Histology of the Reproductive Tract

Question 1

What are the functions of the ovary?

Answer 1

Produces gametes = termed oogenesis in females

Produces steroids = mainly progesterone

Question 2

What are the different parts of the ovary?

Answer 2

Medulla and cortex

Question 3

What are the features of the medulla of the ovary?

Answer 3

Forms core of organ = contains loose connective tissue and contorted vessels, continuous with hilum of organ

Question 4

What are the features of the cortex of the ovary?

Answer 4

Has scattered ovarian follicles in a highly cellular connective tissue stroma
Outer shell is dense connective tissue layer called the tunica albuginea

Question 5

What covers the tunica albuginea of the ovary?

Answer 5

Germinal epithelium = single layer of cuboidal cells

Question 6

What enters the ovary to supply the organ with blood?

Answer 6

A group of helicine arteries = enter hilum from the broad ligament

Question 7

When do the ovaries begin to develop?

Answer 7

Around week 6 = germ cells from the yolk sac invade the ovaries and proliferate by mitosis to form oogonia

Question 8

What happens to the oogonia?

Answer 8

They undergo development and division via meiosis to form mature oocytes

Question 9

What is oogenesis?

Answer 9

Development of oocytes from oogonia

Question 10

What is folliculogenesis?

Answer 10

Growth of follicle = consists of oocyte and any associated support cell

Question 11

What is atresia?

Answer 11

Loss of oogonia and oocytes by apoptosis based process = cell is resorbed following cell death

Question 12

What occurs in oocytes before birth?

Answer 12

Meiosis occurs but halts at prophase I

Question 13

What happens if an oocyte undergoes further development?

Answer 13

Meiosis will restart = many oocytes will remain in dormant state for several decades

Question 14

What happens if an oocyte fails to associate with pregranulosa cells?

Answer 14

It will die

Question 15

What cell type are pregranulosa cells?

Answer 15

Squamous = become cuboidal if the follicle enters the growth phase

Question 16

What are primary follicles defined by?

Answer 16

Cuboidal granulosa cells

Question 17

What occurs in the primary follicle?

Answer 17

Stromal cells associate with the outside of the follicle and go on to form the theca folliculi

Question 18

What is the zona pellucida?

Answer 18

Layer of specialised extracellular matrix in oocyte = forms between oocyte and granulosa cells

Question 19

What happens when the granulosa cell layer proliferates?

Answer 19

Inner layers of adjacent stromal cells (theca folliculi) transform to form the theca interna
Outer layers remain fibroblast-like and form the theca externa

Question 20

What does the theca interna go on to do?

Answer 20

Secretes oestrogen precursors which will be converted to oestrogen by granulosa cells

Question 21

What happens as the follicle enlarges?

Answer 21

The antrum begins to form and enlarge in the granulosa cell layer = forms secondary follicle

Question 22

What is the antrum filled with?

Answer 22

Follicular fluid

Question 23

What happens overall as the follicle enlarges?

Answer 23

Antrum enlarges along with follicle, and the granulosa and thecal layers continue to proliferate

Question 24

What are graafian follicles?

Answer 24

Largest antral follicles = up to 20mm diameter

Question 25

What happens to the oocyte one day before ovulation?

Answer 25

Oocyte in largest graafian follicle completes meiosis 1 = produces secondary oocyte and tiny polar body

Question 26

What does the tiny polar body carry?

Answer 26

Second nucleus = carries it away to degenerate

Question 27

What happens to the secondary oocyte?

Answer 27

Begins second phase of meiosis but stops at metaphase II

Question 28

When does the secondary oocyte complete meiosis?

Answer 28

Becomes fully mature oocyte after it has been released and fertilised

Question 29

What happens to the follicle after ovulation?

Answer 29

Transforms into a corpus luteum = theca and granulosa cells secrete oestrogens and progesterone

Question 30

What happens to the corpus luteum if no implantation occurs?

Answer 30

Becomes a white coloured connective tissue called the corpus albicans

Question 31

What happens to the corpus luteum if implantation occurs?

Answer 31

Placenta secretes HCG which prevents degeneration of the corpus luteum for a time = maintains progesterone levels to maintain pregnancy

Question 32

Why does the infundibulum move?

Answer 32

So that its opening is adjacent to the sites where the follicle ruptures

Question 33

What propels the ovum down the uterine tubes?

Answer 33

Gentle peristalsis and currents created by ciliated epithelium

Question 34

What secretes nutrients into the uterine tubes?

Answer 34

Secretory cells in the epithelium

Question 35

Where does fertilisation usually occur?

Answer 35

In the ampulla of the uterine tubes = fertilised ovum is then transported to the uterus for implantation

Question 36

What are some features of the ampulla of the uterine tubes?

Answer 36

Mucosa is highly folded and lined by simple columnar epithelium with ciliated cells and secretory cells = surrounded by smooth muscle

Question 37

How many layers of smooth muscle are in the uterine tubes?

Answer 37

2 layers in the ampulla | 3 layers in the isthmus

Question 38

What is the lining of the isthmus of the uterine tubes?

Answer 38

Epithelium is mostly secretory with few ciliated cells

Question 39

What are the three layers of the uterus?

Answer 39

Endometrium, myometrium and perimetrium

Question 40

What is the endometrium of the uterus?

Answer 40

Inner secretory mucosa = mostly shed during menstruation, made up of tubular secretory glands embedded in connective tissue stroma

Question 41

What is the myometrium of the uterus?

Answer 41

Coat of three layers of smooth muscle combined with collagen and elastic tissue

Question 42

What is the perimetrium of the uterus?

Answer 42

Outer visceral covering of loose connective tissue covered by mesothelium

Question 43

What is the uterus divided into?

Answer 43

Stratum functionalis = undergoes monthly growth, degeneration and loss Stratum basalis = reserve tissue that regenerates the functionalis

Question 44

What happens to the uterus in the proliferative phase?

Answer 44

Stratum basalis proliferates and glands, stroma and vasculature grow = increases thickness of endometrium be reconstituting stratum functionalis

Question 45

When does the proliferative phase continue until?

Answer 45

Up until about 1 day after ovulation

Question 46

What happens to the uterus during the secretory phase?

Answer 46

Glands become coiled with a corkscrew appearance and secrete glycogen

Question 47

What happens to the uterus during the menstrual phase?

Answer 47

Arterioles in the stratum functionalis undergo constriction = deprive tissue of blood and cause ischaemia with resultant breakdown, leakage of blood and tissue sloughing

Question 48

What is the cervix?

Answer 48

Short cylinder with a small lumen that projects into the upper vagina

Question 49

What cell type covers the cervix?

Answer 49

Mostly fibrous connective tissue covered by stratified squamous epithelium on its vaginal surface Transitions to mucous secreting simple columnar epithelium

Question 50

What is the relevance of the transition zone of the cervix?

Answer 50

Common site for dysplasia = cervical cancer most frequently begins here

Question 51

What forms the endocervical glands of the cervix?

Answer 51

Deeply furrowed mucous secreting epithelium of the canal

Question 52

What do the endocervical glands secrete?

Answer 52

Varies from thin and watery secretions during the proliferative phase to thick and viscous secretions during ovulations

Question 53

What is formed when the outlets to the endocervical glands become blocked?

Answer 53

Nabothian cysts = glands expand due to blocked secretion build up

Question 54

What are the four layers of the vagina?

Answer 54

Non-keratinised stratified squamous epithelium, lamina propria, fibromuscular layer and adventitia

Question 55

What happens to the non-keratinised stratified squamous epithelium layer of the vagina during the reproductive years?

Answer 55

Become thicker and cells enlarge due to glycogen accumulation

Question 56

What lubricates the vagina?

Answer 56

No glands in walls = lubricated by mucous from cervical glands and fluid from the thin walled vessels of the lamina propria

Question 57

How do commensal bacteria of the vagina prevent pathogenic bacterial growth?

Answer 57

Metabolise glycogen to lactic acid = inhibits pathogenic bacterial growth

Question 58

What is the mons pubis?

Answer 58

Skin which contains highly oblique hair follicles = overlies a substantial subcutaneous fat pad which overlies the pubic symphysis

Question 59

What is the labia majora?

Answer 59

Extensions of the mons pubis = similar structure and rich in apocrine sweat glands

Question 60

What are some features of the labia majora?

Answer 60

Contain small smooth muscle bundles | Hair follicles only located on outer surface

Question 61

What is the labia minora?

Answer 61

Thin skin folds that lack subcutaneous fat and hair follicles = rich in vasculature and sebaceous glands that secrete directly onto skin

Question 62

What cell type is present in the labia minora?

Answer 62

Keratinised epithelium extends into opening of vagina to level of hymen = transitions to non-keratinised stratified squamous epithelium

Question 63

What are some features of the clitoris?

Answer 63

Contains two tubes of erectile vascular tissue = corpora cavernosa Covered by fibrocollagenous sheath covered by skin Skin has thin epidermis and rich innervation