Class Eleven Flashcards
main role of the scrotum
temperature regulation
two roles of the testes
synthesis of sperm
secretion of male sex hormones
site of spermatogenesis
seminiferous tubules
walls of seminiferous tubules are formed by..
sustentacular cells
tissue between seminiferous tubules
testicular interstitium
role of interstitial cells (Leydig)
synthesis of testosterone
where to the seminiferous tubules empty into
epididymis
where does the epididymis empty into
vas deferens
how does the vas deferens get to the urethra
by entering the inguinal canal
what two things make up the ejaculatory duct
seminal vesicle duct + vas deferens
what do the seminal vesicles secrete
mostly fructose
60% of semen
what 3 glands secrete the components of semen
seminal vesicles
prostate
bulbourethral glands
what does the prostate gland secrete (2)
fructose
coagulant - allows semen to coagulate after ejaculation
35% of semen
what do the bulbourethal glands secrete
thick, alkaline mucus
lubricates the uretha - neutralizes acids
what do the testes secrete
sperm
3 compartments that have erectile tissue
corpora cavernosa (x2)
corpus spongiosum
three stages of the male sexual act
arousal
orgasm
resolution
arousal is dependent on..
parasympathetic nervous input
2 stages of arousal
erection and lubrication
what happens during erection
dilation of arteries supplying the erectile tissue → causes swelling
what happens during lubrication
bulbourethral glands secrete mucous
what is required for orgasm
stimulation by the sympathetic nervous system
two stages of orgasm
emission and ejaculation
what happens in emission
propulsion of sperm and semen into the urethra by contractions of SM
what happens in ejaculation
semen is propelled out of the urethra
what controls resolution
sympathetic nervous system
main thing that happens during resolution
constriction of the erectile arteries → decreased blood flow to the erectile tissue
syngamy
egg and sperm meeting
when does spermatogenesis begin
at puberty
where are immature sperm precursors found
outer wall of the seminiferous tubules
mature sperm aka
spermatozoan
job of primary spermatocyte
meiosis I
job of secondary spermatocyte
meiosis II
how do we keep spermatozoa inactive
inhibitory substances secreted by the vas deferens
what does the acrosome contain
hydrolytic enzymes to penetrate the ovum’s protective layers
bindin
protein on sperm’s surface
attaches to receptors on the zone pellucida surrounding the ovum
what does luteinizing hormone do - males
stimulates the interstitial cells to secrete testosterone
what does follicle stimulating hormone do - males
stimulates sustenacular cells
what secretes inhibin
sustenacular cells
role of inhibin
inhibit FSH release
where do FSH and LH come from
anterior pituitary
mullerian ducts turn into..
female genitalia
when does mullerian inhibiting factor get produced
in the presence of a Y chromosome
which is the default, wolffian ducts or mullerian ducts developing
mullerian
mullerian inhibiting factor is produced by
the testes
systemic testosterone must be converted into ____ in target tissues to exert effects
dihydrotestosterone
testis is homologous to
ovary
penis is homologous to
clitoris
bulbourethral gland is homologous to
greater vestibular glands
scrotum is homologous to
labia majora
main androgen in the testes
testosterone
main estrogen in the ovaries
estradiol
where does gonadotropin releasing hormone come from
hypothalamus
what does GnRH do
stimulates the pituitary to release FSH and LH
FSH in females
stimulates the granulose cells to secrete estrogen
LH in females
stimulates the formation of the corpus luteum and progesterone secretion
role of inhibin
inhibits the pituitary from releasing FSH and LH
what becomes the scrotum
labioscrotal swellings
what surrounds the urethral opening in females
labia minora
whats between the labia minora
opening to the vagina
what is the cervix
part of the uterus that opens into the vagina
innermost lining of the uterus
endometrium
what surrounds the endometrium
myometrium
mature follicle aka
Graafian follicle
layer of granulose cells surrounding the ovum
corona radiata
what makes and secretes estrogen
granulose cells
what seconds estrogen and progesterone in the second half of the menstrual cycle
corpus luteum
three phases of the ovarian cycle
follicular phase
ovulatory phase
luteal phase
what happens in the follicular phase
primary follicle matures + secretes estrogen
FSH controls maturation of the follicle
what happens in the ovulatory phase
secondary oocyte is release → surge of LH
remnants of the follicle becomes the corpus lute
what happens in the luteal phase
formation of the corpus luteum in the ovary
secretes estrogen and progesterone
three phases of the uterine cycle
menstruation
proliferative phase
secretory phase
what triggers menstruation
degeneration of the corpus luteum
why does the endometrial lining slough off
due to the drop in estrogen + progesterone
what happens in the proliferative phase
new endometrium forms due to estrogen from the follicle
what happens in the secretory phase
estrogen and progesterone from the corpus luteum further increase development of the endometrium
what stimulates the release of FSH and LH from the ant. pituitary
GnRH
secretion of _____________ is initially inhibited by estrogen
GnRH, LSH and FH
what causes ovulation
surge in LH
why does ovulation not occur during pregnancy
inhibition of LH release
what secretes hCG
the chorion
what does hCG do
maintains the corpus luteum
what hormone is tested with pregnancy tests
hCG
where does fertilization occur
uterine tube
fast block to polyspermy
depolarization of the egg plasma membrane
slow block to polyspermy
calcium influx
swelling of the space between the zona pellucida and the plasma membrane
hardening of the zona pellucida
what gives rise to the chorion
trophoblasts
yolk sac purpose
first site of RBC synthesis in the embryo
what is gastrulation
when the three primary germ layers become distinct
three primary germ layers
ectoderm
mesoderm
endoderm
mesoderm develops from..
the endoderm
what does the ectoderm give rise to
nervous system
pituitary gland
cornea + lens
epidermis
epithelium
what does the mesoderm give rise to
muscle, bone, CT
cardiovascular + lymphatic systems
urogential organs
dermis of skin
what does the endoderm give rise to
GI tract/glands
respiratory epithelium
lining of urogenital organs
bladder
when are all major organ systems present
by the eighth week
when is the fetus most sensitive to toxins
first trimester → when organogenesis occurs
lack of folic acid in the mother’s diet
can lead to defects in the formation of the neural tube and CNS
fetal alcohol syndrome leads to
stunted fetal growth
brain damage etc.
totipotent
can generate trophoblast and inner cell mass
pluripotent
can differentiate into any of the 3 primary germ layers
multipotent
can produce many, but not all cell types
dedifferentiation
some cells can go backward and become less specialized
changes in mom’s bodies during pregnancy
increased respiratory rate
increased BV
increased glomerular filtration
parturition
birth
positive feedback cycle of birth
increased pressure on cerix causes oxytocin release
oxytocin causes uterine contractions to increase even more
first stage of labour
dilation of the cervix
second stage of labour
birth
third stage of labour
expulsion of the placenta
what causes breast milk
prolactin
why is prolactin released after birth
due to the drop in estrogen and progesterone (they inhibit prolactin)
what is also required for milk release
oxytocin
estrogen and LH relationship
at low levels of estrogen, it is inhibitory for LH
at high levels of estrogen, it is stimulating for LH
when estrogen and progesterone levels are high..
LH and FSH levels are low
morula
solid ball of cells
blastula
hollow ball of cells
what implants into the uterus
blastula
what secretes hCG
trophoblast
how long does it take to form the placenta
3 months
what eventually becomes the embryo
inner cell mass
foramen ovale
hole between R and L atria
ductus arteriosus
BV between PT and aorta
which umbilical vessels close first
arteries then veins
