General anatomy of the Female Reproductive System

Points to Ponder How many chromosomes do body and sex cells each have? Understand the anatomy of both the male and female. What are the 3 parts of a sperm? How do hormones play a role in the male? Explain the ovarian and uterine cycles. Where do fertilization and implantation occur? What is infertility? What can cause this?

Female anatomy Genital tract: –Ovaries –Oviducts –Uterus –Cervix –Vagina External genitals (vulva): –Labia major –Labia minor –Mons pubis –Clitoris 16.3 Female reproductive system

Female anatomy: Genital tract Ovaries – produce eggs and sex hormones Oviducts – moves eggs and normal site of fertilization Uterus – normal site of implantation and fetal development Cervix – opening to the uterus that can dilate during childbirth Vagina – birth canal 16.3 Female reproductive system

Female anatomy: Genital tract 16.3 Female reproductive system

VAGINAL OPENING Opening may be covered by a thin sheath called the hymen Using the presence of an intact hymen for determining virginity is erroneous Some women are born without hymens The hymen can be perforated by many different events

PERINEUM The muscle and tissue located between the vaginal opening and anal canal It supports and surrounds the lower parts of the urinary and digestive tracts The perineum contains an abundance of nerve endings that make it sensitive to touch An episiotomy is an incision of the perineum used during childbirth for widening the vaginal opening

Perineum (pelvic outlet)

Perineum (pelvic outlet muscles and fasciae)

INTERNAL GENITALIA The internal genitalia consists of the: Vagina Cervix Uterus Fallopian Tubes Ovaries

VAGINA The vagina connects the cervix to the external genitals It is located between the bladder and rectum It functions : As a passageway for the menstrual flow For uterine secretions to pass down through the introitus As the birth canal during labor With the help of two Bartholin’s glands becomes lubricated during SI

The vagina connects the cervix to the external genitals

CERVIX The cervix connects the uterus to the vagina

The cervical opening to the vagina is small This acts as a safety precaution against foreign bodies entering the uterus During childbirth, the cervix dilates to accommodate the passage of the fetus This dilation is a sign that labor has begun

UTERUS Commonly referred to as the womb A pear shaped organ about the size of a clenched fist It is made up of the endometrium, myometrium and perimetrium Consists of blood-enriched tissue that sloughs off each month during menstrual cycle The powerful muscles of the uterus expand to accommodate a growing fetus and push it through the birth canal

FALLOPIAN TUBES Serve as a pathway for the ovum to the uterus Are the site of fertilization by the male sperm Often referred to as the oviducts or uterine tubes Fertilized egg takes approximately 6 to 10 days to travel through the fallopian tube to implant in the uterine lining

FALLOPIAN TUBES

OVARIES The female gonads or sex glands They develop and expel an ovum each month A woman is born with approximately 400,000 immature eggs called follicles During a lifetime a woman 400 to 500 fully matured eggs for fertilization The follicles in the ovaries produce the female sex hormones, progesterone and estrogen These hormones prepare the uterus for implantation of the fertilized egg

OVARIES

Female anatomy: External anatomy Labia major – 2 large folds of fatty skin Labia minor – 2 small folds just inside the labia major that contain the opening to the urethra and vagina Mons pubis – fatty skin covered in coarse hair Clitoris – erectile organ 16.3 Female reproductive system

The ovarian cycle: The ovary Contains many follicles each containing an immature egg (oocyte) At birth a female has ~300, ,000 follicles During the lifetime of a female only ~400 follicles mature One follicle matures each cycle from puberty until menopause Ovulation is the monthly release of an oocyte from the ovary when a follicle ruptures

Anatomy of the ovary 16.4 Female hormone level

The ovarian cycle This is the formation and release of an immature egg 2 phases: -Follicular phase: -FSH promotes the development of a follicle that secretes estrogen -An estrogen spike leads to a surge in LH and ovulation around day 14 in the 28-day cycle -Luteal phase: -LH promotes the develop of the corpus luteum that functions to secrete progesterone -If pregnancy does not occur menstruation begins 16.4 Female hormone level

The uterine cycle A 28-day cyclic event in the uterus: Days 1-5: low level of estrogen and progesterone causing the inner uterine lining (endometrium) to disintegrate and menstruation occurs Days 6-13 (proliferative phase): increase in estrogen causing the endometrium to thicken Day 14: ovulation usually occurs Days (secretory phase): increase in progesterone causes endometrium to double or triple in thickness in preparation for the developing embryo. If the egg is not fertilized then the corpus luteum regresses and the endometrium breaks down 16.4 Female hormone level

Hormones in the ovarian and uterine phase 16.4 Female hormone level

Fertilization and Pregnancy Fertilization – union of a sperm and egg nucleus normally in the oviduct to form a zygote Pregnancy – begins with implantation usually ~6 days after fertilization 16.4 Female hormone level

Some common birth control methods Abstinence – not engaging in sexual intercourse Hormonal control: Birth control pills: blocks FSH and LH release to stop follicular development and ovulation Contraceptive injections: injection of hormones (progesterone and/or estrogen) to stop ovulation Contraceptive implants: synthetic progesterone to prevent ovulation Barrier methods: IUD: small plastic piece inserted into the uterus to prevent implantation Condom (male and female): blocks fertilization Diaphragm: soft latex cup that covers the cervix so sperm cannot enter the uterus Sterilization: Vasectomy: cutting and sealing the vas deferens Tubal ligation: cutting and sealing the oviducts 16.5 Control of reproduction