2006-08-31 20:56:00 · 8 answers · asked by moh a 1 in Health ➔ Men's Health
the hypothalamus in the brain sends signals to the testes to secrete testosterone: http://66.249.93.104/search?q=cache:JIV2jyMK9AgJ:distance.stcc.edu/AandP/AP/AP2pages/reprod/malesex.htm+testosterone+secretion&hl=en&gl=jo&ct=clnk&cd=1
2006-08-31 20:58:10 · answer #1 · answered by I need Answers 5 · 0⤊ 0⤋
Luteinizing hormone, released by the anterior pituitary, acts on the interstitial cells of Leydig located in the testes.
This is, believe it or not, one of the major distinctions between males and females.
All vertebrate embryos are inherently "female". Didn't you ever wonder why guys have nipples?? Did you ever wonder why guys produce sperm year round, while women ovulate once every 28 days?
Concerning gonads, males have testes, females have ovaries. All mammalian embryos have, however, have a hermaphroditic gonad. It is what we call indeterminate. It hasn't been shoved into male or female yet.
Male embryos have the Y chromosome from dad in addition to mom's X chromosome, while females have an additional X chromosome from dad in addition to mom's X chromosome. Located on the Y chromosome is a gene called the SRY gene, and it encodes a protein called "testis determining factor", or TDF. In the presence of TDF, the indeterminate gonad is given a nudge into becoming testes that produce testosterone.
The testosterone then acts on the embryonic hypothalamus (actually, it is converted, believe it or not, to estradiol) to turn the hypothalamus into that of a male, i.e. one that will ultimately stimulate a constant release of luteinizing hormone and follicle stimulating hormone from the male pituitary gland. In contrast, in the absence of the Y chromosome, SRY gene, testicle formation, testosterone production, and estradiol reaching the embryonic hypothalamus , the hypothalamus will by default behave as a female's hypothalamus, causing a monthly surge in luteinizing hormone and follicle stimulating hormone from the anterior pituitary gland.
It is an absolutely remarkable process.
2006-08-31 21:16:35 · answer #2 · answered by Anonymous · 0⤊ 0⤋
A photo of Hillary Clinton.
2006-08-31 20:58:02 · answer #3 · answered by Mr. C 3 · 0⤊ 0⤋
Pamela Lee Anderson's "Ta-Ta's"!!
PURE SILICON !
2006-08-31 20:58:42 · answer #4 · answered by Anonymous · 0⤊ 0⤋
leutinizing hormone
2006-08-31 21:13:10 · answer #5 · answered by Aakash 2 · 0⤊ 0⤋
the sac gland
2006-08-31 20:57:12 · answer #6 · answered by middleshoes 3 · 0⤊ 0⤋
the hypothalamus dude!
2006-08-31 21:13:31 · answer #7 · answered by Anonymous · 0⤊ 0⤋
prostate and testicles
2006-08-31 20:57:24 · answer #8 · answered by viper 3 · 0⤊ 0⤋
testicles beneath the penis
2006-08-31 20:58:01 · answer #9 · answered by Anonymous · 0⤊ 0⤋