Histology

Question 1

Two functions of the ovary?

Answer 1

produce gametes (termed oogenesis in females)
produce steroids, mainly oestrogen and progesterone

Question 2

The ovary has a medulla and a cortex:

The medulla forms the core of the organ and contains ________1_______________, and is continuous with the ___2____of the organ.

The cortex has scattered ______3________. The outer ‘shell’ of the cortex is a ________4___________, which is covered by a ____________5___________

Answer 2

1) loose connective tissue, contorted arteries, veins and lymphatic
2) hilum (where the broad ligament is in contact with the ovary)
3) ovarian follicles in a highly cellular connective tissue stroma
4) dense connective tissue layer called the tunica albuginea
5) single layer of cuboidal cells called the germinal epithelium (a holdover from a time when they were thought to give rise to the gametes).

Question 3

Define oogenesis and folliculogenesis?

Answer 3

Oogenesis is development of oocytes, the female germ cells, from oogonia.
Folliculogenesis is growth of the follicle, which consists of the oocyte and any associated support cells.

Question 4

At birth the ovaries combined contain ___1____ in __2____ form

By puberty only ___3_____ remain in form of ___4_____

By menopause _____5_____

Answer 4

1) 1 000 000
2) primary oocyte
3) 500 000
4) all types of follicles
5) very few remain

Question 5

Before birth, meiosis begins in the oocytes, but halts at ____1______ IF the oocyte undergoes further development, meiosis will restart, but many _______2_________

Answer 5

1) prophase I
2) will remain in this state for several decades
(in a 20 yo more follicles will restart development per day vs in a 40 yo where less will start development each day)

Question 6

What is the first indication that a primordial follicle is going to become a primary follicle?

Answer 6

the pre granulosa cells will become taller and more cuboidal

Question 7

What happens to the primary follicle over time?

Answer 7

the pregranulosa cells multiply and get a late primary follicle, the oocyte now has a well developed zone pellucida

Question 8

What happens to a late primary follicle next?

Answer 8

there is a split in the cells and development of a fluid filled cavity called an antrum, this signals development of the secondary follicle

Question 9

What then happens to the secondary follicle?

Answer 9

it expands significantly and becomes a mature graafian follicle

Question 10

Oocytes are among some of the ______ cells in the body

Answer 10

largest

Question 11

One day before ovulation, the oocyte in the largest Graafian follicle will complete ____1____, but instead of producing two equal cells, it will produce ___________2__________ The secondary oocyte will then begin the second phase of meiosis, but stop at _____3________. It will only complete meiosis to become a fully mature oocyte after ____________4_______________

Answer 11

1) meiosis 1
2) one cell called a secondary oocyte, similar in size to the original primary oocyte, and one tiny polar body that carries the second nucleus away to degenerate.
3) metaphase II
4) it has been released (ovulation) and fertilized by a sperm – producing a second polar body.

Question 12

After ovulation the follicle transforms into a __1_____ with the ________2_________ which helps prepare the uterus for implantation. Assuming no implantation occurs, it will become a white coloured connective tissue called the ____3_____. If implantation occurs, the trophoblast secretes HCG which prevents degeneration of the corpus luteum for a time and so _____4_______

Answer 12

1) corpus luteum
2) theca and granulosa cells secreting oestrogens and progesterone
3) corpus albicans
4) maintains progesterone levels, which in turn maintains the pregnancy

Question 13

Uterine Tubes:

The funnel shaped _____1______ moves so that its opening is ________2_________. The ovum moves down the tube propelled by _______3_________. Secretory cells in the epithelium secrete ____4_____. Fertilization usually occurs in the ___5_____ and the fertilized ovum is then transported to the __6___ for implantation.

Answer 13

1) infundibulum
2) adjacent to the site where the follicle ruptures
3) gentle peristalsis and currents created by the ciliated epithelium
4) nutrients
5) ampulla
6) uterus

Question 14

Compare the histology of the ampulla of the uterine tubes vs the isthmus?

Answer 14

The ampulla of the uterine tube: The mucosa is highly folded and lined by simple columnar epithelium with ciliated cells and secretory cells. This is surrounded by smooth muscle

Isthmus of the uterine tube: Much simpler architecture of the tube lining. The lining epithelium here is mostly secretory with few ciliated cells.

Question 15

Describe the 3 layers of the uterine wall?

Answer 15

An inner secretory mucosa called the endometrium much of which is shed during menstruation. The endometrium is made up of tubular secretory glands embedded in a connective tissue stroma.
A coat of 3 layers of smooth muscle (layers often not very distinct), combined with collagen and elastic tissue, called the myometrium.
An outer visceral covering of loose connective tissue covered by mesothelium, the perimetrium.

Question 16

Describe the 2 layers of the endometrium?

Answer 16

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

Question 17

Describe what happens to the endometrium during the proliferative phase?

Answer 17

During the proliferative phase the stratum basalis proliferates and glands, stroma and vasculature grow and this increases the thickness of the endometrium by reconstituting the stratum functionalis.

Question 18

Describe what happens to the endometrium during the secretory phase?

Answer 18

During the secretory phase the glands become coiled with a corkscrew appearance and secrete glycogen.

Question 19

Describe what happens to the endometrium during the menstrual phase?

Answer 19

During the menstrual phase the spiral 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 20

The cervix is a short cylinder with a small lumen that projects into the ____1_____. It is mostly ______2_________ on its vaginal surface, but transitioning to________3________This transition zone is a common site of ___________4_____________

Answer 20

1) upper vagina
2) fibrous connective tissue covered by stratified squamous epithelium
3) mucous secreting simple columnar epithelium (more consistent of epithelium in uterus itself).
4) dysplasia, and neoplastic changes leading to cervical cancer most frequently begin in this transition zone.

Question 21

Describe the endocervical glands?

Answer 21

Found in the endocervical canal.The secretion of these glands varies from thin and watery in the proliferative phase (allowing the passage of sperm) to thick and viscous following ovulation (preventing the passage of sperm, or microorganisms).

Question 22

Describe the 4 layers of the vagina?

Answer 22

1. Non-keratinized stratified squamous epithelium. During reproductive years, this layer is thicker and cells are enlarged due to glycogen accumulation.
2. Lamina propria: connective tissue rich in elastic fibres and thin-walled blood vessels.
3. Fibromuscular layer: inner circular and outer longitudinal smooth muscle.
4. Adventitia.

Question 23

What is a polar body?

Answer 23

a small haploid cell that is formed concomitantly as an egg cell during oogenesis, but generally does not have the ability to be fertilized (so when the egg does meiosis 1 it gets rid of one of the gametes into a haploid body, the remaining does meiosis 2 and then gets rid of the second cell into a polar body) hence when an oocyte completes meiosis there is only 1 cell as opposed to 4 as you would expect

Question 24

What is the function of the glycogen accumulation in the epithelium of the vagina?

Answer 24

Commensal bacteria metabolize the glycogen to lactic acid which inhibits the growth of pathogenic bacteria.

Question 25

Describe the mons pubis?

Answer 25

Skin which contains highly oblique hair follicles (produce coarse, very curly hair characteristic of pubic hair), overlying a substantial subcutaneous fat pad, which itself overlies the pubic symphysis.

Question 26

Describe the labia majora?

Answer 26

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

Question 27

Describe the labia minora?

Answer 27

Thin skin folds that lack subcutaneous fat and hair follicles, but are rich in vasculature and sebaceous glands that secrete directly onto the surface of the skin. Keratinized epithelium extends into the opening of the vagina to the level of the hymen, where there is a transition to non-keratinized stratified squamous epithelium.

Question 28

Describe the clitoris?

Answer 28

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

Question 29

List the order of names that the follicles go through as they mature?

Answer 29

primordial follicles
primary follicles
late primary follicles 
secondary follicle
mature graafian follicle

Question 30

How are the arteries in the stratum functionalis different from the stratum basalis?

Answer 30

Stratum functionalis has spiral arteries which spasm and constrict in the menstrual phase depriving the layer of blood so it dies and is loss
Stratum basalis has straight arteries