Unit 2 - Breast / Axilla / Abdomen/ Foregut Flashcards
What are the key landmarks of the breast on the surface anatomy of the chest wall?
- Second rib to the sixth
-Edge of the sternum to the mid axillary line
-Prolongation of rib is axillary process
Which rib or intercostal space does the nipple overlie and discuss:
* What intercostal nerve supplies the surrounding skin?
-4th rib , unreliable as is changes with age and lifestyle
> anterior cutaneous branch of the 4th intercostal nerve supplies the largest area of skin in a healthy breast.
What are the 4 quadrants of the breast, and clinical implications?
-Supero lateral quadrant is more likely to be affected by cancer because there’s lots of glandular tissue, closest to axilla.
What are the anatomical structures of the breast?
-Consists of glandular breast tissue
- Name three arteries that supply blood to the breast.
- Medial mammary branches of internal thoracic artery
- Lateral mammary branches of lateral thoracic artery of Axillary artery (superolateral aspect of the breast)
- Lateral mammary branches OF lateral cutaneous branch OF Posterior intercostal artery (lateral part of the breast)
Name the 3 veins that remove blood from the breast?
- Axillary vein: lateral mamary branches OF lateral thoracic veins
- Lateral mammary branches OF Lateral cutaneous branches OF Posterior intercostal vein: Drain the lateral aspect of the breast into the azygos system
- Internal thoracic vein: Drains the medial aspect of the breast into the brachiocephalic vein
What is the lymphatic drainage of the breast?
- Lateral pathway: Drain most of the female breast
Five groups of Axillary lymph nodes: Anterior (pectoral), posterior (subscapular), lateral ( humeral), central, and apical - Medial pathway:Parasternal lymph nodes
- Inferior : Subdiaphragmatic lymph node
> Most of the lymph from the nipple, areola and breast lobules (especially those from the lateral quadrants) are drained into a lateral route by the subareolar lymphatic plexus.
What are some changes that happen to breast during pregnancy and puberty?
Puberty:
-Breast enlarge , glandular development and increased fat deposition
-Areola and nipple enlarge
-Lactiferous ducts give rise buds that develop into 15-20 lobules of mammary glands
Pregnancy:
-Areola sebaceous glands enlarge, produce protective lubricant
-Areola and nipple irritate as baby begins nursing experience
> Breast may enlarge during late phase of menstruation
How is the Retromammary space clinically relevant?
-Implants
-Space and movement
Describe how carcinoma can present differently depending upon what anatomical structures are invaded:
1. Lactiferous ducts
2. Lymphatic ducts
3. Suspensory ligaments + Glandular tissue
4. Pectoral fascia
Using the articulated skeleton and models as a guide, identify the boundaries of the axilla
* Apex
* Base
* Anterior wall
* Posterior wall
* Medial wall
* Lateral wall
Apex – lateral border of the first rib, superior border of scapula, and the posterior border of the clavicle.
Lateral wall – Intertubercular groove of the humerus.
Medial wall – Serratus anterior and the thoracic wall
Anterior wall – Pectoralis major and pectoralis minor
Posterior wall – Subscapularis, teres major and latissimus dorsi muscles
What are the components of the axilla?
- Axillary artery (and branches) – the main artery supplying the upper limb. It is commonly referred as having three parts;
- Axillary vein
- Brachial plexus (and branches) – a collection of spinal nerves that form the peripheral nerves of the upper limb.
- Axillary lymph nodes – they filter lymphatic fluid that has drained from the upper limb and pectoral region. Axillary lymph node enlargement is a non-specific indicator of breast cancer.
What are the components of the brachial plexus?
-Formed by union of anterior rami of the last 4 cervical and 1st thoracic nerves
Describe the difference between lymphatic drainage in the left and right axilla.
-The left side axillary drainage flows into the thoracic duct.
-The right side the drainage is into the right lymphatic trunk.
What is the clinical relevance of lymphatic drainage of the breast to metastatic spread of cancer?
-Malignant cells traveling within the lymphatic system are a common mechanism of tumor metastasis, and examination of lymphatic tissue is essential for cancer prognosis and staging.
Draw a basic diagram outlining the whole-body lymphatic drainage.
-It is a unidirectional low-pressure network of vessels that run parallel to blood vessels and are found in all regions of the body except the central nervous system and bone marrow.
What is the significance of sentinel node biopsy?
-To determine whether cancer has spread beyond primary tumour into lymph system
-1st few lymph nodes in which a tumour drains
Label the surface anatomy of the abdomen.
-quadrants
-regions
Transumbilical plane (transverse when split via 4 quadrants) = L3/4
Subcostal plane (1st transverse line when split via 9 regions) = L3
Intertubercular/ Transtubercular plane (2nd transverse line when split via 9 regions) = L5
Identify the layers of the abdominal wall.
Campers fascia = fatty Layer
Scarpas fascia = membranous layer
Identify abdominal musculature.
What is aponeurosis?
- Remaining fibres at the end of the 3 flat muscles combine together to form rectus sheets.
- Between mid clavicular lines
- Posterior and Anterior layer… attach to abdomen via tendinous intersections
Label the layers. 1. What is the arcuate line?
2. What forms the anterior wall of the rectus sheath? How does this vary along its length?
- Represents inferior and superior part of rectus sheath.
- External oblique muscle aponeurosis and 1/2 of internal oblique muscle aponeurosis > after arcuate line all 3 flat muscles aponeurosis form anterior wall of rectus sheath : including transversus abdominis aponeurosis
- What dermatome supplies the skin around the umbilicus?
- How can you distinguish between internal and external oblique muscles?
- What is the function of the transverses abdominis muscle?
- T10 (Vertebral level L3)
- Eternal oblique fibres > Inferiomedially
Internal oblique fibres > superomedially - Maintaining abdominal tension + increasing intra-abdominal pressure
What are the contents of the rectus sheath? What is its function?
- Rectus abdominis
- Pyramidalis muscle
- Superior and inferior epigastric arteries and veins
- Lymphatic vessels
- Termination parts of lower five intercostal nerves (T7-T11), and the termination of the 12th thoracic nerve (T12).
> The superior and inferior epigastric arteries anastomose with each other at the level of umbilicus after entering into the rectus sheath.
-Protect the muscles and vessels which it encloses.
What is the inguinal ligament, what are its attachments?
- Band of connective tissue that extends from the anterior superior iliac spine of the ilium to the pubic tubercle on the pubic bone. > formed by the free inferior border of the aponeurosis of the external oblique muscle which attaches to these two points.
-Site of attachment for the internal oblique and transversus abdominis muscles.
