Ch. 13 PNS and Reflex Activity

Question 1

These are receptors within the PNS that if stimulated they will generate graded potentials that can activate an action potential.

Answer 1

Sensory receptors.

Question 2

This is any change in environment that activates a receptor.

Answer 2

Stimulus

Question 3

Sensory receptors are classified in what 3 ways?

Answer 3

1. Stimulus Type
2. Stimulus Location
3. Stimulus Structure

Question 4

What are the 5 types of stimulus?

Answer 4

1. Mechanoreceptor
2. Thermoreceptor
3. Photoreceptor
4. Chemoreceptor
5. Nociceptor

Question 5

This stimulus type generates nerve impulses when a mechanical force is applied.

Answer 5

Mechanoreceptor

Question 6

This stimulus type senses temperature changes.

Answer 6

Thermoreceptor

Question 7

This stimulus type responds to light energy.

Answer 7

Photoreceptor

Question 8

This stimulus type responds to chemicals in solution (smell, tastes, changed to internal fluid chemistry.

Answer 8

Chemoreceptor

Question 9

This stimulus type responds to damaging stimulus and can be interpreted as painful.

Answer 9

Nociceptors

Question 10

These sensory receptors respond to stimuli from outside the body.

Answer 10

Exteroceptors

Question 11

These sensory receptors respond to stimuli from inside the body.

Answer 11

Interoceptors

Question 12

These sensory receptors respond to stimuli inn the muscles and joints.

Answer 12

Proprioceptors

Question 13

These sensory receptors are modified dendrites of sensory neurons. There are uncapsulated and encapsulated.

Answer 13

Simple

Question 14

The structure of these sensory neurons are localized collections of cells associated with special senses and sense organs such as the eyes, ears, gates and olfactory bulbs.

Answer 14

Complex

Question 15

This simple structure of sensory neurons are free nerve endings (temperature and pain) associated with skin sensory such as Merkel discs and hair follicle receptors.

Answer 15

Unencapsulated

Question 16

This simple structure of sensory neurons are usually more sensitive and are wrapped around these and contain meissners corpuscles (discriminative touch), pacinian corpuscles (vibration), Ruffini endings (constant pressure), muscle spindles (muscle stretch), golgi tendon organs (muscles stretch), joint kinesthetic receptors (joint stretch).

Answer 16

Encapsulated

Question 17

This is awareness of changes in the environment- activated receptor (PNS)

Answer 17

Sensation

Question 18

This is conscious interpretation of stimuli. Turns change in environment into meaning (CNS)

Answer 18

Perception

Question 19

What are the two types of nerves (axons) that carry into and from the CNS?

Answer 19

Mixed nerves

Ganglia

Question 20

What are the 3 connective tissue structures that help protect the nerves (axons)?

Answer 20

1. Endoneurium
2. Perineurium
3. Epineurium

Question 21

This is a delicate layer of connective tissue that surrounds each Myelin sheath. Most deep.

Answer 21

Endoneurium

Question 22

This is a group of axons (fascicles) wrapped by a coarser connective tissue layer. It wraps around bundles of nerve fibers within a single nerve.

Answer 22

Perineurium

Question 23

This is a tough fibrous connective tissue surrounding all fascicles of a nerve. Outermost layer.

Answer 23

Epineurium

Question 24

This type of nerve contains axons carrying sensory and motor impulses. This is all spinal nerves.

Answer 24

Mixed nerves

Question 25

This is group of neuron cell bodies outside of the CNS. It is mostly sensory neurons.

Answer 25

Ganglia

Question 26

This is the regrowth or repair of nerves. Typically only occurs in the PNS because there are no astrocytes. Damage is usually due to a crushing injury.

Answer 26

Regeneration of nerves.

Question 27

Which end of the axon is able to regenerate?

Answer 27

The proximal end that is still attached to the cell body.

Question 28

This part of the axon degenerated when damaged. The macrophages clean out the dead axon distal to the injury.

Answer 28

Distal axon

Question 29

What happens when the axon regrows?

Answer 29

Axon sprouts or filaments grow through a regeneration tube formed by Schwann cells.

Question 30

What happens when the myelin sheath is repaired?

Answer 30

The axon regenerates and a new myelin sheath forms.

Question 31

How many pairs of cranial nerves are there?

Answer 31

12

Question 32

2 cranial nerves originate in the ______. | 10 cranial nerves originate in the _______.

Answer 32

Forebrain- telencephalon/cerebrum | Brainstem- midbrain, pons, medulla

Question 33

What is the pneumonic to remember the 12 cranial nerves?

Answer 33

On Occasion Our Trusty Truck Acts Funny. Very Good Vehicle Any How.

Question 34

Name the 12 cranial nerves.

Answer 34

``` Olfactory Optic Oculomotor Trochlear Trigeminal Abducens Facial Vestibulocochlear Glossopharyngeal Vagus Accessory Hypoglossal ```

Question 35

Name the pneumonic that gives the cranial nerves functions.

Answer 35

``` Some Say Marry Money But My Brother Says Big Boobs Matter More ```

Question 36

What do the first letters in the functions pneumonic mean?

Answer 36

S- sensory function M- motor function- no sensory B- both motor and sensory

Question 37

How many pairs of spinal nerves are there?

Answer 37

31 pairs

Question 38

Spinal nerves are mixed nerves meaning what?

Answer 38

They both have sensory and motor

Question 39

What are the spinal nerves named for? And how many are there of each?

Answer 39

``` For their corresponding spinal cord level 8 cervical 12 lumbar 5 sacral 1 coccygeal ```

Question 40

Spinal nerves are short and divide into what?

Answer 40

C, L and sacrum go to Dorsal Ramus- back muscles T goes to Ventral ramus- front and limbs Meningeal branch

Question 41

Ventral rami join to for nerve plexuses in order to do what?

Answer 41

Innervate the arms and legs.

Question 42

All nerves innervate the limbs except for which spinal nerves?

Answer 42

T2-T12

Question 43

How many plexuses are there?

Answer 43

4 2 for upper body 2 for lower body

Question 44

The neck contains which plexus? And what does it innervate?

Answer 44

Cervical plexus | Phrenic nerve innervates the diaphragm. (C3-5)

Question 45

This connects rami together so that individual fibers can come off.

Answer 45

Plexuses

Question 46

What are the 4 plexus?

Answer 46

1. Cervical plexus and upper limb 2. Brachial plexus 3. Lumbosacral plexus and lower limb 4. Sacral plexus

Question 47

The brachial plexus is formed by which ventral rami?

Answer 47

``` C5 C6 C7 C8 T1 ```

Question 48

What does the brachial plexus innervate?

Answer 48

From shoulder to fingers

Question 49

What are the 5 nerves of the brachial plexus?

Answer 49

1. Axillary nerve 2. Musculocutaneous nerve 3. Median nerve 4. Ulnar nerve 5. Radial nerve

Question 50

This brachial nerve serves the rotator cuff, the deltoid and teres muscle, skin and joint capsule of shoulder

Answer 50

Axillary nerve

Question 51

This brachial nerve serves the upper flexor at the elbow including biceps brachii and brachialis muscles, cutaneous sensation of lateral forearm.

Answer 51

Musculocutaneous nerve

Question 52

This brachial nerve serves the flexor muscles and lateral muscles of the palm and wrist (middle, pointer and thumb).

Answer 52

Median nerve

Question 53

This brachial nerve serves the hand muscles and skin of the hand

Answer 53

Ulnar nerve

Question 54

This brachial nerve serves the extensor muscles of upper limb.

Answer 54

Radial nerve

Question 55

These plexuses overlap extensively and are often considered together.

Answer 55

Lumbar and sacral

Question 56

The lumbar plexus is L1-L4 and has what two major nerves?

Answer 56

1. Femoral nerve | 2. Obturator nerve

Question 57

This lumbosacral nerve innervates the quadriceps (thigh flexors and knee extensors)

Answer 57

Femoral nerve

Question 58

This lumbosacral nerve innervates the adductor muscles of the thigh.

Answer 58

Obturator nerve

Question 59

The sacral plexus is L4-S4 and contains which 4 nerves?

Answer 59

1. Sciatic nerve 2. Tibial nerve 3. Superior and inferior gluteal nerves 4. Pudendal nerve

Question 60

This sacral nerve innervates the muscles of the entire lower limb except for the anterolateral leg. It is the largest nerve of the body.

Answer 60

Sciatic nerve

Question 61

This sacral nerve innervates the knee joint, skin of the lateral calf, dorsum of foot and anterolateral muscles of the leg.

Answer 61

Tibial nerve

Question 62

This sacral nerve innervates the gluteal muscles.

Answer 62

Superior and inferior gluteal nerves

Question 63

This sacral nerve innervates voluntary control of urination, muscles and skin of perineum and erections.

Answer 63

Pudendal nerve

Question 64

These are segments of skin innervates by each spinal nerve except for C1 which is for internal sensory information only.

Answer 64

Dermatomes

Question 65

These are synaptic connections between neurons and muscles.

Answer 65

Neuromuscular junctions

Question 66

These are varicosities (swelling of axons) along axons over visceral muscles and glands.

Answer 66

En passant synapses

Question 67

What are the 3 levels of motor control?

Answer 67

1. Segmental level 2. Projection level 3. Precommand level

Question 68

This motor integration level is the spinal cord circuits and contains central patter generators (CPGs).

Answer 68

Segmental level

Question 69

This motor integration level is the upper motor neurons ( primary motor cortex and brain stem nuclei). It conveys instructions to spinal cord motor neurons and sends a copy of that information to higher levels.

Answer 69

Projection level

Question 70

This motor integration level is the cerebellum and basal nuclei. It programs and instructs and is modified by feedback

Answer 70

Precommand level

Question 71

This is the nerve pathway involved in a reflex action including at its simplest a sensory nerve and a motor nerve with a synapse between. It requires no conscious control.

Answer 71

Reflex arc

Question 72

These are reflexes mediated by the spinal cord. The brain is informed of these reflexes.

Answer 72

Spinal reflexes

Question 73

This is 3-10 intrafusal muscle fibers enclosed in a connective tissue capsule. It’s job is to detect the stretch of muscle.

Answer 73

Muscle spindle

Question 74

The muscle spindle is innervates by what motor neurons?

Answer 74

Gamma

Question 75

There are 2 types of sensory fibers that wrap the muscle spindle. What are they?

Answer 75

Type Ia fibers | Type II fibers

Question 76

These are primary sensory fiber endings that respond to rage and degree of stretch.

Answer 76

Type Ia

Question 77

These are secondary sensory fiber endings that’s respond only to the degree of stretch.

Answer 77

Type II

Question 78

These are skeletal muscle fibers that aren’t found in muscle spindle and are innervates my alpha motor neurons.

Answer 78

Extrafusal fibers

Question 79

The most common stretch reflex is what?

Answer 79

Patellar or knee jerk reflex

Question 80

These fibers transmit the stretch in a stretch reflex which activates motor neurons of the muscles and inhibits motor neurons of antagonistic muscles.

Answer 80

Afferent

Question 81

These are small bundles of tendon surrounded by a capsule and innervated by sensory fibers and are located in tendons of the muscles.

Answer 81

Golgi tendon organs

Question 82

The golgi tendon is the opposite from stretch reflexes is what way?

Answer 82

It relaxes muscles in response to stretch by inhibiting motor neurons and activating antagonistic muscles

Question 83

This type of reflex is usually accompanied by crossed- extensor reflex. It occurs because noxious stimulus causes flexion of the limb (ipsilateral) and to maintain balance the crosses- extensor reflexes (contralateral).

Answer 83

Withdrawal reflex or crossed-extensor reflex

Question 84

At the site of stimulus of a crossed extensor reflex, a noxious stimulus causes a flexor reflex on the same side withdrawing the limb. At the same time what happens on the opposite side?

Answer 84

The extensor muscles on the opposite side are activated.

Question 85

This type of reflex are responses to gentle cutaneous stimulation.

Answer 85

Superficial reflexes

Question 86

This type of superficial reflex tests integrity of spinal cord from L4-S2. Curling of the toes when a blunt object brushes downward in the bottom of the foot.

Answer 86

Plantar reflex

Question 87

This is dorsi flexion of the great toe and smaller toes fan out. Occurs in infants under one year because the axons from the brain haven’t finished growing to the feet yet.

Answer 87

Babinski’s sign

Question 88

This type of superficial reflex induces contraction of the abdominal muscles of stroking of the skin around the umbilicus occurs. Often a response to tickling.

Answer 88

Abdominal reflexes