Ganong 24e chapter 31 - Blood Circulatory Fluid (1)

Question 1

What percentage of body weight is made up of blood?

Answer 1

8%

Question 2

What percentage of blood volume is made up of plasma?

Answer 2

55%

Question 3

What is red marrow? What is yellow marrow?

Answer 3

Red marrow is active bone marrow. Yellow marrow is inactive marrow that has been infiltrated with fat.

Question 4

Give three examples of granulocytes (polymorphonuclear nucleocytes, PMNs)

Answer 4

Neutrophils, Basophils, Eosinophils.

Question 5

What is the size of a normal platelet? What proportion of the body’s mature platelets are in the spleen?

Answer 5

2-4μm in diameter. About 25% are in the spleen, and 75% are in the circulating blood.

Question 6

What is the diametre of a normal RBC?

Answer 6

7.5 μm

Question 7

How does the spleen filter RBCs?

Answer 7

Abnormal RBCs, which are not as flexible as normal RBCs, are unable to squeeze through the slits between the endothelial cells that line the splenic sinuses. They are thus trapped and destroyed in the spleen.

Question 8

What is the globin chain make-up of the normal Adult Haemoglobin (also called Haemoglobin A)

Answer 8

α2β2

Question 9

Tell me about Haemoglobin A₂

Answer 9

This makes up 2.5% of haemoglobin in adults, and is different to Haemoglobin A in that the beta-polypeptides are replaced with delta-polypeptides: α2δ2

Question 10

How is oxyhaemoglobin formed?

Answer 10

O₂ binds to the Fe²⁺ in the heme moiety of hemoglobin O₂ to form oxyhemoglobin

Question 11

What is methaemoglobin?

Answer 11

When blood is exposed to various drugs and other oxidizing agents in vitro or in vivo, the ferrous iron (Fe²⁺) that is normally present in hemoglobin is converted to ferric iron (Fe³⁺), forming methaemoglobin.

Question 12

What is fetal haemoglobin called, and what is its globin chain structure?

Answer 12

Haemoglobin F. α2γ2

Question 13

In the ABO blood grouping system, what is the H antigen?

Answer 13

This is the antigen that is found expressed on the RBCs in people with Blood type O. The same H antigen is also present in those of type A and B, but it has an extra N-acetylgalactosame or an extra galactose molecule, respectively.

Question 14

In general, to say a person has “Rhesus positive” blood, what does this mean?

Answer 14

It means that they express the Rhesus D antigen on their RBCs.

Question 15

Which type of blood vessel is most responsible for changes in total peripheral resistance?

Answer 15

Arterioles

Question 16

True or False: Transfer of oxygen and nutrients from the blood to tissues, as well as collection of metabolic wastes, occurs in the capillary beds and in the venules.

Answer 16

False. It occurs exclusively in the capillary beds.

Question 17

Describe the velocity of blood flow as blood progresses from the heart, to the capillary beds, and back to the heart.

Answer 17

Velocity of flow is highest in the aorta, decreasing to a nadir in the capillary beds, then very slowly increasing from the venules to the veins to the vena cava.

Question 18

What is the effect of blood viscosity on TPR? What is the chief determinant of blood viscosity?

Answer 18

Increased blood viscosity causes an increase in total peripheal resistance. The haematocrit is the chief determinant of blood viscosity.