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ESA 1 - Body Logistics > The Breast > Flashcards

Flashcards in The Breast Deck (15)
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1
Q

What is the breast?

A
  • Modified apocrine sweat gland.

- Part of the reproductive system: responds to sexual stimulation and to feed babies.

2
Q

How do breasts develop?

A
  1. Breast buds appear in both sexes in 6th - 9th months of foetal life.
  2. At puberty, female breasts develop under influence of oestrogen and progesterone.
  3. Final maturation during 1st pregnancy: mammary glands branch out and expand in response to progesterone and prolactin.
  4. Regression following menopause.
3
Q

Where are breasts located?

A
  • Overlie pectoralis major muscles on left and right sides.
  • From 2nd-6th ribs.
  • From sternal edge to anterior axillary line.
4
Q

What are breasts supported by?

A

Cooper’s suspensory ligaments

5
Q

What is breast tissue made up of?

A
  1. Mostly of adipose tissue (supports glandular structures)
  2. Mammary glands
    - 15-20 lobes encased in a network of myoepithelial cells (contract and squeeze down on glands to excrete milk)
    - milk drained towards nipple via lactiferous ducts
    - expelled through nipple pores
6
Q

What are the functions of areolae?

A
  1. Contain areolar glands which secrete lipoid fluid - moisturises nipple during breastfeeding.
  2. Darkened areolae provide target for baby to aim for.
7
Q

Describe the blood supply to the breast.

A
  1. Internal mammary arteries (derived from internal thoracic artery) - predominant blood supply.
  2. External mammary arteries (lateral thoracic and thoracoaromial) and posterior intercostal arteries - further blood supply.
  3. Axillary vein - venous drainage of breast.
8
Q

What is lactation?

A

Process where milk is made and ejected from the mammary glands inside the female breasts.

9
Q

How is lactation activated?

A
  1. Baby starts to suckle - activates nipple mechanoreceptors - signalling up spinal cord to hypothalamus.
  2. Hypothalamus releases:
    i) Activatory signals to oxytocin neurons in posterior pituitary - oxytocin production.
    ii) Inhibitory signals to PIH (prolactin inhibitory hormone) in anterior pituitary - prolactin production.
  • Cascade stimulated by the sound of any babies’ cry.
10
Q

What are the effects of prolactin and oxytocin?

A
  • Prolactin: stimulates mammary gland to produce milk.

- Oxytocin: stimulates myoepithelial cells surrounding glands.

11
Q

What is accessory breast tissue?

A
  • Relatively common congenital condition: abnormal accessory breast tissue is seen in addition of normal breast tissue.
  • Can present as a mass anywhere along the course of the embryologic mammary streak (axilla to inguinal region).
12
Q

What is Poland syndrome?

A

Rare birth defect characterised by:

  • underdevelopment/absence of chest muscle (pectoralis) on 1 side of the body
  • webbing of the fingers (cutaneous syndactyly) of ipsilateral hand
13
Q

What is the most common cancer in women in the UK?

A
  • Breast cancer
  • 1/8 women
  • > 40,000 cases/year
  • > 10,000 deaths/year
14
Q

Which factors increase the risk of breast cancer?

A
  • woman
  • age
  • family history
  • personal history of breast cancer
  • genetics
  • alcohol
  • obesity
  • radiation
  • high socioeconomic class
15
Q

Which factors decrease the risk of breast cancer?

A
  • 1st pregnancy before age 30
  • breast feeding
  • exercise
  • healthy organic diet?