Axilla and Brachial Plexus Flashcards
What muscles make up the anterior wall of the axilla?
Pectoralis major and minor mm.
What muscles make up the posterior wall of the axilla?
Latissimus dorsi, teres major, and subscapularis mm.
What makes up the medial wall of the axilla?
Serratus anterior m.
What makes up the lateral wall of the axilla?
Intertubercular sulcus of humerus
What makes up the base of the axilla?
Skin and fascia of armpit
Generally what and where is the axilla?
Pyramidal shaped region between the arm and chest
What are the contents of the axilla?
Fat and connective tissue; Axillary veins and lymphatics (outside sheath); cutaneous nerves; and axillary sheath-axillary artery and brachial plexus
What are the five principal groups of lymph nodes in the axilla?
Pectoral, subscapular, humeral, central, and apical
Pectoral lymph nodes drain what?
Anterior thoracic wall and most of breast
Subscapular lymph nodes drain what?
Posterior thoracic wall and scapular region
Humeral lymph nodes drain what?
Upper left except for the portion along the cephalic vein
Central lymph nodes of the axilla drain what?
Pectoral, humeral, and central lymph nodes
Apical lymph nodes of the axilla drain what?
All other lymph nodes of the axilla and proximal cephalic vein nodes
Part one of the axillary artery is located where?
Between the first rib and pectoralis minor muscle
Part two of the axillary artery is located where?
Deep to pectoralis minor muscle
Part three of the axillary artery is located where?
Between pectoralis minor muscle and teres major muscle
What artery comes off the first branch of the axillary artery?
Superior thoracic artery
What arteries come off the second branch of the axillary artery?
Thoracoacromial and lateral thoracic aa.
What arteries come off the third branch of the axillary artery?
Subscapular anterior, subscapular posterior, and circumflex humeral
The brachial plexus is composed of what ventral rami?
C5-T1
The brachial plexus provides nerves for what?
All upper limb muscles except trapezius muscle (CN XI)
What is the structure of the brachial plexus?
Rami(5), Trunks(3), Divisions(6), Cords(3), Branches(5)
The musculocutaneous nerve contains what spinal nerves?
C5-C7
The medial nerve contains what spinal nerves?
C5-T1
Axillary nerve contains what spinal nerves?
C5 and C6
The radial nerve contains what spinal nerves?
C5-T1
the ulnar nerve contains what spinal nerves?
C8 and T1
The musculocutaneous nerve is formed from what?
Lateral cord of brachial plexus
The musculocutaneous nerve passes through what muscle?
Coracobrachialis muscle
What is the major nerve of the anterior arm?
Musculocutaneous nerve
The musculocutaneous nerve innervates what?
Coracobrachialis muscle, biceps, and half of 1/2 of brachialis muscle
The median nerve is formed from what?
1/2 of medial cord and 1/2 of lateral cord of the brachial plexus
What is the major nerve of the anterior forearm?
The median nerve
The median nerve innervates what?
Innervates most of the anterior forearm and muscles of the hand
What is the major nerve of the hand?
Ulnar nerve
The ulnar nerve is formed from what?
Medial cord
The ulnar nerve runs behind what making it susceptible to “bumping” and making the funny bone feeling?
Runs behind medial epicondyle
The ulnar nerve innervates what?
Most of the muscles of the hand, flexor carpi ulnaris muscles, and 1/2 of flexor digitorum profundus muscles
The axillary nerve is formed from what?
Formed from posterior cord
The axillary nerve circles behind the humerus in what space?
Quadrangular space
The axillary nerve innervates what?
Innervates deltoid and terres minor muscles
The radial nerve is formed from what?
Posterior cord
The radial nerve passes posterior to humerus in (1)_____ ______ and within (2)______ ______.
1) Radial groove
2) Triangular interval
What is the major nerve of the posterior arm and forearm?
Radial nerve
The radial nerve innervates what?
Innervates all muscles in posterior arm and forearm, and 1/2 of brachialis muscle
What are the three upper plexus nerves?
Dorsal scapular nerve (C5), Long thoracic nerve (C5-C7), and Suprascapular nerve (C5-C6)
The dorsal scapular nerve innervates what?
Rhomboid and levator scapulae muscles
The long thoracic nerve innervates what?
Serratus anterior muscle
The suprascapular nerve innervates what?
Supraspinatus and infraspinatus muscles
What are the two pectoral nerves?
Lateral pectoral and medial pectoral nerves
The lateral pectoral nerve innervates what?
Pectoralis major muscle
The medial pectoral nerves innervate what?
Pectoralis major and minor muscles
What are the three lower plexus nerves?
Upper subscapular, thoracodorsal, and lower subscapular nn.
The upper subscapular nerve innervates what?
Subscapularis muscle
The thoracodorsal nerve innervates what?
Latissimus dorsi muscle
The lower subscapular nerve innervates what?
Subscapularis and teres major muscle
What are the three additional nerves of the brachial plexus?
Nerve to subsclavius m (C5-C6), medial cutaneous nerve (C8-T1), medial antibrachial cutaneous nerve (C8-T1)
The medial cutaneous nerve innervates what?
Sensory to medial nerve
The medial antibrachial cutaneous nerve innervates what?
Sensory to medial forearm
