Answer:
1) Skeletal system: It provides support and protection to the body. Key structures are bones and cartilage.
2) Muscular system: It provides movement, generates heat that maintains body temperature. Key structures include the muscles.
3) Integumentary system: This system protects against environmental hazards, provides sensory information, regulates body temperature. Key structures include the skin, hair, nails and sweat glands.
4) Nervous system: The nervous system interprets the sensory information and generated a response. The brain, spinal cord and nerves are the key structures of the nervous system.
5) Endocrine System: adjusts metabolic activity, controls structural & functional changes during development (hormones). The organs of the endocrine system include the testes, ovaries, adrenal glands, pituitary glands, pancreas and the thyroid glands.
6) Circulatory System: It supplies blood to all parts of the body. Key structures include heart, blood, blood vessels
7) Lymphatic System: It protects the body from infection and disease. Key structures include spleen, thymus, tonsils and lymph nodes.
8) Respiratory System: It provides oxygen to the body parts and removes carbon dioxide. Key structures include sinuses, bronchi, lungs, alveoli.
9) Digestive system: Breakdown of food. It includes mouth, stomach, pharynx, esophagus, small intestine, large intestine, liver, gall bladder, pancreas
10) Urinary system: it excretes wastes from the body. It includes kidneys, ureters, bladder and urethra
11) Reproductive System: It produces the male sex cells and the human sex cells. Key structures include testes, vagina, uterine tube, penis, scortum