Gametogenesis Flashcards
1
Q
follicle (3)
A
- born with certain amount
- package that contains oocyte
- enables ovary to fulfill dual function
2
Q
folliculogenesis (2)
A
- formation of Graafian follicle
- primary follicle development to mature follicle
3
Q
follicle turnover
A
- frequent emergence of new follicles, following by follicle atresia
4
Q
ovulation
A
- release of oocyte from Graafian follicle
5
Q
follicles development and ovulation (2)
A
- always start with cohort of follicles, with one follicle fully developing and going into ovulation
- 90-95% of follicles are turned over every cycle
6
Q
events during follicle growth (7)
A
- recruitment of follicles
- selection of dominant follicle and atresia of remaining
- nuclear maturation of oocyte
- cytoplasmic maturation of oocyte
- steroid synthesis
- stigma formation
- release of egg
7
Q
- recruitment of follicles (4))
A
- beginning of estrous cycle
- preantral follicles are not hormonal dependent
- cohort of follicles selected in both ovaries
- theca interna and granulosa cells develop FSH receptors and become FSH dependent
8
Q
- selection of dominant follicle (3)
A
- development of LH receptors in granulosa cells
- atresia of remaining follicles
- steroidogenesis; production of estradiol
9
Q
- nuclear maturation of oocyte (2)
A
- meiotic arrent in prophase I until LH surge (ovulation)
- meiotic resumption after ovulation through metaphase I and arrent at metaphase II
10
Q
- cytoplasmic maturation of oocyte
A
- accumulation of mRNA, proteins, substrates, and nutrients required to achieve oocyte and embryonic development
11
Q
polar bodies (2)
A
- primary oocyte splits into 2 cell to form one secondary oocyte and one polar body
- secondary oocyte splits into two cells to form one mature ovum and one polar body
12
Q
polar body purpose
A
- done to conserve cytoplasm into 1 cell
13
Q
- steroid synthesis (3)
A
- cholesterol transport to the ovarian follicle
- testosterone synthesis by theca interna (androstenedione to testosterone) controlled by LH
- estradiol synthesis by granulosa cells (testosterone to estradiol) by aromatase
14
Q
- stigma formation (3)
A
- apical wall becomes thin
- avascular
- rupture of follicle at ovulation
15
Q
- release of egg or ovum (3)
A
- loosening of cumulus-oophorus complex
- prostaglandin role of contracting theca externa
- expulsion and pick up by oviduct
16
Q
follicular fluid
A
- peripheral plasma by transudation across the follicle membrane from mother
17
Q
follicular fluid: general biochemical composition (2)
A
- steroids and glycoproteins secreted by cells of follicle wall and serum exudate
- enzymes, prostaglandins, and gonadotropins
18
Q
follicular fluid: specific components (4)
A
- estradiol
- progesterone
- androstenedione
- oocyte maturation inhibitor and inhibin that keep oocyte in desirable state for certain processes
19
Q
follicular fluid functions (6)
A
- regulation of granulosa cells functions
- initiation of follicular growth, oocyte maturation, ovulation, and egg transport to oviduct
- steroidogenesis
- preparation of corpus luteum
- regulation of follicular cycle
- sperm metabolism, capacitation, and early embryonic development
20
Q
what major changes does the pre-ovulatory follicle undergo (3)
A
- cytoplasmic and nuclear maturation of the oocyte; resumption of meiosis and accumulation of things important to early embryonic development
- disruption of cumulus cell cohesiveness among cells of granulosa layer
- thinning and rupture of external follicular wall
21
Q
site of ovulation
A
- anywhere in the ovary except the hilus (medulla portion)
22
Q
neuroendocrine and biochemical mechanism of ovulation (4)
A
- GnRH and LH surge
- transient progesterone increase
- collagenase loosens cells and thins wall while aromatase inhibition causes estradiol levels to decrease
- synthesis of prostaglandin
23
Q
neuroendocrine and biochemical mechanism of ovulation: PG synthesis (2)
A
- stimulates neuromuscular thecal system
- stimulates remodeling of follicle layers
24
Q
spermatogenesis structures (4)
A
- seminiferous tubules; major structural unit
- sertoli cell; major support cell
- spermatogonium; primary diploid cell (2n)
- leydig cell; steroidogenesis, testosterone production
25
Q
spermatogenesis result
A
- continuous release of haploid (n) cells; spermatozoa
26
Q
semen (2)
A
- liquid cellular suspension
- spermatozoa + accessory glands fluid
27
Q
regulation of seminiferous tubules (3)
A
- leydig cells produce testosterone
- testosterone travels to blood vessels and into seminiferous tubule
- sertoli cells in seminifeorus tubule are affected by testosterone
28
Q
spermatozoa mitotic and meiotic divisions (6)
A
- spermatogonium (2n) undergo mitosis
- spermatogonia (2n) undergo cell growth
- primary spermatocyte (2n) undergo meiosis 1
- two secondary spermatocytes (n) undergo meiosis 2
- four spermatids (n) undergo cell differentiation
- spermatozoa (n)
29
Q
spermatozoa (3)
A
- final male gamete
- haploid (n) cells
- free to go into lumen of seminiferous tubule and go along male pathway
30
Q
spermatozoa components (2)
A
- head
- tail
31
Q
spermatozoa head (4)
A
- protamines condense DNA in similar way to histones so transcription cannot occur
- contains nucleus
- contains acrosome (transformed Golgi apparatus)
- hydrolytic enzymes to penetrate zona pellucida
32
Q
spermatozoa tail
- function (1)
- components (5)
A
- motility using 9 + 2 double tubules arrangement
- neck, middle, annulus, principal, end piece
33
Q
organized migration to form spermatozoa (5)
A
- centrioles reconstruct cytoskeleton to make tail
- sucking of cytoplasm into tail
- mitochondria go into neck portion for energy generation
- excess cytoplasm is removed with help from sertoli cells
- nucleus becomes whole head
34
Q
spermatozoa head layers (6)
A
- plasma membrane
- outer acrosomal membrane
- acrosomal contents
- inner acrosomal membrane
- nuclear membrane
- nucleus
35
Q
hormonal control of spermatogenesis
A
- FSH, LH and testosterone have direct control
36
Q
hormonal control of spermatogenesis: sertoli cells (4)
A
- FSH receptors for FSH from anterior pituitary
- testosterone receptors for T from Leydig cells
- secretion of ABP, inhibin, and activin
- aromatase and 5alpha reductase which are needed for spermatogenesis to occur
37
Q
sertoli cells: inhibin function
A
- important for negative feedback with pituitary
38
Q
sertoli cells: aromatase
A
- turns testosterone into estradiol
39
Q
sertoli cells: 5alpha reductase
A
- turns testosterone into dehydrotestosterone (DHT)
40
Q
hormonal control of spermatogenesis: leydig cells (2)
A
- LH receptors
- testosterone synthesis
