Reproductive L2

Question 1

How many oocytes are released in woman’s lifetime?

Answer 1

~400

Question 2

How many oocytes are released in woman’s lifetime?

Answer 2

~400

Question 3

how is uterus connected to the ovary?

Answer 3

fallopian tube/ oviduct

Question 4

What is the position of the uterus in respect to vagina?

Answer 4

90 degrees ( anteflexed uterus)- normal

Question 5

retroflexed uterus

Answer 5

~20 % of women have it

can cause pain during menstruation

Question 6

Vagina

Answer 6

-elastic muscular tube 7.5-9 cm extending from the cervix to the exterior of the body

Question 7

what are the 3 main functions of the vagina?

Answer 7

• Through menstruation the endometrium comes off. Serves as a passageway for the elimination of menstrual fluid
• it receives the penis during sexual intercourse, and holds spermatozoa before they pass into the uterus
• Forms the lower portion of the birth canal through which the fetus passes during delivery

Question 8

what are the 3 main functions of the vagina?

Answer 8

• Through menstruation the endometrium comes off. Serves as a passageway for the elimination of menstrual fluid
• it receives the penis during sexual intercourse, and holds spermatozoa before they pass into the uterus
• Forms the lower portion of the birth canal through which the fetus passes during delivery

Question 9

Uterus structure

Answer 9

Fundus at the top, at the bottom-cervix. A plug of mucus blocks the entry of the sperm into the uterus. Cervix holds the baby in the uterus to avoid premature release into the vagina

Question 10

uterus functions

Answer 10

-a pathway for sperm transport
-provides mechanical protection, nutritional support, and waste removal for the developing embryo and fetus. (through the placenta)
endometrium provides the optimal environment for embryo implantation
-Contractions in the muscular wall (myometrium) of the uterus are important in ejecting the fetus at the time of birth.
-Source of menstrual fluid

Question 11

What is the name of the layer lost during menstruation?

Answer 11

stratum functionalis of endometrium

Question 12

2 layers of the endometrium

Answer 12

Inner functional zone: stratum functionalis. Contains most of the uterine glands
Outer basilar zone: stratum basalis, adjacent to the myometrium. The basilar zone attaches the endometrium to the myometrium.

Question 13

The uterine(fallopian) tubes

Answer 13

~ diameter of a drinking straw
-provides a rich, nutritive environment containing lipids and glycogen for spermatozoa, oocytes, and developing embryo

Sperm go up the uterine tube (by cilia and sperm tail).
The oocyte is picked up by Fimbriae( projections at the end of uterine tube-infundibulum). Cilia on fimbriae. The oocyte is then carried through the uterine tube.

The uterine tube is covered in cilia. Provide the ability to oocytes to move down. More cilia at the infundibulum end than closer to the uterus. Non-ciliated secretory cells provide nutrients to keep oocytes and sperm alive.

The uterine tube has concentric layers of smooth muscle. Peristaltic contractions allow movement of the oocyte.

Question 14

What is the optimal place for fetilization to occur?

Answer 14

Ampulla of the uterine wall

Question 15

Ectopic(tubal) pregnancy

Answer 15

embryo implanted into the uterine tube

Question 16

what are the risk factors for ectopic pregnancy?

Answer 16

Smoking, advanced maternal age and prior tubal damage are risk factors

Question 17

What is the weight of ovaries?

Answer 17

5-10 g

Question 18

3 layers/regions of the ovary

Answer 18

Outer ovarian cortex- containing the ovarian
follicles

Central ovarian medulla- consisting of ovarian stroma
and steroid-producing cells

Inner hilum (hilus) which acts as a point of entry for
nerves and blood vessels

Question 19

Primordial follicle

Answer 19

oocytes with some cells around it(granulosa cells, squamous)
Sit in ‘nests’
Most stay in this form in the ovaries. Dormant for a long time

Question 20

Primary follicles

Answer 20

As the follicles grow, they are called primary or
pre-antral follicles. Immature primary follicles consist of
only one layer of granulosa cells.

Squamous cells -> cuboidal.

Become mitotically active, hormonal activity

The oocyte secretes glycoproteins, which form a translucent
acellular layer (zona pellucida).
Condensation of ovarian stromal cells, known as
thecal cells, begin to form around the follicle.

Question 21

Zona pellucida

Answer 21

secreted by oocytes.

Allows entry of 1 sperm only

Question 22

What is the importance of thecal cells?

Answer 22

Created from stroma cells

together with granulosa cells produce reproductive hormones

Question 23

Follicle development

Answer 23

In response to FSH once a month, some follicles grow larger( primarily the number of granulosa cells surrounding the oocyte)

Question 24

Secondary follicle

Answer 24

granulosa cells start producing a viscous fluid, which coalesces to form a single follicular antrum. It provides nutrients to the developing oocyte.

It is now referred to as an antral follicle.

The innermost layer of granulosa cells becomes firmly attached to the zona pellucida and is called the corona radiate

Mass of loosely associated granulosa cells is known as the cumulus oophorus

The theca develops to become the inner
glandular, highly vascular theca interna,
and the surrounding fibrous capsule, the theca externa

Question 25

Mature (Graafian or pre-ovulatory) follicle

Answer 25

As the follicular antrum grows, the oocyte becomes suspended in fluid. It is connected to the rim of peripheral granulosa cells by a thin stalk of cells.

Question 26

What happens to the follicle during ovulation?

Answer 26

The increasing size of the follicle and its position in the cortex of the ovarian stroma causes it to bulge out from the ovarian surface. The follicle ruptures, carrying with it the oocyte and its surrounding mass of cumulus cells. The oocyte is collected by cilia on the fimbria, which sweep the cumulus mass into the uterine tube.

Question 27

Corpus Luteum formation

Answer 27

The antrum breaks down, the basement membrane between the granulosa and thecal layers breaks down, and blood vessels invade. The granulosa cells form large lutein (yellow pigment) cells (Corpus luteum =yellow body) This transformation is referred to as luteinisation and is associated with increased secretion of progestagens-progesterone after ovulation.

Question 28

Corpus Albicans

Answer 28

Corpus Luteum disintegrates The whitish scar tissue remaining, the corpus Albicans (white body), is absorbed back into the stromal tissue of the ovary over weeks to months. If fertilization does not occur, then the cycle starts all over again.

Question 29

The process of fertilization

Answer 29

If the oocyte is fertilized and begins to divide, the corpus luteum persists past its normal 2 week life span. It is rescued from degeneration by human chorionic gonadotropin (hCG). The hormone is produced by the chorion of the embryo beginning about 8 days after fertilisation. The presence of hCG in maternal blood or urine is an indicator of pregnancy and is the hormone detected by home pregnancy tests

Question 30

what is the function of Corpus Luteum?

Answer 30

produces progesterone, allowing the endometrium layer to stay stable and ready to support embryo implantation. Usually lasts for 2 weeks, if no hCG-> Corpus Luteum degrade-> endometrium sheds If hCG is present-> corpus luteum is maintained for longer to prolong endometrium

Question 31

How long does an avergae menstrual cycle last?

Answer 31

28 days

Question 32

Phases of menstrual cycle

Answer 32

Two phases in the ovarian cycle: follicular phase (day 1 to ovulation) and luteal phase (ovulation to menstruation) Three phases in the uterine/menstrual cycle: menstruation, proliferative and secretory

Question 33

The length of what phase in the menstrual cycle varies between women?

Answer 33

follicular phase

Question 34

What happens to the follicular phase as the woman gets older?

Answer 34

it shortens

Question 35

Main events of the menstrual cycle

Answer 35

1.After no fertilization has occurred there is a degression in progesterone and estrogen 2.Small rise in FSH-> increased activity of primary and secondary follicles. This leads to increased growth in the follicles 3. By day 6-7 dominant follicle( large amounts of granulosa cells). High production of estrogen. 4. Oestradiol suppress FSH (and LH) production in the pituitary. This stops the production of more follicles and limits the number of follicles to one 5.Oestrogen levels rise, by ~day 12, a threshold concentration of oestradiol is exceeded. If this is maintained for ~36 hours, there is a temporary switch from a negative to positive feedback 6. Oestrogen mediated positive feedback triggers a rise in GnRH leading to an LH surge 7. LH surge induces ovulation 8. Corpus luteum develops, see increased progesterone 9. Elevated progesterone levels inhibit GnRH, lead to decreased FSH and LH 10. Demise of the corpus luteum