reproduction Flashcards
(17 cards)
explain the female reproductive system
ovaries: suspended in the peritoneal cavity by the ligament- not directly connected to fallopian tube
fimbriae: ribbon like extensions of the oviduct that gently interact with ovaries. it directs ovum into fallopian tube. it has cilia that captures egg (usually just floats in peritoneal cavity) and takes it into the uterine tube.
uterus: where implantation occurs
cervix: circular muscle and is half a cm but expands to 10-12 cm.
vagina: acidic to protect it from external environment
what are we referring to when we talk about gonads
ovaries - oogenesies or testes - spermatogenesis
where is successful fertilisation occur
first third of the fallopian tube
explain the male reproductive system
testis and scrotum:where sperm is produced but needs to go to the epididymis- cups the testes
scrotum: maintains sperm at 30 degrees by bringing it closer to the body (when cold) or extending it (when hot).
when a male is excited, the sperm is ejaculated into vas deferent. it has blood vessels and nerves which under go contractions (peristaltic) which will propel the sperm through the gut and pass to somewhere else.
urethra: when the sperm enters here, it has the nutrients, coagulants and mucus it needs to protect the sperm as it goes in male and female reproductive system.
how does sperm travel through the male reproductive system
produced in testes but mature in epididymis. it will travel along the vas deferens, go into the seminal vesicles into the prostate gland into the cowpers glands
what compounds are produced in the seminal vesicle
prostaglandin: stimulate motility of sperm
fructose: nutrient source for the sperm
clotting agents: coagulates semen after ejaculation
why are the prostate gland important
produces citric acid used for ATP production. mid piece of sperm is made of Custer of mitochondria.
proteolytic enzymes to allow semen to break down
what does the cowpers gland do
produce mucous (released pre ejaculation), lubricates the urethra and end of penis to prevent damage to sperm. its an alkaline fluid to neutralises the acidity of the urethra.
what is semen made of
60% seminal vesicle
30% prostate, 5% testes and 5% cowpers gland
explain spermatogenesis
happens in the testes. there are seminiferous tubules. as cells mature they move to the middle of the seminiferous tubules
what are seminiferous tubules made out of
intersitilial cells - basement membrane- Sertoli cells (nursing cells- protect nourish and allow the growth of sperm cells)
stages of sperm
spermatogonia - on the outside, we have diploid cells, they will undergo mitosis. after this, when they are ready to undergo spermatogenesis they are called primary spermatocyte and undergo meiosis 1 and become secondary spermatocyte and then meiosis 2 and they are referred to as spermatid . they will then go to the epididymis to complete maturation.
what happens in the epididymus that compels maturation
they become partially differentiated. they have their head (acrosome) is reconstructed to have receptors so it can interact with it. this is called capacitation.
explain oogenesis
everything happens in the ovaries until fertilisation (except meiosis but it starts there). germ cells know has oogonia. we have 5 million before birth but only 400 000 will survive by birth. they will undergo mitosis and some will undergo mitosis and is now called primordial follicle- has single layer of cells known as granulosa cells which provide support for the developing oocyte. once it is primed, it is called primary oocyte. it will develop and get bigger and the granular cells will multiply so it will become a primary follicle. the granular cells will secrete fluid to form the antrum (fluid filled cavity) it will start to develop zone pellucida - facilitate entry of one sperm,. it is now secondary follicle- but primary oocyte inside because its still in prophase 1. during each menstrual cycle, one will develop into secondary follicle. the Luitenising hormone will trigger primary oocyte to finish meiosis 1- now a haploid cell. one cell will become the secondary oocyte and the other will shrink and becomes the polar body. it degenerates al the energy used to for the crops luteum. one cell is produced a the end. the other three is formed as polar bodies and reused else where. the LH will also trigger the release of the second oocyte into the peritoneal cavity. if there is fimbria caressing the ovary, the cilia on the surface will move the secondary oocyte into the uterine. the corpus lutes is left. it will produce the progesterone to make sure everything is ready if fertilisation occurs.
explain hormones before and after puberty in males
Sertoli cells release a hormone called inhibin - Negative feedback effect on the organs associated with hormone production.
interstitial cells in testes: produce testosterone. it inhibit the activity of immature hypothalamus and immaturity anterior pituitary gland.
after puberty, the hypothalamus has reached maturity and these hormones no longer have a negative effect. the GnRH (gonadotropin releasing hormone) will stimulate the anterior pituitary gland to produce LH and FSH which will signal the testes to start stomatogenesis. the interstitial cells which are still producing testoretone now has a positive feedback- allows more sperm production and more male features
explain hormones before and after puberty in females
granulosa cells produce inhibin to inhibit immature hypothalamus and anterior pituitary gland. oestrogen and progesterone produced by the primordial follicles also has an inhibitory effect on the immature structures. when she has her first day of bleeding, it means that the hypothalamus has matured where its no longer inhibited. it starts producing GnRH which stimulates the production of LH AND FSH by anterior pituitary gland. as follicles develop, more eostrogen and progesterone is made which makes a positive feedback to hypothalamus and secondary female characteristics are formed.
