BPK 105 Study Guide - Final Guide: Vitamin K Deficiency, Medical Test, Bone Marrow
27 Apr 2018
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Modules 7 & 8 - Review Questions - Part 1
1. Describe the process by which more red blood cells are made in response to
low oxygen. What nutrients are required for this process, why? [4 marks]
- In response to low blood oxygen levels, the kidneys produce erythropoietin, which
stimulates red blood cell production in red bone marrow.
- Typical causes of low blood oxygen are decreased numbers of red blood cells,
decreased or defective hemoglobin, diseases of the lungs, high altitude, inability of
the cardiovascular system to deliver blood to tissues, and increased tissue
demand for oxygen, as occurs during endurance exercises.
Low blood oxygen levels stimulate red blood cell production by increasing the formation and
release of the glycoprotein erythropoietin, primarily by the kidneys (figure 11.4).
Erythropoietin stimulates red bone marrow to produce more red blood cells. The greater number
of red blood cells increases the blood’s ability to transport oxygen. This negative-feedback
mechanism increases the blood’s capacity to transport oxygen and maintains homeostasis.
Conversely, if blood oxygen levels rise, less erythropoietin is released, and red blood cell
production decreases.
2. Draw a flow chart indicating the three stages of clot formation following injury
to a blood vessel. Where would there be a problem if the individual was
vitamin K deficient? What diagnostic blood test help determine this, what
would be a normal value for this test? [6 marks]
Refer to figure 11.9 in textbook.
Prothrombin time measurement calculates how long it takes for the blood to start clotting,
which is normally 9–12 seconds. Prothrombin time is determined by adding thromboplastin to
whole plasma.
Thromboplastin is a chemical released from injured tissues that starts the process of clotting
(see figure 11.9). Prothrombin time is officially reported as the International Normalized Ratio
(INR), which standardizes the time it takes to clot on the basis of the slightly different
thromboplastins used by different labs.
Because many clotting factors have to be activated to form fibrin, a deficiency of any one of
them can cause the prothrombin time to be abnormal. Vitamin K deficiency, certain liver
diseases, and drug therapy can increase prothrombin time.
Document Summary
Modules 7 & 8 - review questions - part 1: describe the process by which more red blood cells are made in response to low oxygen. In response to low blood oxygen levels, the kidneys produce erythropoietin , which stimulates red blood cell production in red bone marrow . Low blood oxygen levels stimulate red blood cell production by increasing the formation and release of the glycoprotein erythropoietin , primarily by the kidneys (figure 11. 4). Erythropoietin stimulates red bone marrow to produce more red blood cells. The greater number of red blood cells increases the blood"s ability to transport oxygen . This negative-feedback mechanism increases the blood"s capacity to transport oxygen and maintains homeostasis . Conversely, if blood oxygen levels rise, less erythropoietin is released, and red blood cell production decreases: draw a flow chart indicating the three stages of clot formation following injury to a blood vessel.
