Female Reproductive System

1. Female Reproductive System

2. Major Organs • Ovaries [ gonads] • Uterine tubes [ fallopian tubes] • Uterus • Vagina • Accessory glands • External genitalia • Breasts

3. month in fertile women. . Ovaries Each ovary is about the size and shape of an almond. In young women the ovaries are 4 × 2.5 × 1.5 cm in dimension, each ovary weight 2-5 gm . After menopause they tend to shrink. Function of the ovaries: • They produce eggs (ova) every female is born with a lifetime supply of eggs • They also produce hormones: Estrogen  & Progesterone Male Homolog = testes

4. Oogenesis • When the girl becomes sexually mature, the primary oocytes recommence their development, usually one at a time and once a month. • The primary oocyte grows much larger and completes the meiosis I, forming a large secondary oocyte and a small polar body that receives little more than one set of chromosomes.

5. Oogenesis • In humans (and most vertebrates), the first polar body does not go on to meiosis II, but the secondary oocyte does proceed as far as metaphase of meiosis II and then stops. • Only if fertilization occurs will meiosis II ever be completed. Entry of the sperm restarts the cell cycle

6. Fallopian tubes • Stretch from the uterus to the ovaries and measure about 8 to 13 cm in length. • Range in width from about one inch at the end next to the ovary, to the diameter of thin spaghetti. • The ends of the fallopian tubes lying next to the ovaries feather into ends called fimbria • Millions of tiny hair-like cilia line the fimbria and interior of the fallopian tubes. The cilia beat in waves hundreds of times a second catching the egg at ovulation and moving it through the tube to the uterine cavity. • Fertilization typically occurs in the fallopian tube

8. Functions of the tubes: • Providing a passageway for ova and sperm • Providing a drainage of tubal secretions into the uterus.

10. Uterus • pear-shaped muscular organ in the upper female reproductive tract. • The fundus is the upper portion of the uterus where pregnancy occurs. • The cervix is the lower portion of the uterus that connects with the vagina and serves as a sphincter to keep the uterus closed during pregnancy until it is time to deliver a baby. • the uterus expands considerably during the reproductive process. the organ grows to from 10 to 20 times its normal size during pregnancy.

11. Uterus • The main body consists of a firm outer coat of muscle (myometrium) and an inner lining of vascular, glandular material (endometrium). • The endometrium thickens during the menstrual cycle to allow implantation of a fertilized egg. • Pregnancy occurs when the fertilized egg implants successfully into the endometrial lining. If fertilization does not occur, the endometrium sloughs off and is expelled as menstrual flow.

13. Endometrium • Functional zone – layer closest to the cavity – contains majority of glands. Thicker portion – undergoes changes with monthly cycle • Basal zone – layer just under myometrium, attaches functional layer to myometrial tissue, has terminal ends of glands. Remains constant

14. Functions of the uterus: • Prepare for pregnancy each month • Protect and nourish the growing child • Aid to child birth.

15. The Cervix • The lower portion or neck of the uterus. • The cervix is lined with mucus, the quality and quantity of which is governed by monthly fluctuations in the levels of the estrogen and progesterone. • When estrogen levels are low, the mucus tends to be thick and sparse, hindering sperm from reaching the fallopian tubes. But when an egg is ready for fertilization, estrogen levels are high, the mucus then becomes thin and slippery, offering a “friendly environment” to sperm • At the end of pregnancy, the cervix acts as the passage through which the baby exits the uterus into the vagina. The cervical canal expands to roughly 50 times its normal width in order to accommodate the passage of the baby during birth

16. The Vagina • vagin = sheath • A muscular, ridged sheath connecting the external genitals to the uterus. • Functions as a two-way street, accepting the penis and sperm during intercourse and roughly nine months later, serving as the avenue of birth through which the new baby enters the world

19. External genetalia • Vulva—which runs from the pubic area downward to the rectum. • Mons pubis or "mound of Venus" is the V-shaped area covered with hair • Labia majora or "greater lips" are the part around the vagina containing two glands (Bartholin’s glands)which helps lubrication during intercourse. Male Homolog = scrotum • Labia minora or "lesser lips" are the thin hairless ridges at the entrance of the vagina, which joins behind and in front. In front they split to enclose the clitoris • The clitoris is a small pea-shaped structure (equivalent to penis in males ) It plays an important part in sexual excitement in females. Male Homolog = penis

20. External genetalia • The urethral orifice or external urinary opening is below the clitoris on the upper wall of the vagina and is the passage for urine • The introitus or opening of the vagina is separate from the urinary opening (unlike males) and located below it. • The hymen is a thin cresentic fold of tissue which partially covers the opening of the vagina. medically it is no longer considered to be a 100% proof of female virginity.

22. Mammary Glands [ breasts] • Present in both sexes - normally only functional in females • Developmentally they are derived from sweat glands • Contained within a rounded skin-covered breast anterior to the pectoral muscles of the thorax • Slightly below center of each breast is a ring of pigmented skin, the areola - this surrounds a central protruding nipple • Internally - they consist of 15 to 25 lobes that radiate around and open at the nipple • Each lobe is composed of smaller lobules- these contain alveoli that produce milk when a women is lactating • non-pregnant women - glandular structure is undeveloped - hence breast size is largely due to the amount of fat deposits

25. Breast Structures • The route of descent of milk and other breast secretions is from alveoli to duct, to intralobar duct, to lactiferous duct and reservoir, to nipple. • Breast milk is produced secondary to complex hormonal changes associated with pregnancy. • The breasts respond to the cyclic changes in the menstrual cycle with fullness and discomfort

26. Function of Female Reproductive System • Produce sex hormones • Produce functioning gamates [ova] • Support & protect developing embryo

27. Adolescence • Puberty • Burst of hormones activate maturation of the gonads: ovaries • Begins: 8-13 yrs of age • Abnormally early = precocious puberty • Delayed =Primary Amenorrhea

28. General Physical Changes • Axillary & pubic hair growth • Changes in body conformation [widening of hips, development of breasts] • Onset of first menstrual period [menarche] • Mental changes

29. Menstruation: • Is thecasting away of blood, tissue, and debris from the uterus as the inner lining sheds, is variable in amount and duration. On average, flow lasts 4-6 days, with a total blood loss of 25- 60 mL.

30. Menstrual cycle: • Refers to the recurring changes that take place in woman’s reproductive tract associated with menstruation and intermenstruation.the a average cycle lasts 28 days, approximately one month.

31. The main components of the menstrual cycle: • The ovarian cycle includes changes that happen in the ovaries in response to pituitary hormones. • Uterine cycle: the variations that take place in the uterus. • Cervical mucus changes.

32. Ovarian cycle: • It is controlled by two anterior pituitary hormones: • LH: controls the luteal phase, which includes days of 15-28. • FSH: responsible for the follicular phase. Encompasses days 1-14 of a 28 days cycle. Ovarian cycle consists of three phases: • The follicular phase • Ovulation • The Luteal phase

33. Follicular phase • The follicular phase, typically days 1 to 14, is the period of follicle growth. • At the beginning of each menstrual cycle, a follicle on one of the ovaries begins to develop in response to rising level of FSH. • The follicle produce estrogen, which cause the ovum to contained within the follicle to mature. • As the follicle grows, it fills with estrogen-rich fluid and begins to resemble a tiny blister on the surface of the ovary.

34. Follicular phase • The pituitary gland release LH in response to the high level of estrogen from the mature follicle which is called at this stage graafian follicle. The ovary raises many follicles monthly, but usually one follicle matures to reach ovulation. This rapid increase in the LH cause the follicle burst and releases an ovum (oocyte) into the abdominal cavity.

35. Ovulation • It occurs on day 14of a 28-day cycle when a mature follicle ruptures in response to the rapid increase in LH, releasing a mature oocyte (ovum) • As the ovum floats along the surface of the ovary, the gentle beating of the fimbriae draws it toward the fallopian tube. • The life span of the ovum is only 24hours. Unless it meets a sperm on its journey within that time, it will die.

36. Evidence of ovulation: • Thin, Clear, stretchy, slippery mucus that is designed to help the sperm travel up through the cervix to meet the ovum for fertilization. • Pain on one side of the abdomen.

37. Luteal phase days 14 to 28after ovulation, LH levels remain elevated and cause the remnants of the follicle to develop a yellow body called the corpus luteum. • The corpus luteum secretes increasing amount of progesterone which prepare the endometrium for implantation. The secreted progesterone causes the body temperature to rise 0.5 to 1.0 degree Fahrenheit which is one or tow days after ovulation, the temp. remain elevated for 12-16 days.

38. Luteal phase • If fertilization doesn’t take place, the corpus luteum begins to generate, and both hormones levels fall, then the endometrium undergoes involution. Then menstruation begins approximately 14 days after ovulation in the absence of pregnancy. FSH and LH are generally at their lowest level during the luteal phase and at the highest level during the follicular phase.

40. Endometrial cycle: Occurs in response to the cyclic hormonal changes, and consist of three phases: • Proliferative phase: starts with enlargement of the endometrial glands in response to increasing level of estrogen. Its chch by: • Dilation of blood vessels. • Increased thickness of the endometrium • Lasts from 5th day of menstrual cycle to time of ovulation • Depends on estrogen stimulation.

41. Endometrial cycle: • Secretory phase: follow ovulation to about three days before the next menstrual period. Under the influence of progesterone, the endometrium becomes thickened and more vascular and glandular, these changes prepare fore implantation. Estrogen level drop sharply.

42. Endometrial cycle: • Menstrual phase: begins as the spiral arteries rupture secondary to ischemia, releasing blood into the uterus and the endometrium sloughed off. If fertilization doesn’t occur the corpus luteum degenerate. as a result both estrogen and progesterone fall and the endometrium sloughs away from the uterine wall and passes out via the vagina. The beginning of the menstrual flow marks the end of one menstrual cycle and the beginning of another one.

43. Menstrual cycle hormones: summary • LH rises and stimulates the follicle to produce estrogen. • As estrogen is produced by the follicle, estrogen level rise, inhibiting the out put of LH. • Ovulation occurs after an LH surge damages the estrogen- producing cells, resulting in a decline in estrogen. • The LH surge results in establishment of the corpus luteum , which produces estrogen and progesterone.

44. Menstrual cycle hormones: summary • Estrogen and progesterone levels rise, suppressing LH output. • Lack of LH promotes degeneration of the corpus luteum. • Cessation of the corpus luteum means a decline in estrogen and progesterone output. • The decline in the ovarian hormones ends their negative effect on the secretion of LH.LH is secreted, and the menstrual cycle begins again.

45. Glands • Lesser Vestibular (Paraurethral, Skene's) Male Homolog = prostate located on the upper wall of the vagina, around the lower end of the urethra. They drain into the urethra and near the urethral opening Function - mucus production to aid lubrication during intercourse • Greater Vestibular (Bartholin's) Male Homolog = bulbourethral glands locatedslightly below and to the left and right of the opening of the vagina. They secrete mucus to provide lubrication, especially when the woman is sexually aroused