Reproductive System - Female

Question 1

What are ovaries?

Answer 1

solid, egg-shaped structures

attached to the uterus by ligaments

have 2 main functions

• store and release the ova
• produce female sex hormones Estrogen and Progesterone

Question 2

What is an Ova?

Answer 2

the female reproductive cell

the largest cell in the female body (grain of sand)

female is born with all the ova she will ever have (~200,000)

about 400-500 will mature and are released over a lifetime.

Question 3

What is progesterone?

Answer 3

a hormone that stimulates the building up of the lining of the uterus in preparation for the fertilized ovum

Question 4

What is the lining of the uterus called?

Answer 4

endometrium

It is a blood vascular lining

Question 5

What is estrogen?

Answer 5

the hormone responsible for the secondary sex characteristics and the sex drive in females.

It spurs the onset of puberty and is responsible for ovulation

inhibits the growth of facial hair

Question 6

What is the uterus?

Answer 6

a hollow, muscular organ

its function is to protect and nourish a fetus

the walls of the uterus have the ability to stretch to the size of a small watermelon

After childbirth, the uterus shrinks back to the original shape in 6-8 weeks but it can take up to 9 months for the uterus to fully recover.

Question 7

What is a cervix?

Answer 7

The neck or opening of the uterus

It dips down about half an inch into the vagina

It is normally plugged by mucus. It stays tightly closed during pregnancy, but thins and opens for the delivery of the baby.

It dilates up to 10cm for births.

Question 8

What are the fallopian tubes (oviducts)

Answer 8

2 tubes attached on either side of the uterus

They are about 4 inches long and 3/16 in diameter (the size of a cooked spaghetti noodle)

Carry the egg towards the uterus and sperm cells towards the egg cell

Fertilization takes place in the upper third of the oviduct.

Question 9

What is Ovulation?

Answer 9

When the egg is released from the ovary

Starts occurring at the age of puberty

The ovum moves to the surface of the ovary and bursts out

The ova falls into the fallopian tube and waits for fertilization

happens at about the 14th day of the cycle

Question 10

What is the vagina?

Answer 10

Female organ used for intercourse

an empty passageway leading from the vaginal opening to the uterus

The vaginal walls are made of many small folds of membrane that stretch greatly to accommodate a baby during birth.

secrete a fluid that helps to make intercourse easier.

Question 11

What is the urethra?

Answer 11

The opening to the bladder

Question 12

What is the clitoris?

Answer 12

a small pea-shaped bump at the front of the labia

It contains a small amount of erectile tissue

the clitoris increases sexual pleasure.

Question 13

What is the ovarian cycle?

Answer 13

averages about 28 days but can range from 21-25 days.

It is the cycle of releasing an egg for fertilization.

Question 14

Explain days 1-13 of the ovarian cycle

Answer 14

the follicular stage

follicles are immature eggs

several follicles begin developing (due to FSH - secreted by the anterior pituitary)

The developing follicle begins producing estrogen which stimulates the endometrium to thicken

Question 15

Explain day 14 of the ovarian cycles

Answer 15

This is ovulation

The most developed follicle bursts from the ovary due to the increased amounts of LH

(LH is secreted by the anterior pituitary because of high levels of estrogen)

Question 16

Explain days 15-28 of the ovarian cycle

Answer 16

This is the luteal phase

The remaining follicle tissue develops into corpus luteum

The corpus luteum secretes progesterone which causes the endometrium to become mucosal (ready to accept a fertilized egg)

Question 17

What is implantation?

Answer 17

The process of a fertilized egg embedding into the endometrial layer

Question 18

What happens if implantation does not occur?

Answer 18

the corpus luteum degenerates leading to LOW progesterone

Low progesterone causes the endometrial tissue to break down (bleeding)

Question 19

Describe the Uterine Cycle

Answer 19

Day 1 - Menstruation begins - The endometrium is broken down (menses)

Day 5 - Menstruation is usually ended

Day 6-13 - Proliferation phase - Endometrium thickens and becomes more vascular

Day 14 - Ovum has matured and burst out of the ovary

Day 15 - After 24 hours, the egg is done

Day 26 - in the absence of fertilization, estrogen/progesterone levels drop and the endometrium lining breaks down

Day 28 - Menstruation begins again

Question 20

What happens if fertilization and implantation occur?

Answer 20

The embryo will implant into the endometrium and the placenta begins to develop

The placenta and embryo produce hCG (human chorionic gonadotropin)

hCG prevents the corpus luteum from degenerating (progesterone stays high and the endometrium is NOT shed)

Placenta also produces progesterone and estrogen (this shuts off FSH and LH) - no new follicles develop and no new ovulation.

Question 21

What happens during birth?

Answer 21

The pressure on the uterus wall causes the pituitary gland to secrete oxytocin

Oxytocin promotes contraction of the uterus wall…which leads to MORE pressure…which leads to MORE oxytocin and contractions = a POSITIVE feedback loop

Question 22

What is the Corpus Luteum?

Answer 22

It is made up of the follicle cells that remain in the ovary following ovulation.

If pregnancy does not occur then the corpus luteum degenerates in about 10 days.

If pregnancy does occur then the corpus luteum secretes estrogen and progesterone to prevent more eggs from developing