Biological Sciences 25 Flashcards
where are sperm cells stored?
epididymis
they are kept here until ejaculated
how long must sperm stay in epididymis? whu?
18-24 hours
to gain motility
passage thru here requires several days
what forms testosterone
intersistal cells of leydig
where are cells of leydig found
found outside seminiferous tubules
quantity of cells of leydig thru out life
numerous in newborns and adult male post-puberty
almost nonexistent in testes during childhood
what happens after testosterone is secreted?
binds to albumin
circulates in blood for 30 min to several hours
degraded or transferred
fates of albumin bound testosterone
transferred to tissues
OR
degraded to inactive products to be secreted
testosterone of tissues
converted to dihydrotestosterone
esp. prostate and fetal external genitalia
testosterone not fixed in tissues
converted to andosterone and dihydroepiandosterone
conjugated to glucuronides or sulfates
excreted into gut via bile or urine (kidneys)
abstract testosterone functions
hypertrophy of larynx
increased skin thickness
increased secretion rate of sebaceous glands
increased protein/muscle formation
increased BMR
increased hematocrit
increased sodium reabsorption
location of sertoli cells
seminiferous tubules
function of sertoli cells
nurse cells that surround primary spermatocytes
nurse them thru spermatogenesis/spermiogensis (differentiation)
from estrogen’s from testosterone (important for spermatogenesis)
cells of leydig function
secrete testosterone
what stimulates cells of leydig?
luteinizing hormone
FSH also has important function
seminal vesicles
secretes a mucoid material (semen) that contains
FRUCTOSE citric acid additional nutrients Pgs fibrinogen
paired structures behind prostate
seminal vesicles
located in tube lined with secretory epithelium
ejaculation
contents of seminal vesicles are emptied into ejaculatory ducts with sperm
function of fructose in sperm
provides energy
function of prostaglandins in sperm
makes cervical mucous more receptive to sperm movement
may cause contraction of uterus and fallopian tubes
prostate gland releases what during ejaculation
milky secretion with Ca, citrate, P, clotting, profibrinolysin
secretes alkaline fluid
pH of prostate secretion
alkaline
neutralizes acidity of other seminal fluids and vaginal secretions of femalee
Gonadotrophin releasing hormone
AKA LH releasing hormone
stimulates anterior pituitary to produce LH and FSH
does gonadotrophin releasing hormone release more LH or FSH?
LH
what produces gonadotrophin releasing hormone?
neurons in eructed nuclei of hypothalamus
transported to anterior pituitary via hypothalamic hypophyseal system
