Reflexes

Question 1

What is a reflex arc consist of?

Answer 1

an afferent neuron, spinal cord segment, efferent neuron and motor unit

Question 2

Is the menace response, a reaction or reflex?

Answer 2

Reaction

Question 3

What characterizes a reaction?

Answer 3

• cortical awareness

* voluntary behavior

Question 4

Monosynaptic spinal reflex

Answer 4

involves signal to a single efferent nerve

Question 5

Polysynaptic spinal reflex

Answer 5

• associated with an interneuron

* signals many efferent nerves, inhibitory or stimulatory

Question 6

Upper Motor neuron

Answer 6

cell bodies in the brain, terminate at the spinal cord (synapse with a LMN)

Question 7

Lower Motor Neuron

Answer 7

cell bodies in the spinal cord, terminate at teh target organ (muscle or gland)

Question 8

Pupillary light reflex

Answer 8

afferent: CN2
efferent: CN3`

Question 9

Corneal Reflex

Answer 9

Afferent: opthalmic br. of trigeminal (V)
Efferent: VII (for blink), VI ( retraction of globe and passive movement of 3rd eyelid)

Question 10

Palpebral Reflex

Answer 10

Afferent: maxillary br. of V (lateral canthus)
opthalmic br of V (medial canthus)
Efferent: VII

Question 11

Menace Response

Answer 11

afferent: CN2
Efferent: VII –> orbicularis occuli

Question 12

Is pain a reflex or response?

Answer 12

response

Question 13

Panniculus reflex tests the integrity of

Answer 13

afferent n, spinal cord segments, lateral thoracic nerve and cutaneous trunci m

Question 14

How to test the Panniculus reflex?

Answer 14

pinch the skin over the dermatomal area in dorsal thoracolumbar area (T2-L4)

Question 15

What are the components of the panniculus reflex?

Answer 15

afferent n: superficial pain receptors
spinal segment: thoracic nerve locate (C8-T1)
Efferent n: lateral thoracic n
Motor Unit: Contractin of cutaneous trunci mm

Question 16

Withdrawal reflex is testing

Answer 16

withdrawal of limb being stimulated

Question 17

What are the components of the withdrawal reflex (at teh pes)

Answer 17

Stimulation of plantar surface of pes (tibial n) to lumbosacral intumescence (L4-S2), interneuron excites efferent LMN’s to activate flexors of teh limb and inhibit extensors)

Question 18

What is the crossed- extensor reflex?

Answer 18

extension of teh limb opposite a withdrawal stimulus

Question 19

When is the crossed-extensor reflex normal?

Answer 19

Is is normal in teh standing patient only!!!!!!

***not normal in recumbant patient

Question 20

If crossed extensor reflex occurs while an animal is recumbant, you know the lesion is located where

Answer 20

The defect is located in the spinal cord cranial to the reflex

Question 21

Perineal Reflex tests the integrity of

Answer 21

segments S1-3 and the pudendal n

Question 22

What is the efferent and afferent in the Perineal reflex?

Answer 22

Afferent: caudal rectal and perineal br. of pudendal n.
Efferent: cadual rectal br of pudendal n

Question 23

The myotatic reflex is also known as the

Answer 23

muscle spindle reflex, tendon tap reflex, stretch reflex

Question 24

The myotatic reflex is a protective reflex by

Answer 24

preventing over stretch of a ligament, by increasing tone to the muscle being stretched

Question 25

Patellar reflex is an example of what kind of reflex?

Answer 25

myotatic

Question 26

What two different types of stretch can be used to induce the myotatic reflex?

Answer 26

tonic and phasic stretch reflex

Question 27

Tonic stretch reflex

Answer 27

manipulate limbs to determine resistance to passive movement

Question 28

Phasic stretch reflex

Answer 28

use reflex hammer to strike tendon and rapidly stretch muscle

Question 29

Is clonus normal in a myotatic reflex?

Answer 29

no

Question 30

What is clonus?

Answer 30

When a reflex is repeated, after the initial reflex is over

Question 31

What does the circuit of the pain response involve?

Answer 31

intact nociceptive afferent fibers, spinal segment, ascending UMN tract from initial afferent neuron to the brain and normal parietal lobe in the brain