Reproductive physiology Flashcards
how do we determine the sex of an individual ?
The chromosomal makeup determines it genetically , ( XX or XY) , this leads to behavioural characteristics. The gonadal ovaries and testes also play a role and this is phenotypic. Also the genital of males and females is external and this plays a role.
interstitial cells ?
also called Leydif cells produce testosterone in the presence of luteinising hormone (LH).
seminiferous epithelium tissue ?
is where germ cells proliferate , undergo meiosis and differentiate into spermatozoa.
seminiferous tubules ?
produce sperm, maintain sperm, and store the sperm.
FUNCTION OF THE TESTES ?
include gametogenesis which is what produces spermatozoa. Also the endocrine releases androgens , oestrogen’s and inhibin.
cells that spermatogenesis occurs in ?
the sertoli cells
what does the sertoli cells produce at the top , far away from the lumen ?
produces spermatogonia
what does this become ?
primary spermatocyte which then becomes secondary spermatocyte.
what is produced next
spermatid is produced which undergoes spermiogenesis and the spermatozoa is produced which include the flagellum.
function of the Sertoli cells ?
one of which includes a barrier function to the blood/seminiferous epithelium. Endocrine function is the inhibin , oestrogens , MIF and AMF ( anti – Mullerian factor). Also the Sertoli nourish the sperm. The paracrine function is that they produce growth factors , androgen binding factors. They clear defective cells as phagocytosis occurs.
optimum temp for spermatogenesis ?
34 degrees Celsius which is 2 – 3 below body at 37. This is determined by the function of the scrotum and blood supply. Also the action of various hormones are required.
how is the scrotum adapted for heat lose ?
large surface area and abundant sweat glands.
muscle in scrotum ?
cremaster and dartos
blood supply to testes ?
artery and pampiniform plexus
where does the counter current heat exchange occur ?
the testes
development of testes ?
develop intra abdominally and descend into the scrotum before birth.
what is cryptochidism ?
failure of testes to descend into scrotum , this is sterility
what does gonadotrophin releasing hormone cause to be produced ?
FSH and LH which in turn cause testosterone to be produced.
name the male sex hormones ?
testosterone , oestradiol and dihydrotestosterone are all steroid hormones.
what are androgens required for ?
development of external genitalia ,secondary sexual characteristics , ducts and glands and also for spermatogenesis
vas deferens ?
tiny muscular tube that carries sperm form the epididymis to the ejaculatory gland
ejaculatory duct ?
formed where the vas deferens join together
epidymdimus ?
tube that connects a testicle to a vas deferens , where sperm mature fully.
seminal vesicles ?
pair of simple tubular glands that secretes a fluid that partly composes sperm , adds sugar to the mix.
prostate ?
surrounds the urethra , it produces a thick white fluid that combines with sperm to create semen
bulbourethral gland ?
adds fluids to sperm during the process of ejaculation.
name some secondary sexual characteristics ?
male pattern baldness , aggressiveness , enlarged larynx which causes a deeper voice , muscle mass as well as facial hair , body hair and pubic hair.
what do androgens cause ?
masculinisation of the male foetus.
in the early reproductive system of the foetus what are the 2 types of ducts ?
Mullerian which is the female duct and Wolffian which is the male ducts.
describe how male progression occurs ?
the Y chromosome releases testis determining factor which targets the gonads around day 42 , the testis. This causes MIF or AMF ( anti -Mullerian factor) to be released and there is Mullerian duct regression. The testis then release androgens around day 65-84 and this causes male external genitalia as the male ducts develop.
describe how there could be failure of the foetal testis development ?
due to no androgen secretion or there is no androgen receptor. This causes the external genitalia to develop along the female lines.