Friday lecture

Most animals reproduce sexually by producing haploid gamates (=gametogensis)

1) meiosis and spermatogensis

Druing early development male germs cells go thourgh metitossis and divide

2) meiosis and oogenesis

in many species, including humns, the primary oocyte is arresteed in the early states of meiosis (primary oocyte) and does not complete meiosis until puberty. there is unequil distrabution. you get a polar body will degrade.

The prmary accesory sex organs in males.

1) semilial fluid (seamen or ejaculate) is composed of fluids that support sperm and facilitate fertilization. there are stuff that gets mixed in and less than 5% of seamen. Additonal fluids (sugars, mucus, enzymes, acid neutralizers) comes from the seminal vesicles, prostae, and bulbourethral glands

spermatogensis takes place in the semiferous tubles: are the locate in the gondas were spermagenesis takes place.

steroli cells provide norishment for developing spern and secrete chemicals that promote sperm development.

Leydig cells are outside the seminfours tubules and produces androgenes

gonadal hormones in males:

androgens, like estorgen, are responsible for development of external genitalia but also secondary sexual traits (deep voice, facial hair, musculature)

they are controlled by classic negative feedback loop that also includes inhibin produced by sertoli cells. sertoli cells are invlved in nouritiong that sperm cells.

not that gonal hormones also regulate spermatogenesis ensuring that the two coincide

the primary and accessory sex organs in females:

when the egg is fertilized by sperm it is a secondary oocyte (n) and subsequently completes meiosis followed by fusion of the haploid nuclei

graafian follicle:

the antrum is fluid filed and high conecntratoins of steroids

thecial cells and granulosa cells are collectivly follicular cells.

thecal cells produce androgens

the developoing embryo produces a homrone that resuces the corpus lateum

human corgnic gonadtropin hCG: a hormone that is prodceds by the developng embryo. if hCG is not produces, the corpus leuteum degredes, forming the copus albicans

SHould know human codaic portobian