mcat biology chapter 12 nervous system kaplan

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nerv syst lets org resp to: stimuli
fuct units of nerv syst: neurons
neuron consists of: dendrites, cell body, axon
____________ receive inform and transmit towards the body: dendrites
soma is: neuron cell body
Axon hillock does what?: connects the cell body to the axon
____________ transmits impulses away from cell body: axon
myelin is ?: insulating susb that covers axons
glial cells make?: myelin
Who make myelin in the cns?: oligodendrocytes
who makes myelin in the pns?: schwann cells
when an auto immune disease destroys the myelin what happens: slows information transfer.
name one common demyelinating disorder?: multiple sclerosis
the myelin of what is select targeted in ms?: myelin of brain and spinal cord
ms patients symptoms?: weakness, lack of bal, vision prob, incont
nodes of ranvier?: gaps betw segm of myelin
______________ are gaps betw segm of myelin: nodes of ranvier
axons end in swellings called?: synaptic terminals or symaptic boutons
what are released from the synapse?: neurotransmitters
synaptic left is?: gap betw axon and dendrites of next neuron cell
nerve impulses are?: action potentials
action potentials travel the lenght of the ______________: axon
resting potential: pot diff betw extracell space and intracell space
typical ret membr potent is ?: -70 millivolts
inside of the neuron is ________________ compared to outside: more negative
membr potent of neur is maintained by: na+/K+ pump
na+/K+ pump is also called?: na+/K+ ATPase
concentr of K+ is higher where?: inside the cell
concentr of na+ is higher where?: outside the c
t or f negative charged prot are trapped outside the c: F
they are trapped inside the cell
neurons do not allow much of what to enter the cell?: Na+
Na+/K+ pumps what?: 3 Na+ out for every 2 K+ in.
depolarized neurons become?: less negative
a depolarized neuron bec less?: negative
what is the minimum threshold membr potent?: around -50 mV
Na+ wants to go into the c bec of what 2 things?: electr gradient and chem gradient
an act potent begins when?: volt gated na+ channels open
Na+ goes down its?: electrochem gradient
after na+ gates open what happens?: voltage gated k+ channels open, letting k+ rush out of the c. making cell more negat again
when k+ rushes out of the c it returns the c to a ?: negative potential
cell can become more negat than its resting state. this is called?: repolarization
hyperpolarization is due to: K+ rushing down its electrchem grad (moving out of the cell)
refract period: after act potent, when its hard to start anoth act potential
action pot is often descr as a: all or none response
neuron informat is coded by?: freq and number of act potential but not the size of the act potent
________________ does not code for neuron informat: size of the act potent
puffer fish prod what toxin?: tetrodotoxin
TTX is: tetrodotoxin
tetrodotoxin does what?: blocks the voltage gated na+ channels
local anesthetics work by: blocking teh voltage gated na+ channels
why do local anesthetics work well on sensory neurons?: cause sens neurons have small axonal diam and have little of no myelin. it makes it easier to prev act potent
act pot is initiated at?: axon hillock
as na+ rushes into the neuron and diff into adj parts of the axon it causes what?: other nearby volt gated na+ channels to open
what chain of events happens along the length of the axon?: depolarization followed by subsequent repolarization
inform transf occurs in _____________ direction: one
action pot are propagated in what direct?: dendrite to synaptic terminal
refractory periods make what impossible?: backward travel of action potent
as diameter and amount of myelination incr _____________________: impulses travel faster
myelin ____________________ segments of the axon: insulates
salotatory conduction is when: act potential jumps from node to node
effector cells: cells in muscles or glands that communic w neurons
most synapses are __________: chem synapses
nerve term has membr bound vesicl with?: neurotransmitters
neurotransmt diff across synapse and acts on ?: recept proteins
the symaptic vesicles fuse w presynaptic membr thr a ________________ process of exocytosis: calcium depend
neurotransm can have what 2 effects?: inhib or excitatory
3 ways neurotransm is removed from synapse: 1. taken back up thr uptake carrier
2. degraded by enzymes like acetycholinesterase
3. just diffuse out
which enzyme inactiv acetycholine: acetylcholinesterase
what protein takess the neurotransm back up into nerve terminal?: uptake carrier
afferent neurons are?: sensory neurons
efferent neurons are?: motor neurons
afferent neurons carry information to?: brain or spinal cord
nerves that carry commands from brain to body are?: efferent neurons
interneurons are?: local circuits, cell bodies and nerve term are in same place
nerves are _______________: bundles of axons
sensory nerve has only: sensory fibers
mixed nerve has?: both sensory and motor fibers
ganglia are?: clusters of neuronal cell bodies
clusters of neuronal bodies in cns are called?: nuclei
nerv system is divid into?: cns and pns
amyotrophic lateral scelrosis affects only: motor neurons
ALS is also called: lou gehrig's disease
ALS stands for: amyotrophic lateral sclerosis
central nerv syst is made up of?: brain and spinal cord
periph nerv syst is made up of?: somatic and autonomic nerv systm
autonomic nerv syst is made up of?: sympathetic and parasympathetic nerv systm
brain consists of what kinds of matter?: gray matter and white matter
in the brain, gray matter is?: cell bodies
white matter in the brain is?: myelinated axons
name 3 major parts of brain?: forebrain, midbrain, and hindbrain
Brain The forebrain consists of?: telencephalon and diencephalon
Telencephelon consists of?: righ and left hemispheres
The right and left hemispheres of the telencephelon have what 4 lobes?: frontal, parietal, temporal, and occipital
Cerebral cortex is a major compon of?: telencephelon
cerebral cortex is?: highly convolut gray matter
cerebral cortex does what?: proc and integr sens input and motor resp. It is important for memory and creative thought
right and left cerebr cortices communicate thr?: corups callosum
diencephelon contains?: thalamus and hypothalamus
Thalamus is?: relay and integrat center for spinal cord and cerebral cortex
hypothalamus controls?: hunger, thirst, sex drive, water bal, bl press and and temper regulat and is imp in endocr systm
alcohol has a big effect on what part of the brain?: cerebellum
midbrain is ?: elay center for visual and audit impulses and is imp in motor contr
hindbrain is made up of?: cerebellum, pons, and medulla
cerebellum does what?: modul motor impulses init by motor cortex.
What part of the brain is imp in balance, hand eye coordin and rapid movements?: cerebellum
pons does what?: acts as relay center to let the cortex commun with the cerebellum
The pons helps the ___________ to communiate w the cerebellum: cortex
medulla oblangata controls?: breathing, heart rate, gastrointest activ,
brainstem is made up of?: midbrain, pons, medulla
midbrain, pons, and medulla make up the?: brainstem
spinal cord goes down the ____________ side of vertebrates: dorsal
spinal cord has outer _____________ and inner ______________: outer white matter, inner gray matter
in spinal cord, outer white matter has?: motor and sensory axons
in spinal cord, inner gray matter has?: nerve cell bodies
sensory informat enters the spinal cord?: dorsally
cells of sensory neurons are locat in ?: dorsal root ganglia
motor informat exits the spinal cord?: ventrally
IN the spinal cord roots are?: nerve branches entering and leaving the cord
spinal cord is made up of what 4 regions?: cervical, thoracic, lumbar, sacral
pns has 12 pairs of?: cranial nerves
Pns has _______ pairs of cranial nerves and _________ pairs of spinal nerves: 12 pairs of cranial nerves and 31 pairs of spinal nerves
pns has what 2 primary divisions?: somatic and autonomic nerv syst
somatic nerv syst is resp for?: voluntary movement
motor neurons release what neurotransm?: ACh
somatic nerv syst is resp for volunt movement and ?: reflex action
name 2 types of reflexes?: monosynaptic and polysynaptic
describe a monosynaptic reflex?: one synapse betw sens and motor neuron
in knee jerk reflex what senses the hit of the hammer?: stretch receptors
in what disease does the body do an immune react against acetycholine recept on skel muscle?: myasthenia gravis
in myasthenia gravis what happens?: immune syst attacks Ach recept on skel muslce
withdrawal reflex is a ____________ reflex: polysynaptic reflex
withdrawal reflex is a ?: polysynaptic reflex
in a polysynaptic reflex sesnory neurons?: symapse w more than one neuron
In withdrawal reflex one leg ___________ , and one leg?: one leg moves off the nail and one leg extends to keep your balance
ANS is: autonomic nervous system
ANS innvervates?: cardiac and smooth muscle
name 4 places where smooth muscles is found?: bl vess, dig tract, bladder, bronchi
ANS has a ______________ system: 2 neuron system
what are 2 neurons of ANS?: preganglionic neuron and postgangionic neuron
in ANS preglionic neuron has a cell body in the>?: CNS
The axon synapse of the ANS preglionic neuron is in ?: peripheral ganglia
postganionic neuron has its cell body _______________ and synapses on ______?: cell body in ganglia, synapses on cardiac or smooth muscle
ANS is made up of?: sympathetic and parasympathetic nerv systm
fight or flight comes from?: symp nerv syst
sympath nerv syst does what to the body?: incr bl press and hr, incr bl flow to sk muscles and decr gut mobility
in sympath nerv syst, the preganglionic neurons emerge from?: thoracic and lumbar regions of spinal cords
symph nerv syst the preganglionic neurons use?: Ach
symp nerv syst the postganglionic neurons release?: norepinephrine
first neuron in ans is called ?: preganglionic neuron
second neuron in ans is called ?: postganglionic neuron
the preganglionic symp neurons cause the adrenal medulla to ?: release adrenaline
Which neurons of the ans cause adrenal medulla to release adrenaline (epinephrine): preganglionic neurons
parasymph system is the ?: rest and digest
Which part of ANS does "rest and digest"?: parasymph nerv systm
parasymp does what to hr?: lowers it
vagus nerve is part of ?: parasymp nerv syst
Which nerve innervates many of thoracic and abdom viscera?: vagus nerve
parasymp nerves originate in?: brainstem (cranial nerves) and sacral part of spinal cord
parasym ns pregangl and post gangl neurons release?: Ach
sympath ns has short preganglionic and long?: post ganglionic axons
sympath ns has short ___________ and long ________________: short pregangl and long postganglionic axons
parasymp ns has long ?: long preganglionic ns
Parasym has short?: post gangl axons
what is presbyopia?: as you get older, the lens bec less elastic
as you get older your lens has a harder time "rounding up" this is called?: presbyopia
body has what 3 types of receptors?: interoceptors, propioceptors, and exteroeptors
interoceptors monitor?: inter envir like bl press, parti press of CO2 and bl ph
propioceptors monitor?: posit of body in space
where are propioceptors located?: muscles, tendons
what type of sensory receptor is in the inner ear?: proprioceptors
exteroceptors sense what?: light, sound, taste, pain, touch, and temperat
eye is covered by a thick opaque layer called?: sclera (white of the eye)
what is beneatht the sclera of the eye?: choroid layer
choroid of the eye does what?: supplys retina w blood
The thick opaque layer of the eye is called?: sclera
What layer of the eye has photoreceptors?: retina
what bends and focuses light?: cornea
after light is bent by cornea, it goes thr an opening called?: pupil
Iris does what?: controls the diameter of the pupil
The __________ contrls the diam of the pupil: iris
t or f iris is pigmented: true
What is suspended behind the pupil?: the lens
what contr the shape of the lens?: the ciliary muslces
the lens focuses the image on the ?: retina
The retina has ?: photoreceptors
Photoreceptors transduce ?: light into action potentials
2 types of photoreceptors?: cones and rods
cones are sens to ?: color
rods detect ?: low intensity light,
which photorecp is imp in night vision?: rods
cones pigments absorb what 3 colors?: red, green and blue
what is the rod pigment?: rhodopsin
photorecept cells-----> bipolar cells ----> ?: ganglion cells
right and left optic nerves are made up of?: bundles of axons of the ganglion cells
blind spot in eye is where?: the optic nerve exits the eye.
in the eye, the fovea has?: lots of cones
the fovea is import for: high acuity vision
where does the eye secrete aqueous humor?: near base of iris
aqueous humor travels to?: anterior chamber of the eye
lens of the eye is a ___________ lens: convex lens
the ear transduces?: sound energy (pressure waves)
ear does what 2 things?: 1. transduces sound e
2. equil
outer ear is?: auricle (pinna)
auditory canal
tympanic membrane is at the end of?: auditory canal
middle ear is made up of?: tympanic membrane
what are the ossicles?: malleus, incus, stapes
what do the ossicles do?: amplify the stimulus and transm it thr oval window
oval window leads to?: fluid filled inner ear
inner ear consists of?: cochlea and semicircular canals
organ of corti is in?: the cochlea
organ of corti have what specialized sensory cells?: hair cells
when the ossicles vibrate it exerts pressure on?: fluid in cochlea, stim hair c to transduce press into act potentials
what do the hair cells do?: transd the press into action potent
action potent made by hair c are carried to brain by?: auditory nerve
whats the oth name for audit nerve?: cochlear nerve
the 3 semicirc canals are _________ to each other: perpendicular
the 3 semicirc canals are filled w?: endolymph
what is at the base of each semicirc canal?: chamber w hair c
brain uses infor from semicirc canals to?: determ position of the head
the vestibulocochlear nerve is composed of?: cochlear and vestibular nerve
cranial nerve VIII is?: the vestibulocochlear nerve
chemical senses are?: taste and smell
gustatory and olfactory are?: taste and smell
taste buds are located on?: tonge, soft palate, and epiglottis
taste bud consists of?: 40 epithelial c.
taste pore w microvilli or taste hairs.
what emerges from taste pore?: microvilli or taste hairs
gustatory infor travels to ?: brainstem thr 3 cran nerves
what are the four kind of taste sensations?: sour, salty, sweet, and bitter
taste buds resp preferentially to?: on of the four stimuli
olfactory recept have?: olfactory hairs or cilia
an odor cause the the olfact recept to?: depolarize
olfactory nerves?: made up of axons from olfact recept
olfact nerves go to what part of the brain?: olfactory bulbs in the base of the brain
where are olfactory bulbs located?: in the base of the brain

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Number of cards 234