11 MAJOR ORGAN SYSTEMS IN THE HUMAN BODY

1) Circulatory System Major Structures: Heart, Blood vessels, Blood, lymph nodes and vessels, lymph Functions: Transports nutrients, wastes, hormones, and gases

The Closed Circulatory System ®Humans have a closed circulatory system, typical of all vertebrates, in which blood is confined to vessels and is distinct from the interstitial fluid. ®The heart pumps blood into large vessels that branch into smaller ones leading into the organs. ®Materials are exchanged by diffusion between the blood and the interstitial fluid bathing the cells.

®The Blood ®Carry hemoglobin and oxygen. Do not have a nucleus and live only about 120 days. ®Can not repair themselves.

2) Digestive System Major Structures: Mouth, Throat, Esophagus, Stomach, Liver, Pancreas, Small intestine, Large intestine Functions: Extracts and absorbs nutrients from food; removes wastes; maintains water and chemical balances

3) Endocrine System Major Structures: Hypothalamus, pituitary, pancreas Functions: Regulates body temperature, metabolism, development, and reproduction; maintains homeostasis; regulates other organ systems

4) Excretory System Major Structures: Kidneys, urinary bladder, ureters, urethra, skin, lungs Functions: Removes wastes from blood; regulates concentration of body fluids

® Kidneys and urea ® Lungs – filter out excess water – filter out carbon dioxide, CO 2, from the blood. ® Skin – excretes water, as sweat, which contains some trace chemical wastes, including urea.

I. The Kidneys ® Every drop of blood in your body is filtered by your kidneys more than 300 times per day! ® Kidneys eliminate urea, minerals and excess water. ® Kidneys regulate the amount of water we need to maintain in our bodies.

5) Immune System Major Structures: White blood cells, lymph nodes and vessels, skin Functions: Defends against pathogens and disease * More about this tomorro w!!

6) Integumentary System Major Structures: Skin, nails, hair Functions: Protects against injury, infection, and fluid loss; helps regulate body temperature

7) Muscular System Major Structures: Skeletal, smooth, and cardiac muscle tissues Functions: Moves limb and trunk; moves substances through body; provides structure and support

8) Nervous System Major Structures: Brain, spinal cord, nerves, sense organs Functions: Regulates behavior, maintains homeostasis; regulates other organ systems; controls sensory and motor functions

9) Reproductive System Major Structures: Testes, penis (males), ovaries, uterus, breasts (females) Functions: Produces gametes and offspring

10) Respiratory System Major Structures: Lungs, nose, mouth, trachea Functions: Moves air into and out of the lungs; controls gas exchange between blood and lungs

11) Skeletal System Major Structures: Bones and joints Functions: Protects and supports the body and organs; interactions with skeletal muscles; produces red blood cells, white blood cells, and platelets