Chapter 12: Human Growth and Development
The Male Reproductive System Primary Organs Gonads: testes Accessory Structures Ducts that transport sperm cells & hormones Exocrine glands
The Male Reproductive System (cont’d)
Testes Located outside body, midline below torso Suspended by spermatic cord in scrotum Spermatic cord: bundle of blood & lymphatic vessels & nerves Oval-shaped Site of sperm generation Produce testosterone
Structure of the Testis
Testosterone Main male sex hormone Diffuses from testes into surrounding fluid & is absorbed into bloodstream Functions: Develops & maintains reproductive structures Develops sperm cells Develops secondary sex characteristics (deeper voice, body hair)
Spermatozoa Sperm cells Fertilize egg cell >200 million in average ejaculation Manufactured continuously after puberty in testes Head: nucleus containing chromosomes, enzymes to penetrate ovum Tail: propels sperm through female reproductive system to reach ovum
Accessory Structures Epididymis Vas deferens Ejaculatory duct Coiled tube on surface of testes Stores sperm Vas deferens Duct in spermatic cord Carries sperm to ejaculatory duct Ejaculatory duct Delivers sperm to urethra Penis: delivers sperm to vagina during intercourse
Semen Mix of sperm cells & secretions from other glands Expelled from body in ejaculation Functions of secretions in semen: Nourish sperm cells Transport them Neutralize acidity of male urethra & female vaginal tract Lubricate female reproductive tract during intercourse Prevent infection by using antibacterial enzymes & antibodies
The Urethra and Penis Urethra Penis Tube that transports both urine & semen through pelvic cavity & penis Ejection of semen made possible by erection Penis Made of spongy tissue that engorges with blood when erect Contractions of skeletal muscles in pelvic floor expel semen Penis & scrotum make up male external genitalia
Common Diseases and Conditions of the Male Reproductive System Enlarged prostate Prostate cancer Testicular cancer Orchitis Cryptorchidism Epididymitis
The Female Reproductive System Ovaries Female gonads Site of egg formation Accessory Structures Uterus Various passageways Bartholin glands External genitalia Breasts
The Female Reproductive System (cont’d)
The Female Reproductive System (cont’d)
The Ovaries Outer layer consists of single layer of epithelium Ovarian follicle Cluster of cells where ovum ripens Secretes estrogen, beginning development of endometrium Ovulation Follicle ruptures & discharges ripened egg Menstruation The sloughing off of endometrium Expulsion of unfertilized egg
Accessory Structures Fallopian tubes Uterus Vagina Bartholin glands Vulva & perineum Breasts
The Menstrual Cycle Process that prepares female’s body for pregnancy Egg ripens & is released Endometrium is prepared If no fertilization: Estrogen & progesterone levels decrease Bloody discharge Average duration: 2 to 6 days
Common Diseases and Conditions of the Female Reproductive System Cervical cancer Ovarian tumors Pelvic inflammatory disease Uterine cancer Breast cancer Endometriosis Fibroid tumors Menstrual disorders Yeast infection
Effects of Aging on the Reproductive System Men: decrease in testosterone production Women: menopause—menstruation gradually ceases
Common Diseases and Conditions of Both the Male & Female Reproductive Systems Chlamydia Gonorrhea Syphilis Genital herpes Human papillomavirus (HPV) Pubic lice Infertility
Factors Influencing Growth and Development Heredity Prenatal factors (mother’s age/health during pregnancy) Caregiver factors (mental illness) Individual differences (vision & hearing impairments) Health or illness Environment, including culture Nutrition
Stages of Growth and Development Embryo & fetus Neonate (birth to 1 month) Infant (1 month to 1 year) Toddler (1-3 years) Preschool child (3-6 years) School-aged child (6-12 years) Adolescent (12-18 years) Young adult (18-40 years) Middle-aged adult (40-65 years) Older adult (>65 years)
Stages of Grief Denial Anger Bargaining Depression Acceptance
Theories of Development Erik Erikson Robert J. Havighurst Sigmund Freud Maslow’s hierarchy of needs