AXILLA
LEARNING OBJECTIVES
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Know the position, shape of axilla
Mention the boundaries and muscle forming the boundaries of axilla
Discuss the formation, course and relations of axillary vessels
Describe arrangement and groups axillary lymph nodes
Axilla
Area of transition between neck and arm
An irregularly shaped pyramidal space with:
 4 sides
 An inlet
 A base or floor
Axillary inlet is connected with neck superiorly and with arm
inferiorly
Axillary Inlet
Margins of inlet are completely formed by bone
Medially - lateral border of rib1
Anterior - posterior Surface of clavicle
Posterior - superior border of scapula
Anterior wall
Lateral part of Pectoralis Major
Pectoralis Minor
Subclavius
Clavipectoral fascia
Medial Wall
Upper rib
Serratus Anterior
Long thoracic nerve
Lateral Wall
Narrow
Formed completely by intertubercular sulcus of humerus
Posterior Wall
Costal surface of scapula and subscapularis muscle
Latissimus dorsi and Teres Major
Gaps between posterior wall forms aperatures
Floor
Fascia
Dome of skin connecting inferior margins of walls
Supported by clavipectoral fascia
Contents
Axillary artery and its branches
Axillary vein and its tributaries
Brachial plexus
Nerves - long thoracic nerve, and intercostobrachial nerve
Collection of lymph nodes
Connection of the breast with axilla
Proximal parts of biceps brachii and coracobrachialis
Axillary Artery
first portion:
 Outer border 1st rib to medial edge of pectoralis minor
Second portion:
 behind pectoralis minor
Third portion:
 lateral edge of pectoralis minor to lower border of teres major
Branches Of The Axillary Artery
first part –
 Highest Thoracic
second part –
 Thoracoacromial
 Lateral Thoracic
Third part –
 Subscapular.
 Posterior Humeral Circumflex.
 Anterior Humeral Circumflex
Axillary Vein
Origin:
 basilic vein (lower border of Teres major)
Outflow:
 subclavian vein (outer border of first rib)
Tributaries:
 brachial veins
 cephalic vein
 Venae commitantes to correspond with branches of axillary
artery
Course:
 It lies on medial side of artery
 between two vessels are medial cord of brachial plexus,
median, ulnar, and medial anterior thoracic nerves.
Valves:
 A pair of valves opposite the lower border of subsacpularis
 At ends of cephlaic vein and subscapular vein (the venae
commitantes of subscapular artery)
Brachial Plexus
Each trunk divides into anterior and posterior divisions behind middle
of clavicle at apex of axilla
 Three posterior divisions join to form posterior cord
 Anterior divisions of upper and middle trunks form lateral cord
 Anterior division of lower trunk continues as medial cord
Cords lie around axillary artery
Posterior cord - axillary and radial nerves.
Lateral cord - musculocutaneous and lateral head of median nerves
Medial cord - ulnar and medial head of median nerves
Nerves
Long thoracic nerve:
 supplies serratus anterior
 arises by three roots from C5-C7
 descends behind brachial plexus and axillary vessels, resting on
outer surface of serratus anterior.
 It extends along side of thorax to lower border of serratus
anterior giving its branches.
 Injury:
 during surgery for breast cancer, specifically radical
mastectomies involving removal of axillary lymph nodes
 from a blow to ribs on an outstretched arm
 gives rise to “winged scapula”
Intercostobrachial nerve:
 pierces external intercostals and Serratus anterior, crosses axilla
to medial side of arm
 joins with a branch from medial brachial cutaneous nerve.
 supplies skin of upper half of medial and posterior part of arm,
communicating with posterior brachial cutaneous branch of
radial nerve.
 Injury:
 During lymphectomy eg in breast surgery
 Hypothesia of skin covering axilla and medial side of
arm
Axillary Lymph Nodes
They drain upper limb, upper abdominal wall and pectoral region and
receive most of lymphatic drainage of breast.
Arranged in five groups:
 anterior group - deep to pectoralis major and drain lateral and
anterior chest wall, breast and upper abdominal wall.
 lateral group - lateral wall of axilla. Drain whole arm with
exception of that portion whose vessels accompany cephalic
vein
 posterior group - lateral edge of subscapularis muscle on
posterior wall of axilla. Drain skin and muscles of lower part of
back of neck and of posterior thoracic wall
 central group - arranged around axillary vessels in axillary fat.
Drains the above 4 groups
 apical group (median) - apex of axilla immediately behind
clavicle, they are continuous with inferior deep cervical nodes.
Receive drainage from all preceding groups.
Connection Of Breast With Axilla
Lymphatic drainage of breast
Breast cancer and its staging
Surgery of breast cancer
 Lymph node biopsy
 Lymphectomy
 Damage to the nerves during surgery (Long thoracic nerve,
Intercostobrachial nerve)
CLINICALLY ORIENTED ANATOMY OF K.L.M SIXTH EDITION