reproduction

Question 1

adult testis are composed of 2 things?

Answer 1

coiled seminiferous tubules with epithilial sertoli cells and stages of spermatogenesis
AND interstitial space between tubules with leydig cells

Question 2

leydig cells produce what?

Answer 2

androgen / testosterone

Question 3

sertoli cells have what to form a barrier restricting passage of the substances in blood and lymph

Answer 3

intercellular tight junctions

Question 4

tight juctions provide what?

Answer 4

blood testis barrier

Question 5

where are tight junctions found?

Answer 5

interstitial area and basal region of tubules

Question 6

what can the tight junctions do?

Answer 6

they can open up allowing spermatogoniums to go through

Question 7

germ cells remain —(daughter cells stay together)— all the all the way to the release of spermatozoon

Answer 7

syncytial

Question 8

3 stages of spermatogenesis

Answer 8

• mitotic proliferation
• meiosis
• spermiogenesis

Question 9

mitotic proliferation, where does it occur,

what does it produce and by what process?

Answer 9

occurs in the basal compartment of tubules
producing primary spermatocytes from spermatogonia
by repeated syncytial cell division

Question 10

meiosis, what happens and where do they migrate and by what?

Answer 10

primary spermatocytes replicate DNA
migrate across sertoli cell junctions
by transiently opening then, to reach lumen of tubules

Question 11

meiosis, what do spermatocytes (X X) undergo, then what happens to them

Answer 11

crossing over between homologues chromosome segments
then meiosis 1 forming secondary spermatocytes (X)
which then divides again in meiosis 2 to form round spermatids (I)

Question 12

spermiogenesis

Answer 12

cytoplasmic remodelling to form spermatozoa

Question 13

Cytoplasmic remodeling, acrosome

Answer 13

formed by golgi comprises a vesicle of hydrolytic enzymes to digest surface of egg

Question 14

Cytoplasmic remodeling, nucleus

Answer 14

contains remodeled chromatin in compact packaged form.

Question 15

Cytoplasmic remodeling, midpiece

Answer 15

generated by fusion of mitochondria as a compact power station

Question 16

what happens to the superflurous cytoplasm

Answer 16

it is left behind upon release of spermatozoon as residual body
this is phagocytosed by sertoli cells

Question 17

what does androgen and testosterone go

Answer 17

they enter the lympth
blood
and seminiferous tubules

Question 18

sertoli cells convert testosterone to

Answer 18

dihydrotestosterone (more active)

Question 19

what does androgen do

Answer 19

stimulates rate of spermatogenesis in testies

Question 20

how is androgen stimulated

Answer 20

pituitary gland releases LH which binds to LH receptors on leydig cells

Question 21

pituitary gland releasing FSH does what

Answer 21

also stimulates androgen

Question 22

where are the oocytes released into

Answer 22

the ampulla of fallopian tube

Question 23

what do primordial follicles grow to form

Answer 23

preantral follicles with enlarge oocyte containing germinal vesicle and outer coat

Question 24

what do the zona pellucida and granulosa cells do

Answer 24

they proliferate into multiple layers with outer theca

Question 25

preantral follicles form

Answer 25

antral follicles containing folliclular fluid secreted by granulosa cells

Question 26

oocytes are associated to granulosa cells by

Answer 26

cumulus oophorus linked by stalk of cells to peripheral granulosa cells

Question 27

follicular fluid divides the granulosa cells

Answer 27

by associating the cumulus oophorus and other granulosa cells

Question 28

what hormone stimulates primordial - preantral follicle formation

Answer 28

not known

Question 29

what hormone stimulates preantral to antral follicle formation

Answer 29

Gonadotrophin control

Question 30

Gonadotrophin control, what happens | what on what receptors

Answer 30

LH and FSH from pituitary stimulate antral follicle development lh receptors on theca fsh receptors on granulosa cells

Question 31

what does lh stimulate

Answer 31

thecal cells stimulating androgen formation

Question 32

fsh stimulates what

Answer 32

granulosa cells inducing their capacity to convert thecal androgen into oestrogen

Question 33

what does oestrogen stimulate

Answer 33

granulosa cells proliferation via oestrogen receptors

Question 34

what is the positive feed back mechanism with oestrogen

Answer 34

oestrogen stimulates granulosa cells to produce more oestrogen

Question 35

combination of oestrogen surge and fsh induces

Answer 35

expression of LH receptor on the outer granulosa cells as well as on the theca cells

Question 36

what else does the oestrogen surge cause

Answer 36

a LH surge from the pituitary

Question 37

expanded antral follicle with LH receptors on both theca and granulosa cells can do what

Answer 37

receive LH surge to receive preovulatory growth phase

Question 38

if there is not LH surge the follicles

Answer 38

die

Question 39

peovulatory growth, LH surge causes

Answer 39

oocyte maturation, resumes meiosis 1 division to secondary oocyte and polar body arrested at metaphase at meiosis 2

Question 40

peovulatory growth, what does the oocyte cytoplasm produce

Answer 40

cortical granules containing enzymes required for fertilisation

Question 41

peovulatory growth, oocyte response to LH are

Answer 41

mediated indirectly through granulosa cell signals which have a LH receptor

Question 42

peovulatory growth, follicle cells increase what

Answer 42

they increase substantially the secretion of follicular fluid

Question 43

peovulatory growth, in the thecal periphery of follicle expansion is accompanied by

Answer 43

loosening of matrix

Question 44

peovulatory growth, outer granulosa cells no longer

Answer 44

convert androgens to oestrogen but instead they synthesis progesterone and become insensitive to oestrogen and FSH

Question 45

peovulatory growth, ovulation occurs from what

Answer 45

due to follicular fluid pressure

Question 46

peovulatory growth, cumulus mass with oocyte accumulate in ampulla of oviduct

Answer 46

this is where fretilisation occurs

Question 47

after ovulation what happens to the follicles

Answer 47

they are converted into corpus luteum, with granulosa cells growing into large lutein cells

Question 48

corpus luteums secrete what

Answer 48

progesterone requires to maintain pregnancy

Question 49

after 2 weeks what happens to the corpus luteum

Answer 49

luteolysis occurs (cell death of corpus luteum) caused by prostaglandin secretionfrom the uterus

Question 50

control of follicle maturation and ovulation, regulated by FSH stimulation

Answer 50

can increase the number of follicles recruited for maturation

Question 51

in humans what happens to one follicle | what regulates it

Answer 51

it becomes the dominant follicle which completes pre ovulation growth and can ovulate in response to LH surge this may be controlled by cytokines and insulin like growth factors.

Question 52

ovarian cycle

Answer 52

interval between successive ovulation, comprising follicular and luteal phase, separated by ovulation itself