Reproduction 1, 2 and 3

Question 1

What are the layers of the uterus?

Answer 1

Endometrium

Myometrium

Question 2

What is the menstrual cycle?

Answer 2

2 cycles which make reproduction possible

Ovarian and uterine cycle

Question 3

What happens in the ovarian cycle? What happens in the uterine cycle?

Answer 3

Development of follicle

Thickening and shedding of endometrium

Question 4

What is the 1st menstruation called? What is the stopping of menstruation called?

Answer 4

Menarche

Menopause

Question 5

Describe the levels of GnRH prepubertal

Answer 5

Constant low amount

Question 6

When is the follicular phase in a 28 day cycle?

Answer 6

1 day - 2 weeks

Question 7

Describe the follicular phase

Answer 7

Hypothalamus produces GnRH
This stimulates the anterior pituitary to produce FSH and LH
Follicles compete to grow fastest and become dominant
Other follicles die

Question 8

Describe the structure of a follicle

Answer 8

Immature oocyte surrounded by zona pellucida
Granulosa cells around zona pellucida
Surrounded by theca cells

Question 9

What receptors do theca and granulosa cells have?

Answer 9

Theca - LH

Granulosa - FSH

Question 10

Lots of oestrogen causes lots of FSH/LH. What does this cause at the end of the follicular phase?

Answer 10

Follicle ruptures releasing oocyte

Question 11

After ovulation, which hormone remains high?

Answer 11

LH

Question 12

The remain of follicles become what? What cells are found in this?

Answer 12

Corpus luteum

Luteinized theca and granulosa cells

Question 13

What do theca cells produce in the corpus luteum? What does this hormone do?

Answer 13

Progesterone

Inhibit FSH/LH

Question 14

What do granulosa cells in the corpus luteum produce? WHere does this go to? What does it do?

Answer 14

Inhibin

Goes to pituitary gland, stops FSH (and oestrogen) production

Question 15

What is the secretory phase? When does this take place?

Answer 15

After progesterone production
Uterine glands produce more mucous
Spiral arteries grow longer
Corpus luteum becomes corpus albicans 
Menstruation

Question 16

Which hormone do the follicles produce?

Answer 16

Oestrogen

Question 17

What is the function of the ovaries?

Answer 17

Production and release of female gamete

Maintenance of pregnancy

Question 18

Which animals menstruate?

Answer 18

Primates only

Question 19

What is luteinzation?

Answer 19

Formation of corpus luteum from a follicle

Question 20

When are females in oestrus?

Answer 20

When they are sexullay receptive to a male

Question 21

What is a oestrogen? What does it do?

Answer 21

Group of hormones - oestrodiol most common

Drive sexual behaviour

Question 22

What is proestrus phase?

Answer 22

Follicular phase

Not sexually receptive

Question 23

What is dioestrus?

Answer 23

Progesterone dominant phase

Phase with corpus luteum

Question 24

What is anoestrus and what type of problems cause this?

Answer 24

No cyclic ovarian activity

Pathological or physiological

Question 25

Which animals are non-seasonal polyestrus?

Answer 25

Cow Queen Pig Rodents

Question 26

Polyestrus means multiple cycles per year. What differs about the dominant follicles in polyestrus animals?

Answer 26

Can have multiple

Question 27

What animals are seasonal polyestrus?

Answer 27

Horse - long day breeders | Sheep/doe - short day breeders/autumn

Question 28

How long is the horse ovarian cycle

Answer 28

21 days | +- 4

Question 29

What are reflex/induced ovulators? Why is this?

Answer 29

Need to mate to induce ovulation | GnRH doesn’t produce enough LH for ovulation

Question 30

Spontaneous ovulators do not need stimulation. How many times do they ovulate per cycle?

Answer 30

Once

Question 31

Describe the ovarian cycle in a bitch and what type of ovulators they are

Answer 31

Spontaneous monoestrus Very long porestrus Oestrus Dioestrus - 60-70 days

Question 32

How long is proestrus in a bitch? What are symptoms

Answer 32

9 days | Bloody discharge and swollen vulva attracts male

Question 33

How long is a bitch’s oestrus? When is ovulation? What colour is the discharge?

Answer 33

9 days Day 2 Straw coloured

Question 34

Ovulation takes place how many days after the LH surge? How can bitches have multiple fathers?

Answer 34

2-3 | Ovulation takes many days

Question 35

What is different about the luteolytic mechanism in bitches?

Answer 35

There isn’t one

Question 36

What type of reproduces are cows?

Answer 36

Polyestrus spontaneous

Question 37

What does FSH stimulate? Which cells does it bind to and what does this cause?

Answer 37

Growth of immature follicles Granulosa cells Oestradiol production

Question 38

What does LH stimulate?Which cells does it bind to?

Answer 38

Produces oestrogen precursors (including testosterone) Stimulates maturation, luteinization and ovulation Theca cells

Question 39

How does the oestrus cycle differ from the menstrual phase?

Answer 39

Shorter follicular phase Long literal phase No bleeding Day 0 high oestrogen (menstrual cycle day 0 = low oestrogen

Question 40

Why does spotting occur in the oestrus cycle?

Answer 40

High oestrogen levels

Question 41

What does progesterone do? What cannot happen if progesterone levels are too low?

Answer 41

Inhibits GnRH | Ovulation

Question 42

What are luteolytic signals and which species produce them?

Answer 42

Prostaglandin released by endometrium Oxytocin secreted by corpus luteum Germ cells there at birth and undergo 1st mitotic division, no 2nd until fertilisation Ruminants/horses/pigs

Question 43

Oxytocin is secreted by the corpus luteum in luteolytic signalling. How is this ensured to reach the endometrium?

Answer 43

Counter current system

Question 44

During ejaculation, semen is deposited where?

Answer 44

Vagina | Cervix (horse/pigs)

Question 45

How is sperm moved into the site of fertilisation? Where does fertilisation take place?

Answer 45

Smooth muscle contraction of female reproductive tract and sperm motility Fallopian tubes

Question 46

The majority of sperm die and do not reach the egg. Why is this?

Answer 46

Phagocytosis

Question 47

Sperm in the epididymis are mature but not fertile. How do they become fertile? Can this be reversed?

Answer 47

Remove ‘mask molecules’ whilst in female reproductive tract | Yes

Question 48

What is the fusion of gametes called?

Answer 48

Syngamy

Question 49

Which layer of the oocyte do sperm need to bind to? What happens as they do this?

Answer 49

Zona pellucida Undergo acrosomal reactions to prevent polyspermy Fuses with oocyte membrane

Question 50

What is polyspermy?

Answer 50

Multiple sperm entering and fertilising an egg

Question 51

What is the sperm viability length for cows and bitches?

Answer 51

Cow 18 hrs | Bitches 5 days

Question 52

Progesterone is essential in pregnancy. It is secreted by the placenta. Which structure can secrete it whilst the placenta develops, and what might be prevented by this?

Answer 52

Corpus luteum | Luteolysis