pak Flashcards
(48 cards)
What is the histological organization of the female ovary from outside to inside?
1 Germinal Epithelium (not correct name)
Simple squamous or cuboidal epithelium
*In comparison with male: no peritoneum present
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2 Tunica Albuginea: dense connective tissue, analogous to male
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3 Cortex:
Cortical stroma connective tissue
Primordial follicles (dormant for 12-50 years)
After puberty: Stages of development of oocytes/follicles
(right under tunica albuginea)
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4 Medulla
loose connective tissue, blood/lymphatic vessels, nerves
What are the two functions of the mensturation periods and what are the two main steroids produced and what is their function?
Function 1: Gamete: ovum production in monthly cycles
Function 2: Female sex hormone (steroid) production in monthly cycles
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Estrogen function: development of external sex organs + breast
Progesteron function: development of internal sex organs + lactation
Which part of the histological organization of the ovary is most prone to cancer?
“Germinal” epithelium origin of 70% of ovarian cancers
Where do the germ cells actually come from before reaching the ovary?
Germ cells are extra-gonadal origin:
migration From embryonic yolk sac
To cortex of embryonic ovary
What is the function of the follicular cells of the ovary?
They sustain a single developing primary oocyte which is Dormant: Arrested in prophase of 1st meiotic division
What are follicular cells called later in life?
G cells/granulosa cells
What do Stromal cells eventually become and what is their function?
Eventually become: theca interna and theca externa
Theca interna cells: Produce androgens to get sent to G cells for conversion to estrogen.
Theca externa cells are stromal supporting cells (support theca interna)
What hormones control the menstrual cycle in the first two weeks, on day 14, and on the 2nd two weeks?
Before Ovulation: 1st two weeks: FSH and estrogen control
Ovulation: on day 14: LH control
After ovulation: 2nd two weeks: LH and Progesteron control
What is the structure of a primordial follicle?
A primordial follicle has a primary oocyte (2n) at its center, surrounded by a single layer of squamous follicular cells, a basal lamina, and stromal cells.
In which stage of meiosis are primary oocytes arrested?
Primary oocytes are arrested in prophase of the first meiotic division.
What happens to primordial follicles at puberty?
At puberty, primordial follicles begin to develop further and become primary follicles.
What is the structure of an early primary follicle?
Contains a primary oocyte (2n) at its center, with the zona pellucida (transparent zone) beginning to appear and simple cuboidal epithelium surrounding it.
What is the zona pellucida and what is its function?
The zona pellucida is a glycoprotein coat secreted by the oocyte, playing a key role in fertilization and protection.
What types of cells surround the primary oocyte in a primary follicle?
The primary follicle consists of simple cuboidal follicular cells, basal lamina, and stromal cells.
What clinical implication arises from a defective zona pellucida?
A defective zona pellucida can lead to no fertilization by sperm, resulting in infertility.
What is the structure of the late primary follicle and what is special about it?
Structure: Primary oocyte (2n) in the center, Zona Pellucida
Stratified cuboidal epithelium.
Special: Follicular cells become granulosa cells (zona granulosa)
Stromal cells become: Theca cells or Theca folliculi cells
Q: What characterizes a secondary follicle and what is special about it?
contains a secondary oocyte (n) arrested in metaphase of meiosis II and is pushed off-center by antrum fluid.
Special: Antrum first appears
Q: What is a Graafian follicle and what special structures appear?
A Graafian follicle is a mature ovarian follicle containing a secondary oocyte (n) that is eccentric in position and arrested in metaphase II of meiosis.
Special:
Granulosa cells form the Corona radiata and Cumulus Oophorus
What is the id of each follicle and what is special about each one?
Primordial follicle simple squamous cells with no Antrum
Early primary follicle simple cuboidal cells with no Antrum (zona pellicuda first appears)
late primary follicle stratified cuboidal epithelium with no antrum (follicular cells become granulosa cells and stromal cells become theca cells)
Secondary follicle stratified cuboidal epithelium with a small Antrum
Mature follicle stratified cuboidal epithelium with a large Antrum (With Corona radiata and Cumulus Oophorus)
Corpus leutum: Big cavity with no oocyte
Corpus albicans White lines with big pink
What are the components of the blood-ovum barier?
Components of the Barrier:
Theca Interna Cells: These endothelial cells provide vascular support, ensuring a supply of blood and nutrients.
Granulosa Cells: Providing the next layer within the follicle, these cells are essential for hormone production and contribute to the barrier’s overall integrity.
Avascular Environment: The area surrounding the ovum is avascular, meaning there are no blood vessels directly supplying it, which further protects the ovum from potential immunological attacks or unwanted substances in the bloodstream.
What occurs to theca interna cells during the formation of the corpus luteum?
Theca interna cells fold into surrounding granulosa cells during luteinization.
What is luteinization?
Luteinization is the differentiation of theca interna and granulosa cells into endocrine cells, forming theca lutein cells and granulosa lutein cells, respectively.
Where is the corpus luteum located?
The corpus luteum is located in the cortex of the ovary at the site where ovulation occurred.
What hormones are secreted by the corpus luteum, and for how long?
The corpus luteum secretes estrogen and progesterone for about 10 days following ovulation.
