Reflexes, Spinal Nerves, ANS

Question 1

The spinal cord also serves as an _______ center for spinal reflexes.

Answer 1

Integrating

Question 2

What is a reflex?

Answer 2

A fast, predictable, automatic response to a stimulus

Question 3

Reflexes occur ______ conscious thought and can include ______ secretion and ________ of all three muscle types.

Answer 3

Without
Glandular
Contraction

Question 4

_________ reflexes that are responsible for maintaining relatively constant blood pressure or, for example, blood C02 levels

Answer 4

Autonomic

Question 5

What is a reflex arc?

Answer 5

The smallest and simplest portion of the nervous system capable of receiving a stimulus and producing a response.

Question 6

What fibers are in the dorsal root? What is their polarity?

Answer 6

Contains sensory root fibers, almost always unipolar

Question 7

What fibers are in the ventral root?

Answer 7

Contains motor fibers

Question 8

The stretch reflex is ____synaptic. This means there are ____ nerves in the pathway.

Answer 8

Monosynaptic

2

Question 9

What is an example of the stretch reflex?

Answer 9

The patellar reflex

Question 10

In the stretch reflex, muscle ______ in skeletal muscle are stretched, fires neuron (in ______ _____ _____) and the signal goes to the _____ _______ and returns to same muscle to contract.

Answer 10

Spindles
Dorsal root ganglion
Ventral horn

Question 11

The flexor reflex is also called the ______ reflex

Answer 11

Withdrawal

Question 12

The flexor reflex is ____synaptic and is a reaction to ______ stimuli.

Answer 12

Polysynaptic

Painful

Question 13

What is an example of the flexor reflex?

Answer 13

A hand touching a hot stove and flexing away

Question 14

In the flexor reflex how many neurons are involved? Where are they?

Answer 14

3

1st neuron stops in dorsal horn, 2nd in interneuron, 3rd neuron returns to effector

Question 15

What is the function of the flexor reflex?

Answer 15

This functions to move a limb or body part away from a painful stimulus
Automatic withdrawal of the threatened body part

Question 16

In the crossed extensor reflex, the flexor is ______, extensor is _______.

Answer 16

ipsilateral

contralateral

Question 17

What is a spinal nerve?

Answer 17

A combination of ventral and dorsal roots together

So it’s a “mixed” nerve- has both sensory and motor fibers

Question 18

When/where does the spinal nerve become the spinal nerve?

Answer 18

at or just before the intervertebral foramen

Question 19

What is a dermatome?

Answer 19

For sensory (not motor), each spinal nerve has a specific cutaneous distribution

Question 20

Which nerve has no dermatome?

Answer 20

C1

Question 21

What is a dermatomal map?

Answer 21

A diagram of the cutaneous regions innervated by each spinal nerve— they’re not exact… there’s overlap

Question 22

How are dermatomes useful clinically?

Answer 22

In patients with spinal cord injuries, you can pinpoint the damaged nerves and injured region of the spinal cord by determining which dermatomes are affected

Question 23

Just after the intervertebral foramen, the spinal nerve divides into: (3 things)

Answer 23

Dorsal ramus
Ventral ramus
Meningeal ramus

Question 24

The dorsal ramus innervates….

Answer 24

Innervates the muscles and joints in that region of the spine as well as the skin in that area of the back

Question 25

The ventral ramus innervates....

Answer 25

Innervates the ventral/lateral skin and muscles of the trunk | Gives rise to the nerves to the limbs

Question 26

Which ramus is more complex in the spinal nerve?

Answer 26

Ventral; innervates much more than the dorsal ramus

Question 27

What is the meningeal brach of the spinal nerve?

Answer 27

A small nerve that re-enters the vertebral canal and innervates the meninges and blood vessels there

Question 28

The spinal nerve branches into dorsal and ventral _____ approaching the spinal cord; and ventral ____ leading away from the spinal cord

Answer 28

roots | rami

Question 29

In the thoracic region ventral rami form ______ _______.

Answer 29

Intercostal nerves

Question 30

What do intercostal nerves innervate?

Answer 30

Intercostal nerves innervate the skin, intercostal muscles, and abdominal muscles

Question 31

Where are nerve plexuses formed?

Answer 31

Everywhere but the thorax

Question 32

What is a nerve plexus?

Answer 32

Where nerves branch and merge repeatedly to form web-like braids

Question 33

Where is the cervical plexus located? What nerve is in it?

Answer 33

C1-C4 | Phrenic nerve

Question 34

Where is the phrenic nerve?

Answer 34

Descends along each side of the neck to enter the thorax

Question 35

What does the phrenic nerve innervate? What is this responsible for?

Answer 35

Innervates the diaphragm: is responsible for breathing

Question 36

The phrenic nerve is formed by branches/brains from these nerves

Answer 36

C3, C4, C5

Question 37

If both phrenic nerves are severed the diaphragm is severed and ______ ______ occurs Irritation of the phrenic nerve causes _______

Answer 37

Respiratory arrest | Hiccups

Question 38

Where is the brachial plexus?

Answer 38

C5-T1

Question 39

What nerves is in the brachial plexus?

Answer 39

Ulnar nerve Radial nerve Median nerve

Question 40

The ulnar nerve is called what? Where is it?

Answer 40

Funny Bone” It lies against the medial epicondyle of the humerus

Question 41

Compression of the ulnar nerve causes .....

Answer 41

Compression causes a loss of abduction and adduction of the fingers Also, loss of sensation in the little finger

Question 42

The _____ ______ is the largest terminal branch of the brachial plexus

Answer 42

radial nerve

Question 43

The radial nerve controls the _______ muscles of the _____

Answer 43

extensor | hand

Question 44

What three conditions can arise from compression of the radial nerve?

Answer 44

Wrist drop Crutch paralysis Saturday night paralysis

Question 45

What is wrist drop?

Answer 45

A loss of extensor muscle in the hand

Question 46

What is crutch paralysis?

Answer 46

The nerve lies near humerus in the axilla, so improper use of crutches can press the nerve against the humerus

Question 47

What is Saturday Night paralysis?

Answer 47

If you sleep with your arm over the back of a chair

Question 48

What does the median nerve control?

Answer 48

Forearm flexors and thenar (thumb) group

Question 49

Weak thumb movement occurs from damage to the ________ nerve.

Answer 49

Median

Question 50

Pain from ______ ______ can also result in numbness and tingling in the hands and fingers.

Answer 50

Carpal tunnel

Question 51

Where is the lumbar plexus?

Answer 51

L1-L4

Question 52

What nerve is in the lumbar plexus? What happens if it's damaged?

Answer 52

Femoral nerve | If damaged, cannot extend lower leg or knee

Question 53

Where is the sacral plexus?

Answer 53

L4-S4

Question 54

What nerve is in the sacral plexus? Injury to this nerve is called?

Answer 54

Sacral nerve | Sciatica

Question 55

What is sciatica?

Answer 55

Pain extending from gluteal region along posterior aspect of the thigh and leg

Question 56

What is the most vulnerable nerve in the body?

Answer 56

The sciatic nerve

Question 57

Damage to the sciatic nerve can result in _____ ______.

Answer 57

Foot drop

Question 58

How many nerves are in a sensory pathway?

Answer 58

3

Question 59

How many nerves are in a motor pathway?

Answer 59

2

Question 60

How many nerves are in an autonomic pathway?

Answer 60

2