Chapter 28: REPRODUCTIVE SYSTEM: MALE

Chapter 28: REPRODUCTIVE SYSTEM: MALE I. FUNCTIONAL ANATOMY (Fig. 28.1) A. Testes: glands which produce male gametes, as well as glands producing testosterone 2. Seminiferous tubules (Fig.28.3; 28.5) a. Function: b. Contain Sertoli cells (sustentacular cells) Function: Secrete: c. Leydig cells (interstitial cells) Location: Function: 3. Descent of the testes (Fig. 28.4) a. Time frame b. Route Cryptorchidism B. Scrotum 1. Structure: Skin, smooth muscle, sweat glands 2. Function: : Spermatogenesis requires 3. Effect of higher body temperature on sperm: spermatogenesis 96

97 C. Epididymis 1. Contains 20 foot coiled tube 2. Sperm storage and maturation D. Vas deferens (ductus deferens) 1. 18-inch smooth muscle, ciliated tube 2. Storage, transport of sperm E. Spermatic cord 1. Contains vas deferens, testicular artery and veins, nerves. 2. Covered by. F. Ejaculatory ducts G. Urethra 1. Traverses prostate gland and corpus 2. Internal urethral sphincter prevents urine release during sexual arousal H. Seminal vesicles (paired): 60% semen 1. Secrete fructose-rich, alkaline, viscous fluid 2. Function: sperm noursihment, reduction of vaginal acidity I. Prostate: 30% semen 1. Secretes thin, alkaline, milky fluid 2. Function: sperm transport, reduction of vaginal acidity Prostate cancer Benign prostate hypertrophy

98 J. Bulbourethral glands (paired): 1. Pea-sized exocrine glands 2. Secrete initial thick, alkaline lubricating fluid 3. Function: K. Penis 1. Three erectile tissues, urethra 2. Reproductive function: a. Erection: Parasympathetic activity ---> vasodilation of arterioles b. Emission: Sympathetic activity --> causes all secretions to move toward c. Ejaculation: Sympathetic activity + skeletal muscle contraction Effect: Erectile dysfunction II. SPERM A. Structure (Fig.28.3c) B. Function: C. Life span 1. 2 months to mature 2. Within male: may live 3. Within female: may live Why?

99 D. Sperm and male fertility 1. Quantity a. Average per ml ejaculate: b. Low sperm count and infertility 2. Quality a. Motility b. Morphology E. Spermatogenesis: (Fig. 28.5) 1. Note that 1 diploid spermatogonium produces haploid sperm cells. 2. Where? 3. When? F. Semen 1. Mixture of secretions from: a. Testes b. Seminal vesicles c. Prostate d. Bulbourethral glands 2. ph 7.4 3. Quantity

100 III. HORMONAL CONTROL OF MALE REPRODUCTION A. Testosterone 1. Functions a. Formation of male reproductive organs in embryo b. Descent of testes c. Maintenance of male reproductive organs d. Male secondary sex characteristics e. Anabolism f. Male sexual behavior g. Needed for spermatogenesis 2. Control of testosterone (Fig.28.8) Hypothalamus Gonadotropin Releasing Hormone (GnRH) Pituitary Luteinizing Hormone (LH) Leydig cells Testosterone B. Inhibin 1. Source: Sertoli cells 2. Function: Controls rate of spermatogenesis 3. Control (Fig.28.8) Hypothalamus GnRH Pituitary Follicle Stimulating Hormone (FSH) Inhibin Sertoli cells Seminiferous tubules Spermatogenesis

Chapter 28: REPRODUCTIVE SYSTEM: FEMALE I. STRUCTURAL-FUNCTIONAL OVERVIEW (Fig. 28.10, 28.11) A. Ovary 1. Structure: Many follicles containing within c.t. connective tissue 2. Function: Produces female ; produces the female sex hormones and B. Uterus 1. Structure: Thick smooth muscle lined with vascular 2. Function: 3. Support: Uterine prolapse C. Uterine tubes 1. Structure: muscle lined with ciliated epithelium 2 Function: Movement of 3. Site of fertilization D. Vagina 1. Structure: Smooth muscle lined with stratified squamous epithelium 2. Function: 101

102 II. THE MENSTRUAL CYCLE A. Phases: (Fig. 28.18; Table 28.2) 1. Menses: First day of menses is 2. Preovulatory phase: (includes menses) average 14 days, variable 3. Ovulation: 4. Postovulatory phase: (12-16 days; less variable) B. Preovulatory events: 1. Approximately 20 follicles containing develop 2. Follicle cells release 3. Only about 5 follicles become secondary follicles, 4. One follicle (usually) becomes a mature follicle, releasing C. Ovulation: Release of mature ovum 1. Transport of ovum: 3. Ovum life span: D. Postovulatory phase (luteal phase) 1. Follicular cells become a corpus luteum, releasing + 2. If no fertilization occurs, in 12-16 days, corpus luteum degenerates ----> 3. Resulting in estrogen and progesterone causes menses 4. If fertilization occurs, the corpus luteum persists, and estrogen and progesterone, which supports pregnancy.

103 III. EFFECTS OF ESTROGEN AND PROGESTERONE A. General 1. Estrogen a. Maintains female reproductive organs b. Initiates female secondary sex characteristics c. Fusion of epiphyseal plates d. Initiates but does not complete breast development e. During pregnancy, estrogen 2. Progesterone a. Maintains endometrium b. Completes breast development during first pregnancy c. Elevates basal body temperature d. During pregnancy, progesterone e. During pregnancy: maintains endometrium, uterine contractions B. Endometrial effects of estrogen and progesterone (Fig. 28.18; Table.28.2) 1. Menses: endometrium lost Cause: 2. Preovulatory phase: estrogen causes repair, growth of new endometrium; new endometrial glands develop Function: 3. Postovulatory (luteal) phase: progesterone causes increased vascularity and height of the endometrium; glycogen storage and secretion of glands a. Function: b. If no pregnancy? 4. If pregnancy occurs?

104 IV. HORMONAL REGULATION IN THE NONPREGNANT STATE A. Pre-ovulation Hypothalamus GnRH Anterior pituitary FSH (and LH) Ovary Estrogen Follicular development Note feedback on GnRH; is dominant B. Shortly before ovulation Hypothalamus GnRH Estrogen Anterior pituitary LH FSH Follicular maturation and ovulation Ovary Note brief hours of feedback > "LH surge" and ovulation C. Post-ovulation Hypothalamus GnRH Anterior pituitary LH FSH Progesterone and estrogen Note feedback on GnRF Ovary Corpus luteum

105 V. FEMALE FERTILITY A. Cyclic signs of fertility and infertility cycle 1. Preovulatory: a. Cervical mucus b. Cervix itself c. Control: 2. Postovulatory: Ovulation predictor kits Ultrasound imaging a.. Cervical mucus b. Cervix itself c. Basal body temperature d. Control: 3. If pregnancy occurs (Fig. 28.22): a. Cervix b. Basal body temperature c. Control: d. Human chorionic gonadotropin (HCG) Source Function Early pregnancy tests B. Sperm lifespan vs. ovum lifespan C. Female infertility

106 D. Puberty: Onset of reproductive maturity 1. Cause: Hypothalamus loses its sensitivity to estrogen, > GnRH,---> FSH, LH, ---> estrogen. 2. Menarche E. Menopause: 1. Def.: Natural cessation of female reproductive ability; the last menstruation 2. Causes: 3. Postmenopausal hormones E ; P ; FSH ; LH (See page 104, A) VI. OOGENESIS Events and timing of meiosis (Fig. 28.13) 1. Diploid oogonium begins first meiotic division a. When? b. Result: 2. First meiotic division completed a. When? b. Result: 3. Second meiotic division completed a. When? b. Result: