Blood+HW+CH

=**Blood Homework**= =**SCI Human Biology - 2**= =**Assigned: 1/29 Due: 1/31**= =**Blood (Chapter 6 of new book)**=



(1) What are the functions of blood, and what are its two main portions? The blood transports, defends, and regulates. It is the main transport medium for the body, defends the body from invasion by pathogens in different ways, and helps regulate body temperature by picking up heat.

(2) What is the composition of plasma and what are the functions of plasma proteins? Plasma is about 91% water and 9% of it is made up by a mix of salts and organic molecules. Plasma proteins help maintain homeostasis because they are able to take up and release hydrogen ions, so they remain in the blood and establish an osmotic gradient from blood and tissue fluid.

(3) What substances allow red blood cells (RBCs) to transport oxygen? Hemoglobin substances make it possible for red blood cells to transport oxygen.

(4) Why do RBCs have a bioconcave shape? The shape comes about when they lose their nucleus during maturation. The biconcave shape allows them a greater surface are to apply for the diffusion of gases in and out of the cell.

(5) Name and describe three disorders associated with RBCs. 1. Anemia: when there is not enough red blood cells or the cells don't have enough hemoglobin. It causes a tired, run-down feeling. 2. Sickle-cell disease: a hereditary condition where an individual has sickle-shaped red blood cells that rupture as they pass through the narrow capillaries. 3. Hemolytic disease of the newborn: is a type of hemolytic anemia.



(6) What are the different blood types and what determines blood type? The different blood types are A, B, AB, and O. Someone's blood type is determined by whether or not their blood has A or B antigens present on the surface of their red blood cells.

(7) Among the ABO types of blood, who can give blood to whom? Why? Anti-A antibodies have combined with type A antigens, and anti-B antibodies have combined with type B antigens. Type O blood is compatible with all types. Blood compatibility is determined by the antibodies in the plasma. They must not combine with the antigens on the surface of the red blood cells.

(8) When does hemolytic disease in a newborn occur? The disease occurs when an Rh positive mother has a baby that is Rh negative.



(9) Tell how the functions of the cardiovascular system contribute to homeostasis? The cardiovascular makes everything in the body work, which allows the body to maintain homeostasis.

(10) In what way does the liver contribute to the functioning of the cardiovascular system? The liver regulates blood pressure,since it absorbs water.