Nerves Flashcards by User Unknown

all cells have a resting potential t/f

true. ALL CELLS NOT just excitable cells have a resting potential.

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resting potential means the interior/exterior is negative with respect to the other

interior

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resting potential is _ in excitable cells

-70mV

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name two excitable cells

muscle and neurons

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in neurons the action potential is called

nerve impulse

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as sodium flood the cell during initial depolarization the membrane potential can reach as high as

+55mV (inside positive)

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depolarization is reducing or increasing the charge across the membrane

reducing

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threshold voltage is

-50mV

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neurilemma

aka sheath of Schwann/Schwann’s membrane or neurolemma = thin membrane spirally enwrapping the myelin layers of certain fibers especially those of the PERIPHERAL NERVES, or the axons of UNMYELINATED NERVE FIBERS

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all axons of the (CNS/PNS) have a sheath of Schwann cells (neurilemma)

PNS only. CNS does not have neurilemma = this is why regeneration of these severed axons is more difficult

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in the CNS myelin sheaths are called

oligodendrocytes

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right sided lesions of the spinal cord result in loss of motor activity on the _ side, and pain and temperature sensations on the __ side

lose motor activity on the SAME (ipsilateral) side, and pain and temperature lost on the opposite side (contralateral)

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the primary action of local anesthetics in producing a conduction block is to decrease the permeability of the ion channels to __ions

sodium.

anesthetic will displace the calcium ions from the sodium channel receptor site allowing synesthetic molecule to bind the site, blocking the sodium channels ==> decrease sodium conductance ==> decreases rate of electrical depolarization –> fail to reach threshold potential level so no propagated AP = called CONDUCTION BLOCKADE

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nerve block produced by local anesthetics is called

non-depolarizing nerve block

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local anesthetics reversibly/irreversibly block nerve impulse conduction

reversibly = therefore loss of sensation at site.

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the site of action of local anesthetics is at the ___ of the nerves

lipoprotein sheath

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local anesthetics are effective on?

free nerve endings and on axons

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which are affected first by local anesthetics:

skeletal muscle tone, proprioception, touch myelinated nerve fibers

small, myelinated nerve fibers which conduct pain and temperature are affected FIRST. followed by touch, proprioception and skeletal muscle tone

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emergence from a local anesthetic nerve bock follows the same diffusion patterns as induction does except in

reverse order

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recovery from local anesthesia is usually slower/faster process than induction because the anesthetic is bound to the drug receptor site in the sodium channel and therefore is released more ___ than absorbed.

slower

slowly

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when a local anesthetic is given which conductance is changed and which are not affected: Calcium/chloride/potassium/sodium

only sodium changes!

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what is the function of the lateral spinothalmic tract:

a. discriminating touch and pressure sensations
b. unconscious kinesthesia
c. pain, temp, and crude touch;opposite side
d. crude touch and pressure

lateral spinothalmic =

pain, temp, and crude touch; opposite side

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what is the function of the anterior spinothalmic tract

a. discriminating touch and pressure sensations
b. unconscious kinesthesia
c. pain, temp, and crude touch;opposite side
d. crude touch and pressure

crude touch and pressure = anterior spinothalmic

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function of anterior and posterior spinocerebellar tract

a. discriminating touch and pressure sensations
b. unconscious kinesthesia
c. pain, temp, and crude touch;opposite side
d. crude touch and pressure

unconscious kinesthesia

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function of fasciculi gratis and cuneatus a. discriminating touch and pressure sensations b. unconscious kinesthesia c. pain, temp, and crude touch;opposite side d. crude touch and pressure

discriminating touch and pressure sensations

the white/gray matter of the spinal cord contains tracts that travel up and down the spinal cord

white

_tracts are sensory

ascending

_ tracts are motor

descending

you can tell by the name of tract if they are ascending or descending (usually). most ascending tracts start with "spino" indicating origin in the spinal cord and name ends with the part of the brain that the tract leads to. for example the spinothalmic tract travels from where to where?

spine to thalamus

1. tracts whose names begin with a part of the brain are __

motor

is the corticospinal tract motor/sensory

motor (it starts with a part of the brain-cerebrum) and goes down towards motor neurons in the cord.

the origin of a spinal tract refers to the

location that the cell body of the tract lies

the termination of a spinal tract refers to

where the axon terminates

spatial summation occurs when two excitatory inputs arrive at a postsynaptic neuron in rapid succession or simultaneously?

at the same time (simultaneously)

neurotransmitters that are EXCITATORY will increase the probability of causing an

action potential in the postsynaptic neuron = an excitatory postsynaptic potential (EPSP)

neurotransmitters that are INHIBITORY will decrease the probability of causing an

action potential in the postsynaptic neuron = an inhibitory postsynaptic potential (IPSP)

Can the same NT be excitatory to one receptor and inhibitory effect on another?

yes

there are 2 forms of summation by which EPSPs may combine to reach threshold and initiate an AP: called?

temporal and spatial summation

in spatial summation two excitatory inputs (from multiple presynaptic fibers) arrive at a postsynaptic neuron in rapid simultaneously and produce a greater

depolarization

in temporal summation 2 excitatory inputs arrive at post synaptic neuron in __

rapid succession

in temporal summation 2 excitatory inputs arrive at post synaptic neuron in rapid succession. this causes an increase in

the FREQUENCY OF NERVE IMPULSES in a single presynaptic fiber

if an AP is initiated at the midpoint along the length of an axon it will spread towards the

cell body (soma) and nerve endings

Saltatory conduction occurs in _ neurons only

myelinated

Saltatory conduction: conduction is faster/slower? | consumes more or less energy?

faster and consumes LESS energy | 100 meters/second

Continuous conduction (the opposite of salutatory conduction) occurs in _ nerves

unmeylinated, relatively SLOW (1.0meter/sec)

T/F the myelin sheath decreases membrane capacitance and increases membrane resistance preventing movement of sodium and potassium through the membrane

true

salutatory conduction is of value of value for 2 reasons: 1. increases _ of nerve transmission 2. __energy for the axon bc ONLY THE NODES OF RANVIER DEPOLARIZES

1. velocity | 2. conserves

conduction velocity depends on diameter and presence of nerve myelin sheath. the larger/smaller the diameter of a nerve the faster the conductance velocity.

larger diameter = faster = bc reduces resistance to flow smaller diameter = slower

T/F in most cases acetylcholine has an inhibitory effect

false. AcH is most often an EXCITATORY NT

T/F GABA is believed to ALWAYS cause inhibition

true

excitatory NT's from the presynaptic membrane opens channels in the postsynaptic membrane that leads to an increase in the concentration of ___ w/in the postsynaptic cell and a decrease of __ ions.

increase sodium decrease potassium = this leads to depolarization of the postsynaptic cell which is propagated further along the cell membrane by an AP

inhibitory NT's encourage _ of the postsynaptic cell, making it less likely to generate an AP

hyperpolarization

hyperpolarization created by inhibitory NT's is achieved by either increasing the flow of __ ions out of the cell or increasing __ ions into the cell.

increasing Cl- into the cell or increasing K+ out of the cell = both ways make the inside of the cell more negative

if GABA bind a GABA A receptor which occurs: increasing Cl- into the cell or increasing K+ out of the cell

GABA A = Cl- flow into the cell

if GABA bind a GABA B receptor which occurs: increasing Cl- into the cell or increasing K+ out of the cell

GABA B = K+ out of the cell to remember (think A is closer to Cl-) than and B is closer to K)

whether a NT acts in an excitatory or inhibitory manner is determined by

the kind of receptor it binds-not the NT!!!

where does AcH act as an inhibitor?

inhibition of the heart by the vagus nerves

Norepinephrine usually act as excitatory/inhibitory?

usually act as excitatory

Dopamine usually act as excitatory/inhibitory?

inhibitory

serotonin usually act as excitatory/inhibitory?

inhibitor of pain pathways in spinal cord and brain

1. glutamate is ALWAYS excitatory/inhibitory? 2. GABA is ALWAYS excitatory/inhibitory? 3. glycine is ALWAYS excitatory/inhibitory?

1. excitatory 2. inhibitory 3. inhibitory

nitric oxide = changes intracellular that modify neuronal __ for seconds, minutes or longer

excitability

Monamine oxidase (MAO) is an enzyme that CATALYZES the oxidative DEAMINATION of monoamines such as

NE, serotonin, and epinephrine

deamination by Monamine oxidases(MAO) is helpful because it

metabolizes excess neurotransmitters that may build up at postsynaptic terminals

Parkinson's disease affects which part of the brain

basal ganglia

basal ganglia is important for controlling _ movement and establishing _

voluntary movement and establishing posture

Huntington's disease affects which part of the brain

basal ganglia

when the ___ altered the person has unwanted movements ex. involuntary jerking, spasm movements of facial muscles

basal ganglia Huntington's disease Parkinson's disease

the striatum of the basal ganglia refers to what 2 nuclei? caudate putamen globus pallidus

caudate nucleus and putamen = striatum

striatum gets its name bc it appears

striated

lentiform nucleus is the combo of what basal ganglia nuclei? caudate putamen globus pallidus

putamen and globus palidus

1. putamen and globus palidus | 2. putamen and caudate nucleus

1. putamen and globus palidus =Lentiform nucleus (to remember look at the word Lentiform (L) = gLobus paLLidus 2. caudate and putamen = striatum

basal ganglia and cerebellum = large collections of nuclei that modify movement. they communicate to each other via the ___ and what neurotransmitter?

thalamus dopamine via a direct and indirect path

1. output of cerebellum is excitatory or inhibitory? | 2. output of basal ganglia is excitatory or inhibitory?

1. excitatory | 2. inhibitory

the cerebellum is __ to the cerebrum

posterior

cerebellum is above/bellow the pons and medulla

above

cerebellum is divided into

2 lateral hemispheres and a middle portion

2 functions of cerebellum

maintain equilibrium and muscle coordination

the major parts of the extrapyramidal system are the subcortical nuclei which are the?

basal ganglia nuclei

the two classes of AcH receptors in autonomic ganglia

nicotinic and muscarinic

main type of neuron in autonomic ganglia

postganglionic

the classic NT of autonomic ganglia whether sympathetic or parasympathetic is

AcH

Nicotinic receptors are stimulated by: | AcH/nicotine/muscarine

AcH and nicotine | NOT MUSCARINE

nicotinic receptors are found at _ ganglionic synapses and at neuromuscular junctions and adrenal medulla.

all

nicotinic receptors produce excitation and a __ EPSP which causes ion channels to open

fast

1. curare blocks what receptors? | 2. hexamethonium blocks what receptors

both nicotinic

muscarinic receptors are stimulated by: | AcH/nicotine/muscarine

AcH and muscarine | BUT NOT NICOTINE

muscarinic receptors are found at target organs when AcH is released by postganglionic neurons = all parasympathetic and some sympathetic (heart smooth muscle and glands). a _ EPSP is mediated

slow

atropine blocks which receptor

muscarinic = atropine | curare and hexamethonium = nicotinic

fibers that secrete AcH are called

cholinergic

fibers that secrete NE are called

adrenergic

the cholinergic effects at PRE GANGLIONIC neurons (both sympathetic and parasympathetic) are excitatory/inhibitory

excitatory

the cholinergic effects at PostGANGLIONIC parasympathetic) are excitatory/inhibitory

inhibitory OR excitatory

all preganglionic neurons are

cholinergic in both SNS and PNS

1. all or most of postganglionic neurons in PNS are 2. most of postganglionic neurons in SNS are 3. the exception is in postganglionic sympathetic nerve fibers to the sweat glands and piloerector muscles of the hairs are

1. cholinergic (Ach) 2. adrenergic (NE) 3. cholinergic

corticospinal tract is aka

pyramidal tract

corticospinal tract carries messages for

voluntary motor movement (fine skilled movements of skeletal muscle) to the lower motor neurons (LMN) in the brain stem and spinal cord.

corticospinal tract aka pyramidal tract is direct and monosynaptic = means

does not synapse with other cells until reaches final destination in brain stem or spinal cord. therefore very rapid transmission

fibers of the pyramidal tract that synapse with the cranial nerves located in the brain stem form the _ tract

coticobulbar tract = carries motor messages important for speech and swallowing

the fibers of the pyramidal tract that synapse with spinal nerves sending out messages to skeletal muscle for voluntary movement are called

corticospinal tract

The corticospinal tract DECUSSATE (85%) of the fibers at ___ to cross to opposite side of the brain.

lower medulla

The corticospinal tract DECUSSATE (85%) of the fibers.these fibers are called

the lateral corticospinal tract or the crossed pyramidal tract

corticospinal tract fibers that don't (10-15%) continue down ipsilaterally. they are called

uncrossed or direct fibers aka direct pyramidal tract. or the ventral pyramidal tract or the anterior corticospinal tract

descending pathways are subdivided into a LATERAL AND MEDIAL SYSTEM. the __ ends on motor neurons that go to the limb muscles and on lateral interneurons

lateral

descending pathways are subdivided into a LATERAL AND MEDIAL SYSTEM. the __ ends on medial interneurons

medial

the lateral descending system includes the lateral corticospinal tract that is part of the corticobulbar tract. these will effect ___ motor neurons and supply the muscle of the limbs, digits and muscles of the lower part of the face and tongue

contralateral

the _descending system includes the ventral corticospinal, lateral and medial vestibulospinal, reticulospinal and tectospinal tracts. these affect posture and provide motor background for movement of the limbs and digits

medial

preganglionic fibers always reside in the

cns

postganglionic fibers always lie in

peripheral ganglia

sympathetic/parasympathetic preganglionic neurons are located in the thoracolumbar region of the spinal cord

sympathetic

sympathetic/parasympathetic preganglionic neurons are located in the cranial nerve nuclei or the sacral spinal cord

parasympathetic

sympathetic/parasympathetic postganglionic neurons are located in the paravertebral and prevertrebral ganglia

sympathetic

sympathetic/parasympathetic postganglionic neurons are located in the ganglia in or near the target organ

parasympathetic

sympathetic preganglionic axons are __ while their postganglionic axons are __ (long or short)

short preganglionic | post ganglionic are long

parasympathetic preganglionic axons are __ while their postganglionic axons are __ (long or short)

``` long short (opposite of SNS) ```

the _ nervous system includes the myenteric and submucosal plexus in the wall of the GI tract.

enteric

the myenteric plexus regulates ___

motility

the submucosal plexus regulates

ion and water transport and secretion

preganglionic and postganglionic neurons release _NT that act on _ receptros

AcH | muscarinic

interneurons in ganglia release

catecholamines

sympathetic preganglionic neurons release _ and _ post ganglionic neurons

``` pre = AcH post = NE ```

EXCEPTION: sympmathetic postganglionic neurons that supply sweat glands release

AcH

all __ganglionic neurons are cholinergic in both SNS and PNS = release AcH

pregagnlionic

Either all or almost all of the postganglionic neurons of the PNS are

cholinergic

most postganglionic sympathetic neurons are __ except for the ?

adrenergic | except for sweat glands and piloerector muscles of hairs which are cholinergic

two states of an ion channel Is high conductance = _ | and zero conductance = _

open | closed

sodium channels rapidly open and close and K+ channels _ opening and closing

delay

hyperpolarization of the cell is a hypoexcitable state called the ___ this is happening as the potassium is leaving the interior of the cell making it more negative than the resting potential

RELATIVE refractory period = means in order to trigger a second action potential the depolarizing stimulus must be of a greater magnitude to achieve threshold.

during the absolute/relative refractory period the cell will not respond to any stimulus

absolute

presynaptic neurons transmit info __ a synapse

towards

post synaptic neurons transmit info _ from a synapse

away

nerve impulses only travel in one direction because?

synapses are polarized

electrical synapses are common in __ and rare in: CNS/cardiac muscle/smooth muscle

common in cardiac and smooth muscle | rare in CNS.

electrical synapses are connected by _ junctions which allow the current to pass directly from postsynaptic neuron

gap

a Beta blocker used for hypertension has what mechanism?

blocks beta-1 adrenergic receptors in the heart causing a decrease in heart rate and force of contraction

beta blockers block the effects of

adrenaline on the body's beta receptors = slows nerve impulses that travel thru the heart so that it doesn't have to work as hard and needs less blood and O2. also block impulses that can cause arrhythmia

Selective beta blockers block which receptor more? 1 or 2?

beta 1 (heart)

B1 receptors are responsible for your

heart rate and strength of your heart beat

non selective beta blockers block

both B1 and B2 receptors.

B2 receptors are responsible for the function of your

smooth muscles

adrenergic receptors are located on autonomic effector organs that are regulated by

catecholamines | epinephrine and NE

two types of adrenergic receptors are

alpha and beta adrenergic receptors and Beta receptors (1 and 2)

alpha _ adrenergic receptors are located in sympathetic POSTSYNAPTIC nerve terminal = increase vascular smooth muscle contraction

alpha 1

alpha _ adrenergic receptors are located in sympathetic PRESYNAPTIC nerve terminals.

alpha 2

beta 1 adrenergic receptors are located in the

heart

beta 2 adrenergic receptors are located in the

liver and smooth muscle vasculature, bronchioles and uterus = increase hepatic glucose output, decrease contraction of BV's bronchioles and uterus

NE stimulates mainly which receptors

alpha

epinephrine stimulates_ receptors

alpha and beta receptors

beta cell of pancreas islets cells have which receptors (adrenergic)

alpha 2

when alpha 2 receptors are bound what happens

inhibits NE AND INSULIN release

T/F all cells including neurons have a resting potential that is about -70mV

true

T/F an action potential is propagated with the same shape and size along the entire length of the axon

true

resting potential is est because

there is more sodium ions outside of the cell than there are potassium inside. K+ and Na+ leakage thru potassium sodium leak channel. more potassium leaks out bc the channels are 100x more permeable to K+ than Na+. also due to Na+/K+ pu,p = electrogenic pu,p.

the size of the resting membrane potential varies but in excitable cells ranges bw

-40 and -85mV

what cells lack a STABLE resting membrane potential

visceral smooth muscle and cardiac pacemaker cells

the only mode of communication bw the CNS and effectors = aka Final Common pathway

motor neurons

exteroreceptors, interoreceptors, and proprioceptors are _

sensory recptors

interorecptors are

viscerorecptors

free nerve endings respond to (3)

itch, movement ,pain and temperature

nocireceptors are?

free nerve endings that detect painful stimuli

merkel disks and root hair plexus are

free nerve endings

proprioceptors are found in

joints, muscles and tendons

when scaling and root planning you use a firm finger rest for minutes at a time. which receptors are used in sensing this CONTINUOUS PRESSURE? a. pacinian corpuscle b. meissner's corpuscles c. ruffini's corpuscles d. Krause's corpuscles

ruffini's corpuscles = dermis of skin, exteroreceptors activated by mechanical/thermal stimuli by sensation of crude and persistent touch, heat

which receptor used when you manipulate an instrument in your fingers a. pacinian corpuscle b. meissner's corpuscles c. ruffini's corpuscles d. Krause's corpuscles

pacinian corpuscle dermis of skin, joint capsules deep pressure high frequency vibration and stretch

a sensory receptor that receives external stimuli

exteroreceptor

activated by light pressure; mechanical, low frequency vibration and discriminative touch a. pacinian corpuscle b. meissner's corpuscles c. ruffini's corpuscles d. Krause's corpuscles

Meissner's corpuscle

these receptors are found in mucous membranes and respond to mechanical and thermal stimuli such as touch, low freq vibration and cold a. pacinian corpuscle b. meissner's corpuscles c. ruffini's corpuscles d. Krause's corpuscles

Krause's corpuscle

these receptors are found in the skin and joint capsules and are activated by deep pressure and mechanical, high freq vibration and stretch

Pacinian corpuscle

these receptors feel crude and PERSISTENT touch and heat (thermal) a. pacinian corpuscle b. meissner's corpuscles c. ruffini's corpuscles d. Krause's corpuscles

Ruffini's corpuscle

the only two receptors that are activated by heat a. pacinian corpuscle b. meissner's corpuscles c. ruffini's corpuscles d. Krause's corpuscles

Krause's corpuscle = in mucous membrane | Ruffini's corpuscle (in skin and exterorecptors)

a. pacinian corpuscle b. meissner's corpuscles c. ruffini's corpuscles d. Krause's corpuscles these are all __

encapsulated nerve endings of touch and pressure receptors

nocireceptors, merkel disks, and root hair plexus are all

free nerve endings

when someone tickles you what receptor is activated

nociceptors = pain, temp, itch ,tickle, stretch

___ contains low threshold mechanoreceptors, thermoreceptors, and nocireceptors

skin

muscles joints and viscera contain _ receptors

mechanoreceptors and nociceptors

baroreceptors are found in the __ and sense_

carotid sinus and the aortic arch = stretch receptors that respond to change in blood pressure

1. The ________ is a small cluster of chemoreceptors located near the fork (bifurcation) of the carotid artery (which runs along both sides of the throat).

carotid body detects changes in the composition of arterial blood flowing through it, mainly the partial pressure of oxygen, but also of carbon dioxide. Furthermore, it is also sensitive to changes in pH and temperature.

is the carotid body more sensitive to CO2 or O2 changes

While the central chemoreceptors in the brainstem are highly sensitive to CO2 the carotid body is a peripheral chemoreceptor that mainly provides afferent input to the respiratory center that is highly O2 dependent. However, the carotid body also senses increases in CO2 partial pressure and decreases in arterial pH, but to a lesser degree than for O2

___is a dilated area superior to the bifurcation of the common carotid at the level of the superior border of thyroid cartilage. It is sensitive to pressure changes in the arterial blood at this level.contains numerous baroreceptors which function as a "sampling area" for many homeostatic mechanisms for maintaining blood pressure.

carotid sinus

the primary functional unit of the parasympathetic and sympathetic nervous system is the: one/two/three/four neuron motor pathway

two neuron | preganglionic neuron in the CNS and a postganglionic neuron whose cell body is located in one of the autonomic ganglia

_ nervous system includes all nerves that control the muscles and external sensory receptors (muscle fibers and gland cells are effectors)

somatic

_ nervous system = the organs/viscera of our body such as heart stomach intestines

autonomic

ANS divisions

autonomic and parasympathetic nervous system

the _ nervous system includes the myenteric and submucosal plexus in the wall of the GI

enteric

myenteric plexus regulates

motility (to remember just look at the M)

submucosal plexus regulates

ions and water transport and secretion

1. do motor neurons in the ANS reach their targets directly? | 2. do motor neurons in the somatic nervous system reach their targets directly?

1. no. they connect to a 2nd motor neuron that will reach the target organ 2. yes

motor neurons of the somatic or ANS system cannot send inhibitory signals thru their motor neurons

somatic cannot | ANS can

Parasympathetic system: all preganglionic neurons are ___ and almost all or most postganglionic are

cholinergic

Sympathetic nervous system: all preganglionic neurons are _ and most postsympathetic neruons are _ except for

cholinergic | post: adrenergic except for the sympathetic fibers to the sweat glands, pilorector muscles = cholinergic

adrenergic fibers release

cholinergic fibers release

AcH

__ preganglionic neurons branch extensively and synapse with numerous postganglionic neurons. it is this high ratio of postganglionic to preganglionic fibers that results in widespread effects thru the body

sympathetic

the presynaptic sympathetic nerve fibers originate in the ___ horns of the spinal cord segments: _

lateral | T1-L2

the presynaptic sympathetic nerve fibers exit the spinal cord in the _ roots and eventually enter the ventral primary __

ventral (bc they are motor) | rami

the presynaptic sympathetic nerve fibers exit the ventral primary rami via __ rami communications which carry the presynaptic sympathetic fibers to the sympathetic trunk

white

the main nerves of the PNS are the

vagus nerves.

vagus nerves of the PNS originate in the

medulla oblongata

each preganglionic parasympathetic neuron synapses with just a few postganglionic neurons located

near or in the effector organs muscles or glands

Horner's syndrome is a lack of

sympathetic tone. causes miosis. ptosis, anhydrosis on the affected side

excessive PNS activity carried by the vagus nerve can cause a __ with hypotension and possible syncope (passing out, is defined as a transient loss of consciousness and postural tone)

vasovagal episode

in dentistry excessive PNS activity can be seen as

orthostatic hypotension.

AcH is made from _ using enzyme _

acetyl-CoA and choline | choline acetyltransferase

the AP conducted along the motor nerve causes depolarization and

an influx of calcium, which causes AcH to be released into the synapse

Ach binds to _ receptors on the motor end plate

nicotinic

the stimulation of th each receptor results in the opening of

sodium channels and some potassium channels = influx of sodium and efflux of potassium = small net depolarization termed miniature end plate potentials (mEPP)

if enough miniature end plate potentials (mEPP) occur simultaneously their summation creates a

end plate potential EPP (not an action potential) = a current in muscle tissue that sparks an AP in the muscle fiber

AcH is broken down into

acetate and choline by acetylcholinesterase (AChE) on the motor end plate

if acetylcholinesterase is inhibited there will be a pronlongation of the

EPP end plate potential which can lead to tetanus

synaptic delay

AcH diffuses across cleft and binds receptor changing its ion permeability and potential. this time is the synaptic delay

electrical/chemical synaptic transmission directly connect the cytosol of 2 neurons and allow rapid bidirectional current flow bw the neurons, acting as low pass filters

electrical

electrical/chemical synaptic transmission involves the release of transmitter from presynaptic terminal, diffusion of the NT across the cleft and binding to receptor

chemical

_ junctions correlate electrical synapses

gap

gap junctions contain channels formed by hemichannels called

connexons.

connexons are formed by proteins called

connexins

the single most important tract concerned with skilled voluntary activity is the _

corticospinal tract

the spinal cord extends from the level of the foramen magnum of the skull to the

first lumbar vertebra

the 6 columns of white matter in the spinal cord that contains the ascending and descending tracts are called the

funiculi

most ascending fibers that convey sensory info that originate on the right side of the body will

cross over and reach the region of the left side of the brain

the decussation of the ascending tracts for sensory occurs in the

medulla oblangata

the two major descending tracts from the brain are the

corticospinal (pyramidal) tracts and the extrapyramidal tracts.

the corticospinal tracts carry voluntary motor stimuli from the cerebral cortex to motor neurons in the spinal cord. they are called the pyramidal tracts bc some of them

cross in the pyramids of the medulla

the other tracts such as vestibulospinal anterior corticospinal lateral and anterior reticulospinal etc come from a variety of locations in the brain and are group named

extra pyramidal tracts

extrapyramidal tracts are associated with

muscle tone and balance

Glut-_# mediates glucose transport into RBC's and thru the blood brain barrier

GLUT-1

Glut-_# provides glucose to the liver and pancreatic cells

GLUT-2

Glut-_# is in muscle and adipose tissue and regulated by insulin

GLUT-4

Glut-_# is the main transporter in neurons

GLUT-3

Glut-_# transports fructose in the intestine and testis

GLUT-5

1. glucose transport into RBC's and thru the blood brain barrier 2. provides glucose to the liver and pancreatic cells 3. transporter in neurons 4. muscle and adipose tissue and regulated by insulin 5. transports fructose in the intestine and testis

1. GLUT-1 2. GLUT-2 3. GLUT-3 4. GLUT-4 5. GLUT-5

the classification and naming of stereoisomers are based on the

absolute configuration of the 4 substituents of the asymmetric carbon

what is the compound that is used for reference? it is the smallest sugar to have an asymmetric carbon

glyceraldehyde

the naming of configurations of both _ and _ is based on the absolute configuration of glyceraldehyde as established by x-ray diffraction

amino acids and simple sugars

L- amino acid stands for

levortatory

D- Amino acid stands for

dextrorotatory = the way they rotate light

D- amino acid, although not common are found in some _ and _

anitibiotics and bacterial cell walls

``` which patient has the least chance of edema formation: one with inflammation one who is standing with venous constriction with arteriolar constriction ```

arteriolar constriction bc causes decreased capillary hydrostatic pressure. note arteriolar dilation increases likelihood of edema.

the physical cause of edema is __ pressure in the interstitial places

positive. under normal conditions, negative pressure is in the interstitium

systemic or generalized edema may be due to

heart failure or renal disease

massive systemic edema is called

anasarca

a 0.9% solution of sodium chloride or a 5% glucose solution are both hypertonic/isotonic to plasma

isotonic.

solution of sodium chloride greater than 0.9% is

hypertonic to plasma

solution of sodium chloride less than 0.9% is

hypotonic to plasma

in an isotonic solution the water potential on each side of the membrane is

the same

in an isotonic solution is there water movement

yes but the water that moves in one direction will be balanced by the amount that moves back in the other. There is no NET osmotic movement of water

``` which is not an oncogene: HER-2/neu ras src myc CAAT ```

CAAT = this is the binding site for RNA transcription factors

__ is a defective gene that is involved in triggering cancer cell growth

oncogene

are proto-oncogenes normal or defective

= normal gene that can become an oncogene due to mutations or increased expression. The resultant protein may be termed as oncoprotein. in cancer cells proto oncogenes are mutated and create oncogenes

__ code for proteins that help to regulate cell growth and differentiation. they are often involved in signal transduction and execution of mitogenic signals, usually through their protein products

Proto-oncogenes

one or more _ are mutant in all forms of cancer

oncogenes

a proto oncogene is a gene that has functions to promote

cell division

when proto oncogenes are mutated, defective versions of these genes are formed (oncogenes) they may produce products that promote abnormal cell division. a key feature of oncogene activity is

a single altered allele leads to unregulated growth

in tumor suppressor genes __alleles must be defective to lead to abnormal cell division

both | opposite of oncogenes which appears as only one altered allele

What cancer is associated with the oncogene: | HER-2/neu: a growth factor receptor

30% of human breast cancer

What cancer is associated with the oncogene: ras: a signal transduction molecule

many different cancers of different origins including pancreas (90%), colon (50%), lung (30%), thyroid (50%), bladder 6%, ovarian 15%, breast skin liver kidney and some leukemias

What cancer is associated with the oncogene: myc: a transcription factor

Burkitt's lymphoma, | B cell leukemia and lung cancer

What cancer is associated with the oncogene: src: a protein tyrosine kinase

``` the first oncogene ever discovered neuroblastoma small cell lung cancer colon and breast carcinomas rhabdomyosarcoma ```

osteoblasts make a protein mixture called __ which mineralizes to become bone. it is primarily composed of

osteoid | type 1 collagen

the intracellular matrix of bone contains a calcium binding protein called __ and a calcium and collagen binding protein called

osteocalcin | osteonectin

bone density and structural integrity decrease after age _ in men and _ in women

45 men | 30 women

the pitch of a sound is related mainly to the amplitude or the frequency of the sound wave

frequency

a sound can be characterized according to its pitch, loudness, and timbre. what is timbre

quality

the higher the frequency, the __ the pitch

higher

frequency is measured in

Hz or cycles per second

the __ of a sound is related to the intensity and the amplitude of the wave

loudness

the greater the amplitude of a sound, the __ the intensity of the wave and the louder the sound

greater

intensity is measured in

decibels (dB)

__ is measured in Hz and __ is measured in decibels (dB)

frequency | intensity

the __ of a sound is related to the presence of additional sound-wave frequencies superimposed on the principal frequency

timbre (sound quality)

intracellular fluid (ICF) or extracellular fluid (ECF) compromises 2/3 of the body's WATER

ICF

intracellular fluid (ICF) or extracellular fluid (ECF) compromises 1/3 of the body's WATER

ECF (Outside of the cell)

is the ICF homogenous in the body

the ICF is made mostly of a solution of

POTASSIUM and organic ions, proteins, etc

the ECF is made up of primarily

NaCl and NaHCO3 solution

the __ is further subdivided into 3 subcompartments: plasma, transcellular fluid, and interstitial fluid

ECF

interstitial fluid surrounds the cells but does not circulate. it comprises about __ of the ECF

75%

plasma circulates as the extracellular component of blood. it makes up _ % of the ECF

25%

___ is a set of fluids outside of normal compartments. 1-2 L of fluid that makes up the CSF, digestive juices, mucous etc

transcellular fluid

60-40-20 rule?

60% of body weight is water 40% of body weight is ICF 20%of body weight is ECF

sweating begins at what temp

37degrees celsius and up (98.6F)

human body regulates its core temp bw

98F and 100F

osmolarity vs tonicity: osmolarity compares the amount of solutes in 2 solutions while tonicity compares the

osmotic pressure gradient

tonicity measures _ solutes

impermeable.

osmolarity measures _ solutes

all solutes in solution

heat flows form hot to cold or cold to hot

hot to cold

Isotopes of an element have different ___ but same ___

``` different weights (bc different number of neurons) same chemical properties ```

isotopes are stable or radioactive forms of an element that differ in atomic weight but are otherwise chemically identical to the ___ form of the element

naturally abundant form

isotopes have the same

protons/atomic number

isotopes have different

mass numbers/number of neutrons

the radioactive forms of isotopes are used as _ in medical radiography

tracers

the cell cycle stages are

G1-S-G2-M

the G1 stage stands for

GAP1

the S stage stands for

synthesis (the stage when DNA replication occurs)

the G2 stage stands for

GAP2

The M stage stands for

mitosis

mitosis is divided inot

PMAT = prophase, prmetaphase, metaphase, anaphase, and telophase

interphase is when?

G1, S and G2 (before mitosis)

growth and preparation of the chromosome occurs in what stage

in what stage do we prepare for mitosis

protein and RNA synthesis occur in all phases of the cell cycle except the

M phase (mitosis)

a eukaryotic cell cant divide into 2 or more unless what 2 process occur

doubling of the genome (DNA) in S phase and halving of that genome during mitosis

first antibody to appear in the circulation after antigen stimulation

IgM

the most common antibody in our body is

IgG

the second antibody to appear in circulation after antigen stimulation

IgG

which antibody can pass the placenta and enter the fetal circulation

IgG

second most abundant antibody

IgA

which antibody has a function that is unknown

IgD

what antibody acts as a receptor on the surface of B lymphocytes

IgD

which antibody is LARGE and has 5 antibody units

IgM

which antibody is important in complement activation

IgM

which antibody is the primary antibody against A and B antigens on RBCs

IgM

which antibody is present in only trace amounts in the serum

Ige

Nerves Flashcards

(312 cards)