Histology

Question 1

What are the functions of the ovary

Answer 1

Produce gametes

Produce steroids - oestrogens and progesterone’s

Question 2

Describe the structure of the ovary

Answer 2

Has a medulla and cortex
Medulla is the core and contains loose connective tissue, contorted arteries, veins and lymphatics
Cortex has a connective tissue stroma with ovarian follicles scattered through
Has a dense outer layer called the tunica albuginea
This is covered by a single layer of cuboidal cells called the germinal epithelium

Question 3

Which layer do a lot of ovarian cancers develop from

Answer 3

The germinal epithelium

Outer layer

Question 4

How do the oocytes develop

Answer 4

Germ cells invade the stroma of the developing ovary

They multiply lots to form the mature oocytes

Question 5

What is oogenesis

Answer 5

It’s the development of oocytes, the female germ cells, from oogonia.

Question 6

What is folliculogenesis

Answer 6

It is the growth of the follicle, which consists of the oocyte and any associated support cells.

Question 7

At what stage of life does the number of eggs reach its peak

Answer 7

Around 7 months in utero

Atresia then occurs and some die off

Question 8

When does meiosis of oocytes start and stop

Answer 8

Meiosis starts in the oocytes before birth but stops at prophase 1
If the oocyte develops further (i.e. is ovulated) meiosis will restart
Oocytes can stay in the halted prophase for decades

Question 9

Describe how follicles develop

Answer 9

Cuboidal granulosa cells form the primary follicle
Stromal cells associate with the outer layer and go on to form the theca folliculi
Oocyte enlarges and zona pellucida forms around it
The granulosa cells proliferate
The inner layer of stromal cells transform into the theca interna
The outer layers remain fibroblast-like and form the theca externa.
Follicle enlarges and a space called the antrum forms in the granulosa layer
This fills with follicular fluid and forms a secondary follicle

Question 10

What name is given to the largest and most mature follicles

Answer 10

Graafian follicles

Question 11

What happens to the Graafian follicle just prior to ovulation

Answer 11

One day before the largest Graafian follicle will complete meiosis 1
Instead of producing 2 equal cells it produces the secondary oocyte and a tiny polar body that carries the second nucleus away to degenerate
The secondary oocyte then undergoes meiosis 2 and stops at metaphase II

Question 12

When does the secondary oocyte complete meiosis 2

Answer 12

Only once it has been released by ovulation and fertilised by a sperm

On completion it produces another polar body

Question 13

What happens to the follicle after ovulation

Answer 13

It transforms into the corpus luteum

The remaining theca and granulosa cells secrete oestrogens and progesterone to prep the uterus for implantation

Question 14

What happens to the corpus luteum if an embryo does not implant

Answer 14

It breaks down and becomes the corpus albicans
This is white connective tissue structure
This occurs after around 14 days

Question 15

What happens to the corpus luteum if an embryo does implant

Answer 15

The placenta will secerete HCG to maintain the corpus luteum so that progesterone levels are maintained
This helps maintain the pregnancy
Placenta eventually takes over

Question 16

How does the oocyte move down the fallopian tube

Answer 16

Propelled by gentle peristalsis of the tube

The tube also has ciliated epithelium which create currents to help it move

Question 17

What cells are found in the fallopian tubes

Answer 17

Ciliated epithelium - creates a current

Secretory cells - secrete nutrients

Question 18

Do the fallopian tubes have muscles

Answer 18

They have 2 layers of smooth muscle in the ampulla

3 layers in the isthmus

Question 19

What makes up the uterine wall

Answer 19

Inner mucosa of endometrium - made up of tubular secretory glands embedded in a connective tissue stroma
3 layers of smooth muscle called the myometrium
An outer visceral covering of loose connective tissue covered by mesothelium, the perimetrium

Question 20

How is the endometrium divided

Answer 20

Stratum Functionalis which undergoes monthly growth, degeneration and loss.
Stratum Basalis which is a reserve tissue that regenerates the functionalis

Question 21

What happens to the endometrium during the proliferative phase

Answer 21

Stratum basalis proliferates and glands, stroma and vasculature grow
Thickness increases by reconstituting the stratum functionalis
This is triggered by oestrogen

Question 22

What happens to the endometrium during the secretory phase

Answer 22

The glands become coiled with a corkscrew appearance and begin to secrete glycogen
This is triggered by the release of progesterone after ovulation

Question 23

What causes endometrial shedding

Answer 23

Arterioles in the stratum functionalis undergo constriction, depriving the tissue of blood and causing ischemia, with resultant tissue breakdown, leakage of blood and tissue sloughing.

Question 24

What is the cervix made up of

Answer 24

Mostly fibrous connective tissue covered by stratified squamous epithelium
It transitions to mucous secreting simple columnar epithelium on the internal side

Question 25

What is the clinical significance of the transition zone of the cervix

Answer 25

It is a common site of dysplasia and neoplastic changes

Cervical cancers most frequently start here

Question 26

What is secreted from the endocervical glands

Answer 26

Varies throughout the cycle
Is thin and watery mucous in the proliferative phase - allows sperm to enter
Is thick and viscous after ovulation

Question 27

What can happen if the endocervical glands become blocked

Answer 27

They expand with secretions and form a Nabothian cyst

Question 28

List the layers of the vagina

Answer 28

Non-keratinized stratified squamous epithelium
Then lamina propria - connective tissue rich in elastic fibres and thin walled blood vessels
Fibromuscular layer
Adventitia

Question 29

How is the vagina lubricated

Answer 29

There are no glands in the vaginal

It is lubricated by mucous from the cervical glands

Question 30

How does the vagina protect itself from infection

Answer 30

It has glycogen in the walls which commensal bacteria convert into lactic acid
This inhibits the growth of pathogenic bacteria

Question 31

Describe the structure of the mons pubis

Answer 31

Skin which contains thick hair follicles - pubic hair

Underneath is a substantial subcutaneous fat pad which itself overlies the pubic symphysis

Question 32

Describe the structure of the labia majora

Answer 32

Extensions of mons pubis, similar structure and rich in apocrine sweat glands and sebaceous glands and with small bundles of smooth muscle
Has hair follicles on the outer surface but not inner

Question 33

Describe the structure of the labia minora

Answer 33

Thin skin folds that are rich in vasculature and sebaceous glands
Keratinized epithelium extends into the opening of the vagina to the level of the hymen

Question 34

Describe the structure of the clitoris

Answer 34

two tubes of erectile vascular tissue (corpora cavernosa), covered by a fibrocollagenous sheath covered by skin with rich innervation and a thin epidermis

Question 35

What is a normal endometrial thickness for a women of reproductive age

Answer 35

Thickness goes from around 5mm up to 11mm in the proliferative phase
Can reach up to 16mm