endocrinology - male and female reproductive system

Question 1

Main difference between male germ cells and females?

Answer 1

Males gametogensis begins at puberty and differtiate through out life as pool avaliable for subsequent spermatogenic cycles

Females before before have 1 ‘o’ oocytes within ovarian follicles halted in meiosis prophase

every month released

Question 2

Steps of spermatogenesis (gametogenesis)?

Answer 2

Question 3

Where exactly are sperm produced? (Which tubule)

Answer 3

Seminfierou tubules

Question 4

histology of seminiferous? And function of each hormone?

Answer 4

As cells go to centre, mitosis + meosis until sperm in centre

tunica propia - outer layer

spernatgonium - germ cell

sertoli - help with hormones to make sperm

leydig cell - secrete hormones androgens

Question 5

Specific function of sertoli cells

Answer 5

FSH receptors

Function: support develop germ cell with movement and nutrients from cap to cells

also hormone synthesis: activin/ inhbin (for FSH)

AMH stop develop uterus

androgen binding protien - help testosterone (binds to it) go to right place

Question 6

specific function of Leydig cells?

Answer 6

LH receptors

hormone synthesis: on stimulation of LH produce

tesosterone (oestrogens)

Androstenedione DehydroEpiAndrosterone (DHEA)

(can be aromatised to oestrogens)

Question 7

Female oogenesis stage and timings?

Answer 7

Oogonia develop into primary oocytes, forming primordial follices, during the 2nd trimester of pregnancy of mother

Menarche refers to the beginning of the menstrual cycle in women

Polar body degenerates and eventually does nothing

Question 8

Folliclegenesis in ovaries? FOLLICULAR PHASE and then LUTEAL PHASE

Name each stage + describtion?

Answer 8

1. Primordial follicle (1 ‘0’ Oocyte at birth)

from birth to puberty cells goes from primordial to primary

2. Primary (=Preantral) follicle

1’0’ Oocyte and layers of granulosa (inside) cells and outer theca cells

3. Secondary (=Antral) follicle

Fluid-filled cavity (antrum) develops

FSH and LH receptors

4. Mature (=Graafian/Preovulatory) follicle DOMINANT ONE

Forms due to LH surge

2’ 0’ Oocyte formed

5. Ruptures surface of ovary

6-7. Corpus Luteum

Progesterone & oestrogen (stim by LH)

In pregnancy, progesterone & oestrogen production taken over by placenta

Question 9

Function of Theca Cells?

Answer 9

outer part of ovarian follicles

• support of folliculogenesis by structural and nurional support of growing follcile
• hormone syntheisis LH stimulate synthesis androgens ( testosterone)

Question 10

Function of granulosa Cells?

Answer 10

inner

function: - hormone synthesis, FSH stimulate cells to convert androgens to oestrogens by aromatase.

secretes actin and inhbin (FSH)

after ovulation

turns into lutein cells. Produce progesterone (-ve feedback, promote preg by maint endometrium)

relaxin (helps endometirum prepare for preganancy and soften cervix)

Question 11

What is the hypo thalamic - pit - gondal axis?

Answer 11

kesspeptin at top stimute GnRH releasing neurones

Question 12

Effect of Prolactin on Axis?

Answer 12

ikiss peptin nhbited by prolactin, binds to prolactin receptors on kisspeptin neurones on hypo.

less tesosterone/ostrogen/progesterone ,etc.

lead to amenorrhoea AND osteoprosis as bones need oestrogen

Question 13

Whhy does menstrual cycle has the cycle known?

Answer 13

At beg FSH and LH produced stimulate oestrogen but -ve feedback keeps in check

FSH kept in check/ slightly decreases so only follicle survives/stimulated + becomes dominant.

follicle release more ostrogen, changes to +ve feedback more FSH and LH highly increase causes allows follcile to develop (complete meiosis) and ovulation

LH then drops and leatal produce progesterone

Question 14

compare ovarian cycle (of follicles) and uterine (of endometrial) cycle?

Answer 14

both driven by hormonal changes

Question 15

Does temperature changes after ovulation?

Answer 15

Yes, increase due to progesterone

Question 16

When is HCG produced?

Answer 16

Only produced by placenta, used in pregancy test

Question 17

Which parts of male reproductive system produce seminal fluid?

Answer 17

Mainly acessory sex glands : seminal vesicless, prostate , bulbourethral glands

also small contribution from: epidymis/testis

Question 18

What does semen contain?

Answer 18

speromotza, seminal fluid, leucotyes and poritentially virus

Question 19

capictation of sperm where does it occur? (becoming able to fertilse

and what does it need?

Answer 19

in fallopian tube.

oestrogen and Ca2+ dependent

Question 20

What happens in capacitation of sperm?

Answer 20

loss of glycoprotien coat

change in surface membrane characteristics

development of whiplash movement of tail

Question 21

Describe stages of acrosome rxn

Answer 21

sperm binds to zp3, sperm receptor on zona pellicuda

Ca2+ influx into sperm (stimualted by progesterone)

causes for hyaluronidase and proteoyltic enz released from acrosome

allows sperm to penetrate zona pellicuda

Question 22

Describe corical rxn and effects

Answer 22

fertilisation, entry of sperm into egg trigger cortical rxn,

cortical granules release contents degrade zona pellicuda due ZP2 and ZP3

prevent further sperm binding no receptors

and pronucleus join for diploid

Question 23

What happens after fertilization?

Answer 23

moves down to uterus 3 days

recieves secretionsf rom uterine secretions

free living phase for 10 days before implantations

Question 24

Stages of implantation?

Answer 24

attachment phase: outer trophoblast cells become in contact with surface epthileum

then

decidualisation phase: changes in underlying uterine stromal tissue

REQUIRES prog >>>>>> oesto

Question 25

How do the lining and blastocyst interact to allow for adhesion?

Answer 25

ATTACHMENT PHASE

Question 26

What factors are release that allow for ahesion and what do they do?

Answer 26

Leukaemia inhibtory factor - from endometrial cells stimulate adhesion of blastocyst to endometrial cells

IL11 - from endometrial cells is released intro uterine fluid

Question 27

What happens in decidualisation phase?

Answer 27

AFTER AHDESION

Endometrial changes due to progesterone

Glandular epithelial secretion Glycogen accumulation in stromal cell cytoplasm

Growth of capillaries

Increased vascular permeability (→oedema)

Factors involved:

Interleukin-11 (IL11), histamine, certain prostaglandins & TGFb (TGFb promotes angiogenesis)

Question 28

What hormonal changes happen after pregnancy?

Answer 28

Production of hCG produced by trophoblasts

hCG stimulate corpus luteum by LH receptors to ‘keeping making’ produce progesterone and oestrogen

inhibit LH and FSH (-ve feedback) as no need

without hCG corpus shrivel and prog/oest levels fall + cause endometrial wall to fall off + period

After 40 days

placenta takes over

Question 29

How does placenta produce progesterone and oestrogen?

Answer 29

that placenta oesto and prog

from maternal and fetal DHEAs and pregenolone( for progesterone)

Question 30

Changes in other maternal hormones during pregnancy?

Answer 30

Increase

ACTH, Adrenal steroids, Prolactin , IGF1 (stimulated by placental GH-variant) , Iodothyronines , PTH related peptides

Decrease: Gonadotrophins, Pituitary GH, TSH

Question 32

Which endocrine hormones control partruiton? i.e labour

Answer 32

oxytocin act on myometrial and endometrial

aided by oestrogen and progesteron

uterine contraction, cervical dilation , milk ejection

Question 33

which endocrine control lactation?

Answer 33

oxytocin - ejection

prolactin - prolactin

golacteria - due to prolactin not oxytocin