Flashcards in SBO - Breast and Thoracic Pain Deck (19):
Identify the Location, Structure and Function of the Breast.
Paired structures on the anterior thoracic wall.
Lie in the subcutaneous tissue.
Anterior to the pectoralis major mm (2/3), serratus anterior mm (1/3) and their fascia.
Contains mammary glands (modified sweat glands).
Supported by connective and adipose tissue.
Well developed in women (accessory reproductive function for nursing offspring).
Rudimentary in men (functionless).
Describe the nipple of the breast
Circularly arranged smooth mm
Indented with openings of 15-20 lactiferous ducts
No fat, no hair, no sweat glands.
Describe the areola of the breast
Circular pigmented skin surrounding the nipple
Contains 18-20 sebaceous glands
Secretes an oily substance to protect and lubricate the nipple.
What are the boundaries of the breast
Lateral border of the sternum to mid-axillary line.
Vertically from 2nd to 6th ribs
Describe the tail / axillary process of the breast
Extends along pectoralis major toward the armpit.
Can become enlarged during menstruation
Describe the retromammary space
Between the breast and the deep pectoral fascia
Contain a small amount of fat
Allows some movement of the breast
What is the function of the suspensory ligaments of the breast and where do they attach?
Support the breast tissue
Attach between the mammary gland and the dermis
Describe the components of the lactiferous ducts
Carry milk to the nipple
Open independently on the nipple
Each duct has 15-20 lobules of glandular tissue draining into it.
Milk-secreting alveoli are arranged in grape-like clusters
Alveoli are drained by ducts that converge toward the nipple.
Become Lactiferous sinuses just before reaching the nipple.
Located within the breast tissue between the lobules and the nipple.
Identify the arterial supply of the breast
Anterior intercostal arteries
Lateral thoracic and thoracoacromial arteries
Posterior intercostal arteries (2nd, 3rd, and 4th)
What is the venous drainage of the breast
Axillary vein and internal thoracic vein
Describe the lymphatic drainage of the breast
Begins at the subareola lymphatic plexus
75% drains to the pectoral nodes (anterior axillary) some to other axillary nodes.
Remaining lymph (from medial aspect of breast) drains to the inferior phrenic and parasternal lymph nodes
Skin over the breast: drains to many different nodes around the sternum and clavicle.
What is the nerve supply to the breast
Anterior and lateral cutaneous branches of 4th-6th intercostal nerves
What are the two gonaditrophin hormones released by the pituitary gland. And what do they do
Follicle stimulating hormone (FSH)
Lutenising hormone (LH)
Stimulate the release of oestregen and progestorone
What does oestregen and progestorone do to the breast.
Stimulates growth and function
Where is Prolactin produced and what does it do?
Produced in the anterior portion pituitary gland.
Responsible for milk production.
Where is Oxitocin produced and what does it do?
Produced in the posterior portion of the pituitary gland
Responsible for milk ejection.
What is the definition and aetiology of acute mastitis
Acute inflammation of the breast
Often associated with staphlacoccus aureus and and streptococcal infections.
Usually occurs during lactation i.e. following cracked nipples.
Or from other nipple injuries.
Commensal or hospitial-sourced bacteria gain entry to the duct.
Proliferation occurs in stagnant milk
What are the clinical features of acute mastitis
Hard, painful and inflammed breasts
+/- pyrexia, tachycardia
If not treated effectively
Breast abscess -> extensive scarring