STRUCTION and FUNCTION OF FEMALE REPRODUCTIVE REPRODUCTIVE SYSTEM STRUCTION and FUNCTION OF FEMALE REPRODUCTIVE

See Figures 21-8 pg. 453 and 21-9 pg. 455

OVARIES In lower part of abdominal cavity About the size of an almond Each ovary contains thousands of microscopic sacs See Figures 21-8 pg. 453 and 21-13 pg. 459

Fallopian tubes 4” long – not attached to ovaries Smooth muscle and cilia help propel ova into uterus See Figure 21-8 pg. 453

Uterus and vagina Hollow, thick-walled, pear-shaped, highly muscular organ Lies behind urinary bladder and in front of rectum Fundus – bulging upper part of the uterus Cervix – narrow neck of uterus that extends into vagina Uterine wall Outside thick muscular layer is myometrium Inside mucous lining is endometrium Vagina – smooth muscle with a mucous membrane lining

External genitalia Vulva External organs of reproduction Labia Folds of skin that surround the entrance to the vagina Perineum Area between vagina and rectum See Figure 21-10 pg. 456

Accessory organs Breasts (mammary glands) Areola – darkened area that surrounds the nipple See Figure 21-11

ovaries Primary sex organs of the female Produce ova (female gamete) and manufacture female sex hormones (estrogen and progesterone) During the reproductive years, a single follicle in the ovary matures every 28 days with an ovum inside Reproductive ability begins with menarche (first menstrual cycle) during puberty

ovulation Mature ovum is released (ovulation) about 2 weeks before menstrual period begins After ovulation, the ovum travels down the fallopian tube Fertilization takes place in fallopian tube, usually within two days of ovulation Following fertilization, the zygote implants in the uterus Development of follicle controlled by FSH, ovulation caused by LH Fallopian tubes – smooth muscle and cilia help propel ova into uterus

Menstrual cycle Occurs every 28 days, divided into 4 stages Follicle stage – FSH from pituitary to ovary, stimulates follicle with ovum to mature then releases estrogen and prepares uterine lining, lasts 10 days Ovulation stage – Pituitary stops FSH and releases LH, 14th day – follicle ruptures and mature ovum released Corpus luteum stage – Corpus luteum secretes progesterone. If ovum fertilized, corpus luteum continues secrete progesterone, which prevents further ovulation and maintains uterine lining, lasts 14 days See Figure 21-12 pg. 458

Menstruation stage If no embryo, corpus luteum dissolves > progesterone decreases and uterine lining breaks down and is discharged, 3-6 days

menopause When monthly menstrual cycle comes to an end Starts at approximately age 50 Symptoms include hot flashes, dizziness, headaches, and emotional changes

Conception and pregnancy Figures 21-2, 21-3, 21-4 pg. 448

Gametes are produced by gonads Female gonad = ovary Female gamete = ovum (ova) Male gonad = testes Male gamete = sperm

chromosomes Female gametes have 22 pairs of autosomes and single pair of sex chromosomes – XX Male gametes have 22 pairs of autosomes and single pair of sex chromosomes – XY _____ total chromosomes See Figure 21-1 pg. 447

fertilization When games combine to form a zygote (fertilized egg cell) One sperm penetrates and fertilizes the ovum Zygote has 46 chromosomes Zygote cells divide and multiply as it travels down fallopian tube and implants in uterus At 7 days, zygote becomes an embryo At 3 months it becomes a fetus

pregnancy Gestation Prenatal period or pregnancy Normal pregnancy 40 weeks or 280 days or 3 months Quickening First recognizable movement of fetus in 4th – 5th month Miscarriage – spontaneous abortion See Figure 21-5 pg. 450