Anatomy (Cardiorespiratory) Flashcards
What is the dermatome?
Area of skin innervated by a single spinal nerve
Where are the breasts located?
Superficial to the muscles of the chest wall
Where is breast tissue found?
Extends towards the anterior axils (armpit), this part is called the axillary tissue
What happens to the breasts after menopause?
The breast atrophies
What does the breast contain?
● Fat - variable amounts
● Glandular / secretory tissue arranged in lobules
● Ducts which converge on the nipple. The areola is the region of pigmented
skin that surrounds the nipple.
● Connective tissue and ligaments
● Blood vessels and lymphatics
Figure 3. Anatomy of the female breast.
What is the breast primarily supplied by?
● internal thoracic artery (which arises from the subclavian artery)
● axillary artery
What is the internal thoracic artery?
The internal thoracic artery courses deep to the lateral edge of the sternum. It gives rise to anterior intercostal arteries that supply the breast and the intercostal spaces
Venous blood returns to the internal thoracic vein
What is the breast supplied with?
Somatic nerves and sympathetic fibres via the intercostal nerves
What do the somatic sensory fibres do?
Innervate the skin of the breast
What do the sympathetic fibres do?
Innervate smooth muscle in the blood vessel walls and nipple
What are the 5 groups of lymph nodes in the axilla?
central
pectoral
humeral
subscapular
apical
What do the lymph nodes in the axilla do?
They drain the breast, upper limb, chest wall, scapular region, and the abdominal wall
What are the apical modes?
(in the apex of the axilla)
receive lymph from all other lymph nodes in the axilla.
Because they drain most of the lymph from the breast, the axillary lymph nodes are often involved in the spread of breast cancer
What are the 3 layers of muscles in the intercostal space?
● the external intercostal is most superficial
● the internal intercostal lies deep to the external intercostal
● the innermost intercostal lies deep to the internal intercostal
What are the 3 main muscles in the upper limb?
● Pectoralis major is the most superficial muscle of the anterior chest wall. It attaches to the upper humerus, the clavicle and the upper six ribs.
● Pectoralis minor is a smaller muscle that lies deep to pectoralis major. It attaches to the scapula (shoulder blade) and ribs 3-5.
● Serratus anterior is a superficial muscle that sweeps around the lateral aspect of the thoracic cage. It attaches to the scapula and the upper eight ribs
What is the function of the pectoralis major?
Adducts the humerus
What is the function of the pectoralis minor and serratus anterior?
Protracts the scapula
Why are the upper limb muscles accessory muscles of breathing?
They attach to the ribs and hence can move the ribs if the humerus and scapula are fixed.
In patients, use of these muscles is a sign of respiratory distress
What are rib fractures?
Result from blunt trauma to the chest wall
Painful, worse on inspiration
What are shingles?
Shingles is a common skin condition that usually affects older people.
Patients present with a red, painful, and itchy rash, typically over the chest or abdomen on one side of the body only.
The rash appears in a strip-like distribution, as it affects dermatomes.
Shingles is caused by a reactivation of the herpes zoster virus in people who have previously had chicken pox.
The virus lays dormant in the dorsal root ganglion and when reactivated, it causes a rash and pain in the dermatome associated with the affected spinal nerve.
Why does breast malignancy typically spread to the axillary lymph nodes first?
Most lymph from the breasts drain there
What is a malignant axillary node palpable as?
As a lump in the armpit and notices before a mass in the breast itself.
If a breast mass is confirmed as malignant, the axillary lymph nodes are biopsied to assess if malignancy has metastasized to them.
If so, they are removed as part of a patient’s treatment.
What is lymphoedema?
Fluid accumulation and swelling in the affected upper limb due to the removal of the axillary nodes
What do the intercostal spaces contain?
● three layers of intercostal muscles and their associated membranes
● an intercostal neurovascular bundle, comprising an intercostal nerve, an
intercostal artery, and an intercostal vein.
What are the external intercostals?
External intercostal is most superficial. Its fibres are orientated antero-inferiorly.
● Contraction pulls the ribs superiorly, hence is it most active in inspiration.
● In the anterior part of the intercostal space, the muscle becomes
membranous and forms the external intercostal membrane.
What are the internal intercostals?
External intercostal is most superficial. Its fibres are orientated antero-inferiorly.
● Contraction pulls the ribs superiorly, hence is it most active in inspiration.
● In the anterior part of the intercostal space, the muscle becomes
membranous and forms the external intercostal membrane.
What are the innermost intercostals?
The innermost intercostal lies in the posterior part of the intercostal space deep to the internal intercostal. Its fibres are orientated in the same direction as those of the internal intercostal.
Where is the endothoracic fascia found?
Lies deep to the innermost intercostal and superficial to the parietal pleura, which surrounds the lung
What is the intercostal neurovascular bundle?
Neurovascular bundle which lies in the plane between the internal and innermost intercostal muscle
Supplies the intercostal muscles, the overlying skin and the underlying parietal pleura
What is the pleura?
Two thin layers of tissue that protects and cushions the lungs
Outer layer is called the parietal pleura and attaches to the chest wall
The inner layer is the visceral pleura and covers the lungs, blood vessels, nerves and bronchi
Where does the neurovascular bundle for each intercostal space lie?
Lies along the inferior border of the rib superior to the space.
It lies in a shallow costal groove on the deep surface of the rib.
In medical procedures that involve piercing the intercostal space (such as placing a chest drain), the incision is made in the middle to lower part of the intercostal space, to avoid the intercostal vessels and nerve.
Smaller collateral branches run in the same tissue plane, but in the lower part of the intercostal space.
What does the anterior intercostal artery do?
The anterior intercostal arteries are branches of the internal thoracic artery (a branch of the subclavian artery)
Supplies the anterior parts of the intercostal space
What does the posterior intercostal artery do?
The posterior intercostal arteries are branches from the descending aorta in the posterior thorax.
Supplies the posterior parts of the intercostal spaces
What do the anterior intercostal veins do?
Anterior intercostal veins drain into the internal thoracic vein and posterior intercostal veins drain into the azygos system of veins – we will learn more about these later.
What are the intercostal nerves?
The intercostal nerves are somatic and contain motor and sensory fibres. They innervate the intercostal muscles, the skin of the chest wall and the parietal pleura. Intercostal nerves also carry sympathetic fibres
What do the pleurae do?
Cover the lungs and the structures passing
into and out of the lungs (the pulmonary blood vessels and the main bronchi).
● The parietal pleura lines the inside of the thorax
● The visceral pleura covers the surface of the lungs and extends into the fissures.
Where is the pleural cavity found?
Lies between the parietal and visceral pleura
Describe features of the pleurae
The parietal pleura is visible with the naked eye, but the visceral pleura is not.
The two layers of pleura are continuous with each other.
The pleural cells produce a small amount of pleural fluid, which fills the pleural cavity.
The pleura and pleural fluid are integral to the mechanics of breathing.