Lecture 11: Gametogenesis Flashcards
sperm gametogenesis
spermatogonium–>primary oocyte–>meiosis–>secondary oocyte –> meiosis —> spermatid
oogenesis
primary oocyte
primary oocyte in follicle
primary oocyte in larger follicle
secondary oocyte in larger follicle + polar body
when are mature sperm dormant until
puberty
spermatids to mature sperm called
spermiogenesis
where are sperm stored
epididymis (come from seminiferous tubules)
what happens for sperm to mature
golgi becomes part of acrosome, centrioles go to tail, mitochondria line up around beginning of tail (called thd middle piece)
what does normal spermatogenesis require
the Y chromosome
oogonia
primordial female sex cells
when do oogonia proliferate
fetal life via mitosis
when are primary oocytes formed
before birth (from oogonia)
primary oocytes
surrounded by flattened follicular cells
primordial follicle
primary oocyte enclosed by follicular cells
primary follicle
during puberty, primary oocyte enlarges and follicular cells become columnar. get zona pellucide
where are primary oocytes before puberty arrested (primary follicle)
prophase stage of first meiotic division
whre is the ovulated ovum arrested
metaphase II unless it gets fertilized
what does 1st meiotic division give rise to in oogenesis
secondary oocyte and polar body
gametogenesis timing in female vs male
- embryogenesis and arrests until puberty (female)
- begins at puberty (male)
result of oogenesis vs spermatogenesis
one germ cell is one ovum and 2 polar bodies (female)
one germ cell is 4 mature spermatozoa (men
GRH
released by neurosecretory cells in hypothalamus
FSH
stim follicles, stim production of estrogen by follicular cells
LH
triggers ovulation of secondary oocyte, stimulates follicular cells and corpus luteum
what does corpus luteum secrete
progesterone and estrogen
when does the follicle start pressing on the surface
tertiary stage
corpus luteum arises from
walls of ovarian follicles which develop into gland structure
the primary follicle contains the
zona pellucida
what happens when ovulation occurs
secondary oocyte expelled (surrounded by zona pellucida and corona radiata), resumption of 1st meitoic division
3 phases of menstrual cycle
menstrual, proliferative, and luteal phase
proliferative phase
growth of ovarian follicles, controlled by estrogen, endometrium thickens
luteal phase
formation, functioning, and growth of corpus luteum. Progestterone stim glandular epithelium (glycogen rich!)
how is sperm transported
from epididymis to urethra through peristalsis of vans deference
where does fertilization normally occur
ampullary portion of fallopian tube
capacitation (pre fertilization)
glycoprotein coat and seminal proteins leave acrosome
membrane cholesterol/phospholipid ratios altered
increase in motility
*takes place in uterus or tube and allows acrosome rxn to occur
changes during fertiliztion to sperm
acrosome rxn (acrosome binds to glycoprotein ZP3 on zona pellucida)
fenestrations upon contact w corona radiata
apertures btwn sperm plasma membrane and acrosome
what gets released during acrosome reaction
hyaluronidase and acrosin
phases of fertilization
penetration of corona radiata
penetration of zona pellucida
fusion of PM
zona reaction (no more sperm!)
what happens if fertilization occurs
1) meiosis 2 of oocyte
2) female/male pronuclei form and then fuse
ZYGOTE CREAATED!
