Anatomy and Physiology
Quiz 11 :
The Cardiovascular System
Blood circulates throughout the body through a network of blood vessels. Blood is a type of connective tissue. It is composed of several different types of cells suspended in a fluid matrix. Blood have five major functions. The primary goal of blood is transportation. Blood transports nutrients, gases, hormones, and waste products throughout the body. Oxygen is transported from the lungs to body tissue. Carbon dioxide is carried away from body tissues for expulsion from the lungs. Digested nutrients are absorbed into the blood stream and delivered to respective cells. Hormones are carried from endocrine organs to target cells via blood. Blood also plays a role in regulating pH (acid/base) balance and ion composition of interstitial fluids. Blood can absorb and neutralize acids to maintain body pH. Ion balance is maintained through ion concentration gradients between blood and interstitial fluids. Blood is important during injury to prevent fluid loss. Blood clots form when blood vessels are damaged. Blood clots act as temporary patches until the injury is fully repaired. Blood also helps fight infection from foreign invaders by transporting white blood cells. White blood cells are immune system cells that target and destroy toxins and pathogens. Lastly, blood plays a role in regulating body temperature. Heat generated by skeletal muscles is absorbed by blood and then distributed throughout the body. If the body temperature is high, blood vessels dilate and heat from blood is released through the skin.
Interstitial fluid is a component of extracellular fluid. It surrounds individual cells in the body. It is composed mostly of water, but also contains ions and other molecules. It serves to provide nutrients and helps in waste removal. It also cushions cells and participates in cellular homeostasis. Thus, the correct answer is f.
Blood is specialized connective tissue composed of two components - plasma and formed elements. Plasma comprises approximately 55 percent of the total volume of blood. Formed elements account for the remaining 45 percent. Plasma is the liquid portion of blood. The majority of plasma (approximately 92 percent) is water. Plasma proteins make up 7 percent and other dissolved solutes make up approximately 1 percent. Plasma proteins add volume and pressure, immune system cells, and clotting factors. Other solutes in blood include electrolytes, wastes, and nutrients. Formed elements are cells found in blood. The three types of formed elements are platelets, white blood cells (WBCs) and red blood cells (RBCs). Red blood cells comprise 99.9 percent of formed elements. They give blood its red color and transport oxygen throughout our body. WBCs encompass five different types of immune system cells. Platelets play a major role in clotting.