Anatomy Dissection 9 - Axilla and Brachial Plexus Flashcards
Name of the pyramidal space inferior to the shoulder joint and just superior to what patient’s refer to as the “armpit”?
Axilla
What forms the medial wall of the axilla?
Superolateral aspect of the chest
What forms the anterior wall of the axilla?
Pectoralis major (lower border is contained in the inferior edge of the anterior axillary fold)
Give 2 purposes of pectoralis major?
One of the main muscles of climbing (along with latissimus dorsi)
Important accessory muscle of inspiration
What is the axillary vein a continuation of?
Brachial vein
When does the brachial vein become the axillary vein?
At the lower border of teres major
What marks the inferior extent of the axilla?
Teres major
What aspect of the axilla does teres major contribute to?
posterior wall
When does the subclavian artery become the axillary artery?
at the lateral border of the first rib
What spinal nerves form the brachial plexus?
anterior rami of spinal nerves C5 - T1
Draw the brachial plexus
…
What spinal nerves forms the superior trunk of the brachial plexus?
C5 and C6 anterior rami
what spinal nerves form the middle trunk of the brachial plexus?
C7 anterior rami
What spinal nerves forms the inferior trunk of the brachial plexus?
C8 and T1 anterior rami
What divisions/ trunks gives the medial cord of the brachial plexus?
Direct continuation of the anterior division of the lower trunk
Which divisions/ trunks gives the lateral cord of the brachial plexus?
Anterior divisions of the superior and middle trunks
Which divisions/ trunks gives the posterior cord of the brachial plexus?
Posterior divisions of all 3 trunks
What cords form the ulnar nerve?
Direct continuation of the medial cord
What cords form the musculocutaneous nerve?
Direct continuation of the lateral cord
What does the posterior cord of the brachial cord divide to give?
Axillary and radial nerves
What cords is the median nerve formed from?
Medial and lateral cord
What do the roots and trunks of the brachial plexus lie between?
Anterior and middle scalene muscles in the root of the neck
Where in the neck are the divisions of the brachial plexus located?
Immediately posterior to the subclavian vessels in the root of the neck (deep to the clavicle)
Where in the body do the cords of the brachial plexus lie?
Around the axillary artery (which is distal to the first rib)
What does the musculocutaneous nerve supply?
The muscles of the anterior compartment of the arm
Which compartment of the arm does the axillary and radial nerve pass into?
Posterior compartment
Where does the axillary nerve lie in relation to the radial nerve?
Superior
What structure does the axillary nerve wrap around?
What is it susceptible to here?
The posterior aspect of the surgical neck of the humerus
Injury in shoulder dislocation or fracture of the neck of the humerus
What structure does the radial nerve wrap around?
What is it susceptible to here?
Posterior aspect of the mid-shaft of the humerus
Injury by mid-shaft humeral fractures
What is the most medial of the named nerves of the brachial plexus?
Ulnar nerve
Where does the ulnar nerve pass from the brachial plexus?
posteriorly into the medial aspect of the arm
What forms the middle of the M-shaped configuration of the named nerves of the brachial plexus/
Median nerve
What are the 3 main groups of axillary lymphatics
?
Apical
Central
Basal
What do the apical lymph nodes drain towards?
Right lymphatic/ thoracic duct
What do the central lymph nodes drain towards?
Apical lymph nodes
What do the basal lymph nodes drain towards?
Central lymph nodes
What are the 3 groups of lymph nodes that make up the basal axillary lymph nodes/
Pectoral
Subscapular
Humeral
Name of the lymph nodes located along the lateral border of pectoralis minor?
What does these lymph nodes receive a lot of lymph from?
Pectoral
Breast
What are the name of the lymph nodes that receive lymph from the scapular region?
Subscapular lymph nodes
What are the lymph nodes which receive such of the upper limb lymphatics?
Humeral lymph nodes
