Chapter 16

Question 1

Define hematocrit.

Answer 1

Hematocrit - Volume of blood made of RBC’s expressed as a % of blood volume.

Question 2

The hormone responsible for regulating hematocrit is what?

Answer 2

Erythropoietin (EPO)

Question 3

Describe the negative feedback mechanism for the regulation of hematocrit. Name each of the 7 components, and describe their role in the feedback system.

Answer 3

1. Stimulus - low arterial pressure
2. Sensor - special renal cells/basal production of EPO
3. Input - special renal cells
4. Integrating center - special renal cells
5. Output signal - EPO
6. Effectors - Axial skeletal girdles/hemapoietic stem cells
7. Effect - Increase RBC production and increase in oxygen in the blood.

Question 4

The red bone marrow (hematopoietic tissue) is located in which bones of the body?

Answer 4

Axial skeletal girdles

Question 5

Hematocrit can be increased. Describe three conditions/situations where hematocrit rises (due to negative feedback)

Answer 5

1. Chronic exercise
2. Elevation
3. COPD