LM 1.1: Female Reproductive System

Question 1

what are most of the structures of the female genital tract are derived from?

Answer 1

paramesonephric ducts aka Mullerian ducts

they give rise to the right and left fallopian tubes and fuse centrally to form the structures of the uterus, cervix and vagina

ovaries arise from the genital ridge, a thickening in the mesothelium high on the posterior wall of the peritoneal cavity

Question 2

what are most of the structures of the male genital tract are derived from?

Answer 2

mesonephric ducts aka Wolffian ducts

Question 3

what are Gartner duct cysts?

Answer 3

normally the mesonephric ducts regress in the female, but remnants may persist into adult life as epithelial inclusions adjacent to the ovaries, fallopian tubes and uterus

in the cervix and vagina these remnants may be cystic and are termed Gartner duct cysts

Question 4

what structure holds the ovaries in place?

Answer 4

they are suspended from the mesentery by a connective tissue membrane, the suspensory ligament

the medial poles of the ovaries are attached to the uterus by the ovarian ligament

Question 5

what is the vulva?

Answer 5

labia + clitoris

Question 6

what are the components of the ovarian stroma?

Answer 6

1. spindle shapped cells
2. fine collagen fibers
3. ground substance
4. scattered bundles of smooth muscle

Question 7

what is the cortex of the ovary? what are the different cell types?

Answer 7

they cortex is composed of many follicles that contain female gametes in various stages of development

there may be post-ovulatory follicles of various kinds, such as:

1. corpora lutea: responsible for estrogen and progesterone production
2. corpora albicantes: degenerate and former corpora lutea
3. atretic follicles

Question 8

what are the characteristics and components of the ovary medulla?

Answer 8

1. highly vascular
2. contains hilum cells

it’s the central zone of the ovarian stroma

Question 9

what is the blood supply of the ovary?

Answer 9

1. ovarian artery
2. ovarian branches of uterine artery
3. helicine arteries

the ovarian artery and ovarian branches of the uterine artery form anastomoses in the mesovarium and the broad ligament –> from this arterial plexus, approximately 10 coiled arteries, the helicine arteries, enter the hilum of the ovary

Question 10

what does a primordial follicle look like? where are they found?

Answer 10

primordial follicles are found in the ovarian cortex

these large oocytes have a euchromatic nucleus and densely stained nucleolus

each primordial follicle is surrounded by a single layer of attened cells

Question 11

what is a primary follicle?

Answer 11

under the influence of pituitary follicle stimulating hormone (FSH), the oocyte in the primordial follicle enlarges, and the follicular cells become cuboidal in shape

a layer of glycoprotein develops around the oocyte and several layers of follicular cells are added –> the oocyte and follicular cells are now arranged in the primary follicle

the connective tissue which immediately surrounds the primary follicle is gradually organized into two distinct zones, the theca interna next to the follicular cells and the outer theca externa which is continuous with the ovarian stroma

Question 12

what is a secondary follicle?

Answer 12

the primary follicle continues its maturation and becomes a secondary or antral follicle when a fluid llned cavity which displaces the follicular (granulosa) cells can be identifed – the initial development of the cavity is known as the antrum

the immature secondary follicle consists of the oocyte surrounded by several layers of granulosa cells called the corona radiata, the antrum which contains fluid secreted by the granulosa cells, and the immediate connective tissue organized into the theca interna and theca externa

Question 13

what is a Graafian follicle?

Answer 13

after the secondary follicle is formed, further growth of the oocyte ceases and the first meiotic division is completed just before ovulation

at this stage, the oocyte becomes known as the secondary oocyte and commences the second meiotic division

the follicular antrum (FA) enlarges markedly and the zona granulosa (ZG) now forms a layer of even thickness around the periphery of the follicle – the corona radiata (CR) remains attached to the zona granulosa by thin bridges of cell –> before ovulation, these bridges break down and the oocyte, surrounded by the corona radiata, floats free inside the follicle

at ovulation, the mature follicle ruptures and the ovum, made up of the secondary oocyte, zona pellucida and corona radiata, is expelled into the peritoneal cavity near the entrance to the fallopian tube

the second meiotic division of the oocyte is not completed until after penetration of the ovum by a spermatozoon

Question 14

what happens to the corpus luteum if there is pregnancy?

Answer 14

the granulosa lutein cells and theca lutein cells have formed the corpus luteum which is maintained if pregnancy occurs

the cells of the corpus luteum secrete estrogen as well as progesterone which maintain the uterine endometrium in anticipation of implantation

Question 15

what is the corpus albicans?

Answer 15

if pregnancy does not occur, the corpus luteum degenerates and it becomes infiltrated with collagenous fibrils and the hormone secreting cells cease functioning and die

the luteal cells are removed by macrophages in the area

the fibrous structure is now termed the corpus albicans because of its white appearance in the living ovary; it is essentially an acellular scar

Question 16

what is the function of the fallopian tubes?

Answer 16

they carry ova from the surface of the ovaries to the uterine cavity and are also the site of fertilization by spermatozoa

Question 17

what are the 4 parts of the fallopian tube?

Answer 17

1. infundibulum
2. ampulla
3. isthmus
4. intramural part

Question 18

what are the components of the uterus?

Answer 18

1. ectocervix
2. endocervix
3. endometrium
4. myometrium

Question 19

what are the components of the endometrium?

Answer 19

1. decidua basalis

the decidua basalis is adjacent to the myometrium

2. decidua functionalis

the functionalis is lost in the menstrual ow

Question 20

what does the myometrium of the uterus look like histologically?

Answer 20

it is composed of interlacing bundles of smooth muscle arranged in ill-defined layers

there are bundles of fibers in transverse , longitudinal and oblique section

Question 21

what are the phases of the endometrium during the menstrual cycle?

Answer 21

1. early proliferative
2. proliferative
3. early secretory
4. late secretory
5. early menstrual phase

Question 22

what does the endometrium look like during the early proliferative phase of menstruation?

Answer 22

following the cessation of menstruation, the glands, stroma and vessels proliferate, and the endometrium gradually becomes thicker

at higher magnification straight tubular endometrial glands can be seen

at very high magnification, the proliferating epithelium consists of columnar cells with basally located nuclei, and prominent nucleoli

mitotic figures can be seen in the epithelium and in the stroma

Question 23

what does the endometrium look like during the proliferative phase of menstruation?

Answer 23

this is the late proliferative stage

the functionalis has increased in thickness, while the basalis shows little change

the tubular glands are becoming coiled and more closely packed

mitotic figures are prevalent and the stroma is somewhat edematous

Question 24

what does the endometrium look like during the early secretory phase of menstruation?

Answer 24

ovulation marks the onset of the secretory phase

the coiled appearance of the glands is more pronounced and the endometrium approaches its maximum thickness

under the influence of progesterone, the glandular epithelium is stimulated to synthesize glycogen –> initially, the glycogen accumulates to form vacuoles in the basal aspect of the cells, thus displacing the nuclei towards the center of the now tall columnar cells

this basal vacuolation of the cells appears on day 16 and is the characteristic feature of early secretory endometrium

Question 25

what does the endometrium look like during the late secretory phase of menstruation?

Answer 25

it is characterized by a saw-tooth appearance of the glands, containing copious thick glycogen and glycoprotein-rich secretions

at very high magnification in micrograph the cytoplasmic vacuoles can now be seen on the luminal aspect of the cell, and the nucleus has returned to its basal position –> vacuoles contain glycogen and glycoproteins that are secreted into the glandular lumen by apocrine-type secretion

mitotic figures are absent

the stroma now is at its most vascular and interstitial fluid begins to accumulate between the stromal cells

endometrial stromal granulocytes are found in the stroma at this stage

Question 26

what does the endometrium look like during the early menstrual phase of menstruation?

Answer 26

in the absence of implantation of a fertilized ovum, degeneration of the corpus luteum results in cessation of estrogen and progesterone secretion

in turn, this initiates spasmodic constriction in the spiral arterioles of the endometrial decidua functionalis –> the resulting ischemia is initially manifest by degeneration of the super cial layers of the endometrium and leakage of blood (L) into the stroma – stromal cells disaggregate and the endometrial glands collapse

these features are indicative of early necrosis of glands and stroma – these cells have died by apoptosis

further ischemia leads to degeneration of the whole decidua functionalis, which is progressively shed as menses –> menses is thus composed of blood, necrotic epithelium and stroma

by day 3 to 4 of menstruation, most of the stratum functionalis has been shed and proliferation of the basal layer of the endometrium has begun again

Question 27

what are the characteristics of the endocervix?

Answer 27

the mucous secreting epithelial lining of the endocervical canal is thrown into deep furrows and tunnels, giving the appearance in two dimensions of branched tubular glands

mucous-secreting columnar cells line the cervix in the area adjacent to the uterus

unlike the uterus, the mucosa of the cervix lacks spiral arteries and is not released into the menstrual flow – also there are lymphocytes in the superficial stroma

Question 28

what is the transformation zone of the cervix?

Answer 28

the irregularly defined junction of squamous and columnar mucinous epithelium

this squamocolumnar junction migrates to the ectocervix during puberty

as females age, squamous metaplasia causes the junction to recede back into the endocervical canal

Question 29

what types of cells are in the ectocervix?

Answer 29

the ectocervical epithelium is nonkeratinizing, stratified, squamous, and rich in glycogen in the sexually mature period

it undergoes cyclic changes during the menstrual cycle under the influence of estrogens and progesterone

below the surface epithelium is the stroma of the cervix

Question 30

what types of cells are in the vagina?

Answer 30

it is lined with non-keratinized stratified squamous epithelium, however, a slight amount of keratinization may appear during the menstrual cycle

under the basement membrane of the epithelium is a lamina propria of fibrous connective tissue which becomes less dense near the smooth muscle

several thin-walled veins are found in the deeper regions of the connective tissue

the vagina does not contain glands

the smooth muscle of the vagina is arranged in two indistinct layers; an inner circular layer and outer longitudinal layer

an adventitia of dense connective tissue lies outside of the muscle layer