Reproduction Flashcards
Learn how Female and Male reproductive cycle works.
Bio 121
When do sex organs begin to develop in human embryos?
7th week sexual organs begin to develop
Bio 121
Describe the function of each part.
Testis
Epididymis
Vas Deferens
Urethra
(Cowpers Gland Prostate Gland Seminal Vesicle)
(Fill in the Blank Provided)
T: Made of seminiferous tubules which are where sperm are made by meiosis
E: Stores Sperm
V: Take sperm from epididymis to urethra
U: Takes urine & semen out of body
CG/PG/SV: Make fluid part of semen that nourishes sperm
Bio 121
Female:
Ovaries
Fallopian tubes
Uterus
Cervix
Ovaries – where eggs are made by meiosis
Fallopian tubes – carry egg to uterus
Uterus – will support & nourish developing embryo
Cervix – Supports fetus
Bio 121
What are testes made out of?
Seminiferous tubules
Bio 121
Why are the testes outside of the body cavity?
Colder temp. is better for sperm production
Bio 121
What 3 glands contribute to the fluid part of semen?
Bulbourethral gland, prostate, & seminal vesicle
Bio 121
How many primary follicles are females born with & what stage of meiosis are they frozen in?
400 000 are stalled in prophase 1
Bio 121
Prostate Gland
Seminal Vesicles
Bulbourethral Glands
Produces a whitish fluid that nourishes the sperm (Lots of Zinc to protect DNA in sperm)
Produces a yellowish fluid that protects the sperm from the acidic conditions of the vagina Also lots of fructose to provide sperm with energy
Produce a fluid that makes it easier for sperm to swim
Bio 121
What happens during menopause?
In mid - forties, estrogen levels drop and menstrual cycle stops.
Bio 121
What ar e the 4 phases of the menstrual cycle?
Follicular, Ovulation, Luteal, Menstrual
Bio 121
FOLLICULAR PHASE
Low estrogen levels cause Hypothalamus to release GnRH
GnRH causes Pituitary to release LH & FSH
LH & FSH cause several follicles (~20) to start maturing (only one will fully mature & be released at ovulation)
Follicle – A primary Oocyte + surrounding cells called Granulosa cells & Theca Cells
LH causes Theca cells to secrete Androgens
Granulosa Cells of developing primary follicle turn Androgens into Estrogen
Estrogen causes lining of uterus to thicken (in case it needs to support embryo)
Bio 121
OVULATION
(About 14 days after start of Menstration)
Low levels of estrogen inhibit pituitary from releasing FSH & LH
At a certain point, however, HIGH levels of estrogen cause pituitary to release high levels of LH & FSH (Mostly LH)
A surge in LH causes the selected primary follicle to rupture and it is released into the nearby fallopian tube
Bio 121
LUTEAL PHASE
Leftover cells of follicle (Corpus Luteum) keep releasing estrogen & start releasing Progestrone
Progesterone causes blood supply & surrounding tissue to form around the lining of uterus
Progesterone & Estrogen stop pituitary from releasing FSH & LH to prevent other follicles from developing.
1st two days of Luteal Phase are greatest chance for egg to be fertilized
If egg is fertilized, it releases a hormone (HCG) that gets corpus luteum to continue releasing progestrone & estrogen
Bio 121
What kind of cells are found in a follicle?
The Primary Oocyte is surrounded by Granulosa cells which are surrounded by Theca Cells
Bio 121
What is the Corpus Luteum & what hormones does it release & when does it release these hormones.
After the ovum (egg) is released the granulosa cells and theca cells remain in the ovary become the corpous luteum which releases estrogen & progesterone
Bio 121
What hormone does the hypothalamus in females respond to & what hormone does it release?
GnRH is released when low levels of estrogen
Bio 121
What hormones c ause the lining of the uterus to thicken & where do these hormones come from?
Progesterone & Estrogen come from the corpous luteum.
Bio 121
Where does the hormone come from the causes the corpus luteum to stick around if there is fertilization?
The embryo
Bio 121
How many days does the menstrual cycle last?
28 Days
Bio 121
When does ovulation occur?
Day 14
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When can fertilization occur?
First 2 days after ovulation during the luteal phase
Bio 121
Where does fertilization occur?
Fallopian tubes
Bio 121
What causes menstruation to occur?
Drop in Progesterone & Estrogen when corpus luteum dissolves
Bio 121
On average, how long does menstruation last?
4 - 7 days
Bio 121
HORMONAL CONTROL OF MALE REPRODUCTIVE SYSTEM
HYPOTHALAMUS
Releases GnRH (when there’s low levels of testosterone) Stops releasing GnRH with high levels of testosterone
Bio 121
ANTERIOR PITUITARY
Releases LH & FSH (when it receives GnRH from Hypothalamus) GnRH causes A. Pituitary to secrete LH & FSH LH causes cells surrounding seminiferous tubules (Ledig Cells) to secrete testosterone Testoste rone & FSH cause cells inside se miniferous tubules to make sperm When sperm are made Inhibin is released Inhibin & Testosterone STOP the hypothalamus from releasing GnRH
Bio 121
Cells called _ _ nourish sperm cells as they develop
Sertoli Cells
Bio 121
Where does testosterone come from in males?
Interstitial Cells
Bio 121
Where does Inhibin come from & when is it released?
Seminiferous Tubules during sperm production
Bio 121
Wh at 2 hormones shut down spermatogenesis?
Inhibin & Testosterone
Bio 121
What 2 structures respond to Inhibin & how do these structures respond to this hormone?
Anterior Pituitary & Hypothalamus reduce the their secretions of GnRH, FSH, and LH
Bio 121
What’s a zygote?
A fertilized egg cell
Bio 121
Why can only 1 sperm fertilize an egg?
Granules in outer layer of egg cell are released & their contents create a protective coating around the egg.
