CHPTR 23 PRT 2 CIRCULATION

Which of the following cells are phagocytes?

• Monocytes and neutrophils.

• Basophils and eosinophils.

• Eosinophils and lymphocytes.

• Lymphocytes and basophils.

How long do human red blood cells circulate in the blood before they wear out and have to be replaced?

• 1 to 2 weeks.

• 1 month.

• 3 to 4 months.

• 10 to 12 months.

What is the most common cause of anemia?

• Vitamin deficiency.

• Low blood pressure.

• Iron deficiency.

• Inefficient hemoglobin production.

An adult human's red blood cells are formed in the _.

• Spleen.

• Liver.

• Bone marrow.

• Thyroid gland.

Which of the following can increase red blood cell concentration in a unit of blood?

• Training at low altitudes.

• Reducing blood levels of EPO.

• Blood doping.

• Hydration.

Blood clots are formed by platelets and the plasma protein _.

• Thrombus.

• Fibrin.

• Erythropoietin.

• Fibrinogen.

Which of the following statements about blood clotting is true?

• The first response to an injury is dilation of the damaged blood vessels.

• During the clotting response, platelets rapidly congregate in the interstitial fluid.

• Fibrin is enzymatically converted to fibrinogen.

• Threads of fibrin form a fibrin clot.

Stem cells found in the red marrow inside bones _.

• Phagocytize bacterial cells.

• Are primarily important in blood clotting.

• Are responsible for an immune response.

• Can differentiate into all blood cells and platelets.

Bone marrow stem cells are sometimes used to treat certain blood cell diseases, such as _.

• Leukemia.

• Anemia.

• Cardiovascular disease.

• Hemophilia.

During exercise, your heart rate can increase dramatically in order to meet the metabolic demands of your tissues. If your heart rate increased to 144 beats per minute, approximately how long would diastole last in a single cardiac cycle?

• 0.2 second.

• 0.6 second.

• 0.8 second.

• 1.6 second.