Physiology of Follicular Development Flashcards
During the development of the ovarian follicle, first meiotic arrest occurs at _________ and is associated with elevated levels of ________
Large antral follicles gain meiotic competence and stay in arrest until ____ surge (can stay in this stage 50 years!)
Prophase I; cAMP
LH
Meiosis I finishes before ovulation, at which time the first ______ is extruded. The second is extruded after resumption of meiosis II only after fertilization
Polar body
The second meiotic arrest during follicular development occurs during ________ and is associated with elevated levels of _________. If fertilization occurs, meiosis II resumes and there is rapid degradation of _____ as well as extrusion of a 2nd polar body
Metaphase II; MAPK proteins; MAPK
The adult ovary can be divided into an inner medulla and outer cortex. Differentiate these two components
Inner medulla is highly vascular, contains nerves, interstitial cells, and lymphatics
Outer cortex consists of densely cellular stroma; ovarian follicles reside within the stroma at different points of their development
3 phases of ovarian follicle cycle
Follicular phase
Ovulatory phase
Luteal phase
During the follicular phase, the ______ ____ is the functional unit of the ovary
Ovarian follicle
During the follicular phase, the ovarian follicle is the functional unit of the ovary; it performs ______ and _____ functions
Gametogenic; endocrine
[pre-menopausal cycling woman contains follicular structures at many different stages]
The primordial follicle is surrounded by a single layer of _______ cells; it releases ______ factors but no steroid hormones at this stage. It represents the ovarian reserve, of which most will undergo ________
Pregranulosa; paracrine; atresia
_______ follicles develop prior to the formation of the fluid-filled antral follicles
Pre-antral
The primary follicle as it transitions to the preantral follicle consists of a central ______ oocyte, a single layer of granulosa cells which take on a _____ shape, the size of the follicle increases due to growth of the oocyte, and there is early production of secreted glycoproteins
Primary; cuboidal
At what part of the follicular phase does the zona pellucida begin to develop?
Preantral follicle — early production of secreted glycoproteins ZP1, ZP2, and ZP3
As the preantral follicle grows, it is associated with a secondary follicle, which consists of a primary oocyte surrounded by 3-6 layers of ______ ______ cells.
The secondary follicle secretes paracrine factors which induce local stromal cells to differentiate into ____ cells
Cuboidal granulosa
Thecal
As the secondary follicle secretes paracrine factors to induce differentiation of stromal cells —> thecal cells, these can further be differentiated based on the inner glandular and highly vascular ________, and the fibrous capsule-like ______
Theca interna; theca externa
Progression of the primary follicle to the secondary follicle requires increased vascularization — how does this occur?
The follicle migrates from the outer cortex to the inner cortex, closer to the ovarian vasculature
The follicles release angiogenic factors that induce development of 1-2 arterioles, generating a vascular wreath around the follicle
The increased vascularization that occurs with progression to the secondary follicle also involves development of the _____ ____, which provides binding sites for sperm during fertilization
Zona pellucida
The oocyte itself is avascular, but recieves its nutrition from ____ cells
Granulosa
As preantral follicles grow and progress through secondary follicle stage, contact between the granulosa and oocyte is maintained. Cytoplasmic processes eventually penetrate the ZP and form ____ ____ at the oocyte surface, structures which also form between adjacent granulosa cells for intercellular communication
Gap junctions
T/F: The preantral secondary follicle has minimal endocrine function
True
The preantral secondary follicle has minimal endocrine function. Granulosa cells express ______ receptors (although growth at this point is not dependent on this hormone). Granulosa cells do not produce ovarian hormones at this point. Thecal cells are analogous to testicular Leydig cells. They express _____ receptors and their major product is ________, but at this point production is minimal or absent
FSH; LH; androstendione
In the preantral to antral transition, proliferation of granulosa cells continues, leading to the continued increase in follicular size. _____ ______ from granulosa cell secretions begins to appear between.
Follicular fluid
In the preantral to antral transition, proliferation of granulosa cells continues, leading to the continued increase in follicular size. Follicular fluid from granulosa cell secretions begins to appear between. Fluid drops eventually coalesce to form a singular _____ _____, marking the beginning of the _____ phase
Follicular antrum; antral
The increase of follicular size that occurs with the beginning of the antral phase is dependent on what 3 factors?
Increase in antral size
Volume of follicular fluid
Proliferation of granulosa cells
During the beginning of the antral phase, the oocyte becomes suspended in fluid surrounded by a dense mass of granulosa cells called the _____ ____
Cumulus oophorus
The _____ phase is associated with a 100-fold increase in granulosa cells of 2 different populations: _____ and ______
Antral; mural; cumulus
