Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HUBS192 > Lecture 37: Female reproduction 2 > Flashcards

Lecture 37: Female reproduction 2 Flashcards

1
Q

What is the name given to the predecessor of oocytes?

A

oogonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Can females produce more gametes as they age?

A

females lifetime supply of gametes produced before birth (they don’t produce more as they age)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does the population of oogonia increase and when does this process stop?

A

Population of oogonia increase by mitosis (stops before birth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When is meiosis 1 initiated and where does this process halt?

A

Prior to birth meiosis 1 is initiated, The process halts at prophase 1 and these oocytes stay at these states until mensuration (menarche)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

At what stage of life do oogonia differentiate to form primary oocytes (n=46)

A

This process occurs before birth:

  • Encased in primordial follicle
  • Many primary oocytes undergo atresia (cell death)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How many oocytes do females have at puberty?

A
  • At puberty, females have ~300,000 oocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What process begins to occur when females reach puberty (only focus on primary oocyte)?

A
  • Under GnRH influence, small number of follicles recruited each ovarian/menstrual cycle.
  • Only one oocyte will complete development and ovulate (within dominant follicle).
  • Primary oocyte completes meiosis I.
  • Forms a secondary oocyte and 1st polar body (both haploid, n=23).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the name of the follicle that is chosen for ovulation out of the small group that develops initially?

A

The dominant follicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a polar body and what are their fate?

A

Polar bodies are the ‘reject cells’ of meiosis, they contain excess leftovers from the focused development of the secondary oocyte.

Their fate is atresia (cell death)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the next process that occurs once females reach puberty (think only secondary Oocyte before fertilisation)?

A
  • Secondary oocyte starts meiosis II
  • Halts at metaphase II
  • Suspended until fertilisation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

When does meiosis 2 resume for the secondary oocyte?

A
  • Meiosis II resumes when the sperm penetrates plasma
    membrane of the ovum at fertilisation.
  • If not fertilised, will degenerate (called atresia) and therefore never complete meiosis.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How many polar bodies can be produced during a cycle?

A

Three polar bodies form - these undergo atresia (degeneration).

three because the first polar body can also do meiosis 2 creating 2 polar bodies + the polar body produced from the secondary oocyte that undergoes meiosis 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What structure does the ruptured follicle become?

A

It becomes a corpus luteum and ultimately degenerates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Follicle are multilayered - what are these two layers?

A
  • Granulosa cells (inside little cells)
  • Theca cells (form outside barrier)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What hormone does Granulosa cells produce?

A

Granulosa cells produce estradiol and inhibin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the name for the Granulosa cells that directly surround the oocyte?

A

The Corona radiata,

This stays on the oocyte when ovulation occurs and are released into the peritoneal cavity

17
Q

Primary oocytes start meiosis prior to birth but the process halts at ___________ until puberty begins.

A

Prophase 1

18
Q

The dominant follicle begins meiosis II, but the process halts at ___________ until fertilisation occurs.

A

Metaphase 2

19
Q

What are the ovary hormones in females?

A

Follicles:
- Estradiol
- Inhibin

Corpus Luteum:
- inhibin
- Progesterone

20
Q

What is the role of Follicle Stimulating Hormone in females?

A

Stimulates the growth of ovarian follicles

21
Q

What is the role of Luteinizing Hormone in females?

A

Surge of LH involved in ovulation, formation of corpus luteum.

22
Q

What is the role of Estradiol in females?

A

(developing follicles):
Assists follicle growth (with FSH);
bone and muscle growth;
endometrial growth;
secondary sex characteristics;
feedback to anterior pituitary.

23
Q

What is the role of inhibin in females?

A

Negative feedback to anterior pituitary to suppress FSH.

24
Q

What is the role of Progesterone in females?

A

(corpus luteum):
Negatively feeds back to suppress GnRH (therefore LH and FSH); endometrial maturation; maintains pregnant state.

25
Q

Describe the overall reason for Ovarian/Menstrual cycles:

A

The regular cyclic changes in the ovary and uterus that prepare an oocyte/ova for fertilisation and the endometrium for embryo implantation

26
Q

What is Menarche?

A

first menstrual period
* Occurs at age 12-13 y on average
* Part of puberty – orchestrated by increase in sex steroid
production (estrogens) by the gonads

27
Q

What is menopause?

A

cessation of menstruation
* Typically occurs in early 50s
* Reduction of estradiol and progesterone due to absence of or lack of response by follicles
* Anterior pituitary feedback no longer active ∴ FSH/LH high

28
Q

Describe the Follicular phase (day 1-14) of the cycle: think hormones (probably SAQ better) (basically describe the graph)

A
  • Increased FSH from the anterior pituitary
  • Stimulates follicular growth
  • Growing follicles secrete estradiol and inhibin
  • Reduces FSH from anterior pituitary (negative feedback)
  • Growing follicles undergo atresia, except dominant follicle.
  • Dominant follicle secretes large amounts of estradiol
  • High estradiol stimulates surge of LH (positive feedback)
  • Follicle ruptures and ovulation occurs
  • Oocyte enters peritoneal space/collected into uterine
    tube.
29
Q

Describe the luteal phase of the cycle: think hormones

A
  • Ovulated follicle collapses & forms corpus luteum
  • Secretes progesterone, estradiol & inhibin.
  • These decrease FSH & LH secretion.
  • Negative feedback on hypothalamus.
30
Q

What happens if fertilisation and implantation does not occur in the Luteal phase?

A
  • If fertilisation and implantation do not occur,
    the corpus luteum involutes (luteolysis).
  • Fall in progesterone & estradiol.
  • Removes negative feedback on FSH and LH…. Cycle
    starts again…
31
Q

Be comfortable with Slide 25/26 Graphs

A

YIPEEEEE

NOOOOOOOOOOOOO

32
Q

What specifically happens in the Menstrual and Proliferative phases of the follicle phase?

A

Days 1 – 14

Menstrual:
* Endometrium breaks down and bleeds during menstruation

Proliferative:
* Estradiol stimulates endometrial growth from approx days 6-14
* Rapid tissue growth, including growth of glands and vasculature

33
Q

What specifically happens during the secretory phase of the luteal phase?

A

Days 15 – 28

  • After ovulation (day 14) - corpus luteum secrets progesterone.
  • Progesterone promotes endometrial maturation
  • Glands become secretory
  • Spiral arterioles grow and coil
34
Q

What happens after the secretory phase and fertilisation has not occurred?

A

If fertilisation and implantation do not occur:
* Corpus luteum atrophies
* Progesterone levels fall

  • Spiral arteries contract
  • Endometrial tissue breaks down and bleeding occurs
  • Shed tissue and blood removed via cervix and vagina (menstruation / menses)
35
Q

Secretion of large amounts of estradiol by the ___________
follicle will cause the ___________ and subsequently ovulation and formation of the corpus luteum.

A

Dominant follicle

LH surge

36
Q

The endometrium undergoes cyclic periods of growth,
maturation and breakdown in response to cyclic patterns in ___________ and ___________.

A

Estradiol and Progesterone

37
Q

The definition of menarche is:
a. The cessation of menstrual cycles
b.The onset of menstrual cycles
c. The time of ovulation
d.The onset of meiosis
e. The onset of mitosis

A

B

38
Q

The definition of menopause is:
a. The cessation of menstrual cycles
b.The onset of menstrual cycles
c. The time of ovulation
d. The onset of meiosis
e. The onset of mitosis

A

A

39
Q

GnRH from the hypothalamus directly regulates the secretion of:
a. FSH and estradiol
b. LH and estradiol
c. FSH and progesterone
d. LH and FSH
e. LH and progesterone

A

D

HUBS192 (39 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions