Chapter 23.2: Female Reproductive System

General Anatomy -Ovaries: produce oocytes and hormones -Uterine tubes: transport oocytes from ovaries to uterus -Uterus: pathway for sperm to reach ovaries and development of fetus -Vagina -Mammary glands Vagina Uterine (fallopian) tube Ovary Uterus Cervix Urethra Labium minus

Anatomy of Ovaries Mature (graafian) follicle Ruptured follicle Ovulation (expulsion of a secondary oocyte) Degenerating corpus luteum Corpus luteum Growing follicles

Oogenesis -The process by which ovaries produce eggs -This begins before birth -Three stages: -Meiosis I -Meiosis II -Maturation

Meiosis I -During fetal development -Oogonium (2n) develop into primary oocytes (2n) -About 200,000 to 2,000,000 developed at time of birth -At puberty -40,000 primary oocytes remain -Hormones initiate completion of Meiosis I to produce secondary oocyte (n) and 1 st polar body (n) Oogonium 2n2n Primary oocyte 2n2n n n Secondary oocyte First polar body Meiosis I During fetal development meiosis I begins. After puberty, primary oocytes complete meiosis I, which produces a secondary oocyte and a first polar body that may or may not divide again.

Meiosis II -Secondary oocyte (n) begins Meiosis II -Occurs in the ovary -Ovulation -Secondary oocyte released into fallopian tube -Only about 400 go through this -Fertilization -Sperm penetrates secondary oocyte -Meiosis II resumes -Produces ovum (n) and second polar body (n) -Sperm and ovum nuclei join to produce a zygote (2n) Oogonium 2n2n Primary oocyte 2n2n n n n n n n n 2n2n n n Secondary oocyte First polar body Sperm cell Secondary oocyte Fertilization Second polar body Ovum Zygote Meiosis I Meiosis II During fetal development meiosis I begins. After puberty, primary oocytes complete meiosis I, which produces a secondary oocyte and a first polar body that may or may not divide again. The secondary oocyte begins meiosis II. A secondary oocyte (and first polar body) is ovulated. After fertilization, meiosis II resumes. The oocyte splits into an ovum and a second polar body. The nuclei of the sperm cell and the ovum unite, forming a diploid (2n) zygote. + Ovulation

Uterine Tubes and Uterus -Two uterine (fallopian) tubes -Transport secondary oocytes to uterus -Each tube has a open, funnel- shaped end called infundibulum -Contain fimbriae that sweep oocyte into fallopian tube -Fertilization occurs in the tubes -Fertilized ovum implanted into uterine wall Infundibulum of uterine tube Cervix of uterus Vagina Uterine (fallopian) tube Ovary Fimbriae of uterine tube Body of uterus

Vagina -Extends from the exterior of the body to uterine cervix -Vaginal mucosa produces organic acids -Prevents microbial growth -Harmful to sperm -Surrounded by smooth muscle to allow intercourse and child birth

Mammary Glands -Modified sweat glands that produce milk lobes which contain alveoli -Milk secreting glands -Milk production stimulated by prolactin and milk secretion stimulated by oxytocin Lobule containing alveoli Milk duct Nipple Adipose tissue in subcutaneous layer