Bio 9.3 Female Reproductive System Overview

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Questions and Answers

What is the primary function of the ovaries in the female reproductive system?

Protecting the embryo during pregnancy

Producing gametes and secreting sex hormones (correct)

Facilitating fertilization in the uterus

Receiving sperm

What role do fimbriae play in the female reproductive system?

Regulating hormonal changes during menstruation

Propelling sperm toward the oocyte

Providing structural support to the uterus

Facilitating the transfer of oocytes into the uterine tubes (correct)

Which part of the reproductive system undergoes cyclical changes in thickness during the menstrual cycle?

Vagina

Cervix

Fimbriae

Uterus (correct)

What is the function of the myometrium in the uterus?

Contracting during menstruation and childbirth Signup and view all the answers

Where does fertilization typically occur in the female reproductive system?

In the uterine tubes Signup and view all the answers

Which of the following best describes the function of the cervix?

To serve as the opening into the vagina Signup and view all the answers

What is the primary purpose of the endometrium?

To provide nourishment to the embryo Signup and view all the answers

What is a key anatomical feature of the uterine tubes?

Presence of fingerlike fimbriae Signup and view all the answers

What role do the labia majora and labia minora play in the female reproductive system?

They protect the external opening of the vagina. Signup and view all the answers

What is the primary function of the mammary glands during pregnancy?

To facilitate lactation Signup and view all the answers

Which of the following describes the process of oogenesis?

It begins during embryogenesis with stem cells undergoing mitotic division. Signup and view all the answers

What hormonal changes occur at the onset of puberty regarding primary oocytes?

They resume meiosis I after being arrested in prophase. Signup and view all the answers

Which cells are primarily responsible for supporting developing oocytes in the ovary?

Granulosa cells Signup and view all the answers

What anatomical structures contain immature primary oocytes within the ovaries?

Ovarian follicles Signup and view all the answers

What typically occurs during each menstrual cycle in relation to ovarian follicles?

Hormonally, one follicle is selected to continue meiosis. Signup and view all the answers

What effect does stimulation of the clitoris have on the female body?

It triggers genital changes such as lubrication. Signup and view all the answers

What is the outcome of the first polar body after meiosis I in humans?

It degenerates through apoptosis. Signup and view all the answers

What initiates the development of male reproductive organs in an XY embryo?

Expression of the SRY gene. Signup and view all the answers

What occurs to the secondary oocyte if it is fertilized?

It completes meiosis II and forms an ovum. Signup and view all the answers

What is the zona pellucida?

A thick glycoprotein matrix surrounding the secondary oocyte. Signup and view all the answers

How many haploid gametes does each oogonium yield during oogenesis?

One haploid gamete and two to three polar bodies. Signup and view all the answers

At what stage does the secondary oocyte pause after meiosis II?

Metaphase II. Signup and view all the answers

What happens to oogenesis as a woman ages?

It ceases during menopause. Signup and view all the answers

How does spermatogenesis differ from oogenesis?

Oogenesis produces fewer gametes over a lifetime. Signup and view all the answers

What hormone is primarily responsible for promoting the growth and maturation of female reproductive organs at puberty?

Estrogens Signup and view all the answers

Which phase of the ovarian cycle involves the release of gonadotropin-releasing hormone (GnRH) that stimulates the anterior pituitary gland?

Follicular phase Signup and view all the answers

What primarily happens to the Wolffian ducts when testes are not formed?

They undergo degeneration due to lack of testosterone. Signup and view all the answers

During which period is the progression of oogenesis repressed?

Infancy and childhood Signup and view all the answers

Which hormone acts on the anterior pituitary to inhibit FSH during the ovarian cycle?

Inhibin Signup and view all the answers

What is the average duration of a single female reproductive cycle?

28 days Signup and view all the answers

The hypothalamic-pituitary-gonadal (HPG) axis is critical for what primary function in the female reproductive system?

Regulating cyclical reproductive changes Signup and view all the answers

What must occur for optimal conditions to support fertilization and early pregnancy?

Synchronization of the ovarian and uterine cycles Signup and view all the answers

What triggers the secretion of high levels of estrogen during the late follicular phase?

Emergence of a dominant follicle Signup and view all the answers

What is the role of LH during the luteal phase?

Facilitates the conversion of the ruptured follicle into the corpus luteum Signup and view all the answers

What occurs if fertilization of the secondary oocyte does not happen after ovulation?

The corpus luteum degenerates leading to a decline in progesterone and estrogen Signup and view all the answers

During which phase does the endometrial layer double in thickness?

Proliferative phase Signup and view all the answers

Which hormone is primarily responsible for the thickening of the endometrial layer during the secretory phase?

Progesterone Signup and view all the answers

What is the main consequence of high levels of progesterone and estrogen during pregnancy?

Inhibition of FSH and LH secretion Signup and view all the answers

What occurs during the menstrual phase if fertilization does not happen?

The uterus sheds its endometrial layer Signup and view all the answers

What happens to FSH and LH levels during the luteal phase?

They decrease due to negative feedback from hormonal secretions Signup and view all the answers

Study Notes

Female Reproductive System

The female reproductive system is responsible for producing oocytes, facilitating fertilization, and supporting the growth of offspring.
Oogenesis is the formation of oocytes, which are haploid (n) gametes.

Female Reproductive Anatomy

The ovaries are female gonads that secrete sex hormones (estrogens, progesterone) and produce oocytes.
The uterine (fallopian) tubes connect the ovaries to the uterus and are the site of fertilization.
The uterus is a muscular organ that protects and nourishes the embryo and fetus.
The endometrium is the inner lining of the uterus and undergoes cyclical changes in thickness during the menstrual cycle.
The myometrium is the smooth muscle layer of the uterus that contracts during menstruation and childbirth.
The cervix is the opening of the uterus into the vagina.
The vagina is a muscular tube that functions in menstrual fluid discharge, sexual intercourse, and childbirth.
The vulva includes the labia majora, labia minora, and the clitoris, which protect the external opening of the vagina and facilitate reproductive success.
Mammary glands are located in the chest wall and become fully developed during pregnancy to produce breast milk for nursing.

Oogenesis

Oogenesis begins during embryogenesis when oogonia (stem cells) undergo mitotic divisions to produce diploid (2n) daughter cells.
Primary oocytes are formed when oogonia initiate meiosis I during the fetal period.
Primary oocytes are arrested in late prophase I and remain dormant until puberty.
At puberty, primary oocytes are surrounded by follicular cells, forming ovarian follicles.
During each menstrual cycle, a single ovarian follicle is selected to continue meiosis and undergo ovulation.
Meiosis I results in a larger haploid (n) secondary oocyte and a smaller haploid cell called the first polar body.
The secondary oocyte initiates meiosis II but arrests at metaphase II until fertilization.
During ovulation, the ovarian follicle ruptures and releases the secondary oocyte into the abdominal cavity.
The secondary oocyte is drawn into the uterine tube, where fertilization can occur.
If fertilization occurs, the secondary oocyte completes meiosis II to form a mature ovum and a second polar body.
After fertilization, the male and female pronuclei fuse to form a diploid zygote.
Oogenesis produces one haploid gamete (ovum) and two to three haploid polar bodies, unlike spermatogenesis which produces four haploid gametes (sperm).
Oogenesis begins before birth and can result in mature gametes for many years.
Oogenesis ceases at menopause when sex hormone levels decline.
It is thought that a finite number of primary oocytes are formed during the fetal period and are not replenished later in life.

Hormonal Control of the Female Reproductive System

Development of female reproductive structures is promoted in XX embryos due to the absence of the SRY gene and the production of anti-Müllerian hormone (AMH).
Puberty is marked by the secretion of estrogens and progesterone, promoting the growth and maturation of female reproductive organs, development of secondary sex characteristics, and initiation of the menstrual cycle.
The hypothalamic-pituitary-gonadal (HPG) axis regulates the female reproductive cycle, which includes the ovarian cycle and the uterine (menstrual) cycle.

Ovarian Cycle

Divided into three phases: follicular, ovulation, and luteal phases.
Follicular phase (days 1-13):
- GnRH from the hypothalamus stimulates the anterior pituitary to release FSH and LH.
- FSH and LH stimulate ovarian follicles to release estrogens.
- Only one dominant follicle survives and secretes inhibin, which inhibits FSH.
- High estrogen levels stimulate the HPG axis, resulting in an LH surge.
Ovulation (day 14):
- The mature ovarian follicle ruptures, releasing the secondary oocyte into the abdominal cavity.
Luteal phase (days 15-28):
- LH stimulates the conversion of the ruptured follicle into the corpus luteum, which secretes high levels of progesterone and estrogens.
- Progesterone and estrogens exert negative feedback on the HPG axis, preventing maturation of additional follicles.
- If fertilization does not occur, the corpus luteum degenerates, causing a drop in progesterone and estrogens and initiating the next ovarian cycle.
- If fertilization occurs, the corpus luteum persists, maintaining progesterone and estrogens levels and supporting pregnancy.

Uterine (Menstrual) Cycle

Occurs concurrently with the ovarian cycle and is also divided into three phases: menstrual, proliferative, and secretory phases.
Menstrual phase (days 1-4):
- If fertilization does not occur, menstruation begins, shedding the endometrial lining.
- Estrogen levels rise, stopping blood flow.
Proliferative phase (days 5-14):
- The endometrial layer proliferates and thickens.
- Endometrial glands develop, and vascularization increases to prepare for embryo implantation.
Secretory phase (days 15-28):
- Progesterone and estrogen levels increase due to the corpus luteum.
- The endometrium further thickens and develops.

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Description

Explore the intricacies of the female reproductive system, including its anatomy and functions. This quiz covers key concepts such as oogenesis, the roles of the ovaries, uterine tubes, uterus, and more. Test your understanding of how these components work together to facilitate reproduction.