Reflexes

Question 1

synonyms for myotatic reflexes

Answer 1

deep tendon reflexes, muscle stretch reflexes, tendon jerks

Question 2

stretching of intrafusal fibers sends afferent info to the

Answer 2

dorsal horn of spinal corn, stimulates alpha motor neurons

Question 3

when spinal pathways synapse on the gamma-motor neurons, they influence contraction of the..

Answer 3

muscle spindle, which determines how much contraction happens when the muscle is stretched

Question 4

these fibers have many mitochondria, extensive capillary blood supply, myoglobin for O2 storage

Answer 4

slow twitch fibers (type I) (distance running)

Question 5

these fibers have fewer mitochondria, less extensive blood supply, glycogen store and glycolytic enzymes

Answer 5

fast twitch fibers (type IIb) (sprinting)

Question 6

what determines whether a muscle fiber will be type I or type IIb?

Answer 6

the INNERVATION

Question 7

a single motor neuron innervating a group of muscle fibers

Answer 7

motor unit

Question 8

describe motor unit recruitment as used in motor activity

Answer 8

the maximum force developed by a muscle increases exponentially as the percentage of motor units recruited increases and superimposes

Question 9

describe the pathway in muscle stretch reflex (flexion)

Answer 9

cutaneous afferent fiber enters dorsal horn, synapses, goes to ventral horn, activates motor neuron in the flexor muscle; dorsal horn synapse also goes through ant commissure to contralateral ventral horn to motor neuron to have opposite extensor muscle support

Question 10

describe the muscle stretch reflex pathway (stretch)

Answer 10

muscle spindle afferent fibers enter dorsal horn, synapse, motor neurons activate the muscle to stretch ;while alpha motor neurons activate the antagonist

Question 11

reflexes are hyperactive if the lesion is in..

Answer 11

the upper motor neurons

Question 12

reflexes are hypoactive if the lesion is in the..

Answer 12

lower motor neurons

Question 13

what type of lesion is characterized by increased muscle tone/spasticity?

Answer 13

upper motor neuron syndrome

Question 14

what type of lesion is characterized by loss of cutaneous reflexes?

Answer 14

lower motor neuron syndrome and upper motor neuron syndrome

Question 15

what type of lesion is characterized by Hoffman and Babinski’s sign?

Answer 15

upper motor neuron

Question 16

what type of lesion is characterized by fibrillation and fasciculation?

Answer 16

lower motor neuron syndrome

Question 17

what type of lesion is characterized by decreased muscle tone and flaccidity?

Answer 17

lower motor neuron syndrome

Question 18

the polysynaptic superficial reflexes

Answer 18

abdominal, cremasteric (L1), Hoffman, plantar (Babinski sign is plantar extension, abnormal)

Question 19

jaw jerk reflex tests neurons in the..

Answer 19

pons

Question 20

dermatome of clavicle

Answer 20

C4

Question 21

dermatome of upper arm lateral

Answer 21

C5

Question 22

dermatome of thumb and lateral forearm

Answer 22

C6

Question 23

dermatome of middle figer and first finger

Answer 23

C7

Question 24

dermatome of last 2 digits

Answer 24

C8

Question 25

dermatome of nipple

Answer 25

T4

Question 26

dermatome of umbilicus

Answer 26

T10

Question 27

dermatome of calf

Answer 27

L4, 5

Question 28

dermatome of big toe

Answer 28

L5

Question 29

dermatome of little toe

Answer 29

S1

Question 30

dermatome of perineum

Answer 30

S3-5

Question 31

glove stocking sensory loss indicates lesion in..

Answer 31

peripheral nerves

Question 32

sensory loss of everything below the waist indicates..

Answer 32

complete transection of thoracic cord (T7)

Question 33

sensory loss in S2-S5 indicates lesion in..

Answer 33

cauda equina

Question 34

sensory loss of right side from the waist down, plus left thoracic sensory loss indicates..//this is also called..

Answer 34

left hemisection of thoracic cord; Brown-Sequard syndrome (T4)