27 Flashcards
(16 cards)
primary sex organs (gonads)
testes and ovaries
produce gametes: sex cells (sperm and ova)
secrete steroid sex hormones: androgens (m) and estrogens and progesterone (fm)
accessory reproductive organs
ducts, glands, external gent
sex hormones play role in
– Development and function of reproductive
organs
– Sexual behavior and drives
– Growth and development of many other
organs and tissues
Production of gametes.
– Male sex cells
synthesis of androgens
– Male sex hormones
-sperm
-testerone
Delivery of sperm into the female
reproductive tract.
scrotum
As ambient air T° decreases, the
cremaster muscle contraction will
As ambient air T° decreases, the dartos muscle will
sack of skin, lowers temp by 30
increase and the distance between the testes and abdominal cavity will decrease
contract and the scrotal surface area will decrease to prevent heat loss
Cremaster muscle
Dartos muscle
raises/lowers
adjusts surface area
semen
-2–5 ml semen ejaculated, million
- fructose for ATP production; protects and activates sperm; facilitates sperm movement
* Alkaline → neutralizes acidity of male urethra and female
vagina → enhanced motility
Ovarian Cycle
Monthly series of events associated with maturation of egg
* Two consecutive phases (in 28-day cycle)
* Follicular phase - period of follicle growth (days 1–14)
* Ovulation occurs midcycle
* Luteal phase - period of corpus luteum activity (days 14–28)
follicular phase varies
luteal phase constant- always 14 days from ovulation to end of cycle
Follicular Phase
Primordial follicle becomes primary follicle
* Squamouslike cells become cuboidal; oocyte enlarges
* Primary follicle becomes secondary follicle
* Stratified epithelium (granulosa cells) forms around oocyte
* Granulosa cells and oocyte guide one another’s development via gap
junctions
late secondary follicles become vesicular follicle: antrum forms; expands to isolate oocyte
primary oocyote completes meiosis 1
Ovulation
Ovary wall ruptures, expels secondary oocyte with its corona radiata
to peritoneal cavity
Luteal Phase of the Ovarian Cycle
Ruptured follicle collapses; antrum fills with clotted
blood – corpus hemorrhagicum
* Granulosa cells and internal thecal cells form corpus
luteum
* Corpus luteum secretes progesterone and some
estrogen
if no preg, corpus luteum degenrates into corpus albicans (scar) in 10 days
if preg c.luteum prod hormone that sustains pregnancy until placenta takes over
The Uterine (Menstrual) Cycle
Cyclic changes in endometrium in response to fluctuating ovarian
hormone levels
* Three phases
* Days 1–5 - menstrual phase
* Days 6–14 - proliferative (preovulatory) phase
* Days 15–28 - secretory (postovulatory) phase (constant 14-day length)
Menstrual phase (Days 1 - 5)
Ovarian hormones at lowest levels
* Gonadotropins beginning to rise
* Stratum functionalis shed; menstrual flow (blood and tissue) 3 - 5 days
* By day 5 growing ovarian follicles produce more estrogen
Proliferative phase (Days 6 - 14)
*
Rising estrogen levels prompt generation of new stratum functionalis layer;
increased synthesis of progesterone receptors in endometrium; glands
enlarge and spiral arteries increase in number
* Normally thick, sticky cervical mucus thins in response to rising estrogen
(allows sperm passage)
* Ovulation occurs at end of proliferative phase
Secretory phase (Days 15 – 28)
- Most constant timewise
- Endometrium propares for embryo
- Rising progesterone levels prompt
- Functional layer → secretory mucosa
- Endometrial glands secrete nutrients
- Formation of cervical mucus plug
if fertilization does not occur
for uterine cycle
- Corpus luteum degenerates toward end of secretory phase
- Progesterone levels fall
- Spiral arteries kink and spasm
- Endometrial cells begin to die; glands regress
- Spiral arteries constrict again, then relax and open wide
- Rush of blood fragments weakened capillary beds and functional layer
sloughs
