A&P 2.9. Roots, Rami, intercostal nerves

Question 0

Cranial nerves VII

Answer 0

Facial

Class: mixed

Function: facial expression, secretes saliva and tears

Question 1

Cranial nerve V

Answer 1

Trigeminal

Class: mixed

Function: sensation of head and face; chewing proprioception

Question 2

Root

General

Answer 2

2 bundles of axons called ROOTS connect each spinal nerve to a segment of the cord

Each root has 4 sensory bundles for each segment of the spinal cord

SPINAL NERVES ARE MIXED: BOTH SENSORY AND MOTOR AXONS

SAME only works for roots

Question 3

Posterior (dorsal) ROOT

Answer 3

Contains only sensory axons which conduct nerve impulses for sensations from the skin, muscles and internal organs INTO THE CNS

POSTERIOR, DORSAL, AFFERENT, SENSORY

Question 4

Anterior (ventral) ROOT

Answer 4

Contains axons of somatic motor neurons, which conduct impulses FROM THE CNS to skeletal muscles and

autonomic motor neurons, which conduct impulses to smooth and cardiac muscle, glands FROM THE CNS

ANTERIOR, EFFERENT, VENTRAL, MOTOR

Question 5

Ramus

Answer 5

“Branches”

Soon after each spinal nerve emerges from the spinal cavity, it forms large branches, each called a RAMUS

ALL RAMI ARE MIXED

Question 6

Dorsal RAMUS

Answer 6

Supplies somatic motor and sensory fibers to several smaller nerves

These smaller nerves in turn innervate muscles and skin of the posterior surface of head, neck and trunk.

Question 7

Ventral RAMUS

Answer 7

Branch off to innervate the skeletal muscles and skin of the limbs and the anterior surface of the trunk with their sensory and somatic motor fibers.

Autonomic motor fibers split away from the ventral RAMUS, heading toward a ganglion (unmyelinated grey matter) of the SYMPATHETIC CHAIN.

Question 8

Intercostal nerves

Answer 8

Include T2-T12 where no plexus is formed

Branches run directly to intercostal muscles of the skin and thorax

Question 9

Teres major

A, I, O

Answer 9

A: extend the shoulder, adduct the shoulder, medially rotate shoulder

O: lateral side inferior angle of the scapula, lower half of axillary border of scapula

I: medial lip of bicipital groove. Or crest of the lesser tubercle of the humerus

ANTERIOR

Question 10

Extension

Answer 10

Delts (post)

Trail guides 64-65

Question 11

Teres major follows lattissimus dorsi

Teres minor follows infraspinousatus

Answer 11

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