16 Reproductive Systems 1

Male Reproductive System Figure 16.1 Male Reproductive System Vertebral column Urinary bladder Pubic symphysis Ureter Seminal vesicle Ductus deferens Rectum Ductus deferens Prostate gland Seminal vesicle Bulbourethral gland Penis Ejaculatory duct Urethra Erectile tissue Prostate gland Anus Bulbourethral gland Urethra Figure 16.1 The male reproductive system. Epididymis Testis Scrotum Testis Penis Uncoiled semi- niferous tubule A sagittal cutaway view. A posterior view of the reproductive organs and bladder. 2

Male Reproductive System What is the purpose of the following? -testes -epididymis -ductus (vas) deferens -penis -urethra 3 Accessory glands seminal vesicles prostate gland bulbourethral gland See Table 16.1 Figure 16.1

The Male Reproductive System Delivers Sperm Testes produce sperm Scrotum: sac of skin and smooth muscle that holds the testes Maintains testes at a slightly lower temperature Seminiferous tubules within testes: produce sperm Epididymis and ductus deferens: sperm become motile and are stored here Ductus deferens: transports sperm to where it becomes the ejaculatory duct

Accessory Glands Help Sperm Survive Semen: mixture of sperm and secretions of accessory glands Seminal vesicles Secrete fructose (provides source of energy for sperm) and most of seminal fluid Prostate gland Secretes watery alkaline fluid to raise vaginal pH Bulbourethral gland Secretes lubricating mucus Cleanses urethra

Table 16.1 Table 16.1 Summary of the male reproductive organs and glands. 6

Sperm Production Requires Several Cell Divisions Several cell divisions (mitosis and meiosis) in seminiferous tubules produce sperm Cell divisions produce a large number of sperm with half the number of chromosomes of somatic cells (haploid) Sperm (and eggs) are referred to as gametes and are haploid

Testosterone Affects Male Reproductive Capacity Steroid hormone produced in the testes Function: Stimulates sperm formation Controls growth and function of male reproductive tissues Stimulates sexual behavior Controls development of secondary sexual characteristics

Female reproductive system: What is the purpose? Figure 16.4a PLAY Animation—The Female Reproductive System

Female Reproductive System What is the purpose of the following? Ovaries Oviduct Uterus Cervix Vagina Figure 16.4 Q: what are the 2 layers of the uterus? See Table 16.2

The Female Reproductive System Produces Eggs and Supports Pregnancy Ovaries Release oocytes (immature eggs) secretes the hormones estrogen and progesterone Oviduct (fallopian tube) Leads from the ovary to the uterus Fertilization occurs in the upper third of the oviduct Uterus For development of embryo/fetus

Table 16.2 Table 16.2 Summary of the components of the female reproductive system. 12

Female Reproductive System Mammary gland: -modified sweat glands -nourishes infant (lactation) -not required for viable fetus -enlarge due to estrogen Q: To what organ system do mammary glands belong? Q: What hormones are essential for its function? Figure 16.4 Figure 16.5

Reproductive Hormones GnRH: gonadotropin-releasing hormone LH (luteinizing hormone FSH (follicle-stimulating hormone) Testosterone Estrogen & Progesterone -growth/function -aggression -sexual behavior -facial hair, voice -growth/function -promotes/prevents ovulation -supports pregnancy -facial hair, voice

Comparison between male and female

Menstrual Cycle Consists of Ovarian and Uterine Cycles Pattern of changes, which cycles every 28 days Controlled by hormones of pituitary gland and ovaries Begins at puberty and continues until menopause, except during pregnancy

Menstrual Cycle Consists of Ovarian and Uterine Cycles- two linked cycles Ovarian cycle Series of changes in ovaries associated with oocyte maturation within follicles Leading to release of oocyte (ovulation) Controlled by FSH and LH Uterine cycle Changes in the endometrial lining of the uterus- controlled by estrogen and progesterone Menstrual phase day1-5 Proliferative phase 6-13 Ovulation- day 14 Secretory phase- days 15–28-endometrium continues to proliferate, prepared to accept & nourish a fertilized egg

Ovarian and Uterine Cycle Q: Why does the endometrium change in size? Q: What is the source of the hormones estrogen and progesterone? Q: What is the effect of the elevated levels of these hormones in the secretory phase? Figure 16.7

Fertilization: One Sperm Penetrates the Egg Ejaculate: may contain several hundred million sperm Sperm may reach egg within hours to a day or more One sperm penetrates egg within the oviduct Sperm may be viable for up to 5 days within the female reproductive tract

Disorders of the Reproductive System Sexually transmitted diseases Bacterial Gonorrhea, Syphilis, Chlamydia Viral HIV, Hepatitis B, Human Papillomavirus (HPV), Genital Herpes Fungal Parasitic- Trichomoniasis