2. Female Reproductive System- Hormones and Menstrual Cycle

female sex hormones

HPO Axis, secreted by hypothalamus, AP gland, ovaries, maturation of sex cells, changes during menstrual cycles

hypothalamus sex hormones

GnRH (causes AP to secrete FSH + LH)

AP Hormones

FSH and LH

FSH

stimulates follicle development in ovaries and estrogen

LH

triggers ovulation, stimulates formation of corpus luteum, progesterone

estrogens

produced by ovaries (follicle), fem characteristics, growth of uterine lining (endometrium), regulation of menstrual cycle; maintains bone density

progesterone

secreted by corpus luteum after ovulation, uterus for pregnancy, thickens endometrium for implantation, decreases uterine contractions, supports early pregnancy

androgens

from adrenal cortex, pubic and axillary hair at puberty

menstrual cycle

regulated by hormones, hypothalamus, AP, ovaries, uterus, fallopian tubes

hypothalamus menstrual cycle

GnRH in pulsatile fashion to initiate menstrual cycle

AP menstrual cycle

FSH and LH

ovaries menstrual cycle

follicles that mature and release egg, form corpus luteum

uterus menstrual cycle

inner lining thickens and sheds

fallopian tubes menstrual cycle

transport ovum from ovary to uterus

menstrual phase

FSH rises, progesterone and estrogen low, sheds uterine lining

proliferative phase

FSH stimulates growth of new follicle, estrogen increases from developing follicle → endometrium thickens and repairs itself

ovulation

dominant follicle ruptures + releases mature egg into fallopian tube, massive surge of LH, estrogen peaks, release of egg (~36 hours after LH surge)

luteal phase

ruptured follicle becomes corpus luteum, produces progesterone, endometrium more receptive to implantation, progesterone peaks and if no fertilization → luteum becomes albicans → drop in hormones → start menstrual phase

menopause

ovaries stop responding to FSH, cycling ceases, low conc of estrogens, continuous secretion of FSH + LH, reproductive organs regress

mammary glands

produce milk, in both sexes, functional in females after puberty

structure

lobes (15-20 per breast), surrounded by adipose (fat) tissue and connective tissue

lobes

contain lobules

lobules

contain alveoli

alveolar ducts

carry milk toward nipple

mammary function

milk (nutrition) and immune protection (antibodies in milk)

coitus interruptus

withdrawl of penis before ejaculation

rhythm method

abstinence two days before and one day after ovulation

mechanical barriers

condoms, diaphragms, cervical cups, block sperm

chemical barriers

creams, foams, jellies with spermicidal properties

injectable contraception

injection of depo-provera protects against pregnancy for 3 months → prevents maturation of secondary oocyte

combine hormone contraceptives

employ estrogen and progestin in combination to prevent pregnancy

intrauterine devices

small object placed in uterine cavity → interferes with implantation

surgical methods

male or female sterilized, vasectomy and tubal ligation

STDs (STIs)

can be infected and contagious without symptoms, spread primarily through sexual contact, bacteria, viruses, parasites, can affect reprod system but may involve whole body

pelvic inflammtory disease

infection of female upper reproductive tract, affects uterus, fallopian tubes, and ovaries, usually complication of untreated STIs (gonorrhea and chlamydia)

AIDS

HIV through semen, blood, milk, deteriorate body’s immune disease