Unit# 5 Name: Joane Elsy Date 11-05-2015
Chapter 13: Blood

Human Anatomy & Physiology 11 - Review Packet Circulation and Body Defense.
Chapter 13: Blood

* List the major components of blood.
The blood consists of red blood cells, white blood cells, platelets, and plasma (the liquid portion).

Define hematocrit, and explain how it is determined.
Hematocrit (HCT) is the percentage of the cells in a blood sample. This is obtained by allowing the sample to stand (clotting is prevented), allowing the cells to separate and sink to the bottom. This is further centrifuged and the percentage of the cells and liquid is determined.

Describe a red blood cell.
A red blood cell is a biconcave disk that has no nucleus. Describe the life cycle of a red blood cell. a. Nutrients from food are absorbed from the small intestine into the bloodstream. b. The blood transports the absorbed nutrients to the red bone marrow tissue. c. The red bone marrow produces red blood cells. d. The red blood cells circulate for about 120 days. e. Damaged and old red blood cells are destroyed in the liver. f. The resulting biliverdin is converted to bilirubin that is excreted in the bile from the liver.

2. Distinguish between oxyhemoglobin and deoxyhemoglobin.
Oxyhemoglobin is hemoglobin combined with oxygen. Deoxyhemoglobin is hemoglobin that has released its oxygen.

Explain what is meant by a red blood cell count.
A red blood cell count is the number of red blood cells in a cubic millimeter (mm3) of blood.

Define erythropoietin, and explain its function.
Erythropoietin is a hormone that is released from the kidneys, and to a lesser extent the liver, which stimulates red blood cell production.

3. Explain how vitamin B12 and folic acid deficiencies affect red blood cell production.
Both substances