axilla and brachial plexus

Question 1

what is the axilla?

Answer 1

pyramidal space inferior to the shoulder joint and just superior to armpit medial

Question 2

what is the pectorals major?

Answer 2

forms the anterior wall of the axilla, and its lower border is contained in the inferior edge of the anterior axillary fold

Question 3

2 main muscles of climbing

Answer 3

pectorals major and latissimus dorsi

Question 4

axillary vein

Answer 4

is a continuation of the branchial vein (deep vein of arm), becomes axillary vein at the lower border of theres major muscle

Question 5

teres major muscle?

Answer 5

contributes to the posterior wall of the axilla, inferior border corresponds to the inferior extent of the axilla

Question 6

subclavian artery?

Answer 6

pulsations of the subclavian artery can be where the artery crosses first rib becomes axillary artery at lateral border of first rib

Question 7

what does the brachial plexus supply?

Answer 7

upper limb and is formed from a very specific intertwining of the anterior rami of spinal nerves C5-T1

Question 8

what does the brachial plexus consist of? prox to distal

Answer 8

roots: anterior rami of C5-T1 nerves, which form trunks trunks divisions cords named nerves

Question 9

what are trunks of brachial plexus?

Answer 9

trunks: combination of roots, give rise to divisions (superior, combines anterior rami of C5/6 spinal nerves; middle, anterior rams of C7 spinal nerve; inferior, combined anterior rami of C8 and T1 spinal nerves)

Question 10

what are divisions of brachial plexus

Answer 10

divides to give anterior and posterior divisions, combine to give cords

Question 11

cords of brachial plexus

Answer 11

cords are named according to their relationship to axillary artery medial= direct continuation of the anterior division of the inferior trunk lateral = formed from anterior divisions of superior and middle trunks posterior = posterior divisions of all three trunks

Question 12

named nerves of the brachial plexus

Answer 12

cords combine to named nerves ulnar nerve continues directly from medial cord musculocutaneous nerve from lateral cord median nerve come from medial and lateral cords

Question 13

roots and trunks lie between

Answer 13

anterior and middle scalene muscles in root of neck

Question 14

divisions lie

Answer 14

posterior to subclavian vessels in root of neck (clavicle)

Question 15

where does musculocutaneous nerve supply

Answer 15

corocobrachialis muscle and other muscles of the anterior compartment of the arm: biceps brachia and brachialis muscles

Question 16

what is the brachial plexus

Answer 16

The brachial plexus is a network (plexus) of nerves (formed by the anterior rami of the lower four cervical nerves and first thoracic nerve (C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in the neck, over the first rib, and into the armpit.

Question 17

brachial plexus structure

Answer 17

Question 18

which nerves pass into the posterior compartment of the arm

Answer 18

axillary nerve and radial nerve

Question 19

axillary vs radial nerve

Answer 19

axillary nerve lies superior to radial nerve and wraps around the posterior aspect of the surgical neck of the humerous, injured by dislocation or fractured neck of humerus

radial nerve wraps around the psoterior aspect of the mid-shaft of the humerous, where it may be injured by a mid-shaft fracture

Question 20

ulnar nerve

Answer 20

most medial of the nerves of the brachial plexus

passes posteriorly into medial aspect of the arm

Question 21

median nerve

Answer 21

nerve forms the middle of the M shaped configuration of the named nerves within the axilla