Good Overview of Female Repro Tract
What is menarche?
1st menstrual flow (period); between 9 to 15 years; marks end of puberty and start of reproductive life span.
What marks the end of reproductive years?
Menopause: between 45 to 55 years, cycle become infrequent and then ceases.
Good slide of oocyte stages
Before puberty, what type of follicles are contained within the ovary?
What is the release pattern of gonadotropin-releasing hormone (LHRH)? What does it stimulate?
Stimulates a smiliar pulsatile release of FSH and LH from basophils in anterior pituituary. Ultimately results in follicular development and menstrual cycle.
Hormone Summary slide
Name the layers of the ovary. What covers it?
Cortex and Medulla layers.
Covered by germinal epithelium.
What does the cortex of the ovary contain?
Ovarian follicles and corpus luteum
What does the medulla of the ovary contain?
1. Richly vascularized Loose fibroelastic CT
2. Interstitial glands that secrete estrogen
3. Hilus cells (similar to Leydig cells) that secrete androgens
What is germinal epithelium?
Modified peritoneum that covers ovary.
What is germinal epithelium derived from and composed of?
Derived from mesothelium
Composed of simple cuboidal
Where is the tunica albuginea located in reference to the ovary?
It is the dense CT layer beneath the germinal epithelium
1. Germinal epithelium
2. Ovarian follicles
3. Primordial follicles
4. Cortical region
5. Medullary region
Identify the numbered areas of the ovary.
1. Follicular cells
4. Tunica albuginea
5. Germinative epithelium
Identify the numbered areas of the ovary.
What is housed on the stroma of the Ovarian Cortex?
CT framework, stromal cells and ovarian follicles
When and from where during embryogenesis do primordial germ cells/oogonia come from?
-Derived from the yolk sac endoderm
-Migrate to developing gonads in week 6 of development.
-Undergo mitosis until end of month 5 to make between 5 and 7 million oogonia
-About 1 million get surrounded by follicular cells and survive to birth. Remain undergo atresia.
What are primary oocytes?
Oogonia that survived and entered prophase of Meiosis I
In the ovary, at what stage does meiosis of a primary oocyte stop?
The diplotene stage of meiosis I (prophase)
Of the 1 million oocytes present in an ovary at birth, how many remain at the onset of puberty?
List the 4 types of ovarian follicles. Identify whether each is FSH dependent or independent.
1. Primoridal follicles- independent
2. Primary/preantral follicles- independent
3. Secondary/antral follicles- dependent
4. Mature/Graafian/preovulatory follicles- dependent
What does each follicle contain?
an oocyte surrounded by single or multilayers of follicular or graulosa cells
List the two stages of follicular development.
1. Non-growing follicles: primordial
2. Growing follicles: primary, secondary & Graafian
Name the two types of primary follicles.
1. Unilaminar primary follicles- 1 cell layer, has zona pellucida forms here
2. Multi-laminar Primary follicles: stratified layers
What are the stratified layers in a multi-laminar primary follicle called? what is the proliferation triggered by?
-Proliferation is due to activin produced by the primary oocyte
1. Granulosa layer
2. Basement membrane
3. Zona pellucida
Identify the structures indicated by the numbers.
2. Follicular cells
Identify the two structures
Regarding the zona pellucida, what appears during the primary follicle stage and what are its functions?
Amorphouse substance that separates the oocyte from the follicular cells that contains ZP1-ZP3 secreted by the oocyte to form and extracellular coat of glycoproteins.
Why is ZP-3 the most important protein in the zona pellucida glycoprotein coat?
It acts as receptor for sperm binding and induces the acrosomal reaction.
What do stromal cells around the multilaminar primary follicle form?
1. Inner theca interna (richly vascularized cellular layer), and
2. Outer theca externa (fibrous c.t.)
What do theca internal cells do?
Produce steroids: Has LH receptors, produce androstenedione that is then converted to estrogen estradiol by the enzyme aromatase
What separates granulosa cells and theca interna?
A thickened basal lamina
What are secondary/antral follicles characterized by?
The accumulation of fluid known as liquor folliculi among the granulosa cells
What is the proliferation of granulosa cells dependent on?
FSH (they have FSH receptors)
What induces FSH receptor expression in granulosa cells of secondary/Antral follicles?
FSH + estrogen
What inhibits further oocyte growth during the secondary/antral follicle stage?
What is liquor folliculi?
Plasma exudate that contains GAGs, proteoglycans, steroid binding proteins and hormones (estradiol, inhibin, activin, etc)
What happens to the majority secondary/antral follicles that reach that stage?
They undergo atresia and some of their associated granulosa cells form interstitial glands that will secrete estrogen until menopause.
2. Granulosa cells
3. Zona pellucida
Identify the areas in the secondary follicle.
What are the layers of the Mature Graafian Follicle?
1. Antrum- liquor folliculi form single fluid filled chamber
2. Cumulus Oophorus- rearranged granulosa cells around the primary oocyte
3. Corona Radiata- the single layer of granulosa cells immediately surrounding the primary oocyte
1. Granulosa cells
3. Corona radiata
4. Cumulus oophorus
Identify the labeled parts of the Graafian follicle
2. Granulosa layer
3. Basement Membrane
4. Theca interna
5. Theca externa
Identify the layers of the Graafian follicle.
What causes the cumulus oophorus composed of the primary oocyte, the corona radiata, and associated follicular cells, to detach from its base and float freely within the liquor folliculi?
Continued formation of liquor folliculi. It's like filling a water balloon.
What occurs by the 14th day of the menstrual cycle in regards to estrogen so that ovulation can occur?
Estrogen blood levels are high. This in turn shuts off FSH and stimulates a sudden surge of LH
What does the surge of LH trigger?
Release of a local factor called meiosis-inducing factor, which influences the primary oocyte to complete meiosis I, resulting in the formation of a secondary oocyte and the first polar body.
After the secondary oocyte and first polar body are formed, what happens to the oocyte?
It enters meiosis II and arrests in metaphase.
How is the secondary oocyte released from the ovary?
1. Surface where the Graafian follicle is pressing against tunica albuginea, loses blood supply and forms a spot called stigma.
2. CT tissue at stigma and wall of Graafian follicle contact and degenerate
3. Opening is formed between the peritoneal cavity and the antrum of the Graafian follicle.
What is released during ovulation and where?
-Secondary oocyte w/corona radiata is released.
-Into the peritoneal cavity near the opening of the fallopian tube.
When does ovulation ALWAYS occur?
The 14th day BEFORE the beginning the menstruation.
How long can a secondary oocyte survive after being swept into the fallopian tube?
24 hours then will degenerate if not fertilized.
What is the corpus luteum formed from?
Remnants of the Graafian follicle that ovulated that has its structure changed by high levels of LH
What is the function of the corpus luteum?
A temporary endocrine gland that manufactures and releases hormones that support the uterine endometrium.
1. Theca lutein cells
2. Granulosa lutein cells
Identify the cells types above.
What are granulosa lutein cells? What do they produce?
-Modified granulosa cells that make up 80% of the corpus luteum
-Steroid producing cells; mainly progesterone and some estrogens
What are theca lutein cells? What do they produce?
-Modified theca interna cells that make up 20% of the corpus luteum;
-Secrete progesterone and some estrogens
What is the fate of the corpus luteum if pregnancy does not occur?
It becomes the corpus luteum of menstruation then turns into the corpus albicans
What is the fate of the corpus luteum in pregnancy?
1.The granulosa-lutein and theca-lutein cells produce progesterone and estrogen= suppressed LH/FSH
2. Turns into the corpus luteum of pregnancy after it is maintained for 3 months by hCG from placenta
3. Continues to secrete hormones for several months
What is the corpus albicans?
A remnant of the corpus luteum in non-pregnancy that becomes a fibrous structure composed of collagen type I and fibroblasts
1. Ovarian Stroma
Identify the labeled structures
What are Atretic Follicles?
Follicles that undergo degeneration.
Of all the follicles present in the ovaries at menarche,what percent develop to maturity and undergo ovulation?
Hormonal regulation of ovarian function.
What are the 4 parts of the oviducts?
infundibulum, ampulla, isthmus, and intramural
Where in the oviducts does fertilization usually occur?
In the ampulla (reconstitutes the diploid number of chromosomes)
What are the functions of the oviducts
1. Receiving of ovum from ovary
2. Usual site of fertilization of ovum (ampulla)
3. Provides nourishment for fertilized ovum
4. Transports fertilized ovum to the uterine cavity
Name the 3 layers in the wall of the oviducts.
What types of cells are found in the mucosa layer of the oviduct? What are their functions?
1. Ciliated simple columnar cells- cilia cause movement of viscous film that covers its surface towards the uterus
2. Simple columnar secretory- secrete the viscous film
What is the purpose of the viscous film that is secreted by the secretory columnar cells in the mucosa layer of the oviduct?
1. Protect & supply nutrients to fertilized oocyte
2. Promote capacitation of the sperm
1. Secretory Cells
2. Cilicated Cells
Identify the types of oviduct mucosal layer cells indicated by the arrows.
What is the function of the muscularis layer of the oviduct?
The contractions of muscularis of the oviduct together with the movement of the liquid film in its lumen transport the oocyte or the conceptus towards the uterus.
What layer of the oviduct is this?
Name the 3 regions of the uterus.
4. Internal os
5. External os
Identify the areas of the uterus.
Name the 3 layers of the uterine wall.
2. Myometrium (bulk of the wall)
What is the perimetrium of the uterine fundus and body covered by?
What is the histological make up of the myometrium?
Bundles of smooth muscle fibers separated by CT
In the myometrium, what is the size and number of muscle cells related to?
What happends to the myometrium during pregnancy? Menopause?
Pregnancy- grows by hypertrophy AND hyperplasia
Menopause- it diminishes
What is this tissue?
What cells/glands are present in the endometrium between menarche and menopause?
1. Simple columnar epithilium that is either cliiated or secretory
2. Tubular glands that extend to the myometrium (structure varies depending on phase in cycle)
What are the two layers of the endometrium?
1. Stratum Basale
2. Stratum Functionale
What is the stratum basale of the endometrium?
The basal layer that is retained at menstruation. It regenerates the endometrium for next cycle.
What is the stratum functionale of the endometrium?
The functional layer that is sloughed off at menstruation.
Summary of uterine layers and blood supply.
Name the path that blood takes from the uterine artery to get to the endometrium.
1. Uterine artery to arcuate artery
2. Arcuate artery to radial artery
3. Radial artery to either straight (basal) artery or coiled artery (superficial)
3. Uterine artery
4. Arcuate artery
5. Coiled/Spiral artery
6. Straight artery
7. Radial artery
Identify the layers of the uterus and the arteries.
What are the cyclic changed of the endometrium controlled by?
Estrogen & Progesterone
When does day 1 of the menstrual cycle start?
The first day of menses
Identify the 3 phases of the menstrual cycle.
1. Mense days 1-4
2. Proliferative/Follicular days 5-14
3. Secretory/Luteal days 15-28
What occurs during the mense phase of the menstrual cycle?
Desquamation of the functional layer of endometrium.
What occurs during the proliferative/ follicular phase of the menstrual cycle?
Reepithelization of the lining of the endometrium and renewal of the functionalis layer
What occurs during the secretory/luteal phase of the menstrual cycle?
Thickening of the endometrium as a result of edema and accumulated glycogen secretions of the highly coiled endometrial glands.
Menstrual Cycle Chart
1. Surface epithelium
Identify the layers of the endometrium
Growth of endometrial epithelium & glands
If If implantation occurs, what do embryonic trophoblast cells produce?
What is the function of hCG?
to stimulate the corpus luteum to continue secreting progesterone
What effect does progesterone have on the uterine glands during pregnancy?
Makes the uterine glands wider, more tortuous and able to contain more secretions than during secretory stages.
What happens to the endometrium during the beginning of pregnancy?
It becomes thicker
What is an ectopic pregnancy? What are the complications?
1. Embryo implants in oviduct (or anywhere outside uterus)
2. The oviduct can burst and cause extensive hemorrhage that can be fatal if not treated immediately.
What is placenta previa?
When the embryo implants close to the internal os. Blocks vagina, so must be delivered via cesarean section.
What is special about the cervical part of the uterus?
1. It does not contain spiral arteries
2. Epithelium is not sloughed off during menstruation
Name the two parts of the cervix.
2. Ectocervix (where you do a pap)
What type of epithelium and glands are found in the endo and ectocervix?
1. Endo-Simple columnar epi & cervical glands
2. Ecto- stratified squamous, no glands
Define 'vagina' and its function.
-A fibromuscular tube
-Function is to assist in transport of sperm to uterus and in expulsion of the newborn.
Name the three layers of the vagina.
2. Lamina propria
What types of tissue are found in each vaginal layer?
-Mucosa= non-keratinized stratified squamous epithelium NO GLANDS
-Muscularis=muscle (inner circle, outer longitudinal)
-Adventitia= dense CT, rich elastic fibers
When does glycogen stored in the superficial layer of vaginal epithelial cells, reach maximal levels?
At ovulation (then it is shed)
What breaks down glycogen in the vagina, and what is the by product?
Bacteria break it down. Produces lactic acid.
What is the pH in the vaginal lumen? Why?
pH ~3 due to lactic acid from bacteria
Why is a low pH needed in the vagina?
It inhibits growth of pathogenic bacteria and fungi. It also limits the time in which sperm can survive in the vagina.
Layers of the Vagina
What is a pap smear?
A diagnostic tool in evaluating vaginal and cervical mucosae where superficial epithelial cells are scraped, spread, fixed and stained.
How many lobes of tubuloalveolar compounds are in each mammary gland?
What separated the lobes in the mammary glands?
Denst CT & Adipose tissue
How does each lobe in the mammary gland excrete its products?
Each has an excretory lactiferous duct.
What causes breast enlargement during puberty?
Accumulation of adipose tissue and CT with increased growth & branching of lactiferous ducts due to increase in ESTROGEN