Urinary & Reproductive Systems
Purpose of Urinary System To move liquid waste from the body to the outside
Parts of the Urinary System Kidneys Main organs (2) Fist sized; located at back of abdominal cavity Filters blood of wastes (urea, Na) Connected to bladder by ureter (tube)
Parts of the Urinary System Bladder Storage sac collects waste from kidney Mixed with water and other chemicals to make urine Moved to outside of body in urethra (tube)
Water balance Drink less fluids or sweat more – kidneys produce less urine Drink more, kidneys produce more urine Kidneys maintain levels of electrolytes (dissolved Na, K, Ca)
Water balance Critical in plants, too If dry, guard cells close up to trap water in Guard cells on underside of leaf, away from sunlight
Reproductive System
Purpose of the Reproductive System Do I have to explain this one?
Asexual Reproduction Only 1 parent needed Done by plants and some animals (eg. Aphids) Offspring have identical DNA to the parent (clone)
Sexual reproduction Most animals Requires cells from both parents In humans, only system where parts are different for males and females
Female System Parts specialized for growing and releasing egg cell Also serves to grow and nourish the fetus (if egg is fertilized)
Female System Ovaries – produce egg cell Oviducts – aka ‘Fallopian Tubes’; path for egg to the uterus; site of fertilization Uterus – where fetus grows if pregnant Cervix – opening to the uterus; keeps baby in uterus until delivery Vagina – receives sperm from male; birth canal for baby during delivery
Hormonal Control Gonad Stimulating Hormone (GSH) Estrogen Progesterone Brain triggers gonads to get to work (puberty) Estrogen Regulates menstrual cycle Stimulates breast enlargement Progesterone Works with estrogen to prepare uterus for baby
Male System Parts specialized to grow and deliver sperm cells to female
Male System Testicles – site of sperm production Epididymis – top of testicle; stores sperm Vas deferens – tube carrying sperm from the testes Seminal vesicle – adds fluid to sperm Prostate gland – adds Urethra – releases semen through penis Penis – delivers sperm to female system
Hormonal Control Gonad Stimulating Hormone (GSH) Testosterone Brain triggers gonads to get to work (puberty) Testosterone Stimulates increase in muscle mass; also growth of body and facial hair