Breast, Axilla, Arm & Brachial Plexus Flashcards
(29 cards)
The Breast
Modified sweat gland
- composed of fat, gland lobules, ligaments of cooper, and ducts (helps to drain)
- retromammary space - between and pectoral fascia
- allows some movement of the breast on the thoracic wall
Axillary Process of Breast and lymphatic and veinous drainage
Axillary tail and quadrants used to describe location of pathology in the breast

Breast Arterial Supply
- Thoracoacromial branches
- Lateral thoracic artery
- Posterior intercostal arteries
- Internal thoracic artery

Lymphatic Drainage of Breast
- Initially most lymph drains to subareolar lymphatic plexus
- Most lymph then drains to pector (anterior) nodes of axillary group then central apical and clavicular nodes, then to main lymphatic trunk to venous system
- Remaining to parasternal lymph nodes
Cooper’s Ligaments and Peau d’orange
- Cooper ligaments are networks of fibrous connective tissue that tether superficial and deep fascial layers and provide support for lobules
- Peau d’oragne = organe-colored appearance of breast in inflammatory breast cancer due to infiltration of tumor into dermal lymphatics and skin
Clinical Correlation: Breast Cancer
Carcinoms of breast are arise usually from epithelial cells of the lactiferous ducts
- typicaly spread by means of lymphatic vessels (also via venous system)
- most lymphatic drainage of the breast is to the axillary lymph nodes, they are the most common sidte of mestastasis
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Axilla Boundaries
- Anterior Wall
- Posterior Wall
- Medial Wall
- Lateral Wall
- Base
- Apex
Anterior Wall: pec major & minor and clavipectoral fascia
Posterior Wall: Scapula, subscapularis, Lat, teres major
Medial Wall: 1st to 4th ribs and intercostal spaces covered by serratus anterior
Lateral Wall: Intertubercular groove (humerus)
Base: Skin and fascia of armpit
Apex: between 1st rib, clavic and upper border of scapula
Axillary Artery
Subclavian Artery turns into Axillary Artery at lateral border of 1st Rib
Turns into Brachial Artery at lower border of Teres Major attach in intertuburcular groove of humerus
Has 3 parts, each part has as many branches
- middle part determined by pectoralis minor as its attached at coracoid process of scapula and goes down to ribs 3-5
First Part of Axillary Artery
Boundaries: Lateral border of 1st rib to pec minor
1 branch = Superior Thoracic
2nd Part of Axillary Artery
Deep to pectoralis minor is second part
2 branches
- Lateral Thoracic Branch
- runs with long thoracic nerve
- Thoracoacromial trunk
- 4 branches:
- Acromial
- Clavicular
- Pectoral
- Deltoid
- Remember ACPD by:
- 4 branches:
Atlantic Coast Police Department
3rd Part of Axillary Branch
3 branches
Boundaries from below pec minor to teres major attachment on humerus
- Subscapular
- gives off circumscapular branch and then continues as thoracodorsal artery which innervates lat dorsi
- Anterior Circumflex Humeral
- Posterior Circumflex Humeral
- Forms anastomosis
Axillary Artery Picture
Transverse Cervical Artery
Transverse Cervical supplies trapezius muscle

Veins of the Axilla
Subclavian Vein until lateral border of 1st rib where it becomes the Axial Vein
Brachial vein runs inferior to the Basilic vein

Axillary Lymph Nodes
5 groups of axillary lymph nodes drain the upper extremity, pectoral region and breast
- Humeral (lateral nodes)
- Central Nodes
- Subscapular (posterior nodes)
- Pectoral (anterial) nodes: this group drains the majority of lymphatics from the breast
- Apical (apex of the axilla)
70% of breast lymphatics drain through anterior pectoral nodes, then central nodes, then apical nodes
Arms (Anterior)
Anterior Compartment:
Coracobrachialis,
- the smallest of the three muscles that attach to the coracoid process of the scapula. (The other two muscles are pectoralis minor and biceps brachii.) It is situated at the upper and medial part of the arm.
It is perforated by and innervated by the musculocutaneous nerve.
Biceps brachii
Brachialis muscles
- muscle in the upper arm that flexes the elbow joint. It lies deeper than the biceps brachii, and is a synergist that assists the biceps brachii in flexing at the elbow.

Arms Posterior
Triceps brachii
- Long head medial
- Lateral head laerial
Anconeus
- superficial to elbow
See slide 27:
- Triangular space in between the long head and lateral head, inferior to teres minor and superficial to teres major
- Triangular interval by the medial head

Brachial Plexus
C5-T1 region of Spinal Cord
Randy Travis Drinks Cold Beer
- Rami
- Trunks
- Divisions
- Chords
- Branches
Rami Stage
The ventral primary rami of C5 to T1
Trunk Stage
The nerve roots (5 ventral rami) combine in a particular manner to form 3 trunks:
- C5 and C6 roots - superior (upper) trunk
- C7 root alone - middle trunk
- C8 and T1 roots - inferior (lower) trunk
Division Stage
Each trunk divides into anterior and posterior divisions
- 6 divisions - 3 anterior and 3 posterior
Cord Stage
The cords are named according to their relation to the second part of the axillary artery
- Lateral cord
- Medial cord
- Posterior cord
Spinal Nerve Origin

Brachial Plexus Diagram

Brachial Plexus - Right side, Anterior View




