Spinal Nerves

Question 1

3 layers of connective tissues in a spinal nerve

Answer 1

Endoneurium (most superficial) Perineurium (Organized into fascicles) Epineurium (most deep)

Question 2

How are spinal nerves designated?

Answer 2

Letter + Number C (1-8) T (1-12) L (1-5) S (1-5) Co Coccygeal nerve (when designated)

Question 3

Dermatome

Answer 3

Area of skin supplied with sensory innervation by a pair of spinal nerves

Question 4

Ramus

Answer 4

A major branch of a psinal nerve

Question 5

Doral rami v ventral rami

Answer 5

Dorsal - innervate most of the deep muscles of the dorsal trunk, responsible for moving the vertebral column Ventral rami

Question 6

Intercostal nerves

Answer 6

Formed by ventral rami in the thoracic region

Question 7

Plexuses

Answer 7

ventral rami of remaining spinal nerves. The ventral rami of different spianl nerves, called roots, join with each other to form a plexus.

Question 8

The 5 major spinal plexuses

Answer 8

Cervical (C1-C4) brachial (C5 - T1) Lumbar (L1-L4) Sacral (L4-S4) Coccygeal (Co)

Question 9

Cervical plexus // Origination, innervation

Answer 9

C1-C4 Innervates superficial neck structures, including hyoid bone.

Question 10

Ansa cervicalis

Answer 10

A loop between C1 and C3, which has branches of nerves that go to the infrahyoid muscles.

Question 11

Phrenic nerve

Answer 11

an important nerve for breathing bc it innervates diaphragm Originates from c3-c5

Question 12

Brachial plexus // Origination, innervation

Answer 12

C5 - T1

Question 13

Organization fo the brachial plexes

Answer 13

5 ventral rami > join to form 3 trunks > separate into 6 divisions (posterior and anterior) > going again to create 3 cords > separate into 5 branches of upper limb nerves.

Question 14

5 major nerves emerging from brachial plexus

Answer 14

Axillary

Radial

Musculocutaneous

Ulnar

Median

Question 15

Why can the entire limb be anesthetized at once?

Answer 15

The anatomical organization of the brachial plexus allows for brachial anesthesia.

Question 16

Axillary nerve

Answer 16

Shoulder - deltoid and teres minor muscles.

Question 17

Radial nerve

Answer 17

innervates extensor muscles of upper limb

posterior portion of upper limb (incl. hand)

Question 18

Musculocutaneous Nerve

Answer 18

Anterior muscles of the arm and cutaneous sensory innervation to some of the forearm.

Question 19

If the radial nerve is damaged due to compression against the humorous from improper use of crutches, what results?

Answer 19

crutch paralysis

Question 20

What is the major symptom of crutch paralysis?

Answer 20

Wrist Drop - elbow, wrist, and fingers are constantly flexed

Question 21

Median nerve

Answer 21

C5 - T1

innervates all but one of the flexor muscles of the forearm, most the hand at the base of the thumb

Question 22

Carpal tunnel syndrome

Answer 22

Damage to the median nerve

Causes numbness, tingling, and pain in the fingers.

Question 23

Ulnar Nerve

Answer 23

C8 - T1

Innervate two forearm muscles and most intrinsic hand muscles.

Question 24

Thoracic outlet syndrome

Answer 24

compression inferior root of the brachial plexus, causes pain, tingling, numbness, pain in the elbow.

Question 25

Lumbar Plexus

Answer 25

L1-L4

Question 26

Sacral plexus

Answer 26

L4-S4

Question 27

4 major nerves of the lumbosacral plexus

Answer 27

Obturator

femoral

tibial

common fibular

Question 28

Obturator nerve

Answer 28

L2-L4

Innervates muscles that adduct the thigh

Question 29

Femoral nerve

Answer 29

Innervates iliopsoas and sartorius muslces and quadriceps.

Question 30

Tibial and common fibular nerves - sciatic nerve

Answer 30

L4-S3

Bound together in connective tissue sheath fo rlegth of thigh.

Collectively referred to as the sciatic nerve.

Question 31

Medial and lateral plantar nerves

Answer 31

Tibial nerve branches to form

Innervate plantar muscles of foot.

Question 32

Sural nerve

Answer 32

branch from the tibial nerve

Innervates calf of leg and plantar surface of foot

Question 33

Deep and superficial fibular nerves

Answer 33

brances of the common fibular nerve.

Innervate anterior and lateral muscles of leg and foot.

Question 34

Pudendal nerve

Answer 34

Supplies muscles of the abdominal floor; sexual stimulation

Question 35

Coccygeal plexus

Answer 35

Small plexus from S5 - Co

Motor innervation to pelvic floor muscles