CH15 Flashcards
6 Structure of male reproductive system
Testis
- secretes testosterone
- produces sperm
Sperm duct
- direct sperm from testis
scrotum
- protect testis
seminal vesicle
- secrete fluid and nutrient for sperm
Prostate gland
- secrete fluid to facilitate movement of sperm
urethra
- direct urine and sperm out of the body
Process of Spermatogenesis
Primordial germ cell (2n) -Mitosis-> Spermatogonium (2n) -Cell growth-> Primary Spermatocyte (2n) -meiosis 1-> Secondary Spermatocyte (n) -meiosis 2-> spermatid -cell differentiation-> sperm
Process of Oogenesis
Before birth:
- primordial germ cell 2n undergoes Mitosis to produce oogonium 2n
- Oogonium 2n undergoes mitosis to produce primary oocytes
- Primary oocytes 2n undergoes meiosis i but stops prophase i
- Each primary oocyte is surrounded by a layer of follicle cells that provide nutrient and secrete oestrogen
After birth
- Baby girl has millions of primary oocyte 2n
- Primary oocytes is dormant until she reaches puberty
After Puberty
- Primary oocytes 2n complete meiosis 1 to form secondary oocytes and 1 first polar body
- Secondary oocytes n undergoes meiosis ii and stops at metaphase ii
- Secondary oocytes is surrounded by secondary follicle that develops into graafian follicle and secretes oestrogen
- During ovulation, matured graafian follicle moves toward ovary and releases secondary oocytes into fallopian tube
4 Hormones involved in menstrual cycle
FSH
- stimulate development of follicle in ovary
- stimulate ovary to secrete oestrogen
LH
- stimulates ovulation
- stimulate ovary to secrete progesterone
- stimulate formation of corpus luteum
Oestrogen
- Stimulate pituitary gland to secrete FSH & LH before ovulation
- stimulate hypothalamus to secrete GnRH
- Stimulate thickening of endometrium
- stimulate development of follicle until maturity
Progesterone
- Stimulate thickening of endometrium and enrich it with blood vessel for embryo implantation
- Inhibit secretion of FSH (prevent development of follicle) and LH (prevent ovulation)
Process of menstrual cycle
Week 1 (Secretion & FSH Function)
-GnRH stimulate pituitary gland to secrete FSH and LH into bloodstream
- FSH stimulate development of follicle in ovary
- Primary oocytes in primary follicle will develop into secondary oocytes in Graafian follicle
- Developing follicle secretes oestrogen that stimulate thickening of endometrium & development of follicle
Week 2 (Effect of Oestrogen-Ovulation)
- High level of Oestrogen stimulates hypothalamus to secrete GnRH
- High level of GnRH stimulate pituitary gland to secrete FSH and LH
- LH level peaks on day 13 to stimulate ovulation on day 14 when secondary
oocytes is released from Graafian follicle
- Follicular tissue left behind forms corpus luteum
week 3 (Corpus luteum & Progesterone)
- Corpus luteum formed in ovary secretes progesterone and oestrogen
- Progesterone stimulate thickening of endometrium and enriches it with blood vessel for embryo implantation
- Progesterone inhibits secretion of FSH and LH to ensure follicle doesnt develop
week 4 (fertilisation or not)
- IF fertilisation occur
1. Corpus luteum will continue to develop and secretes oestrogen & progesteron
2. Endometrium will continue to thicken fro support of foetus development
- If fertilisation does not occur,
1 Corpus luteum will disintegrate
2 Secretion of oestrogen and progesterone decreases
3 Endometrium will collapse
Development of embryo after fertilisation until implantation
Zygotes undergoes repeated division through mitosis to form 2-cell embryo
2-cell embryo undergoes mitosis to form 4 cell, 8 cells and finally morula
Morula develops to form blastocyte
Peristalsis action of fallopian tube and action of cilia facilitate movement of embryo into uterus
blastocyte implant in endometrium and continues to grow to form embryo
Formation of identical twins
One sperm fertilises one ovum
Formation of fraternal twin
2 sperms fertilises 2 ovum
