2. author unknown address unknown accessed unknown Excretion Internal Regulation Internal Regulation

3. A. Regulation A. Regulation B. Temperature B. Temperature C. Glucose C. Glucose author unknown address unknown accessed unknown

4. A. Regulation 1. Cells function most efficiently under particular conditions a. temperature- enzyme activity b. water concentration- metabolic reactions and osmosis c. glucose concentration- energy balance and osmosis 2. Homeostasis is the maintenance of the internal environment_ author unknown address unknown accessed unknown HOW DOES YOUR HOUSE MAINTAIN A CONSTANT TEMPERATURE? Think about it! Think

5. B. Temperature 1. Mammals maintain a constant internal body temperature (despite fluctuations in the environmental temperature) a. endotherms- mammals and birds generate heat internally b. ectotherms- reptiles, amphibians, and fish rely on the environment to control temperature_ author unknown address unknown accessed unknown Play

6. 2. Sweating (perspiration) a. sweat is secreted from sweat glands b. as it evaporates, it takes heat from the skin, and so cools it_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click

7. 3. Vasodilation- blood vessels near the surface become wider a. more blood flow through b. heat is lost to the air by radiation 4. Vasoconstriction- blood vessels become narrower a. less blood flows through b. heat is conserved_ author unknown address unknown accessed unknown

8. C. Glucose Concentration 1. Mammals maintain a constant concentration of glucose in the blood_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click

9. 2. The pancreas produces hormone that controls the levels of glucose a. secretion of insulin reduces high blood glucose levels b. glucagon increases low blood glucose levels 3. Failure of this mechanism may lead to diabetes_ author unknown address unknown accessed unknown Play

11. A. Urine A. Urine B. The Urinary System B. The Urinary System C. Kidneys C. Kidneys author unknown address unknown accessed unknown Play

12. A. Urine 1. Urea is a nitrogenous waste product produced in mammals a. formed in the liver from excess proteins b. excreted by the kidneys in the form of urine_ author unknown address unknown accessed unknown author unknown address unknown accessed unknown author unknown address unknown accessed unknown Click WHAT DO YOU THINK URINE IS COMPOSED OF? Think about it! Think

13. B. The Urinary System 1. The urinary system is composed of: a. renal artery- blood with high urea concentration b. kidneys- filter out urea c. renal vein- blood with low urea concentration d. bladder- stores urine (500 ml) e. urethra- carries urine from bladder to outside_ author unknown address unknown accessed unknown

14. C. Kidneys 1. Kidneys are located near the back of the body of mammals a. just above the waist 2. They remove excess water and urea from the blood plasma a. produce urine which is stored in the bladder_ author unknown address unknown accessed unknown

15. 3. The amount of water in the urine can be varied by the kidney a. in response to changes in the water content of the blood b. water and other molecules are filtered into nephrons of the kidney_ author unknown address unknown accessed unknown

16. c. water can be reabsorbed into the kidney and returned to the blood d. dependant on body’s demand for water_ author unknown address unknown accessed unknown Play