Reproduction Flashcards
The final germ cells in males and females
spermatozoa and ova
How does dHT affect the development of spermatogenic cells nourished within sertolli cells.
dHT converted from testosterone by sertolli cells enters the nucleus of the sertolli cells and produce RNA products that affect the development of spermatogenic cells
How does the negative feedback work when the testosterone level is too high?
High testosterone level sends a negative feedback to anterior pituitary to reduce LH
How does the negative feedback work when the dHT level is too high?
The sertolli cells produce inhibin and sends a negative feedback to the anterior pituitary to reduce FSH.
In females, what causes the surge in the LH?
What stage is the secondar oocte suspended in?
Primary oocyte undergoing meiosis I.
The secondary oocyte is now suspended in metaphase of meiosis II
Just before the surge of LH what hormone surges?
Estrogen
Estrogen and progesterone produced in combination by the corpus luteum sends what feedback?
It sends a negative feedback to the hypothalamus and the anterior pituitary, reducing both LH and FSH production. This is what we want to happen because we don’t want another primary follicle to develop (another primary oocyte undergoing meiosis I)
Low level of estrogen produced by the follicle cell results in what feedback?
Negative feedback to both the anterior pituitary and the hypothalamus
High level of estrogen produced by the follicle cell results in what feedback and on where?
Positive feedback to anterior pituitary to release more LH and positive feedback to the hypothalamus to release for GnRH
Inhibin produces what kind of feedback on what, and where?
Produces a negative feedback and signals the anterior pituitary to stop producing FSH
What is the membrane for the ovum?
zona pellucida
What is CG and what’s its function?
Production of estrogen and progesterone by the corpus luteum to: 1) Prevent another primary follicle to develop (low LH and FSH produced by anterior pituitary) and 2( keep up the endometrium lining and 3) stimulate mammary glands.
In an unfertilized egg, what are the two poles, where are they located and what are their characteristics?
Animal and vegetal poles. Animal pole is on top of the vegetable Pole. And the vegetal pole has lots of yolk.
What structure forms on the opposite side of the egg where sperm penetrates and what does this become in the future animal?
Grey crescent; The grey crescent becomes the dorsal back of the animal
Function of sertolli cells
Spermatogenesis Inhibin if the dHT level is too high
How many cells does a morula have?
16
Where does the blastopore develop? What happens to it during gastrulation? In deuterosomes, what does the blastopore become?
Near the grey crescent. During gastrulation, dorsal lip develops and starts the invagination. In deuterosomes, the blastopore develops into an anus.
http://www.nature.com/nrg/journal/v1/n3/images/nrg1200-171a-f1.jpg
Developmental fates of endoderm, mesoderm, and ectoderm
Ectoderm: skin, brain, nervous eyes, lenses of the eyes Mesoderm: notochord, heart, muscle, skeleton, outer covering of the internal organs and the reproductive organs. Endoderm: inner linings of the digestive tract and the respiratory tract, and major glands of the body like liver and pancreas
What induces formation of neural plate?
notochord
What develops into a notochord?
doral lip of the blastopore
what is the chorion and chorionic villi?
projections of the fetal/umbilical blood vessels and the chorion covers the chorionic villi. The chorion preserves the barrier between the maternal and fetal blood
What is a primitive streak?
Cells in the primitive streak migrate down between the ectoderm and endoderm to become mesoderm. Further folding of the primitive streak gives rise to a neural groove and then a neural tube.
During the early part of pregnancy, what releases the CG hormone?
trophoblastic cells. CG causes the corpus lutem to continue to produce estrogen and progesterone.
What causes contractions?
A crucial rate of progesterone concentration to the estrogen concentration when the estrogen concentration far exceeds the progesterone concentration.
