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Flashcards in Ovary And Testis Deck (30):
1

Where does oogenesis begin

In utero
Mitosis division of oogonia

2

At what stage does the oogonia arrest

Prophase where suspended for many years and begins again prior to ovulation
Completed at fertilisation

3

What is the first polar body

One of two products in the first stage of meiosis
Both relatively small and little cytoplasm

4

What does the presence of two polar bodies signify

Spermatogenesis entry and the completion of second meiotic division

5

How long does the average menstrual cycle last

28 days

6

How many stages are in the menstrual cycle and what are they

2 stages
Follicular phase
Lateral phase

7

What roughly happens in the follicular phase

Maturation of the egg
Ready for ovulation at mid cycle
Occupation signals end of follicular phase

8

What roughly happens in the literal phase

Development of the corpus luteum
Induces prep of reproductive tract for pregnancy if fertilisation occurs

9

What is a corpus luteum

A hormone secreting structure that develops in an ovary
after an ovum has been discharged after a few days unless pregnancy has begun

Secretes volumes of progesterone and oestrogens making uterus more favourable for implantation

10

What is GnRH and where is it produced and what does it do

Gonadotropin releasing hormone
Syn by neurones in hypothalamus
Pulsatile release

Stim FSH and LH syn/release form ant pit

11

What is FSH, where is it produced and what does it do

Follicle stim hormone
Secreted by ant pit
Stimulates follicular development
Thickens endometrium

12

What is LH, where is it produced and what does it do

Luteinising homone
Sec by ant pit
Peak stim at ovulation
Stimulates corpus luteum development
Thickend endometrium

13

Where is oestrogen primarily sec form

Ovaries
Adrenal cortex
Placenta when pregnant

14

What does oestrogen do

Thicken endometrium

Prod fertile cervical mucus

Mature ovarian follicles

Responsible for secondary sexual characteristics

Accelerate sodium and water reabs by kidney tubules

15

What does a high or low level of oestrogen do

High - inhibits sec of FSH and prolactin stimulates LH

Low - after pregnancy, stimulates secretion of prolactin

16

What sec progesterone

Corpus luteum and placenta when pregnant

17

What does progesterone do

Inhibit LH sec

Thermogenin effect

Relaxes smooth muscle

Infertile mucus

Maintain thickness of endometrium

Maintain pregnancy

18

What is the follicular phase in full

Follicular development stimulated --> follicle makes follicular fluid which has estrogen --> thicken endometrium --> increase of estrogen inhib FSH and increase LH --> LH stimulates ovulation and initiates development of corpus luteum

19

What is the luteal phase in full

Follows ovulation --> ruptured follicle cavity is replaced by corpus luteum( sec or gesturing and estrogen) --> progesterone stim changes in endometrium for impnatation during early phase of pregnancy --> if fertilisation doesn't happen curious luteum regress and prod progesterone and estrogen decreases

20

What is the menstrual phase in full

Corpus luteum regresses
Progesterone and estrogen decreases
Endometrium degenerates and menstraujtion occurs
Drop of estrogen in blood and progesterone causes a stim production of FSH which starts cycle again

21

What is the LH surge

Oocyte resumes meiosis
Secondary oocyte + polar body (degenerates)
Stops at metaphase II only co,pelted if fertilised
Cytoplasmic maturation
LH receptors stimulated to synthesise orgiesteorne
Collapsed follicle becomes corpus luteum

22

What colour is lutein

Yellow/orange carotenoid pigment

23

What is the route of sperm

Testes --> epididymis --> vas deferens --> ejaculatory duct --> urethra

24

Where does spermatogenesis occur and when

Within seminiferous tubules of testes
Germ cell mitosis re activated at puberty
Constant

25

What hormones control the testes

LH --> acts on leydig cells - reg testosterone sec

FSH --> act of Sertoli cells to enhance spermatogenesis essential for spermatid remodelling

LH and FSH release stimulated by GnRH

26

Where are the Sertoli cells and what do they secrete

In the seminiferous tubule
Sec androgen binding globulin and inhibin

27

What are some adverse effects on human spermatogenesis

Heat
Alcohol
Smoking
Chemo/radiotherapy
Vasectomy

28

What are the two major differences between oogenesis and spermatogenesis

- oogenesis prod one ovum, spermatogenesis prod millions of sperm

- once a month p, spermatogenesis constant

29

What does a high level of FSH mean

Loss of ovarian function
Menopause

30

What is the production of eggs and sperm

Eggs - oogenesis

Sperm - spermatogenesis