U4 lecture 31

Question 1

define a reflex

Answer 1

a rapid automatic response to a stimulus

Question 2

define reflex arc

Answer 2

the wiring of a particular reflex

Question 3

define innate reflex

Answer 3

inborn

Question 4

define learned reflex

Answer 4

reflex acquired through experience

Question 5

what are the pathways of 4 reflex arcs

Answer 5

• stretch reflex
• tendon reflex
• flexor reflex
• crossed extensor reflex

Question 6

all 4 reflex arcs are what??

Answer 6

somatic and spinal

Question 7

what is the purpose of the stretch reflex

Answer 7

to prevent injury from over stretching a muscle

Question 8

the stretch reflex results in what

Answer 8

the contraction of the muscle that was stretched

Question 9

what is stretch sensed by

Answer 9

muscle spindle

Question 10

what kind of reflex is the stretch reflex?

Answer 10

monosynaptic, ipsilateral, spinal, somatic

Question 11

what is the pathway of the stretch reflex

Answer 11

• stretching stimulus sensory receptor (muscle spindle)
• sensory neuron excited
• within integrating center(spinal cord), sensory neuron activates motor neuron
• motor neuron excited
• effector (same muscle) contracts and relieves the stretching

Question 12

what is the tendon reflex’s purpose?

Answer 12

to prevent damage from development of too much tension in a muscle

Question 13

what is the result of the tendon reflex

Answer 13

the inhibition of the muscle that is contracting

Question 14

what is the tension sensed by in the tendon relfex

Answer 14

golgi tendon organ

Question 15

what kind of reflex is the tendon reflex?

Answer 15

polysynaptic, ipsilateral, spinal, somatic, reflex

Question 16

what is the pathway of the tendon reflex

Answer 16

• increased tension stimulates sensory receptor (tendon organ)
• sensory neuron excited
• within integrating center (spinal cord), sensory neuron activates inhibitory interneuron
• motor neuron inhibited
• effector (muscles attached to same tendon) relaxes and relieves excess tension

Question 17

what is the purpose of the flexor reflex

Answer 17

to protect body part from further injury

Question 18

what is the result of the flexor reflex

Answer 18

flexion of the affected limb

Question 19

what is pain sensed by in the flexor reflex

Answer 19

nociceptors (sometimes the threat of pain can stimulate the reflex)

Question 20

what is the flexor reflex pathway

Answer 20

• stepping of tack stimulates sensory receptor (dendrites of pain sensitive neuron)
• sensory neuron excited
• within integrating center (spinal cord) sensory neuron activates interneurons in several spinal cord segments
• motor neurons excited
• effectors (flexor muscles) contract and withdraw leg

Question 21

what is the purpose of the crossed extensor reflex?

Answer 21

to stabilize body position when a painful stimulus results in flexion of the opposite limb

Question 22

what reflex does the flexor reflex have

Answer 22

polysynaptic, ipsilateral, spinal, somatic reflex

Question 23

what is the crossed extensor reflex usually paired with?

Answer 23

the flexor reflex

Question 24

what is the result of crossed extensor reflex

Answer 24

extension of opposite limb

Question 25

what is pain sensed by in crossed extensor reflex

Answer 25

nociceptors

Question 26

what kind of reflexes does the crossed extensor reflex have

Answer 26

polysynaptic, contralateral, spinal, somatic

Question 27

crossed extensor reflex pathway

Answer 27

- stepping on a tack stimulates sensory receptor (dendrites of pain sensitive neuron) in right foot - sensory neuron excited - within integrating center sensory neuron activates several interneurons - motor neurons excited - effectors (extensor muscles contract and extend left leg)