numerical awareness
parietal lobe
Retinal in opsins changed by __
photon
• Babinski's sign • Under a year • Brush something against infant's foot, their toes curl up
plantar reflex
CSF production begins with filtration of the blood ____ through ___ of the brain. ___ cells modify the filtrate as it passes through them, so the CSF has more ___ than blood plasma, but less ____, ____, ____ and ____. the CSF of the lateral ventricles flows through the _____ ____ into the ___ ventricle, then down the ____ ___ to the ___ ventricle. the 3rd and 4th ventricles and their choroid plexuses add more ____. a small amount of CSF fills the ___ ___ of the SC, but ultimately it escapes through pores in the 4th ventricle- the ___ and ____ _____. these lead into the _____ space on the brain and SC. from here, CSF is reabsorbed by ____ _____ protruding through the dura mater into the ____ ____. CSF penetrates the walls of the granulations and mixes with ____ in the sinus.
plasma capillaries ependymal NaCl K+ Ca++ glucose protein interventricular foramen 3rd cerebral aqueduct 4th CSF central canal medial and lateral aperatures subarachnoid arachnoid granulations dural sinus blood
group of nerves
plexus
reflex that has the interneuron for integration
polysynaptic
Hearing, equilibrium, facial sensation, chewing, salivation, urination, etc. A bunch of cranial nerves going in and out of it
pons
hearing, equilibrium, taste, facial sensations such as touch and pain, motor roles in eye movement, facial expressions, chewing, swallowing, urination, secretion of saliva and tears
pons
the ____ is most closely associated with the cerebellum and remains its primary source of input fibers throughout life
pons
• Hearing, equilibrium, facial sensation, chewing, salivation, urination, etc.
pons
equilibrium/balance is based on head and body _____ and ______. the hair cells _____ and _____ detect head position. ____ bends hair cells forward. the ____ _____ detect movement with _____ with hair cells.
position movement utricle saccule fluid semicircular canals ampulla
neural integration is based on the ___ potentials produced by neurotransmitters. a typical neuron has a RMP of ___mV and a threshold of about ___mV. a neuron has to be ____ to this threshold in order to produce APs. any voltage change in that direction makes a neuron more likely to fire and is therefore called an ____ ____ ____. these usually result from ___ flowing into the cell and neutralizing some of the ___ charge on the inside of the membrane. in other cases, a NT ____ the postsynaptic cell and makes it more negative than the RMP. since this makes the postsynaptic cell less likely to fire, it is called an ____ _____ _____. some of these are produced by a NT opening ____-gated ___ channels, causing ___ to flow into the cell and make the cytosol more ____. a less common way is to open selective ___ channels, increasing ___ diffusion out of the cell.
postsynaptic -70 -55 depolarized excitatory postsynaptic potential Na+ negative hyperpolarizes inhibitory postsynaptic potential ligand Cl- Cl- K+ K+
in electrical synapses, ions flow into ____ cell, there is ___ communication, and a _____ of action potentials where they fire at the __ time.
postsynaptic faster synchronization
spinal reflexes play vital roles in _____, ____ ____, and protective responses to ____ or ___
posture motor coordination pain injury
there is subconsious monitoring of ____, ____ control, and corrective ____
posture movement reflexes
electrical potential is a form of ___ energy that can produce a ____
potential current
after the synaptic cleft, the postsynaptic _____ is generated and affects a ____ or ____
potential muscle or gland
• Storing different charges on both sides of the membrane
potential energy
Higher order thinking, emotions, critical thinking
prefrontal
the ____ cortex is a seat of judgement, intent, and control over the expression of our emotions. but the feelings themselves, and emotional memories, arise from deeper regions of the brain, especially the ____ and ____. the _____ receives processed info from the general senses and from vision, hearing, taste, and smell. such input enables it to mediate emotional responses to such stimuli as a disgusting odor, a foul taste, a beautiful sight, pleasant music, or stomachache. it is important in the sense of ____, but also plays a role in ___ intake, ____ behavior, and drawing our ___ to novel stimuli. many important aspects of ___ depend on these. lesions of amygdala can completely abolish the sense of ___.
prefrontal hypothalamus amygdala amygdala fear food sexual attention personality fear
10 parts of the cerebral cortex
prefrontal premotor primary motor primary somatosensory somatosensory association primary visual visual association primary auditory auditory association broca area
the SNS has short _______ and long _____ nerve fibers
preganglionic postganglionic
ACh is secreted by the _____________ fibers in both divisions and the _____________ fibers of the parasympathetic division. a few sympathetic postganglion also secrete ACh-those that innervate ____ ___ and some ___ ____. any nerve fiber that secretes ACh is called a _____ fiber and any receptor that binds to it is a ____ receptor. there are 2 categories of cholinergic receptors: _____ and _____
preganglionic postganglionic sweat glands blood vessels cholinergic cholinergic muscarinic nicotinic
Info being integrated about movement
premotor
the intention to contract a skeletal muscle begins in the ____ area. this is where we plan our behavior. then it goes to the ____ ____. the ___ is highly important in motor coordination
premotor primary motor cerebellum
neurotransmitters are released from a ___ cell, bind to ___ on the ____ cell membrane which has one/more than one binding sites. whatever receptor the neurotransmitter binds to depends on what ___ ___ are open (EPSP or IPSP).
presynaptic receptors postsynaptic more than one ion channels
Receive auditory stimuli
primary auditory
auditory signals are received by the ____ ___ cortex in the temporal lobe. the ____ ____ area is where we become capable of recognizing spoken words, music, or voices
primary auditory auditory association
taste signals are received by the ____ ____ cortex in the parietal lobe. smell signals are received by the _____ _____ cortex in the temporal lobe.
primary gustatory primary olfactory
movement
primary motor
the ___ ___ cortex is the site where sensory input is first received and one becomes conscious of a stimulus. adjacent to this is an association area where this sensory info is ___
primary sensory interpreted
Receive info about Temperature, pain, vibration sensory info
primary somatosensory
Receive visual info
primary visual
visual signals are received by the ____ ____ cortex in the occipital lobe. this is bordered by the ____ _____ area where we recognize faces and other familiar objects
primary visual visual association
what we value most about our NS is its ability to ___ info, ___ it, and make ___-and ____ synapses are the decision-making devices of the system. the more synapses a neuron, the ___ its info-processing ability. at this moment, you are using ____ cells of the cerebral cortex to read. the cerebral cortex is the main info ____ tissue in the brain. the ability of your neurons to process info, store and recall it, and make decisions is called ___ _____
process store decisions chemical greater processing neural integration
Three types of tracts in white matter of cerebral cortex
projection commissural association
extend vertically between higher and lower brain and SC centers and carry info between the cerebrum and the rest of the body
projection tracts
verticle tracts
projection tracts
the nonvisual awareness of the body's position and movement is called ____
proprioception
• Pick up on stretch reception
proprioception
Sense of the position and movement of body parts
proprioceptors
CSF ___ the brain from striking the cranium when the head is jolted. if the jolt is severe, the brain still may strike the cranium or suffer shearing injury from contact with the structures of the cranial floor. this is one of the most common findings in ___ ____ and in _____.
protects child abuse concussions
example of a flexor reflex
pull hand away from hot stove
adenosine and ATP
purines
Tall, and conical, with apex toward the brain surface. A thick dendrite with many branches with small, knobby dendritic spines. Include the output neurons of the cerebrum. Only neurons that leave the cortex and connect with other parts of the CNS.
pyramidal cells
o Output neurons o Synapse with other cortical neurons o Some axons leaving cortex o Throughout all layers
pyramidal cells
the medulla has two structures called ____ and the ____ and ____ ____ of the SC continue as two pairs of ridges on the medulla
pyramids gracile and cuneate fasciculi
the NS carries out its coordinating task in 3 basic steps: 1. it ____ info about changes in the body and external environment and transmits messages to the ___ 2. the CNS ___ the info and determines what ___, if any, is appropriate to the circumstances 3. the CNS issues ____ primarily to __ and __ cells to carry out such responses
receives CNS processes response commands muscle gland
3 zones of a neuron
reception trigger conduction
a sensory ____ is any structure specialized to detect a stimulus
receptor
an odorant molecule binds to a _____. this activates a ___ ____ and then activates the ____ ____-____ system. this system opens ___ channels in the plasma membrane, admitting ___ into the cell and ____ it, creating a ___ potential. this triggers ___ potentials in the axon of the olfactory cell, and a signal is transmitted to the brain. some odorants act on ___ of the trigeminal nerve rather than on olfactory cells such as ______ and _____.
receptor G protein cAMP second-messenger ion cations depolarizing receptor action nociceptors ammonia capsaicin
In order of stimulus perception to an output action, what are the main components of a reflex arc?
receptor sensory neuron integration center motor neuron effector
The initial effect of a stimulus on a sensory receptor is a local electrical change specifically called a(an) __________.
receptor potential
how do we sense sensory input?
receptors
Some neurotransmitters can have either excitatory or inhibitory effects depending on the type of
receptors on the postsynaptic cell
stretch reflexes and other muscle contractions often depend on ____ ____, a reflex that prevents muscles from working against each other by inhibiting antagonists
reciprocal inhibition
A large nucleus of the midbrain that receives inputs from the cerebellum and motor cortex and sends axons to motor neurons in the spinal cord.
red nucleus
Quick, involuntary, stereotyped reactions of glands or muscles to stimulation
reflex
stretch receptors involve ___ to avoid muscle ____. ____ _____ ____ are inside the tendons and help prevent this.
reflexes tearing golgi tendon organs
during an action potential and for a few msec after, it is difficult or impossible to stimulate that region of a neuron to fire again. this period of resistance to restimulation is called the ____ ____. it is divided into 2 phases: an ___ refractory period in which no stimulus of any strength will trigger a new action potential, followed by a ___ refractory period in which it is possible to to trigger a new action potential, but only with an unusually strong stimulus. the absolute refractory period lasts from the start of the action potential until the membrane returns to the resting potential-that is, for as long as the ___ channels are open and subsequently _____. the relative refractory period lasts until _____ ends. during this period, __ channels are still open. by the end of hyperpolarization, __ channels are closed and the cell is as responsive as ever. the refractory period refers only to a small patch of membrane where an ____ potential has already begun, not to the entire neuron. other parts of the neuron can still be stimulated while a small area of it is refractory, and even this area quickly recovers once the nerve signal has passed.
refractory period absolute relative Na+ inactivated hyperpolarization K+ K+ action
o When you can start generating another action potential o Activation gate swaps positions with inactivation gate o Activation gate shuts and is ready to start the whole process again o Higher/stronger stimulus to generate a AP than you normally would = very few channels are reset at that point
relative refractory period
Changes to membrane potential cause signals to be ___
relayed
the preoptic produces hormones that regulate ____ function and goes to the ____ pituitary
reproductive anterior
temporary anosmia can be caused by _____ ____, _____, and _____
respiratory infections inflammation allergies
all cells have ___ ___ ___, not just neurons
resting membrane potential
the charge difference across the plasma membrane
resting membrane potential
while studying in a noisy cafe, you get sleepy and doze off for a few mins. you awaken with a start and realize that the cafe sounds have just "come back." while you were dozing, this auditory input was blocked from your auditory cortex by the
reticular activating system
loose network of nuclei extending throughout the medulla, pons, and midbrain
reticular formation
loose web of gray matter that runs vertically through all levels of the brainstem
reticular formation
the ___ tracts adjust muscle tension to maintain tone, balance, and posture
reticulospinal
the ______ coordinates balance and posture and regulates awareness of pain. the lateral and medial decussate _______
reticulospinal no where
thin membrane around eye
retina
2 neural components of the eye
retina optic nerve
a neurotransmitter or its breakdown products are reabsorbed by transport proteins in the axon terminal, removing them from the synapse and ending their stimulatory effect. ex: choline is recycled to make new ACh.
reuptake
neurons stimulate each other in a linear sequence from input to output neurons, but some of the neurons late in the path send axon collateral back to neurons earlier in the path and restimulate them. it sends repetitious signals to your diaphragm and intercostal muscles, for example, to make you inhale. sustained output from the circuit ensures that the respiratory muscles contract for the 2 seconds or so that it normally takes to fill the lungs. when the circuit stops firing, you exhale; the next time it fires, you inhale again.
reverberating circuit
• Linear, some axons send signals to earlier neurons (feedback loop) o Linear network of axons; branches are called collateral; loop back; sent a 2nd time o Take a single signal and make it last longer
reverberating circuit
Motor effects that depend on repetitive output from a neural pool are most likely to use
reverberating circuits
visual pigment of rods
rhodopsin
• Until ~4 months • Helps acquire food touch side of cheek
rooting reflex
the salty taste comes from ___ crystals called ____ ____
salt sodium chloride
myelinated fibers conduct signals in a very different manner called _____ ____. these fibers cannot conduct a signal in a continuous mode because ___-gated ion channels are too scarce in the myelin-covered _____. there would be little point in having ion channels in the internodes anyway because myelin ____ the fiber from the ECF at these points, and ___ from the ECF couldn't flow into the cell even if more channels were present. therefore, no action potentials can occur in the _____ and the ___ signals requires some other way of traversing the distance from one node to the next. with distance, there is a lower concentration of ___ to relay the charge. with a surplus of ___ charges on the inside and surplus of ___ chargers on the outside, these cations and anions are attracted to each other through the ____. this results in a ___ of unmoving or sluggishly moving charges on the membrane. myelin speeds up signal conduction in two ways: by tightly wrapping around the axon, it seals the nerve fiber and greatly increases its resistance to the leakage of ___ out of the axon and myelin creates a greater ___ between the ICF and ECF. this action potential has the same strength as the one at the previous node, so each node of ranvier boosts the signal back to its original strength of ___ mV. however, the genration of APs is a relatively time consuming process that slows down the ___ signal at the nodes. since APs occur only at the nodes, this mode of conduction creates a false impression that the nerve signal ____ from node to node. saltatory conduction is based on a process that is very fast in the _____ (transfer of energy from ion to ion), but reversible. in the nodes, conduction is ____, but irreversible. since most of the axon is covered with myelin, conduction occurs mainly by the ___ internodal process. this is why ___ fibers conduct signals faster.
saltatory conduction voltage internodes insulates Na+ internodes nerve Na+ positive negative membrane storage Na+ separation +35 nerve internodes slower fast myelinated
muscle spindles have no _____ which are the units of muscle contraction that gets pulled together
sarcomeres
the long midportion of an intrafusal fiber lacks _____ and cannot contract, but is supplied by 2 types of sensory nerve fibers: ____ ____ fibers that monitor muscle length and how rapidly it changes, which are very responsive to sudden movements and ____ ____ fibers that monitor length only, not rate of change. both of these sensory fiber types enter the ___ horn of the SC, synapse on the ___ motor neurons and regulate their ____, and also send ___ up the spinal cord to the brain. through these fibers, the brain constantly but subconsiously monitors the ___ and ____ of nearly every skeletal msucle throughout the body. this input is vital to the maintenance of ____, fine control of _____, and corrective ____.
sarcomeres primary afferent secondary afferent dorsal alpha firing branches length tension posture movements reflexes
Surround somas of neurons in the ganglia; provide electrical insulation and regulate chemical environment of neurons
satellite cells
form neurilemma around all PNS nerve fibers and myelin around most of them; aid in regeneration of damaged nerve fibers
schwann cells
in the PNS, unmyelinated fibers are still enveloped by ___ ____
schwann cells
muscarinic receptors use ____ ____ systems. this affects ____ muscle, ____ muscle, and ______. different subclasses cause different ____. ACh _____ intestinal muscle and constricts pupils. ACh _____ cardiac muscle because it has a different subclass of receptors. ___ reverses the effects of ACh and is considered the _____ of ACh and it ____ HR.
second messenger cardiac smooth glands effects excites inhibits atropine antagonist increases
alpha-adrenergic receptors use the ____ ____ system and different subclasses cause different _____. this usually has a ____ effect such as in labor contractions which causes ____ to be the 2nd messenger. however, it can also be ____ when it lowers intestinal motility by preventing ___ production.
second messenger effects excitatory Ca++ inhibitory cAMP
when the signal reaches the end of a nerve fiber, the neuron releases a neurotransmitter that cross the gap and stimulates the next cell
secretion
in both the PNS and CNS, a nerve fiber is much longer than the reach of a single glial cell, so it requires many schwann cells or oligodendrocytes to cover one nerve fiber. consequently, the myelin sheath is ____. each gap between segments is called a ___ of ____. the myelin covered segments from each node to the next are called ____. the short section of nerve fiber between the axon hillock and the first glial cell is called the ___ ____. since the axon hillock and the initial segment play an important role in initiating a nerve signal, they are collectively called the ____ ___
segmented nodes of ranvier internodes initial segment trigger zone
the receptors for equilibrium include the ____ ___, ____ and _____
semicircular ducts utricle saccule
a subjective awareness of a stimulus
sensation
a ___ ____ is a structure that combines nervous tissue with other tissues that enhance its response to certain type of stimulus
sense organ
postsynaptically, neuromodulators change the ___ of the membrane
sensitivity
what type of neuron is sometimes unipolar
sensory
what type of neuron is usually bipolar
sensory
the hippocampus integrates ___ stimuli and ___ experience and associates it with a certain type of ____. it is active in when a person learns from ___ input during an experience and thus holds ___ ___ ____. memory relayed repeatedly during ___ is brought to the ___ where synapses are strengthened. long term memory is ____, but not ___ here. this is called ____ ____.
sensory cognitive response sensory short term memory sleep cortex formed stored memory consolidation
in reflexes, the stimulus goes to a receptor on a ___ neuron. this goes to the brain for _____ and also to the ____ ____ ____. from the brain, the output goes to the _____ neuron then to the _____ which causes an ____. this is _______ which means there are more than one synapse
sensory integration spinal reflex arc motor effector action polysynaptic
the PNS is functionally divided into ___ and ___ divisions and each of these is further divided into ____ and ____ subdivisions
sensory motor somatic autonomic
afferent neurons carry ___ info, ____ info, _____ info, and _____ senses
sensory somatic visceral special
neurons specialized to detect stimuli such as light, heat, pressure, and chemicals, and transmit info about them to the CNS
sensory (afferent) neurons
carries signals from various receptors (sense organs and simple sensory nerve endings) to the CNS. this pathway informs the CNS of stimuli within and around the body
sensory/afferent division
MDMA targets ______-releasing neurons. this causes a ___ of this and other NT such as _____ and ______. it also damages _____ which lead to problems ___, ____ loss, and _____
serotonin rush dopamine norepinephrine neurons sleeping memory depression
delta waves are found in adults in a deep ____. if these waves are dominant when awake, there is major ___ ____
sleep brain damage
all ___ muscle, ____ muscle, and ____ cells with cholingeric innervation have _____ receptors. there are different ____ of these receptors with different effects; thus ACh ___ intestinal smooth muscle by binding to one type of receptor and ____ cardiac muscle by binding to a different type. there receptors work through a variety of ____-____ systems
smooth cardiac gland subclasses excites inhibits second-messenger
the ANS innervates ___ muscle, ___ muscle, ___ glands, and ___ ___, but does NOT innervate ____ muscle
smooth cardiac salivary blood vessels skeletal
the autonomic system uses ___ muscle, controls ____ rate, and ____. this system has ____ control
smooth heart glands involuntary
o In the signal pathway for bitter and sweet taste, calcium rushes into the cytoplasm. Where does this come from?
smooth ER
____ ___ has high amounts of Ca++. Ca++ acts as a ____ ____ and triggers the release of ___
smooth ER second messenger NT
the control center of a neuron
soma/cell body
large nerve fibers require large ____ and a large expenditure of ___ to maintain them. slow unmyelinated fibers are quite sufficient for processes in which quick responses are not important, such as secreting ____ ___ or ___ the pupil. fast myelinated fibers are employed where speed is more important, as in motor commands to the ___ muscles and sensory signals for ___ and ____
somas energy stomach acid dilating skeletal vision balance
___ motor division carries signals to the skeletal muscles. this produces voluntary muscle contractions as well as involuntary somatic reflexes
somatic
the ___ sensory division carries signals from receptors in the skin, muscles, bones, and joints
somatic
the efferent division of the PNS is divided into the ___ system and ___ system
somatic autonomic
the RF functions in ___ motor control using the _____ tracts. it relays info dealing with ____ and ____ during movement. there are networks for ___ and ___ muscles
somatic reticulospinal posture balance breathing throat
visceral reflexes are similar to ____ reflexes. these have ____ responses. why? what are the 5 parts?
somatic slower last motor neuron is unmyelinated receptor sensory neuron integration center motor neurons effector
5 functions of the RF
somatic motor control cardiovascular control pain modulation sleep and consciousness habituation
4 functions of the reticular formation
somatic motor control pain control sleep and consciousness habituation
Reflexes include glandular secretion and contraction of all three types of muscle. the reflexes of skeletal muscle are called ___ ___. a somatic reflex employs a ___ ____ in which signals travel along the following pathway: (5)
somatic reflexes reflex arc receptor sensory neuron integrating center motor neuron effector
means that they carry sensory signals from bones, joints, muscles, and the skin in contrast to sensory input from the viscera or from special sense organs such as the eyes and ears
somatosensory
Integrate info received about temperature, pain, and vibration integrate sensory info
somatosensory association
___ ___ enter the auditory canal on one side and ___ ___ exit the inner ear on the other. the tympanic membrane moves in ____, vibrates easily, and the stapes must push against the ___ of the inner ear. if the tympanic membrane had fluid on one side and air on the other the sound waves would not have enough ___ to move the fluid. vibrations of the stapes against the inner ear normally have the same ____ as vibrations of the tympanic membrane against the malleus. the ossicles serve at times to ____ the transfer of energy to the inner ear. the ____ relfex muffles the transfer of vibrations from the tympanic membrane to the oval window. this reflex probably evolved in part for protection from ___ but slowly building natural sounds such as thunder. the middle ear muscles also help to coordinate ____ with hearing.
sound waves nerve signals air fluid energy amplitude lessen tympanic loud speech
rods during night vision combine their affects through ____ summation and stimulate the ganglion cell.
spatial
2 types of summation
spatial temporal
this occurs when EPSPs from several synapses add up to threshold at the axon hillock. any one synapse may generate only a weak signal, but several synapses acting together can bring the hillock to threshold. the presynaptic neurons collaborate to induce the postsynaptic neuron to fire
spatial summation
• Increase # neurons • Membrane coverage • Excitatory potentials from many neurons trigger threshold
spatial summation
are limited to the head, innervate by cranial nerves, and employ relatively complex sense organs. vision, hearing, equilibrium, taste, smell
special senses
___ ____ are limited to the head, and some employ relatively complex sense organs. they are ___, ____, ____, ___, and ____.
special senses vision hearing equilibrium taste smell
specific organs for reception eye, inner ear, tongue, nose
special sensory receptor
effectors in the muscles and body wall are innervated mainly by ____ fibers in the ___ nerves, effectors in the head and thoracic cavity by ____ nerves, and effectors in the lumbar region by ___ nerves
spinal sympathetic splanchnic
a cylinder of nervous tissue that arises from the brainstem at the foramen magnum of the skull
spinal cord
sensory input goes towards ____ ____
spinal cord
3 routes the SNS takes
spinal nerve sympathetic nerve splanchnic nerve
slightly distal to the ganglion, the anterior and posterior roots merge, leave the dural sheath, and form the ___ ___ ____. the nerve then exists the vertebral canal through the ____ _____. the spinal nerve is a ___ nerve carrying sensory signals to the SC by way of the ____ root and ganglion and motor signals out to more distant parts of the body by way of the ___ root
spinal nerve proper intervertebral foramen mixed dorsal ventral
sensory pathway that innervates the spinal cord
spinal nerve system
the spinal cord communicates with the rest of the body by way of the ___ ___
spinal nerves
Ascending and descending through white matter of spinal cord
spinal tracts
the cerebellum recieves feedback from the muscles and joint by way of the ___ tracts
spinocerebellar
• Muscle feedback (balance, position/equilibrium) • Spinal cord cerebellum • Posterior and anterior (smaller)
spinocerebellar
the _______ senses feedback from ____. the posterior decussates _____ and the anterior decussates in the ___ ____
spinocerebellar muscles no where SC
the ______ senses pain from tissue injury. it decussates in the ___ ____
spinoreticular SC
the _____ senses light touch, tickle, itch, temperature, pain, and pressure. it decussates in the ___ ____
spinothalamic SC
a patient has a gunshot wound that caused a bone fragment to nick the Sc. the patient now feels no pain or temp sensations from that level of the body down. most likely, the ___ was damaged
spinothalamic tract
What type of nerve do sympathetic fiber leading to the digestive system leave the ganglion chain through?
splanchnic
the sympathetic ganglion taking the splanchnic nerve route goes from the ____ ____ then returns to the ____ ganglia then to the ____. there is no ganglia ____. targets are in the ___, ____, and ____.
splanchnic nerves collateral target synapse liver, spleen, stomach
reflexes are not _____, they involve only a few _____ and have minimum ____ ____, are ___ which means they occur without our awareness and are automatic, and they are very ____
spontaneous interneurons synaptic delay involuntary predictable
a tiny bone that vibrates in the oval window and transfers sound vibrations to the ear
stapes
o Spherical, short dendrites & axons o Receive input from afferent fibers o 4th layer o Afferent sensory signals, where a lot of integration occurs, can then communicate with other cells
stellate cells
spherical somas with short axons and dendrites projecting in all directions concerned with receiving sensory input and processing info on a local level
stellate cells
Two major types of neurons in the cerebral cortex
stellate cells pyramidal cells
all impulses are the same ____ and ____
strength size
muscle spindles involve ___ ____
stretch receptors
The stretch reflex is initiated by ___ of _____ ____. it involves ____, _____/____, and _____
stretching of muscle spindles • Contraction • Posture/stabilization • Equilibrium
for salty and sour taste, higher levels trigger ___ graded potentials
stronger
the number of neurons is affected by _____. the more neurons that are stimulated, the ___ signal detected
stronger
is a neurotransmitter that transmits pain sensations to second-order spinal neurons
substance P
• Touch mouth, reflex of sucking • Helps acquire food
sucking reflex
the ____ ____ control the visual reflexes of the extrinsic eye muscles
superior colliculi
visual reflex
superior colliculi
2 parts of the corpora quadrigemina
superior colliculi and inferior colliculi
storage of vocabulary, memory of faces and objects are stored in the ____ ____ lobe. plans and social roles such as remembering a dr's app from 6 months ago are stored in the ___ lobe
superior temporal prefrontal
Alertness, heart rate, blood pressure, etc. this occurs during exercise, competition, stress, anger, fear fight or flight
sympathetic
adapts the body in many ways for physical activity increases alertness, HR, BP, pulmonary airflow, blood glucose concentration, and blood flow to cardiac and skeletal muscle, but at the same time, reduces blood flow to the skin and digestive tract
sympathetic
fight or flight
sympathetic
tends to arouse the body for action fight or flight
sympathetic
the adrenal medulla consists of modified postganglionic neurons of the _______ NS
sympathetic
the autonomic system is divided into the _____ and ____
sympathetic parasympathetic
2 divisions of ANS
sympathetic and parasympathetic
2 divisions of the ANS
sympathetic and parasympathetic
the sympathetic ganglion taking the sympathetic nerve route goes from the ____ ____ then returns to the ____ or ____ plexus then to the ___. this includes ___ glands, the ____, ___ BV, and ____ BV. this can go ___ or ____
sympathetic nerve carotid or cardiac target saliviary heart thoracic lumbar up down
the grey communicating ramus contains
sympathetic postganglionic fibers
the adrenal gland does not ____ and takes the _____ nerve route. this is located in the ____ and has _____ ganglion. it secretes ____ and _____ which together they are classified as _____
synapse splanchnic medulla sympathetic epinephrine norepinephrine catecholamines
neuromodulators surround important ____, do not directly cause ____ or _____, and affect strength of ______
synapses EPSP IPSP transmission
neurons communicate with other parts of the body through ____. this can be neuron to ____ which relays into through the ___ ___ or neuron to ___ ____ which goes to a ___ cell or ___
synapses neuron nervous system effector cell muscle gland
nicotinic receptors occur at all ___ in the autonomic ganglion, where the preganglionic fibers stimulate the _____ cells; on cells of the ____ ____; and at the neuromuscular junction of _____ muscles. the binding to ACh to a nicotinic receptor is always _____. nicotinic receptors work by opening ___-___ ion channels and producing an ____ postsynaptic potential in the target cell.
synapses postganglionic adrenal medulla skeletal excitatory ligand-gated excitatory
When bipolar cells detect fluctuations in light intensity, they stimulate ganglion cells either directly by ___ with them or indirectly via pathways that go to the ___ cells. ganglion cells are the only retinal cells that produce ___ potentials. ganglion cells respond to the bipolar cells with rising and falling ____. via the ___ nerve, these changes provide visual signals to the brain
synapsing amacrine action frquencies optic
by taking the splanchnic nerve route, postganglionic fibers pass through without ____. beyond the ganglia, they continue as ____ ____, which lead to a second set of ganglia called ___ ____. here, the preganglionic fibers ____ with the postsynaptic
synapsing splanchnic nerves collateral ganglia synapse
the gaps between neurons is called the _____ _____. some neurons, neuroglia, and cardiac and single-unit smooth muscle have ___synapses, where adjacent cells are joined by gap junctions and ions diffuse directly from one cell into the next. these junctions have the advantage of quick transmission because there is no ___ for the release and binding of neurotransmitter. electrical synapses cannot ____ info and make ____. the ability to do that is a property of ____ synapses, in which neurons communicate by neurotransmitters. these synapses are also the site of ___ and ____, the target of many prescription ___, and the site of action of drugs of ____.
synaptic cleft electrical delay integrate decisions chemical learning memory drugs addiction
___ ___ slows the transmission of nerve signals; the more synapses there are in a neural pathway, the ___ it takes information to get from its origin to its destination.
synaptic delay longer
the axon terminal contains ____ ____. the postsynaptic neuron lacks ___ ____ and cannot release _____. its membrane does, however, have neurotransmitter ____ and ___-gated ion channels
synaptic vesicles synaptic vesicles neurotransmitter receptors ligand
• Working together for a common movement • Ex: contact bicep muscle
synergist
stretch reflexes often feed back not to a single muscle but to a set of ____ and ____. since the contraction of a muscle on one side of a joint stretches the ____ of the other side, the flexion of a joint creates a stretch reflex in the _____, and extension creates a stretch reflex in the _____. consequently, stretch reflexes are valuable in stabalizing joints by balancing the ___ of the extensors and flexors. without stretch reflexes, a person's movements tend to be ____. stretch reflexes are especially important in coordinating vigorous and precise movements such as ____
synergists antagonists antagonist extensors flexors tension jerky dance
presynaptically, neuromodulators modify the ____ of NTs, alter ____ of NTs, decrease or increase the rate of ______, and control how much is ____ ____ or how much is ____ ___
synthesis release degradation broken down brought in
presynaptically, neuromodulators modify things in 4 ways
synthesis release degradation reuptake
with anosmia, one can experience mild loss of ____. olfactory neurons repair less with ____ and with too much exposure to _____
taste age salt
o Located on extensions/ends of papillae
taste buds
the _____ coordinates reflexive head turning in response to visual and auditory stimuli. it decussates in the ____
tectospinal midbrain
hearing, smell, emotion, learning, language comprehension and memory of grammar and vocab; memory consolidation; storage of verbal, visual, and auditory memories
temporal lobe
this occurs when a single synapse generates EPSPs so quickly that each is generated before the previous one fades. this allows the EPSPs to add up over time to a threshold voltage that triggers an AP. it can occur if even one presynaptic neuron stimulates the postsynaptic neuron at a fast enough rate
temporal summation
• Fire AP as fast as you can; send signals to postsynaptic cell • EPSP lasts 15 ms • Many excitatory potentials from one neuron trigger threshold • Sequential signals must be close together • Affected by refractory period; cannot be continuous
temporal summation
___ ____ are proprioceptors located in a tendon near its junction with a muscle. the ___ ____ is a response to excessive tension on the tendon. it inhibits ___ motor neurons to the msucles so the muscle does not contract strongly. this serves to moderate muscle contraction before it tears a tendon or pulls it loose from the muscle or bone. the tendon reflex also functions when some parts of a muscle contract more than others. it ____ the muscle fibers connected with overstimulated tendon organs so their contraction is more comparable to the contraction to the rest of the muscle.
tendon organs tendon reflex alpha inhibits
the hypothalamus is beneath the ____ and is an ___control center. it regulates _____.
thalamus endocrine homeostasis
each side of the brain has a ____ which is joined together by the ____ ____. it is the ____ to the cortex. nearly all input to the cerebrum pass by way of ____ in the thalamus including signals for ____, _____, ____, ______, ____ and general senses such as ___, _____, _____ and ____. it also serves in motor control by relaying signals from the _____ to the ______ and providing ____ ____ between the cerebral cortex and the basal nuclei. finally, it is involved in the memory and emotional functions of the ____ _____, a complex of structures that include some cerebral cortex of the temporal and frontal lobes and some anterior thalamic nuclei.
thalamus intermediate mass gateway synapses taste, smell, hearing, equilibrium, vision touch, pain, pressure, temp cerebellum cerebrum feedback loops limbic system
parts of the diencephalon
thalamus and hypothalamus
found in children and drowsy adults if in adults, there under emotional stress or have a brain disorder
theta
why are sensory neurons usually bipolar
they help relay info with special senses
the anterior regulates ____. this works with the _____ because they influence the amount of ____ that is present in the body
thirst supraoptic water
the sympathetic division is in the ____ and ____ regions. this contains ____ ____ which are paravertebral and parallel. the input in these chains are called the ___ ____.
thoracic lumbar ganglion chains white rami
all nerves of the sympathetic division arise from the ___ and ___ regions of the SC. its neurons are in the ____ horns and nearby ___ matter of the SC. its axons form a ____ _____ which is a longitudinal series of ganglia that lie adjacent to both sides of the vertebral column and is ______. they are interconnected by _____ nerve cords. it has ___ preganglionic fibers.
thoracic lumbar lateral grey ganglion chain paravertebral longitudinal short
action potentials are triggered at ___ which is ____mV
threshold -55
stimulus encoding is affected by different ___
thresholds
quantitative info-info about the intensity of the stimulus-is encoded in 2 ways. one depends on the fact that different neurons have different ___ of excitation. a weak stimulus excites sensitive neurons with the ___ thresholds, while a strong stimulus excites less sensitive ___ threshold neurons. bringing additional neurons into play as the stimulus becomes stronger is called ______. it enables the NS to judge stimulus strength by ___ neurons, and how ___ of them are firing. another way of encoding stimulus strength depends on the fact that the more strongly a neuron is stimulated, the more ____ it fires. thus, the CNS can judge stimulus strength from the firing ___ of afferent neurons. there is a limit to how often a neuron can fire, set by its ____ refractory period. mild stimuli excite sensitive, ___ threshold nerve fibers. as the stimulus intensity rises, these fibers fire at a ____ frequency, up to a certain maximum.
thresholds lowest high recruitment which many frequently frequency absolute low higher
in the BBB, Capillaries of brain tissue use _____ _____ _____. in the BBB, Choroid plexuses use ____ ___ of ____ ____ in the BBB, Large molecules use _____
tight endothelial cells tight junctions of ependymal cells transcytosis
autonomic ____ is the balance between both divisions with their shifts in accordance with the body's changing needs. _____ tone is smooth muscles in intestines & slow heart rate and ____ tone is blood vessels partially constricted
tone parasympathetic sympathetic
type A fibers sense ___, ___, ___, ___, and innervate ___ ___ muscle fibers
touch pressure heat pain efferent skeletal
somatosensory signals are for ____, _____, ____, ____, and ____. one of the most important sensory roles of these nerves is ______ in which the brain receives info about body ____ and _____ from nerve endings in the muscles, tendons, and joints. the brain uses this info to adjust muscle actions and therefore maintain ____ and ____. the motor function of these nerves is to stimulate the ____ of ____ muscles
touch temp pressure pain stretch proprioception position movements equilibrium coordination contraction skeletal
bundle of axons traveling in CNS
tracts
white matter is in the ____ of axons, are ____ axons, and ___ signals
tracts myelinated relay
Involves both endocytosis and exocytosis what is an example?
transcytosis insulin
activation of pathways
transduction
the anterior half of the pons is dominated by tracts of ___ matter, including ______ fascicles that cross between left and right and connect the 2 hemispheres of the cerebellum, and _____ fascicles that carry sensory and motor signals up and down the brainstem
transverse longitudinal
the pons have ____ and ____ tracts. crainial nerves ___-___ are here and deal with ___ sensation and motor, ____, ____, and _____
transverse longitudinal 5-8 facial equilibrium hearing taste
the frequency of AP is detected at ___ zone, which is initiated by ___ potentials. the stronger the stimulus, the higher the ____
trigger graded frequency
Spindles are especially concentrated at the ends of a muscle, near its tendons. True or false
true
T/F: a myelinated and larger axon produces a faster signal
true
olfactory cells are neurons and the only cells exposed to the external environment and are replaceable T/F
true
• Largest diameter; thickest • Myelinated • Touch, pressure, heat, pain, innervate efferent skeletal muscle fibers o Fiber = axon • Conduct the fastest signal
type A
3 types of fibers
type A type B type C
• Medium diameter • Myelinated • Fast, but not as fast as Type A • Viscera to CNS (sensory), autonomic (involuntary) axons from CNS to relay centers (smooth muscles and glands) o Ex: stretch signals in stomach
type B
which type of fiber is the least likely to be affected by MS
type C
• Smallest diameter; narrowest • Non-myelinated • Other pain, touch, heat, autonomic branches from relay centers • Stimulate heart, smooth muscle, glands • E.g. dilating pupils, bladder, heart rate (vagus nerve)
type C
1 projection coming off the cell body
unipolar
have a single process leading away from the soma neurons that carry signals to the spinal cord for senses such as touch and pain
unipolar
ascending tracts are going ___ and are carrying ____ info and descending tracts are going ____ and are carrying ___ info
up sensory down motor
• Neurotransmitter transporters to carry back into presynaptic cell • Endocytosis into the cell
uptake by cells
most P pregnaglionic fibers are found in the ____ nerve
vagus
the ____, _____, _____, and _____ cranial nerves carry parasympathetic fibers
vagus facial oculomotor glossopharyngeal
sympathetic fibers to blood vessels maintain a state of partial vasoconstriction called ____ ___
vasomotor tone
CSF is formed in the ____ by the ___ _____. the ventricles contain ___ cells and the ____ ____. it is then filtered by the ____. ependymal cells have ___ juctions and add ____ and removes ___, ___, ___ and ____
ventricles choroid plexus ependymal choroid plexus capillaries tight NaCl K+ Ca++ glucose protein
the brain has 4 internal chambers called _____. the largest are the 2 ____ ventricles, which form an arc in each cerebral hemisphere. through a tiny hole called the _____ _____, each lateral ventricle is connected to the ____ ventricle, a narrow median space inferior to the corpus callosum. from here, a canal called the ___ ___ passes down the core of the midbrain and leads to the ___ ventricle, a small triangular chamber between the pons and cerebellum. this space narrows and forms a ____ ____ that extends through the medulla into the SC. on the floor or wall of each ventricle is a spongy mass of blood capillaries called a _____ ____. ___, a type of neuroglia that resembles a cuboidal epithelial, lines the ventricles and canals and covers the choroid plexuses. it produces ____
ventricles lateral interventricular foramen 3rd cerebral aqueduct 4th central canal choroid plexus ependymal CSF
in spina bifida occulta, a small gap forms between _____ and is not always noticeable.
vertebrae
in myelomeningocele, several ____ are affected. Spinal ____ and ____ protrude through space
vertebrae nerves and tissues
The brain has 4 chambers called ______________ filled with ______________ fluid.
vesicles CSF
the primary target of the ANS are ___ of the thoracic and abdominopelvic cavities and some structures of the body wall, the ANS usually carries out its actions ____
viscera involuntarily
type B fibers deal with ___ to CNS which are ____, ___ (______) axons from CNS to relay centers such as ___ muscles and __
viscera sensory autonomic involuntary smooth glands
the ___ sensory division carries signals mainly from the viscera of the thoracic and abdominal cavities, such as the heart, lungs, stomach, and urinary bladder
visceral
the ANS is responsible for the body's ___ reflexes-unconscious, automatic, stereotyped responses to stimulation. the ANS involves a visceral reflex arc that includes ____ (nerve endings that detect things like stretch, tissue damage, blood chemicals, body temp), ___ neurons leading to a ____ _____ and interneurons in the CNS, ___ neurons carrying motor signals away from the CNS and an ____ that carries out the end response
visceral receptor afferent integration center efferent effector
the responses of the ANS and its effectors are called ____ ____
visceral reflexes
3 examples of electrical synapses in the body
visceral smooth muscle: coordinated action of digestion optic pathway is highly integrated die to so many signals coming in at one time cardiac muscle
perception of objects in the environment by means of light they emit or reflect
vision
Integrate visual info
visual association
potential energy stored creates a ____. what is the RMP
voltage -70 mV
if the cell body is positive enough, it will trigger ____-gated ____channels
voltage Na+
when an action potential is reached, ____-gated ___ channels open and the membrane is _____. action potentials are ___ or ____
voltage Na+ depolarized all or nothing
self-depolarization leads to all ___-gated ___ channels to open. the potential becomes more ___ which is ____mV
voltage Na+ positive +30
the action potential is a rapid up and down shift in ____. when the local potential arrives at the axon hillock, it _____ the membrane. the local potential must rise to a critical voltage called the ___ which is the minimum needed to open voltage-gated channels. the neuron now fires an ___ potential. at threshold, voltage-gated ___ channels open quickly, while gated __ channels open more slowly. the initial effect on the membrane is due to ____. as Na+ enters the cell, it further ___ the membrane. this stimulates more voltage-gated ___ channels to open and admit even more, causing the membrane voltage to rise even ___. as the rising potential passes 0 mV, Na+ channels are ____ and begin ___. by the time they all close and all Na+ inflow ceases, the voltage peaks at approximately ____mV. the membrane is now ___ on the inside and __ on the outside. by the time the voltage peaks, the slow __ channels are fully open. __ ions, repelled by the positive ICF, now exit the cell. their outflow ____ the membrane: it shifts the voltage back into the ___ numbers. __ channels stay open longer than __ channels, so slightly more __ leaves the cell. this causes the voltage to drop more, producing a negative overshoot called ______. Na+ and K+ switch places across the membrane during an action potential. during hyperpolarization, the membrane voltage gradually returns to the ___ because of Na+ diffusion into the cell and the removal of extracellular K+ by ____.
voltage depolarizes threshold action Na+ K+ Na+ depolarizes Na+ more inactivated closing +35 positive negative K+ K+ repolarizes negative K+ Na+ K+ hyperpolarization RMP astrocytes
An electroencephalogram (EEG) measures rhythmic ___ changes in the cortex. it is determined by ____ potentials in the superficial ___ layer. it monitors brain activity in how many ____ ___ are fired. it studies brain function such as in ___ and _____. it helps to diagnose brain ___, ___, and _____ by watching patterns of ___ fluctuations to determine ____ vs _____.
voltage postsynaptic cortex action potentials sleep consciousness diseases tumors trauma voltage normal abnormal
• Need electric stimulation
voltage gated
• Integrates ~5-6 months • Once feet are in contact, infant tries to step
walking/stepping reflex
CSF rinses metabolic ___ from the nervous tissue and regulates its ____ environment
wastes chemical
the color of light is determined by
wavelength
the ____ is responsible for the recognition of spoken and written language. when we intend to speak, this area formulates phrases according to learned rules of grammar and transmits a plan of speech to the _____. this area generates a motor program for the muscles of the larynx, tongue, cheeks, and lips to produce speech. it transmits this program to the ___ ___ cortex
wernicke broca primary motor
most of the volume of the cerebrum is ___ matter. this is composed of ___ and ___ nerve fibers that transmit signals. these fibers form bundles, or tracts, of 3 kinds:
white glia myelinated projection commissural association
myelinated Sending signals to somewhere else Info highways
white matter
7 major components of the spinal cord
white matter grey matter dorsal root ganglion dorsal root ventral root dorsal horn ventral horn
where is the conduction zone
whole length of axon
what are 2 examples of a parallel after-discharge circuit? this involves ____ lasting ___ movement
withdrawl reflexes staring at light longer effector
why are all of our nerve fibers not large, myelinated, and fast?
would make our NS bulky or limited
o Arm sensation and position
• Cuneate fasciculus
grey matter contains ____, ____, and _____ and is located in the _____ and ____ centers. one may find what type of neuron in grey matter?
• Neurosomas • Dendrites • Synapses • Cortex, integration centers interneurons
2 examples of gas NTs these are synthesized as _____ rather than stored in synaptic vesicles, ___ out of axon terminal rather than exocytosis, and diffuse into ______ neuron than bind to a receptor
• Nitric oxide (NO) • Carbon monoxide (CO) needed diffuse postsynaptic
5 components of the spinal reflex arc
• Receptor • Sensory neuron • Integration center o Interneuron • Motor neuron • Effector
5 types of taste
• Sweet • Salty • Sour • Bitter • Umami
somatosensation describes _____, ______, _______, and senses ____, _____, ____, ____, _____. these receptors are located throughout the body/in certain areas
• Touch, proprioception, interoception • Pressure, vibration, itch, pain, temp. receptors throughout the body
