o Head: chromosomes, acrosomes (enzymes necessary for fertilization)
o Midpeice: mitochondria
o Tail: whip like propel sperm
Basics of spermatogenesis
o Spermatogonia divide by mitosis to create 1 daughter cell and 1 Primary spermatocyte.
o The Primary Spermatocyte divides by meiosis to form 2 secondary Spermatocytes o Secondary spermatocytes divide again to form 2 (each) spermatids
o The spermatids then differentiate into sperm cells
Role of FSH and LH in the male
o FSH: stimulates gametogenesis
o LH: stimulates androgen (testosterone) secretion
Role of FSH and LH in the female
FSH: Secreted from the Ant. Pit. FSH and estrogens stimulate follicle growth and development
Role of Estrogen and Progesterone in the female
Estrogen: Inhibit LH & FSH secretion
·Promotes endometrial growth
·Permute oogenesis and follicle development
·Increased LH receptors in granulosa cells
·Increased progesterone receptors in uterus ·Increased LH Secretion (late in follicular phase only)
role of estrogen in Pregnancy and Luteal phase
·Promotes growth of duct tissue and deposition of fat in breasts
·Increased prolactin secretion
·Increased growth and contractile activity of uterine smooth muscle
·Increase oxytocin receptors in uterus
·Premote fluid retention
What are the phases of the menstrual
Menstruation: bleeding due to the shedding of the endometrium 1-5 days
Follicular Phase: when the follicles develop
~includes menstrual phase (1-5 days) and Proliferative phase (17 days)
~Proliferative Phase: endometrial lining develops, grows, glands enlarge, smooth muscle layer thickens and the cervical glands secrete mucus. All stimulated by estrogen.
~Secretory phase: endometrium prepared for implantation, blood supply increases, glands enlarge and secrete glycogen-rich fluids, and cervical secretions more sticky to form a plug.
o during which the corpus luteum forms and secretes estrogen and progesterone. Corpus Luteum reaches a max activity of 10 days then degenerates. The degeneration decreases estrogen and progesterone and results in menstruation or if no degeneration = pregnancy. This is day 15-28
Estrogen is secreted from the
follicle then from the Corpus Leteum
Progesterone is secreted from
LH & FSH are secreted from
the Ant. Pit
Estrogen & progesterone inhibits
LH & FSH secretion
The menstrual cycle lasts about 28 days
The menstrual cycle is started with the beginning of
FSH and LH both released from the antipituitary stimulated a follicle in the ovary causing it to develop so that the ovum matures. This also causes the ovary to release estrogen
The combination of FSH, LH and Estrogen has a positive feedback in the hypothalamus causing more of all 3 to be released
Estrogen causes the muscle and lining layers of the uterus to grown thicker in prep for possible embryo
The LH Surge on or about the 14th day causes ovulation ton. The ovum enters the oviduct and travels towards the uterus. And it may meet up with sperm.
The remaining section of the follicle develops into the corpus luteum which secretes the hormone progesterone for several days.
Progesterone has the effect of maintaining the lining of the uterus by developing more blood vessels that create the change in the uterus for egg implantation.
If an egg implants it releases HCG
If not it combination of estrogen and progesterone has a negative feedback effect on the pituitary, stopping the release of FSH and LH