HISTO - FEMALE Flashcards
What is a primary oocyte?
Egg cell that is arrested in Meisosis I Prophase I
What is a secondary oocyte?
Egg cell that completes Meisosis I after LH surge stimulation, begins Meiosis II but is arrested at Metaphase II
What is a primordial follicle?
Found throughout the ovarian cortex
Primary Oocyte surrounded by a single layer of SIMPLE SQUAMOUS layer of Granulosa Cells
What is a Primary Follicle?
Primordial follicles develop into Primary follicles once the single layer of simple squamous Granulosa Cells becomes a single SIMPLE CUBOIDAL layer of Granulosa Cells
Basal Lamina forms, separating the granulosa cells from the stroma of the ovary
At this stage, the Zona Pelucida begins to form between the Granulosa cells and the Primary Oocyte
What is the Zona Pelucida?
Coating of glycoproteins that encases the Primary Oocyte, separating it from the surrounding Granluosa Cells
What is a Secondary Follicle?
Priamary Oocyte surrounded by stratified cuboidal epithelium composed of Granulosa Cells that have proliferated since the formation of the Primary Follicle
At this stage the Theca begin to organize
- Theca Interna and Theca Externa develop outside the Basal lamina
Also Call-Exner Bodies (small intercellular spaces) are now present
And an osmotic gradient induces the development of an Antrum (collection of follicular fluid within the follicle)
What are the Theca Interna and Theca Externa?
Two tissue layers found just outside the Basal Lamina surrounding the granulosa cells and Primary oocyte
These tissue layers are composed of Theca cells
Theca Internus
- Layer of theca cells adjacent to the Basal Lamina
- Vascualrized
- Theca cells in this layer support the Granulosa Cells
- Produce Androstenedione –> to produce Estradiol
- LIPID DROPLETS PRESENT
Theca Externus
- Fibrous cell layer continuous with the stroma of the ovary
What is the Graffian Follice?
Mature Follicle - very large
- Antrum reaches its maximum size
- Cumulus Oophorous forms
What is the Cumulus Oophorous?
A collection of granulosa cells anchoring the Primary Oocyte to the wall of the follicle
Acts as a nutrient delivery channel to the Primary Oocyte
What are Mural Granulosa Cells?
Mural Grnaulosa Cells are granulosa cells that line the wall of the Mature (Graffian) follicle
These cells actively synthesize and secrete estrogen and follicular fluid
What is the Corona Radiata?
Corona Radiata are a collection of Granulosa cells that surround the Primary Oocyte
They remain in their position, surrounding the Primary Oocyte even after ovulation
Form a barrier that sperm must make their way through in order to achieve fertilization
What is the Stigma?
Stigma is formed when the theca ezterna interacts with the Tunica Albuginea (layer of tissue beneath the Ovarian Surface epithelium) in preparation for ovulation.
At the stigma, proteolytic activity occurs in response to LH surge, resulting in the rupturing of the tissue in order for ovulation to occur
What happens to the gamete upon release from the ovary?
It completes finally completes Meiosis I. Up until this point, it has been arrested in Prophase I of Meiosis I.
It becomes arrested again during Meiosis II Metaphase II until fertilization
What happens after the ovary is ruptured?
The Mural Granulosa and theca interna repair the Ovarian Surface Epithalium
How does the Corpus Luteum form?
Once the gamete is released, blood vessels invade the now empty antrum. Blood flows into the space and coagulates forming a Corpus Hemorrhagicum
The basal lamina of the follicle is also broken down
Mural Granulosa Cells become Granulosa Lutein Cells
Theca Cells become Theca Lutein Cells
What do Granulosa Lutein Cells do?
Express LH receptors
Secrete Estrogen and Progesterone in response to LH and FSH signaling
What do Theca Lutein Cells do?
Synthesize Androstenedione and progesterone in response to LH signaling
What happens to the Corpus Luteum if fertilization occurs?
It continues to enlarge and secrete Estrogen and Progesterone in response to hCG signaling from the Trophoblast layer of the Placenta
What happens to the Corpus Luteum if fertilization does not occur?
Involution of the Corpus Luteum occurs at 14 days after ovulation in a process called Luteolyis
Results in the formation of Corpus Albicans
Stromal connective tissue replaces degenerating luteal cells
What are the segments of the Uterine Tube?
Infundibulum of the Uterine Tube
Ampulla of the Uterine Tube
Isthmus of the Uterine Tube
Uterine Part of the Uterine Tube
What are the tissue layers of the Uterine Tube?
Mucosa, with ciliated and non-ciliated cells
Smooth Muscle Layer
- Inner circular layer
- Outer Longitudinal layer
Serosa Layer
- With large blood vessels
What are the functions of the cells of the Uterine tube Mucosa?
Ciliated Cells of the Uterine tube Mucosa:
- Sweep gamete along uterine tube to uterus
- Cells grow and make cilia in response to folliculogenesis (increased estrogen signaling)
- Cells shrink and lose cilia in response to luteolysis (increased progesterone signaling)
Non-Ciliated Secretory Cells (aka Peg Cells)
- Secrete nutrients for egg during migration (secretions occur in response to increased Estrogen signaling)
What are the tissue layers of the Uterus?
Perimetrium - Serosa covering anterior and posterior surface of uterus
Myometrium - Three layers of smooth muscle
- Inner Longitudinal muscle layer
- Middle Circular Muscle Layer
- Outer Longitudinal Muscle layer
Endometrium - Functional and Basal Layer
- Simple columnar cells with simple tubular glands
What are the functional and basal layers of the endometrium?
Functional Layer: Epithelial layer of endometrium that is lost during menstruation
Basal layer: deep layer of endometrium that is retained during menstruation
What are the vessels that supply the endometrium?
Arcuate arteries, which have two parts to them:
- Straight Segment - supplies the Basal Layer
- Coiled segment - Supplies the Functional Layer (these arteries stretch with endometrial growth
How does the endometrium appear during the Proliferative Phase of cycle?
Days 5-14
Glands proliferate to cover curface
Spiral arcuate arteries elongate and become convoluted
Estrogen dependent
How does the endometrium appear during the Secretory Phase of the cycle?
Days 15-28
Glands are convoluted (SAW TOOTH APPEARANCE)
Endometrium reaches max thickness
Estrogen and Progesterone present
How does the endometrium appear during the Ischemic Phase?
Regression of the Corpus Luteum causes a reduction of blood supply to the functional layer of the endometrium
Results in necrosis of the functional layer and it begins to fall away resulting in menstruation
What are Decidual cells?
Cells found in the lamina propria of the Endometrium
If pregnancy takes place, (and thus progesterone secretion increases) they:
- Increase in Size
- Store lipids and glycogen
- Provide immune-protective environment for the embryo
- Moderate Synciotrophoblast invasion
What are nabothian cysts?
Occluded cervical crypts
What is the Transformation Zone of the Cervix?
Abrupt epithelial transition between the Endocervix and Ectocervix
What is the Endocervix?
Has simple Columnar Epithelium
Has glandular crypts that secrete mucous
What is the Ectocervix?
Nonkeratinized Stratified Squamous Epithelium
No glandular crypts
Continuous with vaginal epithelium
What are the tissue layers of the Vagina?
Mucosal Layer
- Nonkeratinized Stratified Squamous epithelium
Muscularis Layer
- Circulating and longitudinal muscle
Adventitial Layer
- Dense connective tissue
