Axilla and Brachial plexus

Question 1

Axilary Boundaries

Apex

Answer 1

Cervico-axillary canal (between neck and axilla) bounded by
Lateral surface of Rib 1
Posterior surface of clavicle
Superior border of scapula

Question 2

Axilary Boundaries

Anterior wall

Answer 2

Pectoralis major and minor

Question 3

Axilary Boundaries

Posterior wall

Answer 3

Subscapularis
Scapula
Teres major
Latissimus dorsi

Question 4

Axillary Boundaries

Lateral wall

Answer 4

Intertubercular groove of humerus

Question 5

Axilary Boundaries

Medial wall

Answer 5

Thoracic wall

Serratus anterior

Question 6

Axilary Boundaries

Basi

Answer 6

Skin joining upper limb to trunk (armpit)

Question 7

Quadrangular spaces

Answer 7

Superior - teres minor
Inferior - teres major
Medial - long head of tricep brachii
Lateral - surgical neck of humerus

Contains - axillary nerve, posterior humeral circumflex artery and vein

Question 8

Triangular space

Answer 8

Superior - teres minor
Inferior - teres major
Lateral - long head of tricep brachii

Contains - circumflex scapular vessels supplying the scapula

Question 9

Triangular interval

Answer 9

Superior - teres major
Medial - long head of tricep brachii
Lateral - humerus

Contains - radial nerve and profunda brachii artery

Question 10

Axillary artery

Answer 10

Source
Subclavian artery
Branches
1. Superior thoracic, 
2. Thoracoacromial, Lateral thoracic, 
3. Subscapular, Anterior circumflex humeral, Posterior circumflex humeral,

Question 11

Axillary Lymph nodes

Answer 11

Pectoral lymph nodes - anterior thoracic wall
Subscapular lymph nodes - posterior thoracic wall and scapula
Humerus lymph nodes - most of upper limb
Central lymph nodes - receives from pectoral, subscapular and humeral lymph nodes
Apical lymph nodes - receives from central lymph nodes. Apical lymph nodes drain to subclavian lymph nodes and ultimately drain into venous system.

Question 12

Brachial plexus Intro

Answer 12

Network of nerves supplying the upper limb, originates in the posterior triangle of the neck and passes to the axilla.

Formed from the anterior rami of spinal cord segments C5-T1 = roots of brachial plexus

Roots pass through a space between the anterior and middle scalene muscles with subclavian artery, entering the axilla via the cervico-axillary canal.

Question 13

Brachial plexus Nerves

Answer 13

Roots
C5, C6, C7, C8, T1

Trunks
Superior
Medial
Inferior

Divisions
Three anterior
Three posterior

Cords
Posterior
Lateral
Medial

Terminal branches
Musculocutaneous nerve
Axillary nerve
Radial nerve
Median nerve
Ulnar nerve

Innervation
Complete sensory and motor innervation of the arm

Nerve lesions: DR. CUMA

(standing for Dropped wrist = Radial nerve lesion, Claw hand = Ulnar nerve lesion, Ape hand = Median nerve lesion)