Hematology

Question 1

What are the 3 main functions of blood?

Answer 1

1. Transportation (O2, CO2, waste, nutrients, water)
2. Protection (immune response)
3. Regulation (pH, temperature)

Question 2

Blood is composed of 55% ______ and 45% ______ ________.

Answer 2

Blood is composed of 55% PLASMA and 45% FORMED ELEMENTS.

Question 3

What percentage of the blood’s plasma is water? What else is present in plasma?

Answer 3

92% is water. There is also 7% proteins and 1% waste/gases/electrolytes.

Question 4

What 3 components make up the formed elements present in the blood?

Answer 4

1. Erythrocytes
2. Leukocytes
3. Thrombocytes

Question 5

How long does a single erythrocyte last in the body’s circulatory system?

Answer 5

~120 days.

Question 6

Which of the body’s organs is responsible for removing old erythrocytes from circulation and storing them until they can be eliminated?

Answer 6

The spleen!

Question 7

Where in the body are erythrocytes produced?

Answer 7

In the red bone marrow, with the greatest proportion coming from the femurs.

Question 8

With regard to blood composition, how does your body naturally try to compensate for COPD? What are the consequences of this?

Answer 8

Your body makes more erythrocytes to carry O2 to your tissues. However, this increases the viscosity of the blood and also leads to hypertension due to increased blood volume. Over time, this will lead to R-sided heart failure (“Cor Pulmonale”).

Question 9

What is anemia? How does it present in a patient?

Answer 9

Anemia refers to a low erythrocyte count and can present as shortness of breath, pallor, and shock-like symptoms.

Question 10

What is polycythemia? What mechanism(s) can cause this?

Answer 10

Polycythemia refers to excess erythrocytes and therefore an increased blood viscosity. This can be due to uncontrolled erythropoiesis in the red bone marrow, chronic hypoxia, splenic malfunction, etc.

Question 11

What is the purpose of hemoglobin in erythrocytes? What other potentially harmful molecule can bind here as well?

Answer 11

Hemoglobin binds oxygen and CO2. However, carbon monoxide (CO) has a higher affinity for hemoglobin than oxygen does, and will fill up all the possible binding sites, preventing oxygen from being carried.

Question 12

What does the oxyhemoglobin dissociation curve represent? (Ignore the Bohr and Haldane effects)

Answer 12

Represents the variable way that oxygen binds to hemoglobin. When there is very little oxygen bound to hemoglobin it will bind new molecules faster. Once there is already oxygen bound to hemoglobin it is slower to bind the last few molecules.

Question 13

With regards to the oxyhemoglobin dissociation curve, describe the Haldane effect and where in the body it is likely to occur.

Answer 13

The Haldane effect describes the increased binding affinity of hemoglobin for oxygen when in an alkalitic - higher pH - environment (such as in the lungs).

Question 14

With regards to the oxyhemoglobin dissociation curve, describe the Bohr effect and where in the body it is likely to occur.

Answer 14

The Bohr effect describes the decreased binding affinity for oxygen when in an acidic - lower pH - environment (such as the muscles during exercise).

Question 15

What is the difference between a thrombus and an embolism?

Answer 15

Thrombus: A fixed blockage inside the blood vessel
Embolism: A mobile blockage that floats through the circulation and gets stuck somewhere, causing a blockage

Question 16

True or False: Hypoxia and Hypoxemia are synonymous terms and can be used interchangeably.

Answer 16

False! Hypoxia refers to a lack of oxygen in the tissues whereas hypoxemia refers to a lack of oxygen in the blood.