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Flashcards in Spermatogenesis and oogenesis Deck (45):
0

Definition of spermatogenesis

Is the process by which the seminferous tubule of the testes produce haploid sperm.
Begins at puberty
Takes 65-75 days

1

How many chromosomes does Primary spermatocyte has

46 (2n)

2

How many chromosomes does secondary spermatocyte has

23 (n), haploid

3

how many chromosome a spermatid has

23 (n) haploid

4

How many chromosomes a spermatogonium has

46 (2n) Diploid.

5

What differentiates into spermatogonium

Primordial germ cell

6

When and where Primordial germ cell migrate from yolk sac?

To testes at 5 th week of fetal development

7

When spermatogonium wakes up?

Puberty

8

Process of spermiogenesis

-Spherical spermids transform into elongated, slender sperm
- Sertoli cells dispose of excess cytoplasm
- sperm are released from the Sertoli cells, a process known as spermiation
sperm (not able to swim yet) are released into the lumen of the semiferous tubles and are pushed through the tubules by fluid produced by Sertoli cells

9

What is called when sperm are released from the Sertoli cells

Spermiation

10

What does the head of sperm contain

Acrosome

11

What is in Acrosome

Enzyme (hyalurondinase and proteases) that help the sperm penetrate the 2nd oocyte

12

What does the tail of sperm contain

Flagellum used for locomotion
Mitochondria that form ATP for locomotion

13

how many sperm are produced a day and how long can it live after being ejaculated?

300 million per day, once ejaculated, 48 hours within the female reproductive tract

14

what is the secondary male sex characteristics

Sexual behavior and libido
Male metabolism (bone and muscle mass heavier)
Deepening of the voice

15

Definition of oogenesis

formation of gametes on the ovaries
Begins in females BEFORE birth

16

What migrate from yolk sac to ovaries

Primordial germ cells

17

What primordial germ cells differentiate

into oogonia/oogonium (singular) (Diploid 2n)
produce millions of germ cells mitotically
most degenerate by Atresia before birth

18

What is the degenerating process of primary oocyte and germ cells

Atresia
At birth 200,000-2,000,000 primary oocytes in each ovary,
at puberty 40,000
mature and ovulate 400

19

What is surrounding single layer of follicular cells

Primordial follicles

20

what surrounds primordial follicle and what does it contain

Ovarian cortex and contains collagen and fibres and stromal cells (fibroblast - like)

21

what does Sertoli cell sdo

Form blood testis barrier
support developing sperm cells
produce fluid and control release of sperm into lumen
Secrete inhibin which slows sperm production by inhibiting FSH

22

what leydig cells secrete

testosterone in between tubles

23

sequence of spermatogenesis

Primordial germ cells -> spermatogonia - (mitosis) -> primary spermatocytes -(meiosis I) at puberty -> secondary spermatocytes -(meiosis II) -> spermatids - (Spermiogenesis) -> Sperm (spermatozoon)

24

Gonadotropin releasing hormone stimulate what to secrete what

Anterior pituitary gland to secretion follicle-stimulating hormone (FSH) and Luteinizing hormone (LH)

25

What does Luteinizing hormone do

Assists permatogenesis and stimulates leydig cells to production of testosterone

26

What does Follicle stimulating hormone do

with testosterone, stimulates Sertoli cell to secrete Androgen binding protein to keep hormones level high for spermatogenesis

27

Which hormone stimulates final steps of spermatogenesis

Testosterone

28

Testosterone is produced by

Leydig cells
Too much testosterone will inhibit LH to self regulate

29

Inhibin is secreted by

Sustentacular (Sertoli) cell
Inhibit FSH

30

Reproductive system ducts in Testes

Seminiferous tubules - > straight tubules -> rete testis -> efferent ducts -> ductus epididymis

31

Histology of a Graafian Follicle
What is clear area between oocyte and granulosa cells

Zona pellucida

32

What is granulosa cells attached to zona pellucida

Corona radiata

33

Formed by granulosa cells secreting follicular fluid

Antrum

34

What stage oocyte has reached before secondary oocyte

Metaphase of meiosis II and stops

35

what Theca interna cells secrete

estrogen

36

What is the theca externa

Outer layer of stromal cells and collagen fibers

37

What does FSH in female initiate

Growth of follicles

38

What secretes estrogen

Follicles

39

What does Luteinizing hormone in female initiate

Ovulation and promotes formation of the corpus luteum

40

What does corpus luteum secrete

Estrogen, progesterone, relaxin and inhibin

41

What does Estrogen do

Promote development and maintenance of female reproductive structures, female secondary sex characteristics and breasts
Increase protein anabolism
Lower blood cholesterol
Moderate levels inhibit release of GnRH, FSH and LH (Follicular phase)
High level will promote GnRH and LH to trigger ovulation (Luteal phase)

42

What does Progesterone do

Works with estrogens to prepare endometrium for implantation
prepares mammary glands to secrete milk
Inhibits release of GnRH and LH

43

What does relaxin do

Inhibits contractions of uterine smooth muscles
During labor, increases flexibility of pubic symphysis and dilates uterine cervix

44

What does inhibin do

Inhibits release of FSH and to a lesser extent LH