Distribution Of Spinal Nerves And Organization Of Nerve Plexuses

Front 1

What part of the dorsal root ganglia to the DH contains primary neurons and what part contains secondary neurons

Back 1

Primary neurons are located in the dorsal root ganglia, also known as the spinal ganglion. Secondary neurons are located in the DH and receive input from the primary neurons of the dorsal root ganglia

Front 2

What structure do spinal nerves exit from

Back 2

Spinal nerves exit from the intervertebral foramen

Front 3

What do anterior rami have the ability to form

Back 3

The anterior rami can form nerve plexuses or intercostal nerves.

Front 4

What are nerve plexuses

Back 4

Nerve plexuses are the intermingling of anterior rami from nearby spinal segments that combine

Front 5

How many nerve plexuses are there, what are their names, and what do they protect against

Back 5

There are four nerve plexuses: the cervical, brachial, lumbar, and sacral. And they protect against trauma by creating a degree of redundancy by creating many innervation's on the same muscle

Front 6

What do the anterior rami of thoracic nerves form

Back 6

The anterior rami of the thoracic nerves form the intercostal nerves, resulting in segmental innervation of the thoracic wall

Front 7

Do posterior rami for nerve plexuses

Back 7

NO *****

Front 8

What is the organization of the nerve plexuses starting from closest to spinal cord and trending dorsally

Back 8

Roots, trunks, divisions, cords, branches

Front 9

Where can nerves to the body arise from

Back 9

From all levels of the plexus!

Front 10

Tell me about the cervical plexus: where it exists, what rami form it, and where it innervates

Back 10

Cervical plexus sits in the neck, is formed from the anterior rami of C1-C5, and innervates the neck, upper limb, and diaphragm

Front 11

What important nerve exists in the cervical plexus and why is it important. What is its clinical significance

Back 11

The phrenic nerve! It innervates the diaphragm and allows you to breath. Trauma at C3 or superiorly often results in death due to respiratory failure. The phrenic nerve keeps you alive and breathing.

Front 12

Tell me about the brachial plexus: where it exists, what rami form it, and where it innervates

Back 12

The brachial plexus is located in the muscles of the shoulder, is formed from the anterior rami of C5-T1, and innervates the upper limb and the muscles that help control the upper limb

Front 13

What are the 5 brachial plexus nerves to know. Which are superior and which are inferior

Back 13

The axillary nerve, musculocutaneous nerve, the median nerve, and radial and ulnar nerves

The axillary nerve and musculocutaneous nerve are superficial, and the other 3 are inferior

Front 14

What does the axillary nerve innervate

Back 14

The axillary nerve innervates the deltoid muscle and the skin of the shoulder and upper arm

Front 15

What does the musculo-cutaneous nerve innervate

Back 15

This nerve innervates the biceps brachii and the skin of the lateral forearm

Front 16

What does the radial nerve innervate

Back 16

The triceps and posterior forearm, including all the overlying skin

Front 17

What does the median nerve innervate

Back 17

The muscles of the anterior forearm and the first 3 digits of the hand, including all the overlying skin.

Front 18

What can damage to the median nerve cause. How does this happen

Back 18

CARPAL TUNNEL SYNDROME. Ventrally there is a transverse carpal ligament, and dorsally there are carpal bones in the wrist. Chronic overuse of the first 3 digits of the hand can cause inflammation of the transverse carpal ligament resulting in chronic impingement of the median nerve

Front 19

What does the ulnar nerve innervate

Back 19

It innervates the muscles of the fourth and fifth digits, including its overlying skin. The incidence of entrapment here is much smaller

Front 20

What is an avulsion

Back 20

A tearing of a nerve from the spinal cord

Front 21

What is a rupture

Back 21

A tearing of a nerve not at the spinal cord

Front 22

What is a neuroma

Back 22

A neuroma is when is scar tissue forms on a damaged nerve attempting to heal, putting pressure on the nerve and disrupting signals to the muscle

Front 23

What is a praxis

Back 23

A praxis is a stretching, but not tearing of a nerve

Front 24

How do injuries to the superior brachial plexus result and what are the symptoms

Back 24

Injuries of the superior brachial plexus can result from trauma (fall) or obstetrics (pulling a babys head during delivery) and occurs due to excessive increasing of the angle between the neck and shoulder. Paralysis or anesthesia (sensation) can result. Waiters tip or abnormal medial rotation of the arm can result

Front 25

How do injuries of the inferior brachial plexus occur and what are the symptoms

Back 25

They result from a sudden superior pulling of the entire upper limb. Can be trauma related or obstetrics related, and results in an ulnar claw, also known as Klumpke's palsy. 4th and 5th digits curled to the back of the hand.

Front 26

What do the anterior rami of T2-T12 form. What do they innervate

Back 26

These rami form the intercostal nerves that are arranged segmentally between ribs. They innervate the thorax

Front 27

Tell me about the lumbar plexus: where it exists, what rami form it, and where it innervates

Back 27

It is located underneath the psoas major muscle, or underneath the major muscles of the back. L1-L4 anterior rami form the lumbar plexus. It innervates the lower limbs, with branches into the abdominal wall and inguinal region.

Front 28

How can deficits in the movement of lower limbs occur

Back 28

From trauma or diabetes. Diabetes is very rough on the vasculature causing decreased blood flow to the extremities, and the neurotoxic effects can cause neuropathy. Could result from difficult delivery of a baby as well.

Front 29

What are the two nerves of the lumbar plexus to know

Back 29

The femoral nerve and the obturator nerve

Front 30

What does the femoral nerve innervate

Back 30

The femoral nerve travels from the lumbar plexus to the foot, and innervates the quads of the thigh, and the anteriomedial regions of the thigh/knee/lower leg

Front 31

What does the obturator nerve innervate

Back 31

It innervates the adductor muscles of the medial thigh and the overlying skin

Front 32

Tell me about the sacral plexus: where it exists, what rami form it, and where it innervates

Back 32

The sacral plexus is located caudally to the lumbar plexus, is formed by the anterior rami of L4-S4, and innervates the buttocks, pelvis, and lower limb.

Front 33

What are the two nerves of the sacral plexus to know

Back 33

The sciatic nerve and the pudendal nerve. The sciatic nerve also has two branches, the tibial nerve and the common fibular nerve

Front 34

What does the pudendal nerve innervate

Back 34

The sphincters of the bladder and rectum, and the skin of the external genitalia

Front 35

What does the tibial nerve of the sciatic nerve innervate

Back 35

It innervates the muscles of the posterior thigh, muscles and skin of the lower leg and foot

Front 36

What does the common fibular nerve of the sciatic nerve innervate. What can damage to this nerve result in

Back 36

the muscles and skin of the anteriolateral lower leg and top of the foot. Damage to this nerve can result in drop foot

Front 37

What is the effect of vertical compression on the spine

Back 37

Vertebral discs can slip or degenerate causing vertebrae to collapse onto spinal nerves, and causing impingement of the lumbar and sacral plexuses. This can be extremely painful!

Front 38

What do dermatomes and myotomes represent

Back 38

They represent the segmental innervation of the body by spinal nerves

Front 39

What is a dermatome. What can we use a dermatome to figure out

Back 39

A dermatome is a region of skin innervated by a signal spinal nerve. We can use the location of superficial pain or the loss of sensation to tell us about damage to a specific spinal nerve and vice versa.

Front 40

From cervical to sacral what regions of skin do the spinal nerves innervate

Back 40

The cervical nerves, excepting C1, innervate the skin of the neck, jaw, shoulder, and entire upper limb.
The thoracic nerves innervate the entire abdomen and chest
The lumbar nerves innervate the lower limbs
The sacral nerves innervate the genital region and the lateral portion of the ankle

Front 41

What is a clinical correlate of dermatomes

Back 41

Herpes zoster or shingles! Chicken pox lies dormant in dorsal root ganglia and if it becomes activated will usually cause unilateral shingles which terminate medially to appear on the body. It will cause an outburst of a single dermatome

Front 42

What is referred pain and how does it occur

Back 42

Referred pain is pain that is felt somewhere other than where the problem is occurring. For example, pain in the heart is sent to the upper left quadrant of the body. This is because the pain afferent fibers that innervate on the DH share a neuron with sensory fibers from the skin. So when this neuron sends a signal to the brain the brain cannot differentiate where the signal comes from so it will cause pain in the superficial region, rather than the viscera.

Front 43

What are myotomes

Back 43

Myotomes are a collection of skeletal muscles innervated by a common spinal nerve

Front 44

What are the 3 classes of functional classification of peripheral nerves

Back 44

The 3 classes are: 1. nerve origin, General or Special.
2. What it innervates, Somatic or Viscera
3. Direction of nerve impulse, Afferent or Efferent

Front 45

What is the difference between general and special nerves

Back 45

General nerves are found in both spinal and cranial nerves, whereas special nerves are only cranial and are always sensory afferent like taste, vision, olfactory, vestibular, or auditory.
G or S, first letter

Front 46

What is the difference between Somatic or Viscera, second letter, S or V

Back 46

Somatic are types of neurons innervating skeletal muscle, skin, cartilage, etc.

Viscera innervate the internal organs, glands, or erector pili muscles

Front 47

What is the difference between Afferent or Efferent, A or E

Back 47

Afferent are sensory neurons, whereas efferent are motor neurons to skeletal and smooth muscle

Front 48

Describe GSE vs GVE

Back 48

GSE is a nerve from motor to skeletal muscles carrying efferent information whereas GVE is a nerve from motor to viscera carrying efferent information (autonomic efferents)

Front 49

Describe GSA vs GVA

Back 49

GSA is sensory info from the muscles and skin, and GVA is sensory info from the viscera.

Front 50

Describe SSA

Back 50

Sensory info from the special senses of taste, vision, auditory, etc.