Medbear Breast Flashcards
Describe on the breast anatomy
- The breast is a MODIFIED SWEAT GLAND that is located between subcutaneous fat and the fascia of the pectoralis muscle and serratus anterior muscle
- It consists of fat, fibrous tissue and glandular tissue
- It extends from the lateral sternal border to the mid-axillary line, 2nd rib -> 6th rib
- The axillary tail (axillary tail of Spence) pierces the deep fascia and enters the axilla
- It consists of 15-20 lobules of glandular tissue that drains into a lactiferous duct which converges towards the nipple
- Areole is lubricated by glands of Montogomery
- Suspensory ligament of astley cooper divides the breast lobules into segments
In advanced breast carcinoma, what is the pathophysiology of skin dimpling?
It is due to malignant infiltration and contraction of Cooper’s ligament
What is the embryological origin of the breast?
Ectodermal and mesodermal origin
The breast begins development in the embryo about 7-8 weeks after conception
State the arterial supply and venous drainage of the breast.
Arteries
1. Internal thoracic artery
2. Branches of axillary artery
3. 2nd - 5th intercostal arteries
Venous drainage
1. Internal thoracic
2. Axillary vein
3. Lateral thoracic
4. Intercostal veins
State the (5) nerve supplies of the breast
- Long thoracic n -> innervates SERRATUS ANTERIOR (winged scapula)
- Thoracodorsal n -> inervates LATISSIMUS DORSI (weak arm adduction)
- Median pectoral n -> innervates PECTORALIS MAJOR and MINOR
- Lateral pectoral n -> innervates PECTORALIS MAJOR only
- Intercostobrachial n (off 2nd IC nerve) - sensation to medial arm and axilla
State the (3) lymphatic drainage of the breast
- Axillary nodes
- Internal Mammary nodes
- Inter-pectoral (Rotter’s nodes)
List the anatomic/surgical division of axillary nodes into level 1, 2 and 3 (relative to pectoralis minor)***
Level 1 = lateral to lateral border of pectoralis minor
Level 2 = Posterior to pectoralis minor and below the axillary vein
Level 3 = Medial to medial border pectoralis minor, extending up to apex of axilla
State the origin and insertion of pectoralis major
Origin = Medial clavicle, sternum, anterior 2-6th ribs, external oblique, rectus abdominis fascia
Insertion = Upper humerus, 10cm from humeral head on lateral side of intertubercular sulcus
State the nerve supply of pectoralis major.
Medial and lateral pectoral nerve
State the origin and insertion of pectoralis minor
Origin = anterolateral surface of 3rd to 6th ribs
Insertion = coracoid process of scapula
State the innervation of pectoralis minor
Medial pectoral nerve
State the origin and insertion of serratus anterior
Origin = anterolateral aspect of upper 8th ribs
Insertion = anterior surface of medial aspect of scapula
State the nerve innervation of serratus anterior
Long thoracic nerve
State the origin and insertion of rectus abdominis
Origin = Pubic line
Insertion = Xiphoid process and ribs 5-7
State the nerve innervation of rectus abdominis
Segmental motor nerve from 7th to 12th intercostal nerve
State the axilla anatomy based on the following:
Apex
Base
Anterior
Posterior
Lateral
Medial
Apex = Costoclavicular ligament
Base = Skin and axillary fascia
Anterior = Pectoralis major and minor, subclavius muscle
Posterior = Subscapularis, teres major and latissimus dorsi muscle
Lateral = Intertubercular sulcus
Medial = Ribs and intercostal muscle covered with the serratus anterior
State the anatomic boundaries of axillary dissection (level 2 dissection) for the following aspect:
Superior border
Medial border
Lateral border
Anterior border
Posterior border
Superior border = Axillary vein
Medial border = Chest wall
Lateral border = Skin flap
Anterior border = Pectoralis minor
Posterior border = Latissimus dorsi
Differentiate between Paget’s disease and eczema of the nipple.
