UNIT TWO: Breast And Axilla Flashcards
What is fascia?
A thin layer of connective tissue which holds structures in place.
What is pectoral fascia?
A layer of fascia in the breast found superficial to the muscles and deep to the breast tissue
Surrounds the pectoralis major
What is the retromammary space?
A layer of loose connective tissue that separates the breast tissue from the deep fascia surrounding the pectoralis major, contributes to the the movement of the breast tissue along the chest wall.
Describe the location of the breast.
The breasts are circular in shape.
They are located over ribs 2 to 6,
2/3 lie over the pectoralis major muscles
1/3 over the Seratus anterior muscle
What are the main surface anatomy of the breast?
Nipple in the centre of the breast tissue
Surrounded by pigmented tissue called the areola.
What is the key differences between the breast in men and women?
The breast is functional in women. The breast is an accessory to reproduction.
The breast is not functional in men.
How does the breast develop in females?
During puberty the glandular tissue and fatty deposits grow.
Breasts are modified…..
Sweat glands
What is the axillary tail?
A section of breast tissue that leaves laterally and points upwards towards the axilla.
What is the suspensorio Retinacula?
A type of connective tissue that connects the breast tissue to the skin.
Support breasts and helps maintain their shape
What sets of arteries supply the breast and where do they originate from?
Medial mammary arteries from the internal thoracic arteries
Lateral mammary arteries from the lateral thoracic artery
Pectoral branch from the thoracoacromial artery
Describe the veins of the breast.
Medial mammary veins of the internal thoracic vein
Lateral mammary veins of the lateral thoracic vein
Thoracoacromial vein
All drain into the axillary vein
Describe the nerves that supply the breast.
The anterior cutaneous branch of the intercostal nerve (medically located)
The medial supraclavicular branch
The lateral cutaneous branch from the intercostal nerve
How does the lymphatic system link to breast cancer?
Allows cancer to metastasis.
The parasternal nodes are often how cancer spreads from one breast to another
What 3 main routes can lymph take to drain back into the lymphatic system from the breast.
75% drains back into the axillary regions.
24% drains into parasternal nodes.
1% drains back into the inferior phrenic nodes.
What lymphatic feature is found in the centre of the breast?
The subareola plexus,
Found in a circular shape around the areola, then spreads outwards
Name the different groups of lymph nodes found on the breast.
Anterior or pectoral nodes
Lateral axillary nodes
Central axillary nodes
Posterior axillary nodes
Apical axillary lymph nodes
What is the function of the lymphatic system hence what other bodily systems does it interact with?
Filters lymph
Recognises foreign antigen to stimulate lymphocyte production
Drains lymph dark into the blood
Hence overlaps with the circulatory and immune system
How is lymph created?
At capillary beds, extracellular fluid that can not be reabsorbed into the venous end of the capillaries is instead drained into the lymphatic system when pressure exceeds that within the lymphatic system.
Explain the general features of lymph drainage.
Lymph drains in a proximal direction.
Passes through lymph vessels reaching lymph nodes where it is filtered.
All lymph filters into either the thoracic duct into the left venous angle
Or drains into the right lymphatic duct and the right venous angle.
What is mean by the venous angle?
Is a bilateral structure where the subclavian vein and jugular vein meet, this is where the thoracic duct or right lymphatic duct drain lymph back into the cardiovascular system.
Why does lymph drain back into the venous angle?
This is the areas of lowest blood pressure in the cardiovascular system
What area of the body lymph drains into what lymph vessel?
The right upper limb, right head, right neck and right thorax will drain into the right lymphatic duct.
Below the diaphragm, upper left limb, left head, left neck and left thorax will drain into the thoracic duct.
What is this structure?
Lymph node
What are some key points about the lymph node structure?
Has many afferent vessels
Has one efferent vessel
Has its one blood supply
The outer regions are called the cortex and the inner regions the medulla.
The centre of each segment is where lymphocytes mature.
Name the bodily regs with lots of lymph vessels.
The axillary region (armpit)
The cervical region (head and neck)
The lumbar lymph nodes (abdomen)
The inguinal lymph nodes (pelvis)
Identify the red structure
The axillary tail
Identify the blue structure
Sub areola plexus
Identify the four different groups of lymph nodes in the axillary region
Identify the four different groups of lymph nodes in the axillary region
Label the major arteries in the breast
Label the major veins in the breast
What is the axilla?
The armpit
What is the anterior boundary of the axilla?
The pectoralis major, pectoralis minor.
What is the medial border of the axilla?
The seratus anterior and the thoracic wall.
What is the lateral border of the axilla?
The Intertubucle sulcus on the humerus
What is the posterior border of the axilla?
The latissimus dorsi, scapularis and the teres major.
What is the best view to identify the border of the axilla?
Imaging looking at the axilla from a transverse cross section from the feet up.
What arteries go through the axilla?
Axillary artery
Anterior/posterior circumflex humeral artery.
What veins pass through the axilla?
Axillary vein
Describe the location of the axillary vein/artery and nerves?
Vein is located medial and anterior to the arteries
Located anterior to the subscapularis, then travel towards the lateral border of the axilla
What nerves are located in the axilla?
The brachial plexus
In the axilla this consists of the anterior rami of C5 to C8 and most of the anterior ramus of T1
Why is the lymphatic drainage of the breast clinically relevant to the metastasis of cancer?
Lymph travels a relatively short distance by the parasternal nodes to spread to the other breast.
Also a relatively short distance to drain into the thoracic duct or the right lymphatic duct giving access to the rest of the body.
Hence cancer can metastasise quickly, explaining why early diagnosis is important to a successful treatment
What type of tissue is the breast mainly made of?
Connective tissue
Glandular tissue
Fat deposits.
Describe the overview structure of the breast in this image.
Circulating out from the nipple in a bike spoke fashion are fifteen to twenty (diagram is simplified for ease) lobes.
How does the structure of a lobe in the breast breakdown?
Contains many of the following ductules
What are the specific vein branches in the breast?
Medial branches - internal thoracic vein
Lateral branches - lateral thoracic vein
Pectoral branches - thoracoacromial vein
Describe the location of the anterior axillary lymph nodes.
Located on the lateral border of the pectoralis minor muscle
Describe the location of the lateral axillary lymph nodes.
On the axillary vein, inferior to the scapularis muscle
Describe the location of the posterior axillary lymph nodes?
Located on the scapularis, towards the inferior angle.
Describe the location of the apical axillary lymph nodes.
Located towards the medial and superior end of pectoralis minor.
Describe the location of the central axillary lymph nodes.
On a coronal plane with an ven split to the anterior and posterior
Just lateral to the seratus anterior muscle
Describe stage one of lymph drainage in the breast/axilla
The subareola plexus drains into the lateral, anterior, posterior lymph nodes
These drain into the central axillary lymph nodes.
Drains into the apical axillary lymph nodes.
Describe stage two of lymphatic drainage in the axillary region from the apical nodes.
Apical nodes on he right will drain into the right lymphatic duct, then renter the blood at the right venous angle.
Apical nodes on the left will drain into the thoracic duct, then renter the blood at the left venous angle.
Describe the route of lymphatic drainage from the subareola plexus to the parasternal nodes onwards.
24 % from the sub areaola plexus drains into the parasternal nodes.
From here lymph drains into the:
Other breast
The thoracic duct (if from right breast)
The right lymphatic duct (if from left breast)
Notice how it always crosses to the other half of the body.
What is the third least used route of drainage for lymph from the subareola plexus.
Into the inferior phrenic
Where is the latitimus dorsi muscle located?
Posterior wall of the thoracic cage, inferior to the scapula, superficial to the ribs
Where is the scapularis muscle located?
On the anterior surface of the scapula, posterior to the ribs.
Where is the teres major located?
Attaches to the anterior and proximal part of the humerus, then the posterior surface of the scapula.
Inferior to the scapularis muscle
Where is the Intertubucle sulcus located?
Located on the proximal anterior side of the humerus, between the two tubucles.
Shown in green.
What is the function of the lactiferus sinus?
Store breast milk
What structures open from the lobes to the nipple?
The lactiferous ducts
What is meant by superficial lymph vessels?
Follow veins
What is meant by deep lymph vessels?
Follow arteries
What proportion of the bodies lymph drains into the thoracic duct?
75%
Identify the main groups of lymph nodes across the whole body
Where about in the body does lymphatic fluid enter the blood stream?
The left and right venous angle, located near the clavicle bones
Draw a sagital cross section of the breast identifying the bed of the breast features.
Draw a sagital cross section of the breast identifying features on the surface and within the breast.
What is the significance of a sentinel node biopsy?
A sentinel lymph node is removed and studied to look for the presence of cancer cells.
This can indicate if a cancerous cell has began to spread beyond the primary tumour and into your lymphatics system.
What is a sentinel lymph node?
A lymph node to which primary cancer cells are most likely to use to spread to other parts of the body.
What methods can breast cancer use to spread?
The lymphatic system
The cardiovascular system
What breast quadrant is most often affected by breast cancer? What is the significance of this?
The upper outer quadrants are most often affected by breast cancer.
This is because it has larger amounts of epithelial and glandular tissue.
This has more connection to draining out through the axillary nodes hence spreading to other parts of body
Explain the location of the axillary vein and artery.
Divulge from between the first rib and the clavicle towards the lateral border of the axilla,
Axillary artery originates from the subclavian artery
Axillary vein origniates from the brachial vein.
Where is the internal thoracic artery located?
Runs just laterally to the sternum, bilateral structure
What is the fluid surrounding cells called?
The interstitial fluid
What type of epithelium lines the lymphatic vessels?
Simple squamous
What lymph nodes drains the superomedial aspect of the breast?
The parasternal lymph nodes
Label the key arteries in the blood supply to the breast
Labelled is the axillary artery not the lateral thoracic, lateral thoracic is a branch of axillary at a height just inferior to pectoralis minor.
Identify the regional locations of the parasternal nodes and the axillary lymph nodes
