partition and lactation Flashcards
what is polycystic ovarian syndrome (PCOS)?
- the most common endocrine disorder in women aged 18-44
- caused by elevated levels of androgens
what are the symptoms associated with PCOS?
- pelvic pain
- beard - hirsutism
- excess body and facial hair
- acne
- amenorrhea - no periods
what conditions is PCOS associated with?
- type II diabetes - insulin resistance NB
- obesity
- heart disease
- endometrial cancer
what is the treatment for PCOS?
- diet - weight loss
- restoration of fertility - IVF
- can give medication p oral contraceptive pills to normalise periods and reduce hirsutism
what are the 2 components of the placenta & what do they develop from?
- fetal part - develops from the chorionic sac
- maternal part - derived from the endometrium
what are the 5 main functions of the placenta?
- protection
- nutrition
- respiration
- excretion - removal of waste from baby
- hormone production
what is the amnion?
- a membrane that surrounds the embryo/fetus and it increases in size during pregnancy
- functions in mechanical protection
what are the main hormones that the placenta secretes?
- progesterone
- estrogen
- inhibin
- relaxin
- HCG - human chorionic gonadotrophin
- human placetal lactogen
what happens to the corpus leteum if pregnancy does not occur?
- it will degrade
what hormone secreted by the placenta keeps the corpus luteum intact during pregnancy?
- human chorionic gonadotrophin
what are the functions of HCG hormone?
- prevents menstruation
- causes the devlopment of the decidual cells (cells that provide nutrition for the fetus)
- stimulates steroid secretion from placenta during last 6 months of pregnancy
what is the function of human placental lactogen?
- stimulates glucose production and therefore decreases insulin sensitivity
- stimulates breast development in preparation for lactation
stimulates the breakdown of fatty acids
what is the function of the hormone relaxin?
- decreaes uterine muscle contractility
- relaxation of the ligaments of the symphysis pubis - facilitates birth
what is amniocentesis?
testing of the amniotic fluid to screen for genetic diseases
what is chroionic villus sampling?
- involves obtaining tissues form the chorionic villus of the placenta
- there are higher risks of miscarraige
how long does a normal pregnancy last?
40 weeks
what is parturition?
the action of giving birth
what are the several mechanisms that control the events of parturition?
- the pregnant uterus near term secretes prostaglandins which are potent stimulators of contraction
- oxytocin - released by the posterior pituitary gland - also a potent contractor
- fetal production of ACTH can stimulate labor
what is lactation?
the production and secretion of milk by the mammary glands in the breast
what occurs to the mammary glands during pregnancy?
they increase in size and cell number
what is the major hormone that stimulates the production of milk?
prolactin
what hormone inhibits prolactin release?
dopamine
describe the milk ejection reflex
- stimulation of the mechanoreceptors in the nipple by suckling
- this causes oxytocin to be released from posterior pituitary gland
- dopamine decreases, plasma prolactin releasing factor increases
- stimulates release of prolactin from anterior pituitary gland
- prolactin increases milk production
- oxytocin causes the myoepithelial cells to contract and expel milk
what is the first secretion of milk called?
colostrum
Describe the development of the breast from puberty and during pregnancy
- puberty - development of breasts starts - by estrogen
- during pregnancy, there is final differentiation of the duct system, growth of breasts due to increase of stoma (connective tissue) and adipose tissue
- estrogen, GH, prolactin, insulin all encourage the growth of the ductal system
- progesterone stimulates the development of the lobule-alveolar system
what is the function of placental progesterone?
- increase of secretion and uterus before implantation
- development of decidual cells (nutrition cells)
- decreased contractility of the pregnant uterus
what is the difference between a zygote and a blastocyst?
- zygote = the original fertilised egg - a ball of cells
- blastocyst= hollow ball of cells - which implants onto the endometrium
what is implantation?
- the embedding of the blastocyst into the endometrium
what are trophoblast cells and what important roles do they have?
- specialised cells of the placenta
- have an important role in embryo implantation and interaction with the decidual cells of the uterus
what is the menopause?
the cessation of the function of the ovary - occurs between the age of 44-45
