Histology: Female Reproductive System Flashcards
What is the main function of the reproductive system?
to perpetuate the species
What is the role of the reproductive system for males?
production of sperm and delivery to the female
What is the role of the reproductive system for females?
production of eggs, providing a location for fertilization, providing a location to house and support embryonic development
What is the essential organ of the reproductive system?
Gonads
What do gonads produce?
Gametes (or germ cells)
What produces gametes?
Gonads
How many chromosomes do gametes have?
gametes = germ cells
23 chrosomes (haploid); half as many as normal body cell
What are the gonads in males vs females
Males = testes Femaels = ovaries
There are 2 categories of female reproductive system. What are they?
External Organs
and
Internal Organs
What are the external organs of the female reproductive system?
ie external genitalia
mons pubis, labia majora, labia minora, cliteris, external urethral orifice and vaginal orifice
What are the internal organs of the female reproductive system?
vagina, uterus, uterine tubes, ovaries, and ligaments and supporting structures
Do they ovaries have endocrine or exocrine function?
both.
What is the endocrine function of ovaries?
produce estrogens and progesterons
via steroidogenesis
What is produced in female steroidogenesis?
estrogens and progesterones (for endocrine function of ovaries)
What does estrogen do?
(endocrine function of ovaries)
promotes the growth and maturation of internal and external sex organs
development of the secondary female sex characteristics; promotes breast development
What do progestogens do?
(endocrine function of the ovaries)
prepare internal sex organs (mostly uterus) for pregnancy by promoting changes in endometrium
prepare mammary glands for lactation
What is the exocrine function of the ovaries?
produce female gamete (ovum) via gametogenesis
specifically the ovaries produce and ovulate a secondary oocyte
What is produced in female gametogenesis and where does it take place?
ovum is produced
in ovaries (exocrine function)
Ovaries are homologous to male ____. Meaning what?
testes.
meaning the two organs have same embryological origin.
In first month of development ____ migrate from yolk sac to gonadal primordia.
primordial germ cells
Once in primordia, primordial germ cells divide via ___ and differentiate to form ____
PGCs divide via mitosis
differentiate into oogonia
Oogonia take two paths. Some undergo mitosis and others undergo meiosis. When?
beginning of third month
When do oogonia undergo meiosis?
beginning of the third month
Oogonia begin in meiosis and arrest in ___ so that they are called ____
prophase of first meiotic division
arrested cells are called primary oocytes
primary oocytes are in which state of division?
arrested in prophsae of first meiotic division
primary oocytes become surrounded by _____ and are now known as ____
primory oocytes are surrounded by follicular cells
they are now called primordial follicle
What is the primordial follicle?
the primary oocyte surrounded by follicular cells
What is a follicular cell? What does it surround?
flattened supporting cells
surround primary oocyte to form primordial follicle
Most oogonia have transformed into primary oocytes by what point of development?
7th month
What is atresia?
spontaneous death and subsequent reabsorption (of primary oocyte)
when does atresia take place in development?
beginning the fifth month of fetal development.
continuous throughout woman’s lifetime.
In fetus there are # ovarian follicles.
at birth = #
beginning of puberty = #
where did they go?
5 million in fetus
600,000-800,000 at birth
300,000 at start of puberty
most lost to atresia
Where within the ovaries are the ovarian follicles found?
within the cortex of ovaries
Ovarian follicle is composed of ____
oocyte surrounded by one or more layers of epithelial cells
Are all ovarian follicles the same size?
No.
The size indicates the developmental state of the oocyte
What are the three basic types of an ovarian follicle?
- primordial follicle
- growing follicle
3 mature or graafian follicle
What are the two types of growing follicles?
- primary follicles
2. secondary follicles
What are the two types of primary follicles?
- early or unilaminar primary follicles
2. late or multilayered or multilaminar primary follicles
Primordial follicles
where are they relative to epithelium?
just deep to surface epithelium
Primordial follicles
Do they have a tunica albuginea?
yes. this is dense connective tissue layer
Primordilal follicles
What is the surface epithelium?
germinal epithelium.
because we used to think that this was the site of germ cell development (that’s wrong)
Primordial follicles
What effect does release of FSH have?
FSH released from pituitary gland (gonatotropic cell in anterior lobe)
causes a few primordial follicles to begin follicular growth;
growth in size of primary oocyte, proliferation and changes in follicular cells and proliferation and differentiation of fibroblasts just outside of growing follicles
When FSH influences primordial follicles, is it still called a primary oocyte?
yes.
When does the unilaminar primary follicle form?
After the primordial follicle has undergone enough mitosis/differentiation.
primary follicle
what epithelium does it have around a primary oocyte?
simple cuboidal epithelium
How can you tell when you are no longer a primordial follicle and are now a unilaminar follicle?
simple cuboidal epithelium surrounding primary oocyte means you are now a primary follicle
As the oocyte grows it secretes ___
spermatozoa binding receptor (glycoprotein)
this assembles into an extracellular coat between oocyte and granulosa cells (zona pellucida)
What is spermatozoa binding receptor? What is it secreted by?
glycoprotein secreted by oocyte growing.
forms extracellular coat between primary oocyte and granulosa (zona pellucida)
How is the zona pellucida formed?
by spermatozoa binding receptor (glycoprotein secreted by oocyte growth) forming layer between oocyte and granulosa layer
How does the zona pellucida stain?
acidophilic stain
What are granulosa cells?
Follicular growth causes follicles to become stratified epithelium.
that’s granulosa
What is the difference in epithelium between follicular cells and granulosa cells?
follicular - flattened / squamous cells
granulosa - stratified
What do follicular cells become after proliferation?
granulosa cells
How are granulosa cells connected to each other?
gap junctions
What is at the basement membrane of a granulosa cell?
the boundary of the developing follicle
Once stratified granulosa are visible, what state of follicle growth is it?
late/multilayered/multilaminar primary follicle
All together, the granulosa cells make up ___.
stratum granulosum
Is the late primary follicle (multilayered/multilaminar primary follicle) still a primary oocyte?
yes.
What kind of cells surround the developing follicle?
stromal cells
What are theca folliculi?
what are they developed from?
sheath of connective tissue cells
develop from stromal cells surrounding the developing follicle
The theca folliculi differentiate into 2 parts….
- theca interna
- theca externa
often difficult to distinguish
What hormone stimulates theca interna? What does it cause?
LH stimulates theca intera to synthesize/secrete androgens (precursor to estrogen)
this is an endocrine function
What is within the theca interna?
fibroblasts, collagen bundles, blood vessels, CUBOIDAL secretory cells
What is the theca externa made up of?
fibrous outer portion of the theca folliculi.
smooth muscle cells, fibroblasts, bundles of collagen
Granulosa cells secrete ___ to form ____
secrete fluid to form antrum
The antrum is formed by what?
fluid secreted by granulosa cells; and re-organization of granulosa cells so that fluir is near each other
Once the antrum is visible, what follicle is it?
secondary (antral) growing follicle
granulosa cells of secondary follicles begint o form what?
corona radiata (outer layer of ovary)
the corona radiata cells are connected via ___
gap junctions
because they’re granulosa cells and all granulosa cells (also the stratum granulosa) connected via gap junction
Corona radiata is connected to other granulosa cells by ____
cumulus oophorus
What is the cumulus oophorus?
this is the connection of the corona radiata to other granuolsa cells
Once at secondary follicle stage, does primary oocyte continue to grow?
no.
remains this size. this is the final stage of growth for primary oocyte (still arrested in prophase 1 of meiosis 1)
When is follicle called the graafian/mature follicle?
when the secondary/antral follicle reaches 10mm in diameter
Which of the secondary follicles progress into the mature/graafian follicular stage?
the largest and most dominant secondary follicles
How many graafian follicles are produced each month?
Only 1 or 2 because only the largest/most dominant secondary follicles reach graafian/mature follicular stage.
Why is the graafian follicle sometimes called the pre-ovulatory follicle?
because the graafian/mature follicle contains the oocyte that will be ovulated
How large is the graafian/mature follicle?
can be 20-30mm in diameter
so big that protrudes through the surface of the ovary and will extend through the thickness of the ovarian cortex
What happens to the antrum in graafian/mature follicles?
continues to grow larger
What happens to secondary/antral follicles that do not progress into the graafian/mature follicular stage?
undergo atresia
apoptosis of granulosa cells
What happens 24 hours before ovulation?
LH surge from ganatotropic cells from anterior pituitary
causes granulosa cells to secrete progestogen and estrogen
What do progestogen and estrogen do to the follicle just before ovulation?
activate proteolytic enzymes that break down stratum granulosa and tunica albuginea
What is ovulated with the oocyte?
coronada radiata, follicular fluid from antrum, some cells of cumulus oopherus
At what stage is the oocyte when it is ovulated?
secondary oocyte arrested in metaphase of meiosis II
When is the secondary oocyte formed?
After meiosis I is complete
What kind of oocyte is in a graafian/mature follicle?
starts with primary oocyte
just before it ovulates it is a secondary oocyte
What happens to the granulosa cells and theca cells left behind after ovulation?
forms corpus hemeragicum (has a large blood clot)
What is the corpus hemeragicum?
large blood clot with the granulosa cells and theca cells that are left behind after ovulation
What does the corpus hemeragicum become?
after leutinization, granulosa cells and theca interna cells re-organize to form corpus luteum
What is corpus luteum?
the granulosa cells and theca interna cells of the corpus hemeragicum become leutinized to form corpus luteum
What are the 2 cells of the corpus luteum?
- granulosa lutein cells
2. theca lutein cells
What happens to granulosa lutein cells?
undergo hypertrophy (get bigger)
What are granulosa lutein cells derived from?
granulosa cells
What do granulosa lutein cells produce?
progesterone
What happens to theca lutein cells?
increase slightly in size
What are theca lutein cells derived from?
theca interna
What is the difference between theca lutein cells and granulosa lutein cells in their staining and location and size?
granulosa lutein cells are centrally located
theca lutein cells are peripherally located
theca lutein cells stain darker than granulosa lutein cells
theca lutein cells are much smaller than granulosa lutein cells
What do theca lutein cells produce?
estrogens
What do theca lutein cells produce and what do granulosa lutein cells produce?
theca lutein cells produce ESTROGEN
granulosa lutein cells produce PROGESTERONE
What happens to corpus luteum if fertilization does not occur?
begins to degenerate after 10-12 days; becomes nonfunctional in 14 days
corpus luteum of menstruation is 14 days.
What is the degenerated corpus luteum replaced by?
corpus albicans which is scar tissue.
sinks deeper into the cortex and disappears after several months
What is the corpus albicans?
the scar tissue that replaces degneerated corpus luteum if feritlization does not occur
sinks deeper into cortex and disappears after several months
What happens to corpus luteum if fertilization does occur?
it remains and forms the corpus luteum of pregnancy (increases in size)
after pregnancy ends degenerates into corpus albicans
What is the corpus albicans composed of?
primarily collagen
Describe the physical characteristics of uterine tubes?
paired muscular tubes, 12 cm lenght
What takes place in the uterine tubes?
feritlization
What are the wall modification of uterine tube?
folded mucosa with simple columnar epithelium
thick muscularis (interwoven layers of smooth muscle)
and serosa
What type of epithelium is found in the uterine tube?
simple columnar epithlium on folded mucosa
Describe the muscularis layer of the uterine tube
interwoven layers of smooth muscle
Are the uterine tubes covered by serosa or adventitia?
serosa.
What are the two types of cells found in the uterine tubes?
- ciliated cells
2. secretory cells (pegs cells)
What do the ciliated cells of the uterine tubes do?
move the oocyte towards the uterus
What do peg cells of the uterine cells do?
apical end bulges into lumen
produce nutritive fluid covering epithelium
aka secretory cells of uterine tubes
Describe the staining of ciliated cells vs peg cells in uterine tube
peg cells aka secretory cells are darker staining than ciliated cells
What are the 3 layers of the uterus?
- Perimetrium (outermost)
- Myometrium
- Endometrium (Inner)
Describe perimetrium. Is it adventitia or serosa?
Outermost layer of uterus
serosa on upper part; adventitia on lower part
Describe the myometrium
middle (THICKEST) layer of uterus
bundles of smooth muscle (4 poorly defined layers) separated by connective tissue containing many blood vessels
Describe the endometrium.
What kind of epithelium? What kind of cells?
Innermost layer.
simple columnar epithelium with both ciliated and secretory cells.
has underlying lamina propria that contains uterine glands.
What are the two parts of the endometrium?
- basal layer (stratum basale) - deepest layer
2. functional layer (stratum functionale) - superficial layer
What influences thickness change in functional layer of endometrium?
ovarian hormones
What do ovarian hormones do to the functional layer of the endometrium?
induce thickness change by shifting ovarian hormones
What is sloughed away as monthly menstrual flow?
Functional layer (stratum functionale) of the endometrium
What is the cervix?
narrow end of the uterus
Why is the endometrium different at the cervix compared to rest of uterus?
Endometrium is not sloughed off during menstruation in the cervix
contains large cervical galnds (branched mucous glands)
lacks spiral arteries
What are cervical glands?
Large branched mucous glands in endometrium of cervix
increase in mucous production 10fold at mid-cycle to aid in sperm migration
What is the transformation zone of cervix?
squamocolumnar junction
from mucous-secreting simple columnar epithelium of cervical canal (and uterus) to non-keritinized stratified squamous epithelium of ectocervix
What is the ectocervix?
what type of epithelium?
vaginal part of cervix
nonkeratinized stratified squamous epithelium
What part of the uterus is a common site of metaplastic change?
cervix
What are metaplastic changes in the cervix usually due to?
persistent injury due to infection
are often pre-cancerous and seen as metaplastic stratified squamous epithelium
What are the wall modifications of the vaginal canal?
nonkeritnized stratified squamous epithelium of mucosa
muscular layer contains 2 indistinct inner circular and outer longitudinal layers
covered by adventitia because retroperitoneal
What are mammary glands?
modified tubuloalveolar apocrine sweat glands
What do mammary glands produce/secrete? how is it secreted?
milk
released via merocrine and apocrine mechanism
Explain the difference between merocrine mechanism and apocrine mechanism of mammary glands?
Merocrine “mer-exo-crine” = protein component of milk released via exocytosis
apocrine “apinchocrine” = fatty or lipid component of milk to be released by apical portion of cell pinching off
Why is it debatable if apocrine mechanism takes place in mammary glands?
because the secretion is free or contains very little cytoplasm
true apocrine mechanism contains lots of cytoplasm in pinched off portion
What 4 things cause the development of pregnancy mammary gland function?
estrogens and progesterones secreted from corpus luteum and then by placenta
prolactin from pituitary gland
gonatocorticoids from adrenal cortex
