Cognitive/motor 2 Flashcards

1
Q

describe motor behaviour

A

things need cns to move
Purposeful or goal oriented

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

describe 2 types of motor behaviour

A

voluntary
reflexive

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

what do al motor movements require and why

A

2 muscles
agonist muscle contracts and antagonist relaxes
to make muscle contract = activate motor neurons
to make muscle relax = inhibit motor neurons

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

describe extension

A

agonist = extensor muscle contracts
antagonist = flexor muscle relaxes
increases angle around joint

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

describe flexion

A

agonist = flexor muscle contracts
antagonist = extensor muscle relaxes
decreases angle around joint

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

describe reciprocal innervation of muscles

A

coordinated flexor and extensor muscle activation and relaxation
limb position maintained by balance of flexor and extensor muscle tension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

describe motor neurons

A

only excitatory - ach
alpha = innervate skeletal muscle extrafusal (makes big muscles contract)
gamma = innervates muscle spindle - intrafusal (part of proprioceptive feedback)
cell bodies in ventral horn of spinal cord - spinal nerves or brainstem (cranial nerves)
receives inputs mostly from interneurons

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

describe spinal afferent pathway

A

sensory afferent - dorsal root ganglion
synapses both on interneuron and ascends dorsal columns to brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

descrive motor efferent patway

A

descending motor commands = comes from brain and innervate interneurons, voluntary input
Interneurons = integrate info from many things, like sensory info and motor commands and then activates other circuitry and sends axons and forms motor efferent

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

name and describe spinal interneurons

A

descending pathway
other spinal levels = voluntary movements
muscle receptor from antagonistic muscle = length monitoring
spinal interneuron
tendon receptor = tension monitoring, force of muscles
skin receptor = pain, driven by nociceptors
joint receptor = proprioceptive feedback

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

name 3 spinal reflexes

A

withdrawal
stretch
inverse stretch

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

describe withdrawal reflex

A

protects limb from injury
involuntary - happens at level of spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

can most spinal reflexes be overriden

A

yesss
like if pain but its important to withdraw limb

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

describe flexion withdrawal reflex - polysynaptic

A

polysynaptic= more than one synapse between sensory input and motor response
activate nociceptors = aps up leg and enters dorsal horn and branches of axons activate interneurons, synapses on 2nd order neurons
innervates motor neurons in ventral horn of gray matter
Causes inhibition of motor neurons innervating ipsilateral extensor
excitation of motor neurons innervating ipsilateral flexor (contracts)
causes withdrawal

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

describe flexion withdrawal reflex - cross extensor reflex

A

when withdrawal = weight must shift to other leg
motor afferents = cross midline to anterolateral and do opposite
excitation of motor neurons innervating contralateral extensor
Inhibition of motor neurons innervating contralateral flexor

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

what does magnitude of withdrawal reflex depend on

A

magnitude of stimulus
more painful = bigger withdrawal

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

describe irradiation

A

A>b>c = pain input bigger for a and less as go to c
recruitment of interneurons drives increased withdrawal with increased pain, more aps = more drives motor neurons
Increase in rate and magnitude of withdrawal response with increased stimulus strength

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

describe afterdischarge

A

Response maintained after stimulus termination
feedback loops in spinal cord
keep reflex going
ppl withdrawal = tend not to reextend

19
Q

describe polysynaptic - properties of withdrawal reflex

A

Interneurons between sensory input and motor output

20
Q

describe ipsilateral - properties of withdrawal reflex

A

Flexor muscle contraction Extensor muscle relaxation

21
Q

describe contralateral - properties of withdrawal reflex

A

Flexor muscle relaxation
Extensor muscle contraction (cross extensor reflex)

22
Q

describe stretch reflex

A

controls muscle length or involves lengthening of muscles
monosynaptic - primary
polysynaptic - secondary

23
Q

describe monosynaptic stretch reflex - knee jerk

A

little hammer stretches muscles
stretch extensor muscle - tap on tendon = pulls extensor muscle and activates stretch receptors (cell bodies in dorsal root ganglion)
goes up ipsilateral dorsal columns and tells brain muscle length is changing
also branches into spinal cord and synapses and produces motor response = excitation of motor neurons innervating ipsilateral extensor
polysynaptic = interneuron and inhibition of motor neurons innervating ipsilateral flexor = leg kicks

24
Q

what asses muscle tone

A

stretch reflex - knee jerk
ability of muscles to resist being stretched = they pull back
Patient needs to be conscious
if tone gone or too big = indication of porbelm with cns pathways coming down spinal cord

25
name the 2 kinds of stretch receptors = proprioceptive receptors
muscle spindle golgi tendon organ
26
describe golgi tendon organ
located in tendons in series = whatever force muscle generates golgi tendon organ feels force and reports to cns - in tendons = attach muscle to bone Measures muscle tension
27
describe muscle spindle
in parallel with extrafusal muscle has stretch receptor and intrafusal muscle fiber Activated by during stretch reflex and sends ap to spinal cord stretch receptor = in middle, located at each end of part of stretch receptor that measures muscle length intrafusal muscle fiber= activated by gamma motor neurons, regulates stretch receptor measures muscle length - embedded in muscle - however long muscle is when contracts or relaxes = stretch receptor follows same length extrafusal muscle fiber - activated by alpha motor neurons = causes you to move= generate force, causes contraction of muscle and movement, sits around muscle spindle
28
describe muscle spindles
afferents - ia and ii = 2 types of afferents come out of muscle spindles gamma motor axons = come in and innervate both sides of intrafusal muscle fiber
29
describe response of ia and ii afferents
Ia = primary nuclear bag fibers = rapidly adapting indicates change in sensory input = when muscle length is changing when stretch reflex = mediates it, only picks it up and communicates it ii secondar nuclear chain fibers communicates static changes in muscle legth non adapting slower to respond, static steady state muscle length
30
describe ia primary
signal dynamic changes in muscle length and some static changes
31
describe ii secondary
signal static muscle length
32
what can muscle spindles do
lose sensitivy
33
describe muscle spindle during extension
Muscles lengthen feels lengthening of muscle and increases aps and tells cns muscle is longer increase in muscle spindle afferent activity
34
describe muscle spindle during voluntary flexion
alpha motor neuron activity muscles shorten muscle spindle collapses = sensitivity reduced mostly work when stretched - when contracted = does not work, gamma neurons come to rescue
35
what do gamma motor neurons do
maintain muscle spindle sensitivity
36
how does gamma motor neurons maintain muscle spindle sensitivity
causes intrafusal fibers contract and muscle spindle is stretched - stretches them out, maintains muscle spindle sensitivity alpha gamma coactivation
37
describe alpha gamma coactivation
descending pathways come down spinal cord and activate both alpha and gamma Alpha = extrafusal muscle contraction and shortening gamma = intrafusal muscle activation and maintains spindle sensitivity change in length activates muscle spindle
38
describe properties of stretch reflex- 3
Resists changes in muscle length (sets muscle tone) Mono- and polysynaptic components Feedback from muscle spindles
39
describe properties of muscles spindles - 6
1) Reports muscle length. 2) In parallel with extrafusal muscle fibers (does not contribute to the force of muscle contraction). 3) Ia primary: Detects changes in muscle length and some static length (nuclear bag fibers). 4) II secondary: Detects static length (nuclear chain fibers). 5) Intrafusal fibers: Maintain muscle spindle sensitivity. 6) Alpha-gamma coactivation
40
describe inverse stretch reflexes
controls muscle tension
41
what does golgi tendon organ respond to
tension
42
describe golgi tendon organ - for inverse stretch reflex
in series with muscle passive stretch = might activate a few aps fully contracting muscle = much force, many aps, lots of tension, active contraction of extrafusal muscle fibers active contraction of muscle produces more tension than stretching collagen fibers pinched inside golgi tendon organ = tough fibers, in between = free nerve endings = pinch free nerve endings = activate mechanically gated ion channels
43
describe inverse stretch reflex pathway
Activation of golgi tendon organ via 1b afferents, goes up ipsilateral dorsal columns increased tension in extensor muscle = increased afferent activity from golgi tendon organ = branches in gray matter and interneurons Inhibition of motor neurons innervating ipsilateral extensor - both alpha and gamma excitation of motor neurons innervating ipsilateral flexor - antagonist muscle
44
describe properties of golgi tendon organ
1) Reports muscle tension. 2) In series with extrafusal muscle fibers 3) Ib afferents 4) Underlies inverse stretch reflex (polysynaptic)