histology of the female reproductive tract

Question 1

describe the different components of the ovary

-blood supply?

Answer 1

cortex-contains follicles
Medulla- highly vascular, connective tissue, nerves, lymphatics
superficial fibrous cortex- surrounded by epithelium

-group of helicon arteries enter the hilum from the broad ligament and supply blood to the organ

Question 2

describe the histology of the cortex

Answer 2

(superficial to deep)
simple cuboidal epithelium
dense connective tissue: tunica albuginea (collagen blue w stain)
connective tissue with stroll cells and scattered smooth muscle fibres
ovarian follicles at various developmental stages

Question 3

what is

• oogenesis?
• Folliculogenesis?

Answer 3

• the development of oocytes, the female germ cells from oogonia
• growth of the follicle, which consists of the oocyte and any associated support cells

Question 4

follicular development

• largest no. follicles when?
• what do oocytes need to survive?
• desribe the pregranulosa cells and how they change?

Answer 4

• at birth, primordial follicles
• the are required to associated with pregranulosa cells (follicle cells) or it will die
• squamous, if the follicle enters the growth phase they become cuboidal

Question 5

describe the structure of primary follicles

Answer 5

they are defined by cuboidal granulosa cells (zona granulosa)
stromal cells are assoc with the outside of the follicle and will go on to form the theca
there is a layer of special extracellular matrix called the Zona pellucida is beginning to form

Question 6

describe what happens to the stroll cells when the granulosa layer proliferates

• what do granulosa cells do?
• why will the theca interna take up less stain?

Answer 6

inner layers of the adjacent stromal cells transform to form a layer called the theca interna (will secrete oestrogen precursors)
outer layer remains fibroblast like and forms the theca externa

• convert oestrogen precursors to oestrogen
• it secretes steroids and so is lipid dense

Question 7

what needs to occur for a secondary follicle to form?

Answer 7

a space called the antrum filled with follicular fluid begins to form and enlarge in the granulosa layer
follicle enlarges as the antrum enlarges while the granulosa and theca cells continue to proliferate

Question 8

name given to the follicles with the largest antrum?

Answer 8

graafian follicles, these can reach about 20mm in diameter

Question 9

what change occurs in a follicle 1 day prior to ovulation?

Answer 9

the oocyte in the largest graafian follicle will complete meiosis 1 producing a secondary oocyte.
there is a tiny polar body that carries the second nucleus away to degenerate
the secondary oocyte will then begin the 2nd phase of meiosis but stop at metaphase 2. it will only complete meiosis and become a fully matured oocyte after ovulation and fertilisation

Question 10

What happens to the follicle after ovulation?

• what is secreted by which cells?
• if implantation does not occur?
• if implantation occurs?

Answer 10

it transforms into the corpus luteum

• theca cells- oestrogen, granulosa cells- progesterone
• becomes a white coloured connective tissue called the corpus albicans
• placenta secretes HCG preventing degeneration of the corpus luteum to maintain progesterone levels

Question 11

describe the histology of the uterine tubes

• at the ampulla (mucosa/epithelium/cells)
• Isthmus

Answer 11

-mucosa folded and lined by simple columnar epithelium
ciliated cells and secretory cells
all of this is surrounded by smooth muscle

-lining epithelium mostly secretory with 3 layers of smooth muscle

Question 12

what does the uterine wall consist of?

Answer 12

endometrium- Inner secretory mucosa called the (much of which is shed during menstruation)
myometrium- a coat of 3 layers of smooth muscle combined with collagen and elastic tissue
perimetrium- outer visceral covering of loose connective tissue covered by mesothelium

Question 13

what is endometrium made up of?

Answer 13

tubular secretory glands embedded in a connective tissue stroma

Question 14

name and describe the 2 functional layers of the uterus

Answer 14

stratum Functionalis-undergoes monthly growth, degeneration and loss
Stratum Basalis- reserve tissue that regenerates the funtionalis

Question 15

describe the histological changes that occur in the endometrium during the proliferative phase

• what lines the glands?
• what stimulates the stroma to proliferate

Answer 15

glands (get longer), stroma and vasculature grow and this increases the thickness of the endometrium

• pseudostratified columnar epithelium
• oestrogen

Question 16

describe the endometrium during the secretory phase?

Answer 16

glands become coiled with a corkscrew appearance and secrete glycogen
glycogen accumulates below the nucleus in the early stages and then moves to the apical end of the cell

Question 17

describe the menstrual phase changes in the endometrium?

Answer 17

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

Question 18

describe the histology of the cervix

• type of tissue and epithelium?
• commonest site of dysplasia?
• at the endocervical canal? what are the glands here called?
• variation of secretions due to changes in what?

Answer 18

mostly fibrous connective tissue covered by stratified squamous epithelium on the vaginal surface this TRANSITIONS to mucous secreting simple columnar epithelium

name of the point of transition is the TRANSITION ZONE

• transition zone, common sit of dysplasia and neoplastic changes leading to cervical cancer
• mucous secreting epithelium of the canal is deeply furrowed, forming what appear to be glands: these are known as endocervical glands

-thin and watery in the proliferative phase
thick and viscous following ovulation

Question 19

describe the 4 layers of the vagina

• why is glycogen necessary here?
• how is the vagina lubricated

Answer 19

1. non-keratinised stratified squamous epithelium, thicker during reproductive years and cells 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
   - commensal bacterial metabolise the glycogen to lactic acid which inhibits the growth of pathogenic bacteria
   - no glands, lubricated by mucous from the cervical glands and fluid form the thin walled blood vessels of LP

Question 20

name the skin overlying a substantial subcutaneous fat pad, which itself overlies the pubic symphysis.

Answer 20

mons pubis

contains highly oblique hair follicles

Question 21

describe the histology of the labia majora

Answer 21

extensions of the mons pubis, rich in sweat glands and sebaceous glands (+ sebaceous ducts) and with small bundles of smooth muscle. hair follicles on outer surface, not inner

Question 22

describe the histology of the labia minora

• lack what?
• rich in what?
• epithelium?

Answer 22

• subcutaneous fat and hair follicles
• vasculature and sebaceous glands
• keritinised epithelium extends into the opening of the vagina to the level of the hymen where there is a transition to non-keratinised stratified squamous epithelium

Question 23

describe the histology of the clitoris

-tissue?

Answer 23

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