1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Human Biology Sylvia S. Mader Michael Windelspecht Chapter 16 Reproductive System Lecture Outline Part 2

2 Male anatomy: Penis Penis –This organ is used for sexual intercourse and urination. Glans penis –Tip of the penis, usually covered by foreskin, that is intensely sensitive. –____________ is the removal of all or part of the foreskin. –Erectile dysfunction (impotency) occurs when the erectile tissue does not expand enough to compress the veins Male Reproductive System

3 Male anatomy: Penis Figure 16.3a The structure of the penis Male Reproductive System erectile tissue foreskin glans penis a. skin connective layers external urethral opening dorsal vein dorsal artery dorsal nerve Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

4 Hormonal regulation in males Gonadotropin-releasing hormone (GnRH) – secreted by the thalamus to control release of other hormones ________________________ (FSH) – promotes the production of sperm _______________________ (LH) – controls the production of testosterone Testosterone – important for normal development and functioning of the male reproductive organs 16.2 Male Reproductive System

5 Hormonal regulation in males Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. hypothalamus LH FSH testis GnRH anterior pituitary Seminiferous tubules produce sperm plus inhibin. Interstitial cells produce testosterone. Figure 16.5 The hormones that control the production of sperm and testosterone by the testes Male Reproductive System

6 Female anatomy Genital tract –Ovaries –Oviducts –Uterus –Cervix –Vagina External genitals (vulva) –Labia major –Labia minor –Mons pubis –Clitoris 16.3 Female Reproductive System

7 Female anatomy: Genital tract ________ – produce eggs and sex hormones ________ – move eggs and normal site of fertilization _______ – normal site of implantation and fetal development _______ – opening to the uterus that can dilate during childbirth Vagina – birth canal and the copulatory organ of the female 16.3 Female Reproductive System

8 Female anatomy: Genital tract Figure 16.6 The female reproductive system Female Reproductive System Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. ovary uterus urinary bladder pubic bone urethra glans clitoris labium minora labium majora vaginal orifice fimbriae cervix vagina uterus fimbriae ovary rectum vagina anus uterine tube (oviduct)

9 Female anatomy: External anatomy Labia major – 2 large folds of fatty skin Labia minor – 2 small folds just inside the labia major that contain the openings to the urethra and vagina Mons pubis – fatty skin covered in coarse hair Clitoris – erectile organ and site of intense sexual feeling 16.3 Female Reproductive System

10 The ovarian cycle: The ovary An ovary contains many _________, each containing an immature egg (oocyte). At puberty a female has 300, ,000 follicles. During the lifetime of a female, only _____ follicles mature The Ovarian Cycle

11 The ovarian cycle: The ovary One follicle matures each month from puberty until ______________ (end of ovarian and uterine cycles). __________ is the monthly release of an oocyte from the ovary when a follicle ruptures The Ovarian Cycle

12 Anatomy of the ovary primary follicles 1. A primary follicle contains an oocyte and begins producing the sex hormone estrogen. 6. Corpus luteum degenerates. 5. Corpus luteum produces the sex hormones progesterone and some estrogen. secondary oocyte 4. Ovulation: The secondary oocyte is released. 3. Vesicular (Graafian) follicle develops. 2. The secondary follicle contains a secondary oocyte and produces the sex hormones estrogen and some progesterone. vesicular (Graafian) follicle secondary follicle oocyte corpus luteum Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Ed Reschke/Peter Arnold/Photolibrary Figure 16.8 The ovarian cycle The Ovarian Cycle

13 Anatomy of the ovary Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. primary oocyte (46 chromosomes) secondary oocyte (23 chromosomes) zygote Sperm enters, fertilization occurs, and meiosis II proceeds to completion. second polar body sperm first polar body meiosis Imeiosis II Figure 16.9 Oogenesis produces egg cells The Ovarian Cycle

14 The ovarian cycle This is the formation and release of an immature egg. It is controlled by GnRH from the _________________ 16.4 The Ovarian Cycle

15 The ovarian cycle 2 phases -___________ phase -FSH promotes the development of a follicle that secretes estrogen. -An estrogen spike leads to a surge in LH and ovulation around day 14 in the 28-day cycle. -_________ phase -LH promotes the development of the corpus luteum that functions to secrete progesterone. -When pregnancy does not occur, menstruation begins The Ovarian Cycle

16 Hormonal control of the ovaries Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. estrogen hypothalamus GnRH FSH anterior pituitary LH follicle oocyte progesterone corpus luteum Figure The hormones that control the production of estrogen and progesterone by the ovaries The Ovarian Cycle