Exam 2 Study Guide 2

Question 1

stretch reflex

Answer 1

• monosynaptic

- muscle contraction in response to a quick stretch

Question 2

stretch reflex aka

Answer 2

• myotatic
• muscle stretch reflex
• deep tendon reflex

Question 3

cutaneous reflex

Answer 3

• goes along with flexion withdrawal reflex

- If you step on something sharp, you have a cutaneous reflex that causes a flexion withdrawal reflex

Question 4

flexion withdrawal reflex

Answer 4

movement of a limb away from a stimulus

Question 5

inverse myotatic reflex

Answer 5

AUTOGENIC INHIBITION

• agonist muscle relaxes after being stretched
• ex. stretching quads causes them to relax

Question 6

reciprocal inhibition in a stretch reflex

Answer 6

• monosynaptic to agonist

- polysynaptic to antagonist

Question 7

stretch reflex: decussation?

Answer 7

no

Question 8

withdrawal reflex: poly/mono

Answer 8

polysynaptic

Question 9

flexion reflex: decussation

Answer 9

• no decussation

- ipsilateral inhibition of extensors + contraction of flexors

Question 10

crossed extension portion: decussation

Answer 10

• decussates in SC

- contralateral inhibition of flexors + contraction of extensors for WB

Question 11

medial CST: direct connection from

Answer 11

cerebral cortex to SC

Question 12

path of medial CST

Answer 12

motor cortex
» medullary pyramids
» SC

(descends in ventral funiculus)

Question 13

medial CST: decussation

Answer 13

does not cross

• innervates ipsilateral side of LMN of trunk, neck, and shoulder

Question 14

Which tract is the most important one controlling voluntary movements?

Answer 14

lateral CST

Question 15

path of lateral CST

Answer 15

motor cortex (motor planning areas)
» axons through internal capsule in peduncles
» through pons/medulla
» 90% of neurons cross at pyramidal decussation
» travels to SC and synapses with LMN

Question 16

reticulospinal tract

Answer 16

• begins in reticular formation

- facilitates bilateral LMNs that innervate postural and gross limb movement of muscles throughout the body

Question 17

rubrospinal tract path

Answer 17

red nucleus
» decussates immediately in brainstem
» travels to cervical cord
» innervates UE (extensors of wrist/fingers)

Question 18

corticobulbar tracts: purpose

Answer 18

• how we get info through cranial nerves and to the face

- motor homunculus through brainstem

Question 19

corticobulbar tracts are important for

Answer 19

• expression
• swallowing
• talking

Question 20

medial CST: synapse between UMN/LMN

Answer 20

cervical spinal cord

Question 21

medial CST: decussation

Answer 21

no

- ipsilateral only

Question 22

medial CST: muscles innervated

Answer 22

• back muscles
• shoulder
• neck

Question 23

medial CST: function

Answer 23

control neck, shoulder, and trunk muscles (posture)

Question 24

lateral CST: start/finish

Answer 24

start: primary motor, premotor, supplementary motor areas
finish: contralateral innervation of limbs

Question 25

lateral CST: synapse between UMN/LMN

Answer 25

cervical spinal cord

Question 26

lateral CST: decussation

Answer 26

some do (lower medulla), some dont

Question 27

lateral CST: muscles innervated

Answer 27

• distal limbs

- fractionate movements

Question 28

lateral CST: function

Answer 28

precise control of contralateral movements of limbs, fractionate movements

Question 29

rubrospinal tract: start/finish

Answer 29

start: red nucleus in midbrain
finish: contralateral upper limb muscles

Question 30

rubrospinal tract: synapse between UMN/LMN

Answer 30

cervical spinal cord

Question 31

rubrospinal tract: decussation

Answer 31

yes, midbrain

Question 32

rubrospinal tract: function

Answer 32

extends wrist and fingers

Question 33

lateral and medial vestibulospinal tracts (inputs)

Answer 33

receive inputs from vestibular apparatus in the ear

• about head position and movement (medial)
• about gravity (lateral)