Gametogenesis Flashcards
Theca interna secretes what which is converted into what?
Androstenedione–> estrogen
Theca externa form what part of the ovary?
Stroma
Where is the embryo formed?
Epiblast
Immature ova (eggs) are called?
Oogonia
What hormone stops oocyte maturation?
Oocyte Maturation Inhibitor
Secreted by follicular cells
3 Steps of Follicular Maturation
1) Primordial Follicle
2) Primary follicle
3) Secondary/Antral Follicle
What are the two layers of the secondary follicle?
Theca interna– secrete steroids
Theca externa–form a fibrous coat
What are the names and functions of the two granulosa cells?
1) Cumulus oophorus which attaches oocyte to the antral follicle wall
2) Corona radiata which surrounds the oocyte and will be ovulated with it and the zona pellucida.
In what stage of follicular maturation does the zona pellucida occur?
Primary Follicle Stage
When does the first meiotic division take place and what phase does it arrest in?
When does it resume?
12th fetal week
Prophase I
Resuems at puberty
When does the second meiotic division take place and what phase does it arrest in?
Begins at ovulation
Arrests in Metaphse II
What cells are left with the oocyte once fertilization occurs?
Zona pellucida and corona radiata
What is the Graafian (tertiary) follicle?
The follicle that immediately precedes ovulation. It bulges out of the surface of the ovary.
What do you call the finger-like projections of the uterine tube that move the secondary oocyte toward the uterus for fertilization?
Fimbriae
What is the name of the uterine tube contractions and ciliary action of the cells in mucous to move it toward the uterus?
Peristalsis
Fertilization typically occurs where?
Ampulla of the uterine tube
Ruptured follicles become what?
Corpus luteum
An endocrine structure that secretes steroids
What do you call the process of pushing the egg through the wall to get released?
Stigma
Spermatogonia are divided into spermatocytes via?
Mitosis
Secondary spermatocytes are formed via?
Meiosis
What are the 3 types of spermatogonia?
Type A (dark)--reserve stem cells Type A (pale) renew stem cells Type B differentiation progenitors--become spermatocytes.
What cells help nourish spermatocytes and are factories for testosteorne?
Leydig Cells
Spermatogenesis
1) Spermatagonium
2) Spermatagonia
3) Primary Spermatocytes
4) Secondary Spermatocytes
5) Spermatid
6) Spermatozoa
What is capacitacion?
Interaction between sperm and mucosa uterine tube
Removes acrosomal cap and sperm become fertile
What layer of the ovum must the sperm pass through to fertilize egg?
Corona radiata
What is the last layer of the ovum that the sperm must pass through? (The spermatozoa release an enzyme)
Zona pellucida
As sperm heads fuse with oocyte plasma membrane, a calcium wave spreads quickly which is called?
Cortical reaction
The oocyte releases cortical granules which make what layer impenetrable and what is the name of this process?
Zona pellucida
Zona reaction
