Blood Physiology

Question 1

How is RBC production regulated?

Answer 1

The amount of oxygen is assessed in our kidney & liver

Question 2

Enzyme that accumulates if O₂ levels are low.

How does it act to increase O₂?

Answer 2

HIF alpha

Continuely ubiquinated in destroyed during times of sufficient oxygen

Binds as a transcription factor and upregulates genes

Question 3

Proteins that are upregulated by HIF alpha and is involved in upregulation of proerythroblasts.

Answer 3

Erthropoietin in the kidney and liver

Transferrin and its receptor

Question 4

How does Erythropoietin increase the amount of red blood cells?

Answer 4

JAK2/STAT5 parhway to increase stem cell differentiation into proerythroblasts

Increases maturation rate

Prevents apoptosis of hemocytoblasts

Question 5

What may cause anemia?

Answer 5

Decreased RBC or Hb

Folate/B12 deficiency

Iron deficiency

Bone marrow damage

Kidney Damage (loss of erythropoietin)

Question 6

Microcytic anemia

Answer 6

Caused by deficiency in iron

Question 7

What allows Fe⁺⁺ into the cell.

Answer 7

Divalent Metal Transporter (DMT1)

Question 8

Converts Fe²⁺ back to ferric state

Answer 8

Hephaestin or Ceruloplasmin

Question 9

How much oxygen bound to Hb?

Answer 9

1.32 O₂ml/g of Hb

Question 10

What is the normal amount of Hb per 100 ml of blood in an average person.

Answer 10

15gHb/100ml

Question 11

Formula for oxygen content

Answer 11

oxygen capacity x % saturation

Question 12

Why do RBC’s perform anareobic glycolysis

Answer 12

To maintain a flexible membrane

Ion-transport (ATPase)

Maintain Fe²⁺ in it’s ferrous state

Prevent oxidation of Hb

Question 13

How are RBC phagocytosed

Answer 13

In spleen or by other macrophages

Iron is recycled

Heme broken down to bilirubin

Question 14

What is Polycythemia and why is it dangerous?

Answer 14

More oxygen carrying capacity

BUT

Blood becomes more viscous and heart must work harder to pump it.

Can be primary (vera) or secondary

Question 15

What can be the mutation in Hemochromatosis?

Answer 15

Hepcidin Mutation (Heridtary mutation in HFE)

Blocks ferroportin to reduce intestinal uptake of iron

Question 16

What is secondary polycethemia caused by?

Answer 16

Bone marrow is normal

Too many RBCs responding to altitude (physiological polycythemia)

Lung/heart disease

Question 17

What is Primary polycethemia (Polycythemia vera) caused by?

Answer 17

Bone marrow is making RBC when there is no need

May be caused by a mutation in the receptor thrombopoietin.

Question 18

Which way does an Hb-O₂ curve shift in an increased affinity for O₂?

Answer 18

To the left

Question 19

What does the Bohr effect show about the effect of CO₂ or ph on a oxygen binding curve?

Answer 19

High C0₂ (which makes ph low) = left shift in affinity

Low C0₂ (which means pH is high) = right shift in affinity

Question 20

A temperature increase has what effect on the affinity for oxygen to Hb?

Answer 20

Decreases it.

Question 21

Disease that exhibits the presence of large amounts of ferric iron (3+) in the heme.

Why is bound ferric iron dangerous?

Answer 21

Methemoglobinemia

Ferric iron cannot bind oxygen, this increases the affinity of oxygen in other chains so drastically that they cannot release O_2.

This disease results in symptoms like anemia.

Question 22

What are the four functions of blood?

Answer 22

Delivery of nutrients/oxygen

Removal of wastes

Homeostasis (thermoregulation/hormones)

Immune

Question 23

A bluish tint in lips, skin, extremidies.

Answer 23

Cyanosis

Question 24

Where is iron absorbed

Answer 24

20% liver

70% bone marrow

Question 25

What is the effect of hemochromatosis?

Answer 25

Iron overload associated with cardiomyopathy

Reduced transferin levels