Blood, RBCs, and Hemoglobin

What is hematocrit (PCV)?

the ratio of the volume of RBCs to the total volume of blood 

What is the clear fluid layer at the top of the centrifuge tube?

plasma and serum

List plasma compostion. 

1. Water - 92% 

2. Plasma Proteins - 8%

What is the function of erythrocytes? 

transport of gases (O2, CO2) 

What does the biconcave disc shape of erythrocytes allow for?

1. Hemoglobin to be close to the cell surface 

2. Increased flexibility 

Why don’t erythrocytes contain mitochondria?

they would use all the oxygen up

True or False: Erythrocytes are enucleated.

True

What is known as “Bags of hemoglobin”?

Erythrocytes

What is responsible for most O2 transport within Erythrocytes?

Hemoglobin

Hemoglobin is made up of two parts:

1. Globin → protein portion 

2. Heme → iron portion 

Presence of hemoglobin in RBCs
substantially ____________ the total
O2 carrying capacity of blood.

increases

What does a left shift imply?

promotes O2 binding to Hb in the lungs (higher affinity)

What does a right shift imply?

Promotes release of O2 from Hb in the tissues (lower affinity)

List the factors affecting Hb affinity for O2.

1. decrease pH

2. temperature 

3. 2,3 BPG 

What % of CO2 is dissolved in the blood?

7%

What % of CO2 turns to bicarbonate ions?

70%

What % of CO2 is bound to globin?

23%

List the forms of Hb.

1. Oxyhemoglobin - bright red color, reversibly bound 

2. Deoxyhemoglobin - maroon in color, hemoglobin w/ no O2 bound 

3. Carbaminohemoglobin - bound to globin not heme 

What is an abnormal form of hemoglobin that can no longer transport O2?

carboxyhemoglobin → CO binds almost irreversibly to heme portion of Hb

What is methemoglobin?

iron oxidized to the ferric form → incapable of binding O2 → iron must be in ferrous form to carry O2 

RBC are removed from circulation by __________ in the spleen, liver, and bone marrow.

macrophages

True or False: Hemoglobin does not have to remain inside RBCs.

False: Hemoglobin MUST remain inside RBCs.

What is the difference between hematopoiesis and erythropoiesis?

• Hematopoiesis → formation of all types of blood cells 

• Erythropoiesis → production of RBCs that occurs in the bone marrow 

What type of cell do all blood cells begin their lives as?

multipotential hematopoietic stem cell

True or False: Erythropoiesis regulation is a negative feedback system centered in the kidney.

True

Where does about 90% of all erythropoietin formed?

kidneys → then remainder is formed in the liver