LM 1.1: Female Reproductive System Flashcards
what are most of the structures of the female genital tract are derived from?
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
what are most of the structures of the male genital tract are derived from?
mesonephric ducts aka Wolffian ducts
what are Gartner duct cysts?
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
what structure holds the ovaries in place?
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
what is the vulva?
labia + clitoris
what are the components of the ovarian stroma?
- spindle shapped cells
- fine collagen fibers
- ground substance
- scattered bundles of smooth muscle
what is the cortex of the ovary? what are the different cell types?
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:
- corpora lutea: responsible for estrogen and progesterone production
- corpora albicantes: degenerate and former corpora lutea
- atretic follicles
what are the characteristics and components of the ovary medulla?
- highly vascular
- contains hilum cells
it’s the central zone of the ovarian stroma
what is the blood supply of the ovary?
- ovarian artery
- ovarian branches of uterine artery
- 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
what does a primordial follicle look like? where are they found?
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
what is a primary follicle?
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
what is a secondary follicle?
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
what is a Graafian follicle?
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
what happens to the corpus luteum if there is pregnancy?
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
what is the corpus albicans?
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
what is the function of the fallopian tubes?
they carry ova from the surface of the ovaries to the uterine cavity and are also the site of fertilization by spermatozoa
what are the 4 parts of the fallopian tube?
- infundibulum
- ampulla
- isthmus
- intramural part
what are the components of the uterus?
- ectocervix
- endocervix
- endometrium
- myometrium
what are the components of the endometrium?
- decidua basalis
the decidua basalis is adjacent to the myometrium
- decidua functionalis
the functionalis is lost in the menstrual ow
what does the myometrium of the uterus look like histologically?
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
what are the phases of the endometrium during the menstrual cycle?
- early proliferative
- proliferative
- early secretory
- late secretory
- early menstrual phase
what does the endometrium look like during the early proliferative phase of menstruation?
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
what does the endometrium look like during the proliferative phase of menstruation?
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
what does the endometrium look like during the early secretory phase of menstruation?
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
what does the endometrium look like during the late secretory phase of menstruation?
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
what does the endometrium look like during the early menstrual phase of menstruation?
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
what are the characteristics of the endocervix?
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
what is the transformation zone of the cervix?
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
what types of cells are in the ectocervix?
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
what types of cells are in the vagina?
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
