Question

1. the brain and the spinal cord are referred to together as the: a. peripheral nervous system. b. central nervous system. c. somatic nervous system. d. automatic nervous system. 2. the integumentary system consists of the: a. processes involved in the digestion and elimination of waste. b. skin, hair, and nails. c. testes and ovaries. d. lymphatic and immunity tissues. 3. which of the following is not considered part of the endocrine system? a. gallbladder b. pancreas c. adrenal gland d. pituitary gland 4. what is the approximate percentage of oxygen found in atmospheric air? a. 19 percent b. 20 percent c. 21 percent d. 22 percent 5. which component of blood helps it to clot? a. red blood cells b. plasma c. white blood cells d. platelets

Explanation:

1. The central nervous system is composed of the brain and spinal cord. The peripheral nervous system is outside of these. The somatic nervous system controls voluntary muscles and the automatic (autonomic) nervous system regulates involuntary functions.
2. The integumentary system is made up of the skin, hair, and nails, which serve as a protective barrier. Digestive processes are part of the digestive system, testes and ovaries are in the reproductive system, and lymphatic and immunity tissues are part of the lymphatic - immune system.
3. The endocrine system consists of glands that secrete hormones directly into the bloodstream. The pancreas, adrenal gland, and pituitary gland are endocrine glands. The gallbladder stores and releases bile and is part of the digestive system, not the endocrine system.
4. Atmospheric air is approximately 78% nitrogen, 21% oxygen, and small amounts of other gases like carbon - dioxide, argon, etc.
5. Platelets are cell - like fragments in the blood that play a key role in blood clotting. Red blood cells carry oxygen, white blood cells are involved in the immune response, and plasma is the liquid part of blood that contains various substances.

Answer:

1. b. central nervous system
2. b. skin, hair, and nails
3. a. Gallbladder
4. c. 21 percent
5. d. Platelets