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Question 1

What are gametes produced from?

Answer 1

From germ cells which have been separated from somatic cells at a very early age. The germ cells proliferate by mitosis and undergo genetic reshuffling before being reduced to haploids by meiosis

Question 2

Where do germ cells colonise in the female?

Answer 2

The gonadal cortex

Question 3

What do germ cells become in females?

Answer 3

Oogonia

Question 4

When do you find the highest number of oogonia?

Answer 4

In the middle of the gestation of that woman

Question 5

How many oogonias enter meiosis before the birth of that individual?

Answer 5

2 million– started with 7 million

Question 6

How far in meiosis will the oogonias progress?

Answer 6

The will only reach the prophase of the first division before they will stop.

Question 7

Why does meiosis stop?

Answer 7

The release of oocyte maturation inhibitor prevents the further progression of meiosis.

Question 8

What are the oogonias known as once they have started meiosis?

Answer 8

Primary oocytes

Question 9

What is a primordial follicle?

Answer 9

Follicular cells surround the oocyte forming a multi-layered epithelium which are then known as granulosa cells. The granulosa cells secrete glycoproteins which form a zona pellucida. Connective tissue cells surrounding the follicle form a theca folliculi which is made up of two parts.

Question 10

What are the two layers of theca folliculi?

Answer 10

Theca interna – is vascular and endocrineTheca externa – is a fibrous capsule

Question 11

What do the theca and granulosa cells do?

Answer 11

They collaborate to secrete oestrogens

Question 12

How is a gamete matured in order for it to be fertilised?

Answer 12

The follicle goes through three stages of development1. Pre-antral/primordial2. Antral3. Pre-ovulatory

Question 13

What is ovulation?

Answer 13

The process through which an ovum is released. Begins the 36 hour period in which a woman is fertile per month.

Question 14

What has to happen before ovulation can take place?

Answer 14

The ovum developsThe reproductive tract is prepared for sperm transport and conceptus implantationChanges also occur in the body that help to maximise conception

Question 15

What happens to prevent the release of extra gametes?

Answer 15

Gamete production is stopped after the initial release of a gamete as a fertilised oocyte is not larger enough to signal its presence. This prevent the fertilisation of another gametes. The pregnancy is confirmed by the release of placental hormone. This is known as the period of waiting.

Question 16

Why does menstruation occur?

Answer 16

It occurs at the end of an unsuccessful reproductive cycle.

Question 17

Describe the menstrual cycle

Answer 17

is about 28 days long. The first day of bleeding signals the start of the cycle, initiating the preparatory phase (follicular or proliferative phase), ovulation occurs around days 12-14 and the waiting phase (luteal or secretory phase) occurs from days 14-28.

Question 18

What are the different stages of menstrual cycle?

Answer 18

Preparatory phase (0-12 days)Ovulation (at around 12-14 days)Waiting phase (days 14-28)

Question 19

How do primordial follicles develop into antral follicles?

Answer 19

Granulosa cells secrete a fluid which causes the formation of the antral space. Initially, it is independent of hormones, but in order to get to teh sizes required, FSH and LH will stimulate.

Question 20

What cells does FSH bind to?

Answer 20

Granulosa cells

Question 21

What cells do LH bind to?

Answer 21

Thecal cells

Question 22

What does the binding of LH stimulate?

Answer 22

The release of androgens from thecal cells which are converted to oestrogen by granulosa cells, due to FSH

Question 23

What stimulates ovulation?

Answer 23

An increase in LH levels which stimulate meiosis to being again.

Question 24

What is produced after the first division of meiosis?

Answer 24

One daughter cell which receives all the cytoplasm and a polar body which only contains DNA.

Question 25

What happens after ovulation to the follicle?

Answer 25

It reorganises to form a corpus luteum because of LH presence. It the secretes oestrogen and progesterone.

Question 26

What is the purpose of the corpus luteum secreting oestrogen and progesterone?

Answer 26

It prevents the release of further oocytes. If pregnancy occurs, then it will continue to prevent further release. If pregnancy does not occur, then it undergoes apoptosis.

Question 27

What is the rout of the released oocyte?

Answer 27

It travels from the pre-ovarian peritoneal cavity to the uterine cavity, via the fallopian tubes.

Question 28

Describe the structure of the ovaries

Answer 28

– almond shaped and sized female glands – where the oocytes develop as well as endocrine glands which produce reproductive hormones. – — is suspended by a short peritoneal fold which contains the short ovarian ligament which connects the ovary to the uterus.

Question 29

Describe the outer structure of the ovary

Answer 29

They have a connective tissue capsule, which is known as the tunica albuginea of the ovary. It is covered by a smooth layer of ovarian mesothelium, which has a dull, greyish appearance.

Question 30

What can happen to ovaries as women age?

Answer 30

It becomes progressive more scarred over time due to the repeated rupture of ovarian follicles and discharge of oocytes during ovulation.