THE AXILLA It is a four sided pyramidal space between root of arm and chest wall. It allows the passage of the nerves and blood vessels from neck to upper limb. It has a base, apex and four walls. The base is directed downwards and is formed by the axillary fascia. The apex is directed upwards posterior to the clavicle.
THE AXILLA The boundaries of the apex of the axilla are: Anteriorly; the clavicle. Posteriorly: the superior border of the scapula. Medially: the outer Border of 1st rib.
Walls of the axilla Anterior wall is formed by the pectoralis major and minor muscles, clavipectoral fascia and subclavius muscle. The lower border of the anterior wall is called the anterior fold of the axilla (pectoralismajor muscle). Posterior wall is formed by the subscapularis muscle above and the latissimusdorsi and teres major muscles below. The lower border of the posterior wall is called the posterior fold of the axilla (latissimusdorsi and teres major muscles). Medial wall is formed of the thoracic wall with the serratus anterior muscle. Lateral wall is narrow and formed by the upper pert of the shaft of the humerus.
Contents of axilla • Axillary artery and branches. • Axillary vein and tributaries. • Brachial plexus (cords and branches). • Axillary lymph nodes. • Lateral cutaneous branches of intercostal nerves. • Axillary fat. • Axillary tail of breast.
AXILLARY ARTERY Beginning It begins as a continuation of the subclavian artery at outer border of 1st rib. Termination It ends at the lower border of teres major and continues as brachial artery. Parts The artery is divided into 3 parts by pectoralis minor muscle.
Parts 1stpart: From lateral border of 1st rib to upper border of pectoralis minor 2ndpart: Behind pectoralis minor 3rdpart: From lower border of pectoralis minor to lower border of teres major
Branches From the 1st Part: Superior thoracic artery. From the 2nd Part: 1.Thoracoacromial artery. 2. Lateral thoracic artery. From the 3rd Part: 1. Subscapular artery 2. Anterior circumflex humeral artery. 3. Posterior circumflex humeral artery.
AXILLARY LYMPH NODES Axillary lymph nodes are arranged in the following groups: Anterior (pectoral) axillary lymph nodes. Posterior (subscapular) axillary lymph nodes. Lateral (brachial) lymph nodes. Central lymph nodes. Apical lymph nodes.
AXILLARY LYMPH NODES Anterior nodes The anterior nodes (pectoral nodes) are related to the lateral thoracic artery. Posterior nodes The posterior nodes (subscapular nodes) lie on the lower margin of the posterior wall of the axilla, along the course of the subscapular artery. Lateral nodes The lateral nodes lie along the lateral wall of the axilla. Central nodes The central nodes are a group of nodes in the adipose tissue at the base of the axilla. Apical nodes The apical nodes are present in the apex of the axilla.
BRACHIAL PLEXUS It is the plexus of spinal nerves supplying the upper limb. 1- Roots: It takes origin in the neck from: The ventral rami of the lower 4 cervical nerves (C.5,6,7,8). The ventral ramus of first thoracic nerve (T1). 2- Trunks: Upper trunk, middle trunk & lower trunk. 3- Divisions: Each trunk divides into 2 divisions: anterior and posterior division. 4- Cords: Lateral cord (anterior divisions of the upper and middle trunks; C.5,6,7). Medial cord (anterior division of the lower trunk only; C.8, T.1). Posterior cord (posterior divisions of the 3 trunks; C.5,6,7,8, T.1).
Position of the plexus: Roots & trunks: are present in the posterior triangle of the neck. Divisions: are present behind the clavicle. Cords: are present in the axilla. Branches of the plexus: Branches from the roots: Dorsal scapular nerve. Long thoracic nerve. Branches from the trunk: Suprascapular nerve. Nerve to subclavius.
Branches from the cords Medial cord: Medial Cutaneous nerve of the arm. Medial Cutaneous nerve of the forearm. Medial pectoral nerve. Medial root of median nerve. Ulnar nerve. Lateral cord: Lateral pectoral nerve Lateral root of median nerve. Musculocutaneous nerve. Posterior cord: Upper subscapular nerve. Lower subscapular nerve. Nerve to latissmusdorsi. Axillary nerve. Radial nerve.
Thank You Prof.: Dr. Wafaa Abdel-Rahman