Histo Lecture 20 - Female Reproductive System

Front 1

Functions of the Female Reproductive System

Back 1

Produce ova through oogenesis
Facilitate and transport female germ cells and spermatozoa to increase the changes of fertilization
Maintain implanted embryos through gestation
Nurture infants postnatally through lactation

Front 2

Components of the Female Reproductive system

Back 2

Ovaries
Uterine tubes (oviducts)
Uterus - myometrium, endometrium, cervix
Vagina
External genitalia
Mammary glands
Placenta

Front 3

Ovaries

Back 3

Almond shaped, attached by mesovarium to broad ligaments of uterus, covered with simple squamous epithelium continous with meosthelial lining of peritoneal cavity, therefore germ cells released directly into peritoneal cavity

Front 4

Oviducts

Back 4

attached to broad ligaments of uterus, undergoes peristaltic contraction conveying oocyte to uterus

Front 5

Uterus

Back 5

Looks like a slightly flattened inverted hollow pear, lies medially in the pelvic cavity,opens into the upper end of the vagina via the uterine ostium

Front 6

Vagina

Back 6

Latin for sheath, distensible, muscular walled tube, functions as lower end of birth canal, folds lined with stratified squamous

Front 7

Describe the histology of the ovary in the 7th month of fetal development

Back 7

By the 7th month of fetal development, a single layer of flattened follicular cells surrounds the primary oocyte. This encapsulation arrests the first meiotic division and no further development occurs until sexual maturity.

Front 8

Primary follicles

Back 8

Primary oocyte larger
Follicular cells are cuboidal-granulosa cells

Front 9

Zona pellucida

Back 9

Glycoprotein & acid proteoglycans
ZP!, ZP2, ZP3
both cells types contribute to ZP

Front 10

Secondary follicle structural features

Back 10

Antrum
Liquor folliculi
-FSH
-ESH

Theca externa becomes more fibrous, the continuity of the granulosa cells is disrupted by the appearance of space filled with fluid-- the antrum

Front 11

Mature Graafian Follicle

Back 11

Antum enlarges and the oocyte is displaced to one side and is surrounded by granulosa cells - cumulus oophorous

Front 12

Describe secondary oocyte extrusion

Back 12

The Graadian follicle begins to bulge from the ovary surface. THere is an increase in LH which interacts with receptors on the granulosa and theca cells.

Depolymerization of the mucopolysaccharides in the antrum fluid and an increase in colloid osmotic pressure - granulosa cells less cohesive and cumulus loosens.

Follicular wall breaks down at a specific site on the ovary surface called a stigma. Decrease in blood flow, thinning and depolymerization of CT.

LH stimulates granulosa cells to produce plasminogen activator which cleaves plasminogen to plasmin and acts on the follicle wall causing rupture and secondary oocyte extruded with corona radiate of granulosa cells.

Front 13

When does 2nd meiotic division of the oocyte occur?

Back 13

After fertilization

Front 14

Describe the layers of a secondary follicle

Back 14

Antrum
Granulosa layer
Basement Membrane
Theca interna
Theca externa

Front 15

Describe Follicle Atresia

Back 15

Atresia occurs at birth, puberty, and pregnancy
Only 300-400 follicles can reach maturity, the rest degenerate or become atretic.

Front 16

Functions of the Oviduct

Back 16

1. Transport Germ Cells
2. Capacitation & fertilization
3. Transport of Zygote

Front 17

Describe the cells of the oviduct

Back 17

Simple columnar epithelium
1. Ciliated - aid transport of sperm up through isthmus
2. Nonciliated secretory cells

Muscle coat creates peristaltic waves to aid transport of oocyte

Front 18

Describe the endometrium of the uterus

Back 18

Large mucus membrane with glands that go down as far as the myometrium. Function layer 0 shed during menstruation every month. Basalar layer - retained and regenerates functional layer every month. Under the influence of estrogen and progesterone, the uterus undergoes cyclical changes.

Front 19

Describe endometrium development through the menstrual cycle

Back 19

Menstrual phase (4-5 days) - endometrium extruded
Proliferative phase (6-14 days) - Endometrium regenerates doubling of tripling its thickness under control of estrogen produced by maturing ovarian follices
Secretory phase - Endometrium thickens under influence of progesterone and estrogen produced by the corpus luteum - glands secretory
Ischemic phase - causedby decline in corpus luteum and drop in hormons
Menstrual phase - functional layer undergoes episodes of hypoxia because of interruption of blood supply

Front 20

What causes menstrual bleeding?

Back 20

The withdrawal of progesterone secretion at the end of the secretory phase causes the spiral arteries to constrict, producing ischemia. The capillaries above the constrictions rupture and bleeding begins.

Stratum basalis layer survives because it has blood supply from straight arteries.

Front 21

Endocervix

Back 21

Simple columnar mucus-secreting cells
"Endocervical gland"
During menstrual cycle, secretory activity shows cyclic changes. Around ovulation, the mucous secretion is thin and watery; estrogen.
After ovulation; secretion is viscous; progesterone.

THERE ARE NO GLANDS IN THE VAGINA; secretions come from endocervical glands

Front 22

How is the low pH of the vagina created?

Back 22

Glycogen secreted by vaginal epithelium in response to estrogen. This glycogen is metabolized by bacteria into lactic acid.

Front 23

Describe structures of inactive breast tissue

Back 23

Irregular lobes
Dense connective tissue (green)
Cells cuboidal or low columnar
Lots of adipose tissue

Front 24

Describe breast tissue histology taken from a pregnant woman

Back 24

Many secretory lobules under influence of estrogen, progesterone, and lactogenic hormones

Front 25

Describe mammary gland after menopause

Back 25

Lots of fat, very few secretory units