Exam 2 - Reflex Mechanisms

Front 1

What is the function of a sensory receptor?

Back 1

Initiates a nerve impulse or action potential

Front 2

What is the function of a afferent neuron?

Back 2

Transmits the nerve impulse through a peripheral nerve to the central nervous system where it synapses.

Front 3

What is the function of a integrating center?

Back 3

Synapse with the spinal cord, relays the impulse to the motor neuron.

Front 4

What is the function of a efferent neuron?

Back 4

Delivers the nerve impulse to an effector via the spinal nerve and peripheral nerve.

Front 5

What is the function of a effector?

Back 5

Muscle or gland, responds to the efferent neuron impulses.

Front 6

What is the main characteristic of a reflex?

Back 6

They are always involuntary.

Front 7

What causes a reflex?

Back 7

Always occur because of a sensory stimulus. The response produced by the reflex is stereotyped.

Front 8

What is the basic function of a reflex?

Back 8

Protection, maintain muscle tone, and allows body to maintain homeostasis.

Front 9

What are somatic spinal reflexes?

Back 9

Reflexes that result in the contraction of skeletal muscles.

Front 10

What are Visceral spinal reflexes?

Back 10

Reflexes that cause the contraction of smooth muscle, cardiac muscle or the secretion by glands.

Front 11

What type of reflex is a visceral reflex?

Back 11

Autonomic

Front 12

What is the receptor for the Muscle stretch reflex?

Back 12

Muscle spindle

Front 13

What is the stimulus for the muscle stretch reflex?

Back 13

Change in length of muscle. Slight stretching of a muscle stimulates the sensory ending in the muscle spindles.

Front 14

What is the response of the muscle stretch reflex?

Back 14

Causes the stretched muscle to contract.

Front 15

What is the ipsilateral reflex arc of a muscle stretch reflex?

Back 15

The sensory impulse enters the spinal cord on the same sie that the motor impulse leaves the spinal cord.

Front 16

What is the monosynaptic reflex of the muscle stretch reflex?

Back 16

The sensory neron synapses with the motor neuron within the spinal cord directly.

Front 17

What is the purpose of the muscle stretch reflex?

Back 17

Maintains muscle tone and protects the muscles from overstretching.

Front 18

How is muscle stretch relfex used clinically?

Back 18

To check for neurological damage.

Front 19

What is an example of muscle stretch reflex?

Back 19

Patellar tendon reflex. When patellar ligament is tapped. Muscle spindles in quadriceps femoris muscle send sensory impulse to spinal cord. Cause muslce to contract and leg extension at knee.

Front 20

What is the receptor for the gamma reflex loop?

Back 20

Muscle spindle.

Front 21

What is the stimulus for the gamma reflex loop?

Back 21

Change in length of the muscle.

Front 22

What is the response to the gamma reflex loop?

Back 22

Continuous partial skeletal muscle contraction for postural muscle tone.

Front 23

What type of reflex/reflex arc is the gamma reflex loop?

Back 23

Ipsilateral/Polysynaptic

Front 24

What is the purpose of the gamma reflex loop?

Back 24

Length monitoring system/postural tone.

Front 25

What is an example of gamma reflex loop?

Back 25

When muscles in the back of the neck are in tonic contraction, they hold the head in the anatomical position and preven it from slumping forward, but not enough force to pull the head back into hyperextension.

Front 26

What kind of neurons does the muscle stretch reflex use?

Back 26

Alpha motor neurons.

Front 27

What kind of neurons does the gamma reflex loop use?

Back 27

Gamma motor neurons.

Front 28

What is the receptor for flexor reflex?

Back 28

Free nerve endings.

Front 29

What is the stimulus for flexo reflex?

Back 29

Pain

Front 30

What is the response of flexo reflex?

Back 30

Withdrawl (flexion) of stimulated extremity.

Front 31

What type of reflex, reflex arc is a flexor reflex?

Back 31

Ipsilateral/Polysynaptic

Front 32

What is the purpose of the flexor reflex?

Back 32

Protects the body from painful stimuli.

Front 33

What is the clinical use for flexor reflex?

Back 33

Can be used in paralyzed patients to stimulate flexion patterns.

Front 34

What is the receptor for crossed extension reflex?

Back 34

Free nerve ending.

Front 35

What is the stimulus for crossed extension reflex?

Back 35

Pain

Front 36

What is the response of crossed extension reflex?

Back 36

Withdrawl (flexion) of stimulated extremity and extension of the contralateral extremity.

Front 37

What is the type of reflex/reflex arc of a crossed extension reflex?

Back 37

Part ipsilateral / part contralateral, and polysynaptic

Front 38

What is the purpse of crossed extension reflex?

Back 38

Protection of the threated side while maintenance of posture on the contralateral side.

Front 39

What is the law of reciprocal innervation?

Back 39

A reflex which when a muscle is stimulated to contract (agonist), causes inhibition of the opposing muscle (antagonist)

Front 40

What does (-) mean for law of reciprocal innervation?

Back 40

Means inhibition of activity.

Front 41

What does (+) mean for law of reciprocal innervation?

Back 41

Mean enhancement of activity.

Front 42

What is another name for Extensor Thrust Reflex?

Back 42

Positive Support

Front 43

When does Extensor Thrust reflex become abnormal?

Back 43

After 6 months of age.

Front 44

What is the stimulus of extensor thrust reflex?

Back 44

Pressure receptors (pacinian corpuscles) on the bottom of the foot are stimulated.

Front 45

What is the response of extensor thrust reflex?

Back 45

The lower extremity extensor skeletal muscles are activated causing the hip, knee, and ankle to extend.

Front 46

What are the functions of extensor thrust reflex?

Back 46

Aids in maintaining the standing position.

Front 47

What is the clinical aspects of extensor thrust reflex?

Back 47

Can be used to stimulate extensor patterns in patients with a neurological disorder for both the upper and lower extremities.

Front 48

When does asymmetric tonic neck reflex become abnormal?

Back 48

After 6 months of age.

Front 49

What is the stimulus for asymmetric tonic neck reflex?

Back 49

Proprioception receptors of the neck are stimulated with neck rotation.

Front 50

What is the response of asymmetric tonic neck reflex?

Back 50

Extension of the arm and leg on the side to which the face is turned, and flexion of the arm and leg on the contralateral side.

Front 51

What is the function of the asymmetric tonic neck reflex?

Back 51

Child developmental testing / neurological testing.

Front 52

What is the pathological reflex of extensor thrust reflex?

Back 52

Impairs gait - during weight bearing the LE goes into an extension pattern offsetting balance and the normal gait pattern.

Front 53

What is the pathological reflex of asymmetric tonic neck reflex?

Back 53

Interferes with the development of symmetry and independent movements of the trunk and limbs. Interferes with rolling from supine to prone.

Front 54

When does symmetric tonic neck reflex become abnormal?

Back 54

After 6 months of age.

Front 55

What is the stimulus of symmetric tonic neck reflex?

Back 55

Proprioception receptors are stimulated with neck extension or flexion.

Front 56

What is the response of symmetric tonic neck reflex?

Back 56

With neck extension, the upper extremities extend and lower extremities flex. With neck flexion, the upper extremities flex and the lower extremities extend.

Front 57

What is the pathological effects of symmetric tonic neck reflex?

Back 57

Interferes with independent movement of the head and extremities.

Front 58

When does babinski sign become abnormal?

Back 58

Past 1 year of age.

Front 59

What is the stimulus for babinski sign?

Back 59

Touch receptors stimulated on the lateral aspect and plantar surface of the foot over the metatarsal heads.

Front 60

What is the response of babinski sign?

Back 60

Extension of the first toe with or without fanning of the other toes (positive babinski sign)

Front 61

What is the function of babinski sign?

Back 61

Child developmental testing and neurological testing of LE

Front 62

When does hoffman's sign become abnormal?

Back 62

Abnormal past 1 year.

Front 63

What is the stimulus for hoffman's sign?

Back 63

Flicking the distal phalanx of the third digit.

Front 64

What is the response of hoffman's sign?

Back 64

Clawing movement of the fingers to the thumb (positive hoffman sign).

Front 65

What is the function of hoffman's sign?

Back 65

Child development testing / neurological testing of UE.

Front 66

When does superficial abdominal reflex become abnormal?

Back 66

This reflex does not go away.

Front 67

What is the stimulus for superficial abdominal reflex?

Back 67

Light touch around the umbilicus unilaterally stimulates the touch receptors.

Front 68

What is the response of superficial abdominal reflex?

Back 68

The umbilicus deviates slightly to the side stroked.

Front 69

What is the function of superficial abdominal reflex?

Back 69

Neurological testing of the trunk region.

Front 70

What are upper motor neuron lesions?

Back 70

Damage to the anterolateral coricospinal tract's upper motor neuron which lies in the brain and spinal cord.

Front 71

Where can the damage from upper motor neuron lesions be found?

Back 71

Damage can be to the cell bodies in the precentral gyrus or to the descending internuncial axons in the internal capsule, brainstem, or spinal cord.

Front 72

If damage to anterolateral corticospinal tract is above the medulla, where would the effects present themselves?

Back 72

Characteristics of an UMN lesion will be seen on the contralateral side of the body.

Front 73

If damage to anterolateral corticospinal tract is below the medulla, where would the effects present themselves?

Back 73

Characteristics of an UMN lesion will be seen on the ipsilateral side of the body.

Front 74

What are the common causes of upper motor neuron lesions?

Back 74

CVA, head trauma, spinal cord injury, multiple sclerosis

Front 75

What kind of lesion presents as spastic paralyses?

Back 75

UMN lesion

Front 76

What kind of lesion presents as increased muscle tone?

Back 76

UMN lesion.

Front 77

What kind of lesion presents as increased muscle stretch reflex (hyperreflexia)?

Back 77

UMN lesion.

Front 78

What kind of lesion results in pathological reflexes present?

Back 78

UMN lesion.

Front 79

What kind of lesion presents as muscle wasting secondary to disuse atrophy?

Back 79

UMN lesion.

Front 80

Where does the lower motor neuron lie?

Back 80

IIn the spinal cord and periphery.

Front 81

What can cause lower motor neuron lesions?

Back 81

Damage to spinal nerve, peripheral nerve, synapse of the neuron with the skeletal muscle, and/or cell bodies within the anterior (ventral) horn.

Front 82

Where do lower motor neuron lesions present themselves?

Back 82

Ipsilaterally.

Front 83

What are the common causes of lower motor neuron lesions?

Back 83

Herniated disc, peripheral nerve injury.

Front 84

What kind of lesion presents as flaccid paralyses?

Back 84

LMN lesion.

Front 85

What kind of lesion presents as decreased muscle tone?

Back 85

LMN lesion.

Front 86

What kind of lesion presents as no muscle stretch reflex?

Back 86

LMN lesion.

Front 87

What kind of lesion presents as absense of pathological reflexes?

Back 87

LMN lesion.

Front 88

What kind of lesion presents as muscle wasting secondary to neurogenic atrophy?

Back 88

LMN lesion.