BIOL 220: CH. 28 - FEMALE REPRODUCTIVE SYSTEM

What are the ovaries responsible for?

The ovaries are responsible for producing egg cells and hormones such as estrogen and progesterone, which are vital for reproductive health.

What are the two functions of the ovaries?

The ovaries have both exocrine and endocrine functions.

• They produce egg cells (exocrine) and secrete hormones (endocrine).

What is the medulla of the ovary?

The medulla is the inner part of the ovary, composed of connective tissue and blood vessels that supply the ovary with nutrients and support.

What is the cortex of the ovary?

The cortex is the outer region of the ovary where developing follicles are located.

• It is involved in the maturation of eggs.

What is a developing follicle in the ovary?

A developing follicle is a fluid-filled structure in the ovary that contains an oocyte (immature egg cell).

• These follicles play a key role in egg maturation.

What are the fallopian tubes also known as?

The fallopian tubes are also referred to as the uterine tubes or oviducts.

• They connect the ovaries to the uterus.

What is the structure near the ovary of the fallopian tube?

The structure near the ovary of the fallopian tube is called the infundibulum, which is funnel-shaped to capture the egg released from the ovary.

What is the function of the fimbriae?

The fimbriae are finger-like projections at the flared distal end of the fallopian tube, which help to guide the egg from the ovary into the tube.

What type of muscle is found in the wall of the fallopian tube?

The wall of the fallopian tube consists of smooth muscle, which helps move the egg towards the uterus through peristaltic contractions.

What type of cells line the fallopian tube?

The fallopian tube is lined with epithelium that includes ciliated cells and secretory cells.

What is the function of ciliated cells in the fallopian tube?

The ciliated cells in the fallopian tube help move the egg towards the uterus by creating a wave-like motion.

What is the role of secretory cells in the fallopian tube?

The secretory cells in the fallopian tube produce fluids that nourish the egg and support fertilization.

What is the uterus?

The uterus is a thick, muscular organ that nourishes and houses the developing fetus during pregnancy.

What is the fundus of the uterus?

The fundus is the broad superior curvature of the uterus, located above the opening of the fallopian tubes.

What is the body of the uterus?

The body of the uterus is the middle portion, where the fetus develops during pregnancy.

What is the cervix?

The cervix is the inferior end of the uterus, which connects the uterus to the vagina through the cervical canal.

What is the function of the cervical canal?

The cervical canal allows the passage of menstrual blood from the uterus and the passage of the baby during childbirth.

• It also connects the uterus to the vagina.

What is the role of cervical glands?

Cervical glands secrete protective mucus that helps guard against infections and supports sperm survival.

What are the three layers of the uterine wall?

The three layers of the uterine wall are the:

• perimetrium

• myometrium

• endometrium

What is the perimetrium, and where is it located?

The perimetrium is the outermost layer of the uterine wall, consisting of simple squamous epithelium with loose connective tissue, and it functions as the serosa of the uterus.

What is the myometrium, and what does it consist of?

The myometrium is the middle layer of the uterine wall, made up of smooth muscle, and it forms the majority of the uterine wall.

• It becomes more fibrous near the cervix.

What is the endometrium, and what are its features?

The endometrium is the innermost layer of the uterine wall, composed of columnar epithelium, glands, and lamina propria (connective tissue).

• It plays a role in the menstrual cycle.

How does the endometrium change during the menstrual cycle?

The top 1/2 to 2/3 of the endometrium is shed during the menstrual cycle, while the basal layer remains behind to regenerate the new functional layer for the next cycle.

What is the vaginal tract like in terms of its structure?

The vaginal tract has a thin but flexible wall that allows it to stretch and accommodate various functions such as childbirth and intercourse.

What are the three layers of the vaginal tract?

The vaginal tract consists of three layers:

• an outer connective tissue (CT) layer

• a middle muscularis layer

• an inner mucosa layer

What type of epithelium is found in the vaginal tract at puberty?

At puberty, the vaginal tract is lined with stratified squamous epithelium, which provides protection and allows for the tract's functions.

Does the vaginal tract contain glands?

The vaginal tract does not have its own glands but is lubricated by secretions from cervical glands located above it.

What is the function of rugae in the vaginal tract?

Rugae are folds in the vaginal tract that allow it to expand and accommodate various activities, such as intercourse and childbirth.

What type of epithelial cells are found in the vaginal mucosa?

The epithelial cells in the vaginal mucosa are rich in glycogen, which is important for maintaining the health and acidity of the vaginal environment.

How does the vaginal tract maintain its acidic environment?

The glycogen in the epithelial cells is metabolized into lactate by bacteria via anaerobic fermentation, which creates an acidic environment that helps protect against infections.

What is oogenesis?

Oogenesis is the process of egg cell (ovum) development in females, which produces haploid gametes through meiosis.

How is oogenesis cyclical?

Oogenesis is cyclical because it occurs in repeated cycles, typically once a month during the female reproductive years, where one egg is released from the ovary.

When does the process of oogenesis begin?

The process of oogenesis begins before birth, as oogonia (precursor cells) develop early in fetal life.

What happens during the first 5 to 6 weeks of oogenesis?

During the first 5 to 6 weeks, oogonia develop and multiply until the 5th month of fetal development, reaching a number of 6 to 7 million.

What occurs after the oogonia multiply until the 5th month?

After the 5th month, development of the oogonia halts until around birth, and they transform into primary oocytes by the time of birth.

What happens to oocytes after birth?

At birth, oocytes are arrested in their development, and this process remains halted until puberty.

What percentage of oocytes undergo degeneration?

Around 90% of oocytes undergo degeneration, a process known as atresia, which leads to the formation of atretic follicles.

How many oocytes are typically present by puberty?

By puberty, approximately 200,000 oocytes remain in the ovaries, ready for potential ovulation.

How many follicles begin the path to maturity each month, and how many finish?

Each month, about two dozen follicles begin the path to maturity, but only one completes the process and is ovulated.

When does meiosis I finish during oogenesis?

Meiosis I finishes on the day of ovulation, leading to the formation of a secondary oocyte and a polar body.

What happens to the polar bodies during oogenesis?

In oogenesis, one small polar body is produced alongside one secondary oocyte.

• If the oocyte is fertilized, meiosis II is completed, resulting in a second polar body.

Why are eggs so large?

Eggs are large because they contain a significant amount of cytoplasm and organelles, which provide the necessary nutrients and structures to support early development if fertilization occurs.

What structures does the uterine tubes have to help move an egg through the reproductive system?

cilia and secretory cells

What contributes to the acidic environment of the vagina?

• anaerobic fermentation

• bacteria break down glycogen into lactate

LH stimulates the release of ________ from ________ cells in the testes.

testosterone; interstitial

ABP is released from _______ cells, when stimulated by _______.

nurse (sertoli); FSH

Testosterone plays a role in negative feedback regulation; it inhibits the ________ from releasing _________.

hypothalamus; GnRH

What is the follicular phase of the ovarian cycle?

The follicular phase of the ovarian cycle is the period from the beginning of menstruation to ovulation, typically lasting the first two weeks.

What hormone stimulates follicle growth during the follicular phase?

Follicle-stimulating hormone (FSH) stimulates the growth of follicles during the follicular phase.

What does FSH stimulate follicles to release?

FSH stimulates the follicles to release estradiol, a hormone that plays a role in regulating the ovarian cycle.

How does estradiol affect the dominant follicle?

Estradiol causes the dominant follicle to add more receptors, which increases its sensitivity to hormones like FSH and LH.

Which hormones are involved in the follicular phase?

FSH, LH, and estradiol are the key hormones involved in the follicular phase, each contributing to the growth and maturation of the follicles.

What effect does estradiol have on GnRH?

Estradiol inhibits the release of gonadotropin-releasing hormone (GnRH), which helps regulate the menstrual cycle.

What happens just before ovulation?

Just before ovulation, there is a surge of luteinizing hormone (LH), which triggers the release of the egg from the dominant follicle.

What occurs during ovulation?

During ovulation, the mature egg is released from the dominant follicle and enters the uterine tube, where it can potentially be fertilized.

What happens to the remaining follicle after ovulation?

After ovulation, the remaining follicle stays behind in the ovary and transforms into the corpus luteum, which produces hormones necessary for the next phase of the cycle.

What happens during the luteal phase of the ovarian cycle (days 15-28)?

During the luteal phase, the corpus luteum develops and secretes hormones, primarily progesterone, as well as some estradiol, in response to stimulation by LH.

How does LH affect the luteal phase?

LH stimulates the corpus luteum to continue developing and producing hormones, especially progesterone, during the luteal phase.

What hormones are secreted during the luteal phase?

During the luteal phase, the corpus luteum secretes estradiol and a large amount of progesterone, which help prepare the body for potential pregnancy.

What is the effect of progesterone and estradiol secretion on the pituitary?

The secretion of progesterone and estradiol during the luteal phase provides negative feedback to the pituitary gland, causing a drop in the levels of FSH and LH.

What happens if pregnancy does not occur after the luteal phase?

If pregnancy does not occur, the corpus luteum shrinks approximately 8 days later, leading to a decline in progesterone and estradiol levels.

What is meant by "three overlapping cohorts of developing follicles"?

The three overlapping cohorts of developing follicles refer to groups of follicles that mature at different stages but overlap in their development, with each cohort following the previous one in a continuous cycle.

When is the oocyte that ovulates each month reactivated?

The oocyte that ovulates each month was reactivated 290 days earlier, meaning it is not reactivated during the cycle in which it actually ovulates, but in a previous cycle.

How often are new cohorts of developing follicles activated?

New cohorts of developing follicles are activated every 28 days, and these cohorts overlap, with each new cohort trailing the previous one.

What is the timing of ovulation for dominant follicles in overlapping cohorts?

The dominant follicles from overlapping cohorts ovulate 28 days apart, ensuring a continuous cycle of ovulation.

What is the relationship between the menstrual cycle and the ovarian cycle?

The menstrual cycle runs concurrently with the ovarian cycle, meaning both cycles occur simultaneously but have distinct phases that influence each other.

What happens during the proliferative phase of the menstrual cycle?

During the proliferative phase (days 5 to 14), the endometrial tissue lost from the previous cycle is rebuilt in preparation for potential implantation.

When does the proliferative phase begin in the menstrual cycle?

The proliferative phase begins after day 5 of menstruation.

What role do developing follicles play during the proliferative phase?

Developing follicles secrete estrogen during the proliferative phase, which helps stimulate various changes in the endometrium.

How does estrogen (estradiol) affect the endometrium during the proliferative phase?

Estrogen stimulates the mitosis of the basal layer of the endometrium, causing it to become thicker, growing from 0.5 mm on day 5 to 2-3 mm by day 14.

• It also prompts the cells to produce progesterone receptors.

What happens during the secretory phase of the menstrual cycle (day 15–26)?

During the secretory phase, which lasts from day 15 to 26, the endometrium thickens more due to the accumulation of fluid, not mitosis, in preparation for potential implantation of a fertilized egg.

What hormone is produced after ovulation, and what is its source?

After ovulation, progesterone is produced by the corpus luteum (CL).

• This hormone helps maintain the thickening of the endometrium and supports pregnancy if fertilization occurs.

How does progesterone affect the endometrium?

Progesterone stimulates the endometrial glands to grow and secrete glycogen, which helps nourish the potential fertilized egg.

How thick is the endometrium during the secretory phase, and what condition is it in?

During the secretory phase, the endometrium becomes 5-6 mm thick and is ready to accept a fertilized egg.

• It forms a soft, wet, and nutritious bed ideal for implantation.

What happens during the premenstrual phase of the menstrual cycle?

The premenstrual phase occurs during the last two days of the menstrual cycle, leading up to menstruation.

What happens if there is no pregnancy during the menstrual cycle?

If there is no pregnancy, the corpus luteum in the ovary shrinks, which leads to a decrease in progesterone production.

How does low progesterone affect the body during the menstrual cycle?

Low progesterone levels cause spasms in the blood vessels, which interrupt the blood supply to the endometrium.

What happens to the endometrium when blood supply is interrupted?

When the blood supply is interrupted, the endometrium breaks down, particularly the functional layer.

What is the composition of menstrual fluid?

Menstrual fluid consists of necrotic endometrial tissue that mixes with blood and serous fluid.

What happens during the menstrual phase (days 1–5) of the menstrual cycle?

During the menstrual phase (days 1–5), fluid in the uterus is discharged, which includes blood and other materials from the uterine lining.

What is the role of fibrinolysin in the menstrual phase?

Fibrinolysin is present in the menstrual fluid, and its role is to prevent the blood from clotting during the discharge.

What happens if pregnancy occurs regarding the fertilized egg?

If pregnancy occurs, the fertilized egg divides into a blastocyst, which will eventually implant in the uterine wall.

When does implantation of the blastocyst happen?

The blastocyst implants in the uterine wall during the secretory phase of the menstrual cycle.

What happens to the blastocyst after implantation?

After implantation, the blastocyst is housed in the developing placenta, which supports its growth and development.

What hormone does the blastocyst release, and what is its function?

The blastocyst releases human chorionic gonadotropin (HCG), which stimulates the growth of the corpus luteum, in cooperation with luteinizing hormone (LH).

What happens if HCG is not present?

If HCG is not present, the corpus luteum shrinks, and it is no longer able to maintain pregnancy.

How do hormone levels change after the first few weeks of pregnancy?

After the first few weeks of pregnancy, hormone secretion shifts to being primarily carried out by the placenta, rather than the corpus luteum.

What are mammary glands?

Mammary glands are specialized glands found in the breast that are responsible for producing milk.

Where is the mammary gland located?

The mammary gland is located in the breast, which is a mound of tissue that overlays the pectoralis major muscle.

How do mammary glands change during puberty?

During puberty, the mammary glands enlarge, and this enlargement typically remains throughout a woman's life.

How does the mammary gland function during pregnancy?

During pregnancy, the mammary glands develop further within the breast to prepare for milk production.

What happens to the mammary glands during lactation?

The mammary glands remain active in the lactating breast, continuously producing milk.

What occurs to the mammary glands when a woman stops nursing?

When a woman ceases to nurse, the mammary glands atrophy, meaning they shrink or decrease in size.

Choose all the organs that are part of the internal female genitalia.

• Vagina

• Uterine tubes

• Uterus

• Ovaries

Which female reproductive organ produces egg cells and sex hormones?

Ovary

The ______ of the ovary contains most of the large arteries and veins.

medulla

Within the ovary, eggs develop within encircling structures called _____.

follicles

The lateral pole of the ovary is attached to the pelvic wall by which of the following?

Suspensory ligament

Choose all the organs that are part of the external female genitalia.

• Clitoris

• Labia minora

The uterine tubes are also called ______.

oviducts or fallopian tubes