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Reproductive System Chapter 22 Continued

Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

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Page 1: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Reproductive System

Chapter 22

Continued

Page 2: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Female Reproductive System• Ovaries – gonads – produce oocytes and

hormones

• Uterine (Fallopian) tubes or oviducts

• Uterus

• Vagina

• Vulva (female external reproductive organs)

Page 3: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 4: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Ovaries• Located in upper pelvic cavity, on either side of

uterus

• Held in place by a number of ligaments

• Descend from abdominal cavity to pelvic brim

Page 5: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 6: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 7: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Each ovary has a hilus – blood vessels and nerves enter

• Several layers:– Germinal epithelium – simple squamous cells– Tunica albuginea- white capsule of C. T.– Stroma – connective tissue, can be divided into:

• Medulla – loose connective tissue, blood vessels, nerves

• Cortex - contains ovarian follicles – consist of oocytes at various stages of development

Page 8: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Single layer – follicular cells

• Several layers – granulosa cells

• Mature or Graafian follicle is a large, fluid-filled follicle that will rupture and release a secondary oocyte in process called ovulation.

• Corpus luteum is the remnant of a ruptured follicle – produces estrogen, progesterone and relaxin until degenerates into the corpus albicans.

Page 9: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 10: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Oogenesis • During fetal development, germ cells

differentiate into oogonia millions of germ cells.

• Many degenerate, but a few develop into primary oocytes that enter Prophase I of meiosis before birth – stop there.

• At birth, about 1 million oogonia and primary oocytes in each ovary

• About 400 mature over a woman’s lifetime.

Page 11: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Primordial follicle – primary oocyte and single layer of follicular cells

• Under influence of FSH, become primary follicles which have several layers of cells.

• Layer of glycoprotein, the zona pellucida, separates oocyte from the granulosa cells.

• Ovarian cells outside follicle form two layers:– Inner vascular layer (theca interna) that secretes

hormones– Outer fibrous layer (theca externa) – connective

tissue.

Page 12: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 13: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Granulosa cells begin to secrete fluid, forms a cavity called the antrum.

• Now called a secondary follicle.

• After puberty, each month one secondary follicle resumes meiosis.

• Meiosis I results in two unequal cells – secondary oocyte and a polar body.

• Begins to divide again but stops at metaphase II.

Page 14: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 15: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 16: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• At ovulation, secondary oocyte and polar body are released.

• If not fertilized, degenerates.

• If penetrated by sperm, meiosis resumes, forming ovum and another polar body.

• Nuclei of ovum and sperm unite to form a zygote. (2n or diploid)

• So, meiosis results in ONE OVUM and three polar bodies (which degenerate)

Page 17: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 18: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 19: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 20: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 21: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 22: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 23: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Uterine (Fallopian) Tubes• Extend laterally from uterus

• Open end is funnel shaped – infundibulum

• Many finger-like projections – fimbriae

• Local currents produced by movement of fimbriae draws ovum into uterine tube.

• Uterine tube is lined with ciliated columnar epithelium, which move ovum along.

• Peristaltic movements also propel ovum toward uterus.

Page 24: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 25: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• The secondary oocyte is usually fertilized in the outer one-third of the uterine tube, although fertilization may occur in the abdominopelvic cavity.

• Fertilization can occur up to about 24 hours after ovulation.

• If oocyte is fertilized, it will reach the uterus in about 7 days.

Page 26: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 27: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

The Uterus• Is an organ about the size and shape of an

inverted pear.

• Functions in menstruation, implantation of zygote, development of the fetus, and labor.

• Also part of the pathway for sperm to reach ovum.

• Normally held in position by ligaments

Page 28: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 29: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Uterus can be divided into the fundus, body and cervix.

• Secretory cells of the cervix produce about 20 – 60 ml of mucus / day.

• At time of ovulation, this mucus becomes thinner and more alkaline.

• Mucus provides for the energy needs of the sperm, protects sperm from environment of the vagina, and protects them from phagocytes.

• At other times, mucus becomes thick and can form a cervical plug which impedes passage.

Page 30: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Layers of uterus : perimetrium, myometrium and endometrium

• Perimetrium – a part of visceral peritoneum

• Myometrium – bulk of uterus – three layers of muscle that contract under influence of oxytocin during labor.

• Endometrium – highly vascular mucosa– Stratum functionalis – shed during menstruation– Stratum basalis – deeper, permanent layer, gives

rise to new stratum functionalis after each cycle.

Page 31: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 32: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

The Vagina• Passageway for sperm and menstrual flow• Receptacle for penis during intercourse• Inferior portion of birth canal• Capable of considerable distention (stretching)• Mucosa is continuous with that of uterus and

consists of nonkeratinized stratified squamous epithelium.

• Contains large stores of glycogen which decomposes to organic acids – lower pH = less susceptible to infection & less hospitable to sperm

Page 33: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 34: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

The Vulva• External genitals of female

• Mons pubis – pad of adipose tissue which cushions pubic symphysis

• Labia majora (labium majus) – folds of skin analogous to the scrotum– Adipose tissue, sebaceous glands, sweat glands

• Labia minora (labium minus) – folds of skin with many blood vessels and sebaceous (oil) glands

Page 35: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Clitoris – homologous to the penis, also composed of two corpora cavernosa and a glans.

• Vestibule – between the labia minora– External urethral orifice– Openings for ducts of paraurethral glands :

secrete mucus and are homologous to prostate– Beside vaginal orifice are the vestibular

(Bartholin’s) glands – produce mucus during arousal – homologous to bulbourethral glands

Page 36: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 37: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 38: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Female Reproductive Cycle• Two cycles:

– Ovarian cycle – leading to maturation and release of oocyte

– Uterine or menstrual cycle – prepares uterus to receive the fertilized ovum.

• Both controlled by GnRH from the hypothalamus, which stimulates release of FSH and LH.

• Estrogen and progesterone are produced by the ovaries.

Page 39: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Estrogens 1. Stimulate the growth, development, and

maintenance of female reproductive structures, secondary sex characteristics and the breast.

2. They help regulate fluid and electrolyte balance.

3. The stimulate protein synthesis

4. They lower blood cholesterol levels

Page 40: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Moderate levels of estrogen in the blood inhibit the release of GnRH, LH and FSH.

• This is the basis for the birth control pill.

Page 41: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Progesterone

• Is secreted mainly by the corpus luteum and works with estrogen to prepare the endometrium for implantation and mammary glands for lactation.

• High levels of progesterone also inhibit GnRH, LH and FSH.

Page 42: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Relaxin• Produced by the corpus luteum

• Inhibits uterine contractions which aids implantation.

• During pregnancy, it is produced by the placenta, and continues to relax uterine smooth muscle.

• Also relaxes the pubic symphysis and helps dilate the uterine cervix for delivery.

Page 43: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Phases of the Female Reproductive Cycle

• Type cycle runs 24 -35 days, 28 days ave.

• Three phases:

– Menstrual phase

– Preovulatory phase

– Postovulatory phase

Page 44: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Menstrual phase• Days 1 – 5

• FSH release stimulates the maturation of follicles. 20 or so follicles, some in each ovary begin to enlarge.

• In the uterus, the stratum functionalis is shed, discharging 50 -150 ml of blood, tissue fluid, mucus and epithelial cells.

• Declines of estrogen and progesterone cause the spiral arteries to constrict, cells become ischemic and die, and are sloughed off.

Page 45: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 46: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Preovulatory phase• Most variable in length, us. Day 6 – 13

• Follicles continue to grow, granulosa cells produce increasing amounts of estrogen and some progesterone. This causes LH to be secreted, but stored in the pituitary.

• Dominant follicle secretes inhibin, inhibiting growth of other follicles, and continues to develop into a mature follicle.

• Called follicular phase in ovary.

Page 47: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• In the uterus, the estrogens produced by the developing follicles cause the cells of the stratum basalis to produce a new stratum functionalis, and thickness of endometrium doubles.

• Proliferative phase in uterus.

Page 48: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 49: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• About day 14, when estrogen levels are high enough, cause anterior pituitary to release a surge of LH that lasts about 36 hours.

• This is what ovulation tests measure.

• LH weakens wall of follicle, and ovulation occurs.

• Secondary oocyte is released into pelvic cavity, taking the zona pellucida and first layer of granulosa cells.

Ovulation

Page 50: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 51: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Postovulatory phase• Mature follicle forms the corpus luteum

(yellow body) under influence of Luteinizing Hormone (LH) and secretes progesterone, estrogen and relaxin.

• Slight rise in progesterone just before ovulation causes an increase in basal temperature of about 0.4 -0.6 oF – next 24 hours most likely time for conception.

• Also see changes in cervical mucus

• Mittelschmerz – pain around ovaries

Page 52: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 53: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Postovulatory phase most constant in duration at 14 days, days 15 – 28.

• In ovaries called the luteal phase.

• If fertilization does not occur, at end of two weeks the secretions of corpus luteum decline, and it degenerates into corpus albicans (white body)

• The decline in estrogens and progesterone bring on menstruation, and promote the release of GnRH and FSH and the cycle repeats.

Page 54: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• In the uterus, progesterone promotes :– growth of endometrial glands which secrete

glycogen– Vacularization of stratum functionalis– Increase in amount of tissue fluid

• These changes reach a peak about one week after ovulation, about the time the fertilized ovum would arrive.

• Called secretory phase in uterus.

Page 55: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 56: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 57: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 58: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 59: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

Mammary glands • Accessory organs of the female

reproductive system

• Modified sweat glands

• Function is to synthesize, secrete and eject milk (lactation)

• Lie over the pectoralis major muscles

• Are attached to fascia by the suspensory ligaments (of Cooper)

• Breast size is determined more by fat than by glandular tissue.

Page 60: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 61: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Each breast has 15 – 20 lobes made up of several lobules.

• Lobules are made of milk-secreting cells arranged in alveoli.

• Alveoli are surrounded by myoepithelial cells which contract to move milk out of alveoli.

• Milk passes from alveoli to secondary tubules into mammary ducts

Page 62: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 63: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts

• Close to nipple, ducts expand to form lactiferous sinuses where some milk may be stored.

• Milk then passes through lactiferous ducts which open onto the nipple.

• Colored area around the nipple is the areola.

• Milk production is stimulated mostly by prolactin with some help from estrogen and progesterone.

• Ejection or milk let down occurs under the

• Influence of oxytocin.

Page 64: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 65: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
Page 66: Reproductive System Chapter 22 Continued. Female Reproductive System Ovaries – gonads – produce oocytes and hormones Uterine (Fallopian) tubes or oviducts
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