Podcast
Questions and Answers
What is the duration of the menstrual phase?
What is the duration of the menstrual phase?
Which hormone primarily influences the proliferation of the endometrium during the proliferative phase?
Which hormone primarily influences the proliferation of the endometrium during the proliferative phase?
What begins after ovulation and lasts for approximately 13-14 days?
What begins after ovulation and lasts for approximately 13-14 days?
During which phase do follicles undergo three stages of development?
During which phase do follicles undergo three stages of development?
Signup and view all the answers
Which of the following is NOT a stage of follicular development?
Which of the following is NOT a stage of follicular development?
Signup and view all the answers
What role does FSH play in the ovarian cycle?
What role does FSH play in the ovarian cycle?
Signup and view all the answers
What happens to the hormone levels at mid-cycle (around day 13 or 14)?
What happens to the hormone levels at mid-cycle (around day 13 or 14)?
Signup and view all the answers
What stimulates the production of progesterone after ovulation?
What stimulates the production of progesterone after ovulation?
Signup and view all the answers
What initiates the menstrual cycle?
What initiates the menstrual cycle?
Signup and view all the answers
What hormone does the hypothalamus release to start the menstrual cycle?
What hormone does the hypothalamus release to start the menstrual cycle?
Signup and view all the answers
Which hormones are primarily responsible for controlling cyclic changes in the ovary?
Which hormones are primarily responsible for controlling cyclic changes in the ovary?
Signup and view all the answers
When does ovulation typically occur in the menstrual cycle?
When does ovulation typically occur in the menstrual cycle?
Signup and view all the answers
What happens to the secondary oocyte if fertilization does not occur?
What happens to the secondary oocyte if fertilization does not occur?
Signup and view all the answers
What happens to the other follicles after ovulation?
What happens to the other follicles after ovulation?
Signup and view all the answers
Which phase of the menstrual cycle involves the sloughing of the uterine endometrium?
Which phase of the menstrual cycle involves the sloughing of the uterine endometrium?
Signup and view all the answers
Which hormone is primarily secreted by the corpus luteum?
Which hormone is primarily secreted by the corpus luteum?
Signup and view all the answers
What is the role of progesterone during the menstrual cycle?
What is the role of progesterone during the menstrual cycle?
Signup and view all the answers
What is the consequence of the corpus luteum degenerating?
What is the consequence of the corpus luteum degenerating?
Signup and view all the answers
Where does fertilization of the ovulated oocyte typically occur?
Where does fertilization of the ovulated oocyte typically occur?
Signup and view all the answers
What triggers the release of the oocyte from the follicle?
What triggers the release of the oocyte from the follicle?
Signup and view all the answers
What structure is formed if the corpus luteum degenerates?
What structure is formed if the corpus luteum degenerates?
Signup and view all the answers
How is the ovulated oocyte transported to the uterine cavity?
How is the ovulated oocyte transported to the uterine cavity?
Signup and view all the answers
What happens to the first polar body created during oocyte maturation?
What happens to the first polar body created during oocyte maturation?
Signup and view all the answers
What initiates the formation of the corpus luteum?
What initiates the formation of the corpus luteum?
Signup and view all the answers
What is the primary function of capacitation in sperm maturation?
What is the primary function of capacitation in sperm maturation?
Signup and view all the answers
What triggers the acrosome reaction in sperm?
What triggers the acrosome reaction in sperm?
Signup and view all the answers
Which of the following occurs as a result of sperm-egg membrane fusion?
Which of the following occurs as a result of sperm-egg membrane fusion?
Signup and view all the answers
What change prevents additional sperm from penetrating the oocyte after the first fertilization?
What change prevents additional sperm from penetrating the oocyte after the first fertilization?
Signup and view all the answers
Capacitation primarily occurs in which part of the female reproductive system?
Capacitation primarily occurs in which part of the female reproductive system?
Signup and view all the answers
What is produced as a result of the second meiotic division in oocytes during fertilization?
What is produced as a result of the second meiotic division in oocytes during fertilization?
Signup and view all the answers
Which fertilization phase involves only capacitated sperm passing through the corona radiata?
Which fertilization phase involves only capacitated sperm passing through the corona radiata?
Signup and view all the answers
Which of the following is a method of hormonal contraception?
Which of the following is a method of hormonal contraception?
Signup and view all the answers
What condition may result in male infertility due to an insufficient number of sperm?
What condition may result in male infertility due to an insufficient number of sperm?
Signup and view all the answers
What structure is formed by the outer cell mass of the morula?
What structure is formed by the outer cell mass of the morula?
Signup and view all the answers
Which process occurs within 24 hours after fertilization resulting in divisions but no cell growth?
Which process occurs within 24 hours after fertilization resulting in divisions but no cell growth?
Signup and view all the answers
What is the term used for the state of the embryo when it consists of 16 to 32 cells?
What is the term used for the state of the embryo when it consists of 16 to 32 cells?
Signup and view all the answers
What occurs by day 4 of development when the morula begins to absorb fluid?
What occurs by day 4 of development when the morula begins to absorb fluid?
Signup and view all the answers
What are the cells within the inner cell mass of the morula called?
What are the cells within the inner cell mass of the morula called?
Signup and view all the answers
What is the role of the trophoblast in the embryo?
What is the role of the trophoblast in the embryo?
Signup and view all the answers
What happens to the pronuclei after the sperm penetrates the oocyte?
What happens to the pronuclei after the sperm penetrates the oocyte?
Signup and view all the answers
Study Notes
Ovarian and Menstrual Cycles
- The menstrual cycle, from menarche to menopause, is controlled by hypothalamic, pituitary, and ovarian hormones, resulting in oocyte production and uterine preparation for a fertilized embryo.
- The hypothalamus secretes GnRH, stimulating the anterior pituitary to release LH and FSH.
- FSH and LH regulate ovarian changes, while the ovaries produce estrogen and progesterone, preparing the uterus and breasts.
- The 28-day cycle involves follicular recruitment and growth (15-20 primary follicles), endometrial proliferation, ovulation (usually a single follicle), corpus luteum development, and endometrial shedding (unless implantation occurs).
- The menstrual cycle has three phases: menstrual (4-5 days, endometrial shedding), proliferative (9 days, estrogen-driven follicular growth), and secretory (13-14 days, progesterone-driven endometrial thickening).
- The ovarian cycle (average 28 days) includes the follicular phase (primary, secondary/vesicular, and mature Graafian follicle development), ovulation, and the luteal phase (corpus luteum formation and progesterone secretion).
- Follicular development involves granulosa cell formation, antrum formation, theca cell differentiation (interna and externa), and cumulus oophorus formation.
- FSH stimulates follicular cells to produce estrogen, causing endometrial proliferation, cervical mucus thinning, and LH surge stimulation.
- Ovulation (day 13-14) involves an LH surge, oocyte meiosis resumption (meiosis I and initiation of meiosis II), progesterone production, and follicle rupture.
- The luteal phase involves corpus luteum formation (from granulosa cells transforming into lutein cells), progesterone secretion, and endometrial thickening.
- If fertilization doesn't occur, the corpus luteum degenerates into the corpus albicans, causing progesterone decrease, endometrial degeneration, and menstruation.
- If pregnancy occurs, the corpus luteum persists as the corpus luteum of pregnancy, secreting progesterone until the placenta takes over.
Oocyte Transport and Fertilization
- Ovulated oocytes enter the fallopian tube via fimbriae and are propelled towards the uterus by tubal muscle contractions and cilia.
- Fertilization occurs in the ampulla of the uterine tube.
- Capacitation, the final sperm maturation step, involves acrosome changes enabling zona pellucida penetration. This includes glycoprotein and seminal plasma protein removal.
- The acrosome reaction, triggered by sperm-oocyte binding (ZP3), releases enzymes (acrosin, trypsin-like) to penetrate the zona pellucida.
- Sperm penetration triggers a calcium wave in the oocyte, cortical granule release, and zona reaction (preventing polyspermy).
- Oocyte meiosis II completion occurs after sperm penetration.
- Fertilization results in diploid chromosome restoration, sex determination, and cleavage initiation.
- Fertilization phases: corona radiata penetration, zona pellucida penetration (ZP3 binding, acrosome reaction), and oocyte plasma membrane penetration.
Contraception and Infertility
- Contraceptive methods include barrier methods (condoms, diaphragm), hormonal contraception (inhibits ovulation, alters endometrium, thickens cervical mucus), and IUDs.
- Infertility (affecting ~15% of couples) can result from male factors (oligospermia, asthenospermia, teratospermia) or female factors (blocked fallopian tubes, hostile cervical mucus, anovulation).
- Infertility treatments include intrauterine insemination, in-vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI).
Post-Fertilization Events: Cleavage and Blastocyst Formation
- After fertilization, the zygote undergoes cleavage (rapid mitotic divisions without cell growth), producing blastomeres.
- Compaction occurs after the third cleavage, forming a compact cell ball with inner cell mass (embryoblast) and outer cell mass (trophoblast).
- The inner cell mass forms embryonic tissues, and the outer cell mass contributes to the placenta.
- Blastocyst formation involves fluid absorption creating a blastocyst cavity (blastocele).
- By day 5, the blastocyst hatches from the zona pellucida and adheres to the uterine lining.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on the hormonal regulation of the ovarian and menstrual cycles. This quiz covers the phases of the menstrual cycle, the roles of hormones, and the changes occurring in the ovaries and uterus throughout the cycle. Perfect for students studying reproductive biology!
