Pregnancy and lactation Flashcards
What is witch’s milk?
Milk produced by neonates due to the influence of maternal hormones
How do the breasts differ during the menstrual cycle?
May increase in size due to fluid retention at each period
Where are breasts found?
Between ribs 2-6 in the anterior chest wall
Where does the nipple lie in the breast?
In the centre of the pigmented areola
How does the breast change in puberty?
Rudimentary duct system-> branches
20 lobes, each draining into a lactiferous duct to the nipple
Bundles of smooth muscle arise between nipple and areola
How do the breasts change in pregnancy?
Breasts grow and become more vascular
Ducts grow and branch and secretory alveoli replace adipose tissue
Describe the blood supply of the breast
Branches of internal thoracic artery, lateral thoracic artery and thoraco-acromial artery (from axillary artery) and by intercostal arteries 3-5
Describe the blood supply of the breast
Branches of internal thoracic artery, lateral thoracic artery and thoraco-acromial artery (from axillary artery) and by intercostal arteries 3-5
Describe the venous drainage of the breast
Superficial venous plexus around areola
Blood drains to axillary vein, internal and lateral thoracic veins and intercostal veins
What is the innervation of the breasts?
T4-6
What is the innervation of the breasts?
T4-6
What causes the nipple to become erect?
Sympathetic innervation of the smooth muscle between nipple and areola
Describe the lymphatic drainage of the breast
Interlobular lymph vessels-> subareolar plexus-> axillary/pectoral/parasternal/apical axillary nodes
What are the first secretions of the breast called?
Colostrum, rich in protein, IgA,
Function of myoepithelial cells in breast?
Contract to move milk out of epithelial cell into lactiferous ducts
What hormones control the development of breasts?
Progesterone, oestrogen, prolactin, human placental lactogen (hPL), dopamine (inhib)
Action of oestrogen
Needed for development of ducts in puberty and pregnancy
Inhibits milk secretion in pregnancy by stimulating dopamine
Action of progesterone
Needed for development of alveoli in puberty and pregnancy
Inhibits milk secretion in pregnancy by ↓prolactin receptors
What are the first secretions of the breast called?
Colostrum, rich in protein, IgA, minerals, vitamins
Action of progesterone
Needed for development of alveoli in puberty and pregnancy
Inhibits milk secretion in pregnancy by ↓prolactin receptors
What is galactopoesis?
Maintenance of milk production, needs sustained prolactin levels
How is galactopoesis achieved?
Needs high sustained prolactin levels
Regular suckling and removal of milk decreases dopamine and increases prolactin and oxytocin
How is milk ejection achieved?
Suckling or conditioned stimuli causes oxytocin to be released and myoepithelial cells to contract in alveoli
What is milk ejection associated with?
Afterpains of the uterus contracting (due to oxytocin release)
What is the composition of ‘mature’ milk?
High in fats, proteins, lactose, essential amino acids
What proteins are found in breast milk and how are they secreted?
casein, α-lactalbumin and lactoglobulin
secreted from vesicles by merocrine method
What proteins are found in breast milk and how are they secreted?
casein, α-lactalbumin and lactoglobulin
secreted from vesicles by merocrine method
How is fat secreted into breast milk?
Fatty acids synthesis in ER, secreted by apocrine method
What sugars are found in breast milk and how are they made?
Lactose
Made in golgi but dependent on α- lactalbumin to make lactose synthetase complex
Why is lactose crucial?
Component of myelin and promotes growth of intestinal flora
Why is lactose crucial?
Component of myelin and promotes growth of intestinal flora
When are non-breastfeeding women fertile again?
After 4 weeks post partum
After loss of suckling stimulus, when does milk production stop?
2-3 weeks
When do breasts return to normal after stopping breastfeeding?
After 3 months
Milk accumulates, ducts swell and compress capillaries. alveoli then dissapear
What is galactorrhoea?
Milk production in the absence of pregnancy or lactation
What is gynecomastia?
Male breast development, mild and transient
Function of placenta
Exchange of fetal CO2 and waste products to be exchanged for O2 and nutrients from maternal blood
Stores nutrients
Produces hormones
What part of the embryo forms the placenta?
The chorion (and chorionic villi)
Name the parts of the maternal endometrium forming the placenta and surrounding structures in pregnancy
Decidua basalis, decidua capsularis, decidua parietalis
What is the decidua parietalis?
Modified endometrium lining the walls of the uterus (not near embryo)
Describe the arrangement of the umbilical cord
Single umbilical vein containing oxygenated blood, two umbilical arteries from internal iliac artery
Describe the arrangement of the umbilical cord
Single umbilical vein containing oxygenated blood, two umbilical arteries from internal iliac artery
Outer layer of amnion (Wharton’s jelly)
Role of relaxin
Hormone which allows pelvis to widen-> pregnancy waddle
What happens to the mother’s spine in pregnancy?
Increased weight so lumbar lordosis
How does the vagina change in pregnancy?
Becomes more vascular- has a blue/purple hue
Walls become thicker and softer
Increased sexual sensitivity
How does the face change in pregnancy?
Increased pigmentation- chloasma (mask of pregnancy)
What is a cotyledon?
A section of the decidua basalis of the placenta, consists of a main stem of chorionic villus and its branches etc
Why might you see scapula winging after breast cancer?
Damage to the long thoracic nerve-> serratus anterior not innervated
