Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

from flashcardlet > anatomy final (section 3) > Flashcards

anatomy final (section 3) Flashcards

1
Q

sensory afferent division

A

carries sensory signals from receptors to CNS1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Motor (efferent) division-

A

carries signals from CNS to glands and muscle cells to respond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

 Sympathetic division

A

arouse for action, accelerates heartbeat and respiration, inhibits digestive/urinary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

parasympathetic division

A

calming, slow heartbeat and respiration, stimulates digestive and urinary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Afferent neurons

A

sensory detectors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

interneurons

A

association- within CNS

  • Carryout integrative functions
  • Process, store, retrieve info
  • Between sensory and motor
  • 90% of neurons are interneurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

efferent neurons

A

motor- to effectors (muscles, glands)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Soma

A

control center- neurosome, cell body, perikaryon

  • Single large nucleolus
  • Cytoplasm- mitochondraia, lysosomes, golgi, inclusions, rough ER
  • Neurofibrils- bundles of actin filaments
  • No cell division
  • Nissl bodies- dark staining of rough ER, protein synthesis
  • Inclusions- glycogen granules, lipids, melanin, lipofuscin (golden brown pigment when lysosomes digest organelles), found more in old neurons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

nissil bodies

A

dark staining of rough ER, protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Inclusions

A

glycogen granules, lipids, melanin, lipofuscin (golden brown pigment when lysosomes digest organelles), found more in old neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q
  • Terminal aborization
A

fine branches at distal end that include synaptic knob-terminal button that forms a synapse with next cell and synaptic vesicles which contain neurotransmitters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

axon

A
  • nerve fiber- originates from axon hillock- mound on soma, cylindrical, no branches until distal end
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

4 neuron types

A

multipolar, bipolar, unipolar, anaxonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

multipolar neuron

A

1 axon multiple dendrites, most common, in brain and spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

bipolar neuron

A

1 axon and 1 dendrite eg olfactory, retina, inner ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

unipolar

A

single process leading away from soma eg sensory, skin, organs to spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

anaxonic

A

many dendrites and no axon, eg visual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

axonal transport and function

A

proteins made in the soma need to be transported

Functions: repair, be proteins in gated ion channels, enzymes, neurotransmitters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

anterograde

A

move down an axon away from soma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

retrograde

A

move up an axon towards soma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

kinesin

A

motor protein in anterograde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

dynein

A

motor protein in retrograde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

fast anoxal transport

A

20-400 mm/day

  • Anterograde fast transports organelles, enzymes, molecules
  • Retrograde fast transports recycled materials or pathogens eg rabies, herpes, tetanus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

slow axonal transport

A
  1. 5-10 mm/day, only atnerograde, moves enzymes, repairs cytoskeleton
    * speed of repair and regeneration is governed by slow axonal transport
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

glial cells

A

support and protect neurons, bind neurons together, form framework

  • Fetal- guides migrating neurons to destination
  • Mature- if a mature neuron is not in contact with another neuron, it si covered by glial cell, prevents neurons from touching and allows for precise conductivity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

oligodendrocytes

A

CNS; form myelin sheath in CNS, wraps around nerve fiber, insulates, conducts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

ependymal

A

CNS; lines internal brain cavity and secretes cerebrospinal fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Microglia

A

CNS; small wandering macrophages from WBC, perform checkups on brains many times a day wander in search of cell debris to phagocytize

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Astrocytes

A

CNS; most abundant glial cells in CNS, covers entire brain surface and nonsynaptic regions
• Supportive framework with perivascular feet with blood capillaries that form blood brain barrier
• Converts glucose to lactate to nourish neurons
• Secretes nerve growth factor which allows cells to grow and function
• Communicates electrically
• Absorbs excess neurotransmitters and ions
• Astrocytosis or astrosclerosis- form hardened scar tissue over damaged neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Schwann cells

A

PNS; form myelin sheath in PNS, covers neurons and assists in regenerations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Satellite cells

A

PNS; surround somas in ganglia, provide electrical insulation & regulates chemical environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

glioma

A

malignant tumors in brain, grow rapidly, chemo isn’t effective because of blood brain barrier, instead best treatment is surgery or radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

myelination in PNS

A

Schwann cells wrap about 100 layers around nerve fiber; neurilemma-thick outermost coil that contains nucleus and cytoplasm, endoneurium- external to neurilemma and is fibrous connective tissue
**wraps in to out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

myelination in CNS

A

oligodendrocytes myelinates several cells, anchored to multiple nerve fibers, cant migrate, push a new layer under the old myelin laer so that it spirals inward, no neurilemma or endoneurium
**wraps out to in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

multiple sclerosis

A

myelin sheath deteriorates and is replaced with scar tissue, nerve conduction is disrupted, onset between 20-40 fatal within 25 years after diagnosed, cause may be autoimmune trigger by a virus, symptoms include double vision, tremors, numbness, and speech defects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Tay-Sachs

A

hereditary disorder of eastern European Jewish descent, abnormal accumulation of glycolipid GM2 which is normally composed of a lysosomal enzyme, the abnormal amount disrupts nerve conduction and leads to blindness, coordination loss and dementia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Mesaxon

A

neurilemma wrapping of an unmyelinated nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

speed of nerve conduction depends on _______ and __________

A

diameter of nerve fiber and presence of myeline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

fast conduction has (and example)

A

large diameter and myelin; skeletal muscle, vision, balance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

slow conduction has (example)

A

small diameter and no myelin; stomach and pupil dilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

regeneration of peripheral nerves

A

cannot occur in CNS
• Can only occur if soma is intact and some neurilemma remains
• Fiber distal to injury degenerates, macrophages clean up debris
• Soma swells, endoplasmic reticulum breaks up, nucleus moves off center
• Axon stump sprouts growth, severed distal end still degenerates bc loss of NGF
• Schwann cells, basal lamina and nuerilemma form regeneration tube which guides the growing sprout to original target cell to reestablish synaptic contact
• Nucleus returns to normal shape and position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Nerve growth factor- NGF

A

protein secreted by gland/muscle/glial cells and picked up by axon terminals, prevents apoptosis, enables growing neurons to make contact with target cells
- Rita levi-Montalcini- 1950s, won noble prize in 1986 with Stanley Cohen for NGF research

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

3 factors the leads to resting membrane potential

A
  1. Ions diffuse down their concentration gradient
  2. Plasma membrane is selectively permeable
  3. Electrical attraction exists between cations and anions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

in Na K pump, pumps out ____ for every ____ brings in

A

3Na, 2K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

how are local potentials different from action potentials

A

locals are:
Graded- varies in magnitude
Decremented- weaker as it spreads farther away from origin
Reversible- K+ diffuse out to reestablish RMP
Excitatory or inhibitory- can hyperpolarize, become more negative than RMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

local potential

A

disturbances in membrane potential when neuron is stimulated,; response begins at dendrite and spreads to soma and then travels down axon to synaptic knobs
When stimulated-
- Open Na gates and Na rushes in
- Neutralizes the internal negative charge, DEPOLARIZATION, makes less negative
- Na diffuse for short distance inside producing a current to trigger zone= short range charge=LP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

action potential

A

dramatic change in membrane voltage, generated when it hits trigger zone

  • If excitatory local potential hits trigger zone and is strong enough, can generate action potential
  • Spike- rapid rise in membrane potential, positive feedback
  • Once passes 0 mV, Na becomes inactive and it peaks at +35 mV
  • Positive inside and negative outside- depolarization
  • At the peak, slow K gates are opened and K exits the cell to repolarize
  • K gates stay open longer than Na gates do, Na and K switch places
  • Is NONDEREMENTAL and IRREVERSIBLE
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

refractory period

A

no stimulation can cause and action potential; only occurs at some small areas of the membrane at a time, other parts can be stimulated but one may not be able to be

  • Absolute- no chance of stimulation
  • Relative- a very strong stimulation can cause action potential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Salutatory conduction

A

in myelinated fibers, nerve signals jump from node to node, fast conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

4 categories fo NT

A

acetylcholine, amino acids, monoamines, neuropeptides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

acetylcholine NT

A

in its own class, made of acetic acid and choline, muscle movement, mood, memory and learning possibly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

amino acid NT

A

excitatory and inhibitory responses, eg glycine, glutamate, aspartate, gamma-aminobutyric acid (GABA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

monoamine NT

A

arousal, emotion and cognition, epinephrine, norepinephrine, dopamine, histamine, serotonin, made by removing –COOH from amino acid and keeping the –NH2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

neuropeptides

A

long amino acid chains, feelings, hormones, modulators, has lasting effects, stored in secretory granules, eg substance P (pain), beta-endorphin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

how do neurotransmitters work

A

Neurotransmitters are released and the bind to receptors which induce altering of cell physiology; there are varied effects depending on location and receptor (eg serotonin has 14 different receptor types)

56
Q

3 kinds of synapse modes of action

A

excitatory cholinergic response
acetylcholine is the NT
a. Nerve signal approaches synapse, opesn Ca2+ gates, Ca enter the knob, triggers exocytosis of the vesicles releasing acetylcholine into cleft, vesicles drop down into cytoplasm to refill with Ach, other vesicles move to active sites and release more Ach, diffuses across synaptic cleft, binds to ligand gates in postsynaptic neuron, gates open, Na+ enters, K+ leaves, depolarizes cell=local potential (postsynaptic potential), if its strong enough, it will open the voltage regulated ion gates in trigger zone= neuron fires

57
Q

Inhibitory GABA-ergic synapse

A

employs gamma-aminobutyric acid as NT
a. Nerve signal triggers GABA release in cleft, receptors are chloride channels, Cl- enters the cell and makes it more negative causing a postsynaptic hyperpolarization inhibiting the call and the neuron is less likely to fire

58
Q

excitatory adrenergic synapse

A

norepinephrine (NE) is the NT

a. Has secondary messenger system with other monoamines and neuropeptides
b. Receptor is a transmembrane protein asso with a guanine nucleotide binding protein
c. Unstimulated NE is bound to a g protein, binding of NE to receptor causes dissociation of G protein, which then binds to adenylate cyclase, activates enzyme, induces the conversion of ATP to cyclic AMP and cAMP can induce several other effects such as: production of chemical that opens gate and depolarizing cell, activates cytoplamsic enzymes to do diverse metabolic changes, induce genetic transcription
d. Slower to respond than cholinergic or GABA-ergic, has advantage of enzme amplification, a single molecule of NE can produce vast molecules in cell

59
Q

how to stop a signal in a neuron

A
  • SOLUTION- stop adding NT and get rid of whats already there
    o Stop signals in presynaptic neuron
    o Get rid of NT by:
     diffusion into ECF and removal by astrocytes in CNS
     Reuptake by synaptic knob by endocytosis
     Breakdown by MAO enzyme
     Degradation of synaptic cleft- enzyme acetylcholinesterase degrades Ach
60
Q

MAO

A

monoamine oxidase enzyme breaks down NT, some antidepressants work by inhibiting MAO

61
Q

neuromodulators

A

hormones, neuropeptides, and other messengers that modify synaptic transmission, stimulate neuron, make sensitive to, synthesize, release, reuptake breakdown NT, changes rate

62
Q

encephalin

A

neuromodulator family- small peptides that inhibit spinal interneurons from sending pain signals to the brain

63
Q

nitric oxide

A

simpler neuromodulator that is a gas released by post synaptic neuron involved in learning and memory that diffuses through synapse and stimulates next neuron “give me more” NT

64
Q

neural integration

A

ability of neuron to process, store, and recall info and make decisions
Synaptic delay slows the transmission of a signal
based on postsynaptic potentials produced by neurotransmitters -70mv to -55mv

65
Q

pyramidal cells

A

cells in the cerebral cortex with 40,000 synaptic contacts

66
Q

EPSP

A

Excitatory post synaptic potential- EPSP- more likely to fire given action potential
Glutamate and aspartate are excitatory NT

67
Q

IPSP

A

Inhibitory post synaptic potential- IPSP- less likely to fire, hyperpolarization
Glycine and GABA are inhibitory NT; acetylcholine and norepinephrine can be excitatory or inhibitory
Eg. In skeletal muscle Ach is excitatory but in cardiac muscle Ach is inhibitory

68
Q

temporal summation

A
  • 1 synapse generates excitatory potentials and before 1st fades,, next is generated
69
Q

spatial summation

A

several synapses ass up to threshold at axon hillock

70
Q

facilitation

A

process where one neuron enhances the effects of another neuron

71
Q

presynaptic inhibition

A

opposite of facilitation- 1 neuron suppresses next, releases GABA, Ca don’t open

72
Q

how does info arise in neural pool

A

through input neurons,

  • Branch and synapse with many interneurons
  • Discharge zone- one single input neuron alone can make post synaptic cells fire
  • Facilitated zone- synapse with other still neurons and can only stimulate with help from other IN
73
Q

neural pool

A

neurons function in large groups, each consists of millions of interneurons that are concerned with a particular body function like rhythm of breathing or limb movement while walking

74
Q

divergent circuits

A

1 nerve fiber branches and synapses with several others

75
Q

convergent circuits

A

1 neuron receives input from many source neurons

76
Q

reverberating circuits

A

loop system, stimulates linearly and circles back to starting neuron, starts over

77
Q

parallel after discharge circuits

A

input neuron diverges to stimulate many chains of neurons, eventually all end up converging on a single output neuron

78
Q

how many pairs of spinal nerves exist

A

31

79
Q

thicker parts of the spinal cord are

A

cervical C1-C7 and lumber L1-L5 enlargements

80
Q

cauda equine

A

bundle of nerves that are L2-S5

81
Q

medullary cone

A

conus medullaris- the cord tapers to a point inferior to the lumbar region

82
Q

filum terminale

A

fibrous strand of pia mater that extends beyond meduallry cone with lumbar cistern

83
Q

Meninges

A

fibrous CT that covers the brain and spinal cord, 3 layers

84
Q

dura mater

A

outer covering, most superficial, tough collagen fiber- dural sheath; surrounded by epidural space- filled with fat, blood vessels, loose CT

85
Q

arachnoid mater

A

simple squamous epithelium, has collagen and elastic fibers that line aura mater; subarachnoid space- gap between arachnoid and pia mater fileld with cerebrospinal fluid, lumbar cistern- inferior to medullary cone and contains cauda equine and CSF

86
Q

pia mater

A

delicate collagen membrane that follows spinal contours
Coccygeal ligament- formed from fusion of terminal filum and dura mater, anchors the cord and meninges
Denticulate ligaments- extend through arachnoid to dura, anchors to limit side movement

87
Q

gray matter of spinal cord

A

neuron cell bodies with little myelin- info processing, synaptic integration

88
Q

white matter of spinal cord

A

abundantly myelinated axon bundles, carry signals, surround the gray matter

89
Q

fasiculi

A

spinal tracts

90
Q

ascending tracts

A

carry sensory info up the spinal cord across 3 neurons from receptor to destination
– first order neurons – detect stimulus and transmit signal to spinal cord or brainstem
– second order neurons – continues to the thalamus at the upper end of the brainstem
– third order neurons – carries the signal the rest of the way to the sensory region of the cerebral cortex

91
Q

descending tracts

A

carry motor information down the spinal cord
– all nerve fibers in a given tract have a similar origin, destination, and function
– upper motor neuron originate in cerebral cortex or brainstem and terminates on a lower motor neuron
– lower motor neuron in brainstem or spinal cord
• axon of lower motor neuron leads the rest of the way to the muscle or other target organ

92
Q

1st order neurons

A

detect stimulus and transmit signal to spinal cord or brainstem

93
Q

2nd order neurons

A

continues to the thalamus at the upper end of the brainstem

94
Q

3rd order neurons

A

carries the signal the rest of the way to the sensory region of the cerebral cortex

95
Q

Decussation

A

as the fibers pass up or down the brainstem and spinal cord they cross over from the left to the right side and vise versa

96
Q

contralateral

A

when the origin and destination of a tract are on opposite sides of the body

97
Q

ipsilateral

A

when the origin and destination of a tract are on the same side of the body
– does not decussate

98
Q

major ascending tracts

A 
Gracile Fasciculus
Cuneate Fasciculus
Spinothalamic tract
Spinoreticular tract
Spinocerebellar tracts
99
Q

major descending tracts

A

Corticospinal tracts
Tectospinal tract
Lateral and medial reticulospinal tract
Lateral and medial vestibulospinal tract

100
Q

breakdown of 31 pairs of spinal nerves

A

each has two points of attachment to the spinal cord
• 8 cervical (C1 – C8) C1 between skull and atlas- others exiting at intervertebral foramen
• 12 thoracic (T1 – T12)
• 5 lumbar (L1 – L5)
• 5 sacral (S1 – S5)
• 1 coccygeal (Co)

101
Q

poliomyelitis

A

caused by the poliovirus, destroys motor neurons in brainstem and anterior horn of cord Signs of polio include muscle pain, weakness, and loss of some reflexes followed by paralysis, muscular atrophy, and respiratory arrest, the virus spreads by fecal contamination of water

102
Q

amyotrophic lateral sclerosis

A

(ALS) – Lou Gehrig disease- destruction of motor neurons and muscular atrophy, also sclerosis (scarring) of lateral regions of the spinal cord, astrocytes fail to reabsorb the neurotransmitter glutamate from the tissue fluid and can accumulate to toxic levels
Early signs – muscular weakness, difficulty speaking, swallowing, and use of hands, sensory and intellectual functions remain unaffected

103
Q

Perineurium

A

wraps fascicles of nerve fibers, composed of up to 20 layers of overlapping squamous , epithelium-like cells

104
Q

Epineurium

A

bundles numerous fascicles that constitutes whole nerve are composed of dense irregular connective tissue and protect nerve from stretching and injury

105
Q

posterior proximal branches

A

root is sensory input to spinal cord
– posterior (dorsal) root ganglion – contains the somas of sensory neurons carrying signals to the spinal cord
– six to eight rootlets that enter posterior horn of cord

106
Q

anterior proximal branches

A

root is motor output out of spinal cord
– six to eight rootlets that leave spinal cord and converge to form anterior root
• these merge to form spinal nerve proper that enters intervertebral foramen

107
Q

distal brances

A

anterior ramus, posterior ramus, meningeal ramus

108
Q

anterior ramus

A

innervates the anterior and lateral skin and muscles of the trunk and gives rise to nerves of the limbs

109
Q

posterior ramus

A

innervates the muscles and joints in that region of the spine and the skin of the back

110
Q

meningeal ramus

A

reenters the vertebral canal and innervates the meninges, vertebrae and spinal ligaments

111
Q

Anterior rami branch and anastomose repeatedly to form what five nerve plexuses

A

– cervical plexus in the neck, C1 to C5- supplies neck and phrenic nerve to the diaphragm
– brachial plexus near the shoulder, C5 to T1 supplies upper limb and some of shoulder and neck
median nerve – carpal tunnel syndrome
– lumbar plexus in the lower back, L1 to L4 supplies abdominal wall, anterior thigh and genitalia
– sacral plexus in the pelvis, L4, L5 and S1 to S4 supplies remainder of lower trunk and lower limb
– coccygeal plexus, S4, S5 and C0

112
Q

Radial nerve injury

A

passes through axilla, causes wrist drop or crunch paralysis

113
Q

sciatic nerve injury

A

sciatica- sharp pain that travels from gluteal region along the posterior side of the thigh to ankle; 90% of cases result from herniated intervertebral disc or osteoporosis of lower spine

114
Q

Dermatome

A

a specific area of the skin that receives sensory input from a pair of spinal nerves
Dermatome map – a diagram of the cutaneous regions innervated by each spinal nerve, dermatomes overlap their edges as much as 50%, necessary to sever or anesthetize three successive spinal nerves to produce a total loss of sensation in one dermatome

115
Q

4 important properties of a reflex

A
  1. Require stimulation- not spontaneous actions, but responses to sensory input
  2. Quick- involve few if any interneurons and minimum synaptic delay
  3. Involuntary-occur without intent and difficult to suppress, automatic response
  4. Stereotyped- occur essentially the same way every time
116
Q

pathway of a reflex arc

A

Somatic receptorafferent nerve fiberintegrating centerefferent nerve fiber skeletal muscle

117
Q

integrating center

A

a point of synaptic contact between neurons in the gray matter of the spinal cord or brainstem, determines whether the efferent neurons issue a signal to the muscles

118
Q

muscle spindle

A

stretch receptors embedded in skeletal muscles
• inform the brain of muscle length and body movement
• enables brain to send motor commands back to the muscles that control coordinated movement, corrective reflexes, muscle tone, and posture
• intrafusal fibers- muscle fibers within a spindle- nuclear chain and nuclear bag fibers
• nerve fibers- primary (Ia) and secondary (II) afferent fibers and gamma motor neurons

119
Q

stretch reflex

A

myotatic- when a muscle is stretched, it fights back and contracts with increases tetanus and makes it stiffer than an unstretched muscle, mediated primarily by the brain

  • maintain equilibrium & posture, eg head tips as you fall asleep so muscle contract to raise head
  • stabilize joints by balancing tension between extensors and flexors
120
Q

tendon reflex

A

reflexive contraction of a muscle when its tendon is tapped, can diagnose diseases
Example: Knee jerk (patellar) reflex- monosynaptic reflex

121
Q

Reciprocal inhibition-

A

reflex phenomenon that prevents muscles from working against each other by inhibiting the antagonist

122
Q

Flexor (withdrawl) reflex

A

the quick contraction of flexor muscles resulting in the withdrawal of a limb from an injurious stimulus, requires contraction of the flexors and relaxation of the extensors
- is an ipsilateral reflex arc- input and the motor output are on the same side of the spinal cord

123
Q

crossed extension relfex

A

the contraction of extensor muscles in the limb opposite of the one that is withdrawn, maintains balance by extending other leg
- contralateral reflex arc –input and output are on opposite sides of the spinal cord

124
Q

Intersegmental reflex

A

one in which the input and output occur at different levels (segments) of the spinal cord

125
Q

Polysynaptic reflex arc

A

pathway in which signals travel over many synapses on their way back to the muscle

126
Q

gracile fasciculus

A

ascending tract, dorsal column, decussates in medulla, functions in limb and trunk movement, deep touch, visceral pain and vibration BELOW T6

127
Q

cuneate fasciculus

A

ascending tract, dorsal column, decussates in medulla, functions in limb and trunk movement, deep touch, visceral pain and vibration ABOVE T6

128
Q

spinothalamic

A

ascending tract, lateral and ventral columns, decussates in spinal cord, functions for light touch and tickle, itch, temperature, pain and pressure

129
Q

dorsal spinocerebellar

A

ascending tract, lateral column, proprioception (nonvisual) feedback from muscles

130
Q

ventral spinocerebellar

A

ascending tract, lateral column, proprioception (nonvisual) feedback from muscles

131
Q

lateral corticospinal

A

descending, lateral column, decussates in medulla, fine limb control

132
Q

ventral corticospinal

A

descending, ventral column, fine limb control

133
Q

tectospinal

A

descending, lateral and ventral columns, reflexive head turning in response to visual and auditory stimuli

134
Q

lateral and medial reticulospinal

A

descending, lateral is lateral column and medial is ventral column, balance and posture, regulation fo pain awareness

135
Q

vestibulospinal

A

ventral column, balance and posture control from inner ear

136
Q

5 nerve plexuses are formed from the what?

A

anterior rami, distal branch of spinal nerves

from flashcardlet (34 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions