Blood Physiology Part 3

Question 1

What happens when there’s inadequate hemoglobin production?

Answer 1

the number of the erythrocytes decreases, and the volume of erythrocytes becomes small

Question 2

What does Megaloblastic anemia result from?

Answer 2

inhibition of DNA synthesis during erythrocytes production, when there are not enough folic acid and vitamin B12

Question 3

What does impaired DNA lead to?

Answer 3

continuing without division, which presents as macrocytosis

Question 4

Q: What maintains the number of circulating erythrocytes in the body?

Answer 4

A balance between red blood cell production and destruction.

Question 5

What are the consequences of having too few erythrocytes?

Answer 5

It leads to tissue hypoxia (oxygen deprivation

Question 6

Q: What happens if there are too many erythrocytes?

Answer 6

Blood becomes undesirably viscous.

Question 7

Q: What happens if there are too many erythrocytes?

Answer 7

Blood becomes undesirably viscous.

Question 7

Where is erythropoietin (EPO) mainly secreted from?

Answer 7

a particular group of hormone secreting connective tissue cells in the
kidneys.

Question 7

What hormone directly controls erythropoiesis?

Answer 7

Erythropoietin (EPO).

Question 8

Under normal conditions, how much erythropoietin is secreted?

Answer 8

normally secreted in small amounts that stimulate the bone marrow to produce erythrocytes at a rate
adequate to replace the usual loss

Question 9

What increases erythropoietin secretion above basal levels?

Answer 9

When there is Decreased oxygen delivery to the kidneys

Question 10

What does erythropoietin do in the bone marrow?

Answer 10

acts on the bone marrow to stimulate the proliferation of erythrocyte progenitor cells and their
differentiation into mature erythrocytes.

Question 11

What is the The average life span of an erythrocyte?

Answer 11

Approximately 120 days

Question 12

What happens to dying erythrocytes?

Answer 12

Damaged or dying erythrocytes are engulfed by macrophage in spleen and liver.

Question 13

The body has a considerable store of …..

Answer 13

Iron

Question 14

What percentage of total body iron is in other heme-containing proteins in other heme-containing proteins (mainly the cytochromes) in the cells of the body?

Answer 14

25%

Question 15

What percentage of the total body iron is in hemoglobin?

Answer 15

About 50 %

Question 16

Where is iron mostly stored in the body?

Answer 16

the liver, bound up in a protein called ferritin. Ferritin serves as an iron storage protein.

Question 17

What percentage of iton is stored in the liver ferritin?

Answer 17

25%

Question 18

What happens to iron stored in erythrocytes when the erythrocytes are destroyed?

Answer 18

liver), their iron is released into the plasma and bound to transferrin, an iron-
transport plasma protein.

Question 19

What percentage of iton is stored in the liver ferritin?

Answer 19

25%

Question 20

What is the role of transferrin ?

Answer 20

Transferrin delivers iron to the bone marrow to be incorporated into new
erythrocytes.

Question 21

Why is iron recirculation important?

Answer 21

It recycles about 20 times more iron daily than the body absorbs and excretes.

Question 22

Why is iron recirculation important?

Answer 22

It recycles about 20 times more iron daily than the body absorbs and excretes.

Question 22

What is anemia?

Answer 22

defined as a decrease in the ability of the blood to carry oxygen due to (1) a decrease in the total number of erythrocytes, each having a normal quantity of hemoglobin; (2) a diminished concentration of hemoglobin per erythrocyte; or (3) a combinationof both

Question 23

What are the major causes of anemia?

Answer 23

•Dietary deficiencies of iron (iron-deficiency anemia), vitaminB12 or folic acid •Bone marrow failure due to toxic drugs or cancer •Blood loss from the body(hemorrhage) •Inadequate secretion of erythropoietin in kidney disease Excessive destruction of erythrocytes (for example, sickle-cell disease)

Question 24

What causes sickle-cell anemia?

Answer 24

a genetic mutation that alters one amino acid in the hemoglobin chain.

Question 25

What are the major causes of anemia?

Answer 25

•Dietary deficiencies of iron (iron-deficiency anemia), vitamin Biz, or folic acid •Bone marrow failure due to toxic drugs or cancer •Blood loss from the body (hemorrhage) Inadequate secretion of erythropoietin in kidney disease Excessive destruction of erythrocytes (for example, sickle-cell disease)

Question 26

What is sickle cell anemia?

Answer 26

Sickle-cell anemia is due to a genetic mutation that alters one amino acid in the hemoglobin chain. This alteration causes the beta chains to link together under low-oxygen conditions, forming stiff rods so that hemoglobin S becomes spiky and sharp

Question 27

What do beta chains to linking together under low-oxygen conditions, and forming stiff rods so that hemoglobin S becomes spiky and sharp cause?

Answer 27

, causes the red blood cells to become crescent shaped when they unload oxygen molecules or when the oxygen content of the blood is lower than normal, as during vigorous exercise and other activities that increase metabolic rate.

Question 28

The stiff, deformed erythrocytes……

Answer 28

rupture easily and tend to dam up in small blood vessels.

Question 29

What does the rupturing of redblood cells and damming of the blood vessels result in?

Answer 29

These events interfere with oxygen delivery, leaving the victims gasping for air and in extreme pain. Bone and chest pain are particularly severe, and infection and stroke are common sequels

Question 30

There are typically …….leukocytes in blood in adults, higher in infants and young children.

Answer 30

4.5~11 ×10%/L

Question 31

The leukocytes are all involved in immune defenses and include?

Answer 31

include neutrophils, eosinophils, monocytes, macrophages, basophils, and lymphocytes.

Question 32

What are platelets?

Answer 32

Platelets/ thrombocytes are colorless, nonnucleated cell fragments that contain numerous granules. •

Question 33

When are platelets produced?

Answer 33

• Platelets are produced when cytoplasmic portions of megakaryocytes pinch off and enter the circulation.

Question 34

Platelets are ……. in diameter.

Answer 34

2~4 um

Question 35

What does the Normal platelet counts range from?

Answer 35

from 150~400×109/L of blood.

Question 36

What is life span of platelets?

Answer 36

Circulating platelets have a life span of about 10 days.

Question 37

What is major physiological regulator of platelet production?

Answer 37

Thrombopoietin (TPO)