Female Histology & VM Lab - Bolender Flashcards
What are the three major components of the male or female reproductive system?
- Gonads
- Ducts
- External genitalia
- The ovary is covered by an epithelium that goes by what name?
- What type of epithelium is it?
- What other epithelium is continuous with this one?
-
Germinal epithelium
- Note the misnomer - this epithelium does not give rise to the gametes or even the follicular cells surrounding the oocytes.
- (Simple) Cuboidal
- Epithelium of the mesovarium
What thin layer is located just deep to the germinal epithelium of the ovary?
What is this layer rich with?
Tunica Albuginea
rich in collagen
The ovary is subdivided in to what two general areas?
Where are they in relation to each other?
Cortex and medulla
(the boundary between them is indistinct)
The medulla is in the central part of each ovary (i.e., deep to the cortex)
What does the medulla of the ovary contain?
- blood vessels
- nerves
- lymphatics
- loose connective tissue
What does the cortex of the ovary contain?
- Ovarian follicles!
- follicles are surrounded by stromal (intersitial) cells
- Where are hilar cells located in the ovary?
- What do they secrete?
-
BONUS CHALLENGE:
- Under what circumstances would hilar cell hyperplasia occur?
- Near the hilum! (where blood vessels and nerves enter & exit the ovary)
- Similar to Leydig cells - secrete testosterone
- Possilbly a remnant from the developmental ambisexual gonad? (Web)
- Any condition where hCG is increased:
- choriocarcinoma
- pregnancy
- hCG administration
Name five stages an ovarian follicle will pass through prior to fertilization.
- Primordial follicle
- Ulilaminar primary follicle
- Multilaminar primary follicle
- Secondary follicle
- Mature or Graafian follicle
- In what stage of meiosis is a primary oocyte held in?
- When does this last until?
- In what stage of meiosis is a secondary oocyte held in?
- When does this last until?
- Primary oocyte: Halted at Prophrase I
- This ends shortly prior to ovulation
- Note: this is the state most oocytes are suspended in while they wait to mature, etc.
- Secondary oocyte: Halted at Metaphase II
- This ends with fertilization
What are the two components of a primary follicle?
- Primary oocyte
- Follicle cells (single layer)
True or false: the follicle cells of the primordial follicle have a basement membrane.
At the primordial follicle stage, what type of epithelia are follicular cells?
False
Simple squamous
What is the (notably large) nucleus of the oocyte called during the primary oocyte phase of oogenesis?
The Germinal Vesicle
What protein keeps immature oocytes arrested in the first meiotic prophase?
What secretes this protein?
Oocyte Maturation Inhibitor
Secreted by the follicle cells surrounding the oocyte
[Sensible name, sensible source? Witchcraft!]
Explain the difference between a primary oocyte and a primary follicle.
[Making sure you’re really awake!]
Primary oocytes are found within primordial follicles up through ovulation, and become secondary oocytes around that time.
The follicle, on the other hand, passes through all of its phases prior to ovulation, from primordial, through primary, to mature/secondary.
What do the follicle cells of a primary follicle have that those of a primordial follicle do not?
At the primary follicle stage, what type of epithelia are the follicle cells now?
A basement membrane
Cuboidal (recall: in the primordial follicle, they are more squamous)
Once a primary follicle has reached the multilaminar stage, what new name is given to the follicle cells?
What collective name is given to the layers altogether?
Individually: Granulosa cells
Collectively: Membrana Granulosa
- What acellular layer comes to directly surround the oocyte of a primary follice?
- What cells are responsible for secreting the components that form this layer?
- How does this layer appear on H&E stain
- Zona Pellucida
- Secreted by the innermost layer of granulosa cells
- Eosinophillic
As the primary follicle continues to grow, it **compresses **the surrounding stromal cells, forming a capsule-like layer called what?
Theca Interna
What space forms within the membrana granulosa of secondary follicles?
How does the space form?
The Antrum
The granulosa cells create spaces within the membrana by secreting “follicular fluid” which coalesce into a single antrum.
How does the theca externa of the secondary follicle form?
Same way as the theca interna:
Continued expansion of the follicle results in the formation of a second thecal layer.
The morphological changes in the follicle as it matures from primary to secondary are mediated by what?
FSH
- What determines which secondary follicles will containue maturation to the point of ovulation?
- Once a follicle reaches the Mature or Graafian stage and becomes dominant, how does it inhibit the further maturation of other follicles?
- Density of FSH receptors
- Production of inhibin (Inhibin B), which negatively regulates FSH release from the pituitary
[aka the first one to eat up all the FSH gets big and mean and doesn’t let anyone else have any]
What physiological mechanism explains why women are born with hundreds of thousands (even millions?) of follicles, but will only ovulate ~400 times during their life?
Follicular Atresia (Degeneration)
- Atresia is a hormone-controlled apoptotic event.
- Around 20 follicles can become mature during any given ovarian cycle. Only one becomes dominant and undergoes ovulation. The others become atretic.
- However, follicles can become atretic and degenerate at any time during follicle development.
What stages of follicles leave a scar in the ovary if they become atretic?
Secondary (antral) or Mature follicles that become atretic will leave a scar.
Primordial or primary follicle atresia leaves no visible scar.
What is a “glassy membrane”?
A thickening of the follicle BM along with a scar forms during follicle atresia (of a secondary or mature follicle only)
In a Mature / Graafian follicle:
- Where is the oocyte?
- What is the corona radiata?
- What is the cumulus oophorus?
- Displaced to one side of the antrum
- Granulosa cells immediately surrounding the oocyte
- A cluster of granulosa cells that both surround the oocyte + corona radiata and form a bridge to the rest of the membrana granulosa.
In the hours leading up to ovulation, what changes occur in:
- The oocyte nucleus?
- The ovarian wall adjacent to the dominant follicle?
- The BM of the follicle?
- The oocyte and its corona + cumulus cells?
- The follicle cells of the membrana granulosa?
- Nuclear breakdown and progression to Metaphase II
- Wall thinning due to **collagenases **and prostaglandins
- BM disolved via plasmin
- Follicle cells secrete plasminogen activator
- Detachment from the membrana granulosa
- Start production of progesterone, decrease estrogen release
What is Lutenization?
The process by which the granulosa cells of the post-ovulatory follicle are transformed into steroid secreting cells.
What are the three products of the corpus luteum?
What is the overal purpose of the corpus luteum?
- Progesterone
- Estrogen
- Relaxin
Purpose: Maintain the endometrial lining during pregnancy
Other than lutenized granulosa cells, what other cells of the corpus luteum contribute to hormone production?
Theca interna cells also become lutenized (recall: they were originally stromal cells) and secrete progesterone and androgens.
- What is the lifespan of a normal corpus luteum (CL) of menstruation, assuming pregnancy does not occur?
- When the CL regresses, what does it leave behind?
- 10-12 days
- A scar called the corpus albicans
- What hormone maintains the corpus luteum prior to pregnancy?
- During pregnancy?
- LH (Lutenizing hormone)
- hCG
- What hormone stimulates theca cell androgen production?
- Bonus: Which androgen, specifically?
- What hormone stimulates follicle cell aromatase activity, generating estrogen from that androgen?
- LH
- Androstenedione
- FSH
- What hormone maintains the uterine endometrium in the secretory phase of the menstrual cycle?
- What hormone mediates ovarian wall rupture for ovulation?
- Progesterone
- Progesterone also
- Local levels produced in the follicle prior to ovulation
What are the four sections of the oviduct?
From distal (ovary) to proximal (uterus):
- Infundibulum (+ fimbria)
-
Ampulla
- Longest; over 2/3 of total length
- Isthmus
-
Intramural division
- Within the wall of the uterus
What two types of epithelium are found in the mucosa of the oviduct?
ciliated and non-ciliated simple columnar
Describe the muscularis component of the oviduct wall.
- Inner circular layer
- Outer longitudinal layer
What hormones regulate peristalsis of the smooth muscle of the oviduct?
Estrogen & Progesterone
What are the three layers of the uterus?
From superficial to deep:
- Serosa
- Myometrium
- Endometrium
Describe the muscle layers of the myometrium.
- Inner circular
- Middle oblique
- Outer longitudinal
What hormones stimulate contraction of the myometrium?
What hormones inhibit (“quiet”) contraction of the myomterium?
Stimulate: Oxytocin
Inhibit: Progesterone & Relaxin
What type of epithelium is present in the endometrium?
What about the epithelium of the cervical canal?
Both: Simple columnar
Name and describe the zones of the endometrium.
- Outer (closest to lumen) 2/3: Functional zone
- Undergoes cyclic changes; sloughed at end of cycle
- Further subdivided:
- Outer compact layer
- Inner spongy layer
- Inner 1/3: Basal zone
- Does not undergo cyclic changes
Describe the dual blood supply of the endometrium.
-
Straight arteries
- Supply only the basal zone
- Insensitive to hormonal fluctuations
-
Spiral arteries
- Supply the functional zone
- Sensitive to progesterone & estrogen; spasm and constrict in the absence of these hormones
- Ischemia contributes to sloughing of tissue during menses
How do the endometrial glands appear during the:
- Proliferative phase?
- Secretory phase?
- Relatively straight but wavy in appearance
- Glands become coiled and sacculated (as they secrete glycogen and other carbohydrates)
Is the cervical endometrium also sloughed off during menstruation?
No.
What epithelium covers the exocervix?
Stratified squamous nonkeratinized epithelium
What is the name for the area at the interface between the simple columnar and stratified squamous epithelia in the cervix?
How is this area clinically important?
Transformation Zone
Exfoliated cells from this area are what are gathered during a PAP smear to check for changes that may suggest cervical cancer.
What are the three layers of the vaginal wall?
- Mucosa
- stratified squamous nonkeratinized epithelium
- Muscularis
- inner circular
- outer longitudinal
- Adventitia
- elastic fibers & pressure receptors
- How many days is the “model” menstrual cycle?
- Of these, which days are the menstrual phase?
- Which days are the proliferative (folliclar) phase?
- Which days are the secretory (luteal) phase?
- 28 days
- Days 1-5
- Days 5-15
- Days 15-28
Describe the condition of anovulatory cycling.
What hormones are dominant in this condition?
-
No ovulation occurs during the menstrual cycle
- Thus, no progesterone is produced
-
Estrogen remains dominant
- Endometrium remains in a proliferative state
- Eventually, shedding of a proliferative endometrium occurs along with some irregular bleeding
- (Wiki) Menstrual periods are often irregular and of varying lengths
Describe primary vs. secondary amenorrhea.
- Primary: Woman has never menstruated
- (e.g. testicular feminization)
- Secondary: Woman who was menstruating has stopped
- (e.g. instense athletic training)
What is dysmenorrhea?
What is thought to mediate the primary symptom of this condition?
Severe pain during menstruation
Pain is thought to be mediated by prostaglandin production
What is endometriosis?
Condition in which endometrial tissue is found in abnormal locations (e.g. ovary, myometrium).
What are the three primary sites of carcinoma in the female reproductive system?
- Endometrial
- Cervical
- Ovarian
What is leiomyoma uteri?
- Condition in which there are benign uterine smooth muscle growths / tumors called leiomyomas or fibroids
- Stimulated by estrogen
Histologically, why do some oocytes appear to lack nuclei?
Oocytes are big.
Oftentimes in histological sections, the nucleus is out of the plane of the section
What surrounds the muscularis of the oviduct wall?
Mesosalpinx
How thick is the endometrium following menses?
How thick can the endometrium become during the secretory phase?
~1mm
5-6mm
Why does the basal zone of the endometrium appear denser than the functional zone?
The functional zone contains more fluid in the insterstitial areas between the endometrial glands
What type of intercellular specializations would you expect to see between the smooth muscle cells of the uterine myometrium?
Gap junctions
Facilitate contraction of all muscle cells as a unit during partuition
The lamina propria of the vaginal wall contains a large plexus of vessels. Does this plexus consist of arteries or veins?
Veins
