17. The Blood

Describe the process of erythropoiesis

What name is given to the immature cell type released to the circulation?

How does it differ from a mature erythrocyte?

Name as many different categories of substances carried in plasma as you can.

Name the formed elements that arise from myeloid stem cells. Name those arising from lymphoid stem cells.

Describe the appearance of platelets and state their major function

Why should platelets not be called 'cells'?

Erythropoietin directly stimulates RBC formation by:

(a) Increasing rates of mitotic divisions in erythroblasts

(b) Speeding up the maturation of red blood cells

(c) Accelerating the rate of hemoglobin synthesis

(d) All of these

If you had a high hematocrit, would you expect your hemoglobin determination to be high or low? Why?

The waste product bilirubin is formed from:

(a) Transferrin

(b) Globin

(c) Heme

(d) Hemosiderin

(e) Ferritin

Discuss hemoglobin relative to its chemical structure, its function, and the color changes it undergoes during loading and unloading of oxygen.

A middle-aged college professor from Boston is in the Swiss Alps studying astronomy. He arrived two days ago and plans to stay the entire year. However, he notices that he is short of breath when he walks up steps and that he tires easily with any physical activity. His symptoms gradually disappear; after two months, he feels fine. Upon returning to the United States, he has a complete physical exam and is told that his erythrocyte count is higher than normal.

(a) Attempt to explain this finding.

(b) Will his RBC count remain at this higher-than-normal level? Why or why not?

Relate the structure of hemoglobin to its function.

Which of the following is not a formed element of blood?

a. Erythrocyte

b. Leukocyte

c. Mast cell

d. Platelet

Which of the following plasma proteins is responsible for osmotic pressure?

a. γ-Globulins

b. Albumin

c. α-Globulins

d. Clotting proteins

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Erythrocytes are biconcave discs with prominent nuclei.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

The main function of erythrocytes is to transport oxygen on the protein hemoglobin.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

Hemoglobin forms oxyhemoglobin when it binds to oxygen.