Female reproductive system: Structure and function
Intro0:00–0:25
The female reproductive system consists of internal sex organs, which include the ovaries, the fallopian tubes, the uterus, and the vagina; and external sex organs, such as the mons pubis, the labia, and the clitoris.
Ovaries & the fallopian tubes0:25–1:06
On the ovarian cross-section, we can see an outer layer, with ovarian follicles scattered throughout it, and an inner layer, where most of the blood vessels and nerves are.
At birth, there are about two million primordial follicles, which are future ovarian eggs, also called ova. Once the egg has matured, it is released from ovaries into the first part of the fallopian tube: the fimbriae.
Fimbriae are the finger-like projections that guide the egg into the Fallopian tube. The egg then travels to the uterus.
The uterus & the vagina1:06–2:10
The uterus, also known as the womb, is a hollow organ that has several parts and looks like an upside down pear. The top of the uterus above the openings of the fallopian tubes is called the fundus, and the region below the openings is called the uterine body.
The uterus is lined with a soft inner layer, called endometrium, that undergoes changes during menstrual cycles. Next up is the vagina, which is an approximately 3 inch long muscular canal that extends from the cervix to the vulva.
During sexual intercourse, the vagina receives the penis, but during birth, it also serves as the birth canal. Finally, the vagina has a mucous membrane lining that lubricates the cavity during sexual intercourse and protects the body from infection.Now, switching gears and moving on to the external sex organs, together referred to as the vulva.
The vulva2:10–2:37
The space between the vaginal opening and the anus is called the perineum.Now, let’s switch our focus to the accessory organs of the female reproductive system, the breasts.
The breasts2:37–3:10
The breasts typically develop during puberty, and they contain fat and glandular tissue full of mammary glands. At the end of the pregnancy, mammary glands are stimulated by the hormone prolactin to produce milk.
Once produced, the milk flows from mammary glands through milk ducts to the nipple. This process is also known as lactation, and it's an important part of providing nutrients for a newborn’s early development.
Moving on to the menstrual cycle, which is under the influence of two main female hormones, called estrogen and progesterone.
The menstrual cycle & ovulation3:10–4:03
The first menstrual cycle or, more specifically, the first menstrual bleeding, typically occurs in puberty, and it’s called the menarche.
Now, the menstrual cycle starts on the first day of menstrual bleeding and lasts 28 days, on average. Around day 14 of a 28 day cycle, ovulation occurs.
In ovulation, a mature egg that is ready to be fertilized, also called an ovum, is released from the ovary into the Fallopian tube.
The egg then travels down the fallopian tube, where fertilization occurs. In the meantime, the endometrium has grown thicker in order to receive the fertilized egg.
If fertilization doesn’t occur, the endometrium dies. Finally, during menstruation, this dead tissue is sloughed off and removed through the vagina.As a woman ages, she encounters problems, such as difficulty getting pregnant.
Effects of aging and menopause4:03–4:57
This is a natural and progressive process that accelerates after the 30s due to decreased ovarian function and production of female sex hormones.
Additionally, less female hormones cause variations in the menstrual cycle length and the eventual permanent end of the menstrual cycle.
This is called menopause, and it typically sets in around age 50. To be specific, a woman has entered menopause when an entire year has passed since her last menstrual period.
Common symptoms and manifestations of menopause include hot flashes, night sweats, sleep disruption, vaginal dryness, irritability, and mood swings.
Also, individuals in menopause have an increased risk of cardiovascular disease and decreased bone density, also known as osteoporosis.
All right, as a quick recap... The female reproductive system consists of internal sex organs, which include ovaries, the fallopian tubes, the uterus, and the vagina; and external sex organs, such as the labia, the mons pubis, and the clitoris.
Recap4:57–5:53
The first menstrual bleeding typically occurs in puberty, and it’s called menarche. The menstrual cycle usually lasts for about 28 days, and it’s associated with changes that occur in the ovaries and the uterus.
Eventually, as a woman ages, there is decreased ovarian function and production of hormones. The permanent end of the menstrual cycle is called menopause.
Common symptoms and manifestations of the menopause include hot flashes, night sweats, sleep disruption, vaginal dryness, irritability, and mood swings.
Finally, as a woman ages, she encounters difficulty getting pregnant because, with each menstrual cycle, the number and quality of
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