14.5- Spinal Nerves

Question 1

What are spinal fevers called after they split?

Answer 1

Rami

Question 2

Posterior Ramus

Answer 2

Smaller of the two branches of spinal rami. Innervates the deep muscles of the back including the erector spinae and the transversospinalis.

Question 3

Anterior Ramus

Answer 3

Larger of the two main branches of the rami.

Associated with the autonomic nervous system.

Question 4

Dermatomes

Answer 4

Special segment of skin innervated by a single spinal nerve.

Question 5

Referred visceral pain

Answer 5

When pain from an organ is mistakenly referred to a dermatome.

Question 6

Nerve plexus

Name the four main plexuses.

Answer 6

Network of interweaving anterior rami.
Cervical
Brachial
Lumbar
Sacral

Question 7

T1-T11- What are they called?

Answer 7

Intercostal nerves

Located in the intercostal space.

Question 8

Subcostal nerve

Answer 8

T12

Question 9

Intercostal nerves

Answer 9

Don’t form plexuses

Question 10

Cervical plexus locations

Answer 10

Deep on the side of the neck, lateral to C1-C4. Made up of the anterior rami of C1-C4.

Question 11

Phrenic Never

Answer 11

Important part of the cervical plexus.
Formed primarily from C4 but some of it from C3 and C5.
Innervates the thoracic diaphragm.

Question 12

Brachial plexus

Answer 12

networks of nerves the supply the upper limbs.
Made of the anterior rami of C5-T1.
Extend laterally from the neck and pass superior to the first ribs and continue into the axilla.
Innervates the pectoral girdle and the entire upper imbecile of one side.

Question 13

What are the pars of the brachial plexus from medial to lateral?

Answer 13

Rami, trunks, divisions, and cords.

Question 14

Superior, middle, and inferior trunks

Answer 14

Where the cervical rami (C5-T1) meet to form the trunks.
C5-C6- Form superior trunk
C7- Middle trunk
C8 and T1- Inferior trunk.

Question 15

How are the cords fate brachial plexus named?

Answer 15

With respect to the brachial artery.

Question 16

What are the cords of the brachial plexuses names?

Answer 16

Posterior-C5-T1 posterior parts
Medial- C8-T1- Anterior division of inferior trunk
Lateral cords- C5-C7- Anterior division of the superior and middle trunks.

Question 17

What are the five major terminal branches that emerge from the three cords?

Answer 17

Axillary nerve- Deltoid and teres minor muscles- Sensory info fro superolateral part of arm.

Median nerve- anterior forearm muscles, thenar, and lateral two lumbrical muscles- sensory info from palmar side of lateral 3.5 fingers.

Musculocutaneous nerve- Innervates the anterior arm muscles- sensory from the lateral surface of the forearm

Radial nerve- Innervates some of the anterior forearm muscles. Sensory from the posterior arm and forearm surface and dorsolateral side of hand.

Ulnar nerve- Innervates the anterior forearm muscles, most of intrinsic hand muscles- Sensory info from the dorsal and palmar portions of the medial 1.5 fingers.

Question 18

Lumbar plexuses

Answer 18

Formed from L1-L4

Innervates inferior abdominal wall, anterior thigh, midial thigh, and skin of the medial leg.

Question 19

Femoral nerve

Answer 19

Main nerve of the posterior lumbar plexus.
Innervates anterior thigh
Sensory from anterior and inferomedial thigh and medial aspect of the leg.

Question 20

Obturator Nerve

Answer 20

Main nerve of the anterior lumbar plexus.
Innervate the medial thigh muscles
Sensory- superomedial skin of thigh

Question 21

Sacral plexus

Answer 21

Anterior Rami of L4-S4.

Innervate and sense gluteal, pelvis, perineum, posterior thigh, and almost all of leg and foot.

Question 22

Sciatic Nerve- what are its branches?

Answer 22

Forms portions of the anterior and posterior sacral plexus.
Tibial-
Common fibular

Question 23

Tibial Neve

Answer 23

Anterior division of sciatic nerve.

Innervates hamstring and hamstring portion of abductor magnus.

Question 24

Common Fibular nerve

Answer 24

Posterior portion of sciatic nerve
Innervates short head of biceps femoris
This splits into the deep fibular and superficial nerves.

Question 25

Deep fibular nerve

Answer 25

Extend through the anterior compartment of the leg and terminates between the first and second toes.

Question 26

Superficial nerve

Answer 26

Extends through lateral portion of leg

Innervates later leg muscles. for foot eversion and weak plantar flexors.