3. labia majora – The two outer rounded folds of adipose tissue that lie on either side of the vaginal opening and form the external lateral boundaries of the vulva running downward and backward from the mons pubis. Labia majora
4. labia minora The two small, thin inner folds of skin, one on each side running backward from the clitoris between the labia majora and the vaginal opening enclosing the vestibule of the vagina. Labia minora
5. Clitoris – A small, elongated erectile body situated at the anterior portion of the vulva and projecting between the branched extremities of the labia minora which is homologous with the male’s penis. Clitoris
6. vestibule of vagina – the space between the labia minora into which the urethra and vagina open. urethral opening vaginal opening Vestibule of vagina
7. Its walls are made of smooth muscle and connective tissue lined with squamous epithelium cells. These structures are arranged in transverse or “rippled” folds called ragae. Vagina – A fibromuscular tube about 4 to 6 inches long extending from the vestibule to the cervix of the uterus. It passes upward and backward between the bladder and the rectum. vagina urinary bladder rectum cervix uterus
8. The wall of the vagina is capable of constriction and tremendous dilation. Normally, it is folded into a collapsed tube designed to adapt itself to the size and shape of the male’s penis, but the vagina actually serves three functions: vagina urinary bladder rectum cervix uterus
9. vagina urinary bladder rectum cervix uterus 3. Acts as the avenue for discharge during menses. 2. Acts as the birth canal during childbirth. 1. It receives the penis of the male during copulation.
10. which constitute “normal” vaginal secretions is produced by glands in the cervix and is designed to moisten and cleanse the vaginal walls. The wall of the vagina does not contain any mucus producing glands. All the mucus found in the vagina vagina cervix
11. vagina cervix The vestibular glands of the vaginal orifice also produce a type of mucus designed to moisten and lubricate the vestibule of the vagina for sexual intercourse. vestibular glands
12. vagina cervix Cervix – The narrow, lower portion of the uterus opening into the vagina and containing mucus secreting glands. uterus Cervical cancer can develop within the cell of the lower uterus and can be detected in the early stages by a procedure called a Pap smear test.
13. Uterus – A pear shaped organ about 3 inches long and 2 inches across. It has a diameter of 1 inch. The normal non-pregnant state of the uterus is flattened from front to back and normally tilted forward to an angle of 90 ْ to the vagina. vagina urinary bladder rectum cervix uterus
14. The uterine wall is very muscular and thick. It has three (3) distinct layers. 1. The endometrium , which is the inner most layer. This is the layer that goes through considerable changes during a woman’s monthly menstrual cycle. vagina cervix uterus ovary fallopian tube endometrium
15. 2. The myometrium which is the thick muscular, middle layer composed mostly of bundles of smooth muscle . vagina cervix uterus ovary fallopian tube endometrium 3. The perimetrium or outermost layer. myometrium perimetrium
16. Menstrual cycle – The purpose of a woman’s “monthly” cycle is to prepare the uterus for the implantation of a fertilized “egg”. During the course of about 1 month, the endometrium undergoes cyclic changes which occur in three (3) stages over an average of twenty-eight (28) days, but which have a “normal” range from twenty-one (21) to forty-two (42) days. A menstrual cycle begins with menses, or menstrual bleeding, and when pregnancy does not occur, the cycle ends with the next menses. The menstrual cycle can be divided into three stages. These are as follows:
17. 1. Menstrual phase – This constitutes the time of menses , or menstrual blood flow. Menses is specifically the time of “red” blood flow and does not include the time of “discharge” of non-red flow. In other words, this is the time of a woman’s “ period .” It occurs when patches of the endometrium die. This is due to the blood flow to the area being shut off. The dead tissue then begins to “slough” off. Not all the endometrium dies at once so blood flow or loss is controlled and is usually not excessive. After the tissue is sloughed, the blood flow to the area is restored leaving a raw bleeding area.
18. The dead, superficial layer of the endometrium is swept out of the uterus as the blood flows out the vagina. Menstrual cramps are caused by contractions of the myometrium which help to “slough” or tear away the dead endometrial tissue. Repair of the raw area underneath begins even before blood flow ceases, and a new superficial layer of endometrium is regenerated as the uterine wall heals. Note: menstrual blood is non-clotting . The menstrual phase lasts an average of five (5) days but ranges from four (4) to seven (7) days.
19. 2. Follicular phase (also called the Proliferative phase or Growth phase ) – This phase begins on about the fifth day of the cycle. The endometrium begins to thicken very rapidly. There is a restoration of the overall framework of cells including glands and a very rich blood supply. By the time ovulation occurs, the endometrium is about 2 to 3 mm thick in an average 28 day cycle. This phase lasts through about the 14 th day in an average, regular cycle and ends at the time of ovulation. This means that the follicular phase lasts about nine (9) days on average.
20. The follicular phase is the phase that varies in an irregular cycle or has the greatest variation from one woman to another because it is linked to ovulation. This phase will either last longer or be shorter, depending on when ovulation occurs. This is because the last stage, which is post ovulatory, remains constant in length.
21. 3. Luteal or Secretory phase (also called the Post ovulatory or Premenstrual phase ) – During this phase, the endometrium continues to grow in preparation to receive the fertilized ovum. It can reach as much as 6 mm thick. During this time, the endometrium becomes even more vascularized and fluid begins to accumulate in the tissue causing it to swell. days mm
22. Hormones being secreted by the corpus luteum (the area in the ovary where the ovum came from which changed to a glandular structure after ovulation) stimulate the glandular structures of the endometrium to begin accumulating glycogen and lipids. This causes the endometrium to become even more swollen with fluids, nutrients and electrolytes which presents favorable conditions for embryo implantation.
23. If the ovum is not fertilized, and implantation does not occur, then the hormone secretions from the corpus luteum will decrease. This causes the blood vessels in the endometrium to suddenly constrict, cutting off the blood supply to the newly formed tissue. This causes the tissue to die, and the cycle begins over again.
24. If the ovum is not fertilized, and implantation does not occur, then the hormone secretions from the corpus luteum will decrease. This causes the blood vessels in the endometrium to suddenly constrict, cutting off the blood supply to the newly formed tissue. This causes the tissue to die, and the cycle begins over again.
25. Premenstrual syndrome (PMS) is a condition that occurs during the post ovulatory phase . It can be characterized by headache, irritability, tiredness, nausea, aching joints and feelings of heaviness or pain in the breasts. The main cause of the PMS symptoms is the increase retention of fluid which can be 6 to 7 pounds in some women. This is caused by the increased secretion of progesterone during the cycle. In extreme cases, PMS can become something called PMDD, or Premenstrual dysphoric disorder.
26. Fallopian tubes – or oviducts – These are small tubes about 10 cm (4 inches) long that extend laterally from the body of the uterus. They do not form a completely continuous pathway from the uterus to the ovaries. Each tube ends just before the ovaries in a funnel shaped structure called the infundibulum . This opening surrounds a fringe of finger processes called the fimbre . When an “egg” is released from an ovary, it must cross the small gap before entering the tube. Infundibulum & Fimbre
27. Occasionally an “egg” does miss and an ectopic pregnancy can occur if the sperm travel up and fertilize the ovum in the abdominal cavity. Inside the tube, smooth muscle contractions and actions of cilia help to move the ovum or embryo towards the uterus. This takes between 3 to 5 days. If the ovum is fertilized within the first 24 hours of ovulation, it will occur in the tube. If fertilization does not occur, the ovum begins to deteriorate during the final stage of the journey. At this point, if sperm encounter the ovum, fertilization may or may not occur, but if it does, the embryo will not be viable.
28. 500 ovum will actually develop and be released from the ovaries and of these, only a few will actually be fertilized. The ovaries are oval shaped structures, about 3 cm long in an adult. They are located on the lateral wall of the pelvis, anchored to the uterus by ligaments. The primary oocytes develop while the female is still in the uterus of her mother. Ovaries – At puberty, a girl’s two ovaries will have about 500,000 follicles each containing a primary oocyte that could develop into an embryo. But over a lifetime only about 400 to
29. Oogenesis – On the first day of menstruation, several primitive follicles and the primary oocytes they contain begin to grow and develop. The follicular cells begin to divide and secrete estrogen and small amounts of progesterone. The primary oocyte then goes through a meiotic division to become a secondary oocyte and the first polar body. oogonium Primary oocyte
30. Oogenesis differs from spermatogenesis in that in the first meiotic division, two cells of different size are produced. Each receives equal genetic material, but one receives nearly all the cytoplasm. The larger cell is the secondary oocyte. The secondary oocyte is released from the ovary upon ovulation. The secondary oocyte does not divide until after it unites with a sperm . Secondary oocyte First polar body
31. Ovulation and the corpus luteum – Ovulation is the release of the secondary oocyte from the ovary. After this event, the secondary oocyte is swept into the fallopian tubes by the fimbriae of the infundibulum. After ovulation, the ruptured follicle left behind on the surface of the ovary is transformed into a glandular structure called the corpus luteum which means “ yellow body ” because it contains yellow pigmented lipids. The corpus luteum secretes large amounts of estrogen and progesterone.
32. What happens to the corpus luteum from this point depends on whether fertilization occurs. If the egg is not fertilized, the corpus luteum reaches its maximum development about 1 week after ovulation. When implantation does not occur, the corpus luteum degenerates to form a white colored fibrous scar on the ovary called the corpus albicans , and secretions of hormones stop. This is what causes constriction of the blood vessels and endometrial tissue death and what triggers menses then about 3 to 5 days later.
33. If fertilization and implantation do occur, the corpus luteum continue to grow and secrete hormones into the second month of pregnancy. After this, it begins to regress because the placenta is developed enough to take over secretion of hormones. The corpus luteum will not form the corpus albicans, however until after the birth of the child.
34. In humans, the gestational period (the time from fertilization of the ovum to the birth of the child) is on average 266 days. During development, two different terms are used to describe the developing organism. In the first 10 to 12 weeks it is called and embryo . After this, it is called a fetus .