lec3: Regulation of erythropoeisis

Question 1

Requirements for erythropoiesis:

Answer 1

-Normal functioning :
 bone marrow , kidneys , liver 
 Hormones
Proteins
iron
Vitamin B12 and folic acid

Question 2

the site of erythropoiesis is ………………….

Answer 2

Bone marrow

Question 3

Kidneys secrete ……………….of erythropoietin hormone

Answer 3

85%

Question 4

iron and vitamin B12 stores in

Answer 4

liver

Question 5

where does the globin part of hemoglobin synthesizes?

Answer 5

in liver

Question 6

liver secretes ……………….. of erythropoietin

Answer 6

10 %

Question 7

which hormones are stimulate erythropoiesis

Answer 7

Androgens
thyroxine
glucocorticoids

Question 8

which hormones are inhibits erythropoiesis

Answer 8

estrogen

Question 9

why Proteins of high biological value are important in erythropoiesis?

Answer 9

to build up the globin part of Hb.

Question 10

the principle constituent of Hb molecule……..

Answer 10

iron

Question 11

why Vitamin B12 and Folic acid are called “Maturation factors”??

Answer 11

as they are essential for normal formation of DNA and cell division

Question 12

Deficiency of vitamin B12 and Folic acid results in

……………………….

Answer 12

megaloblastic or macrocytic anemia

Question 13

cofactors for the formation of Hb…………… , …………..

Answer 13

Copper and cobalt

Question 14

the most important regulator of erythropoiesis is

Answer 14

Tissue oxygenation

Question 15

Erythropoietin is ……………….

Answer 15

Glycoprotein

Question 16

Erythropoietin Comes from:
❖………………. kidneys
❖ ……………….. liver

Answer 16

85-90% kidneys

15-10% liver

Question 17

Negative feedback control of erythropoiesis

Answer 17

Hypoxia
 Stimulates
erythropoeitin production
 Increase RBCs production

Question 18

Factors stimulating erythropoietin secretion:

Answer 18

• Hypoxia
• Hormones
• Alkalosis as in high altitudes

Question 19

Hormones stimulating erythropoietin secretion:

Answer 19

androgens (testosterone), catecholamines,
corticosteroids, growth hormone, and thyroxin increase
erythropoietin secretion

Question 20

………………..is associated with anemia that can

be treated only by erythropoietin

Answer 20

Renal failure

Question 21

in……………. the stem cells do not respond to erythropoietin

Answer 21

aplastic anemia

Question 22

-Iron intake ……………

Answer 22

15-20 mg%

Question 23

Absorbed iron ……………………………

Answer 23

(3-6%of the intake)

Question 24

-Iron homeostasis depends on………………………………

Answer 24

control of iron absorption from the intestine (Duodenum)

Question 25

Iron functions in the body

Answer 25

HB synthesis myoglobin synthesis cytochrome oxidase , peroxidase , catalase

Question 26

total body iron ..........

Answer 26

4-5 g

Question 27

Iron absorption in ................

Answer 27

duodenum

Question 28

Heme absorption Through the enterocyte ......................

Answer 28

Heme carrier protein (HCP-1)

Question 29

Iron is released from heme by .......................

Answer 29

Heme oxygenase enzyme

Question 30

Fe2+ is transported out of the enterocyte by the ................................................

Answer 30

basolateral membrane protein (ferroportin)

Question 31

Ferrous iron is transported into the enterocyte with a proton via a ................................................

Answer 31

divalent metal transporter (DMT-1).

Question 32

Ferric is reduced by ferric reductase helped by ................... to ferrous iron

Answer 32

HCL, | vitamin C

Question 33

Hepcidin Hormone Released from .............when .......................

Answer 33

liver | iron levels are high

Question 34

which hormone Inhibit ferroportin transporter?

Answer 34

Hepcidin

Question 35

Hepcidin deficiency causes.....................................

Answer 35

tissue iron over load

Question 36

Regulation of iron absorption by | hepcidin

Answer 36

```  Hypoxia, erythropoeisis Depleted iron stores increase iron absorption  Saturated iron stores Liver releases hepcidin Hepcidin inhibits ferroportin ```

Question 37

Factors Increase iron absorption

Answer 37

```  Gastric acidity, vitamin C aids iron reduction  Increased erythropoietic activity e.g. bleeding, hemolysis, high altitude.  Increased demamd Infancy, adolescence ```

Question 38

Factors Decrease iron absorption

Answer 38

```  Phytic acid, oxalates and phosphates form insoluble salts  Iron overload  Calcium in dairy food ```

Question 39

Heme iron is absorbed better than.......................

Answer 39

inorganic iron.

Question 40

Ferrous iron is absorbed better than ...............

Answer 40

ferric iron

Question 41

Iron is transported as transferrin normally ............. saturated

Answer 41

35%

Question 42

Iron is stored as.............. in the.......................

Answer 42

ferritin | hepatocytes

Question 43

............... is the predominant storage form. It keeps | iron in a .............. and ..............form

Answer 43

Ferritin soluble non-toxic

Question 44

Excess iron is stored as.........................

Answer 44

hemosiderin

Question 45

Iron deficiency Can result in ........................ due to ............................................

Answer 45

microcytic hypochromic anemia | decreased hemoglobin synthesis and RBC size.

Question 46

.....................and........................ are | essential for normal formation of DNA and hence for nuclear maturation.

Answer 46

vitamin B12 and folic acid

Question 47

......................... is absent from plant sources

Answer 47

Vitamin B12

Question 48

The minimum requirement of Vitamin B12 is ...................

Answer 48

1-3 microgram/day

Question 49

Folic acid and vitamin B12 Absorbed in terminal ileum by ...........................

Answer 49

endocytosis

Question 50

Vitamin B12 deficiency Leads to a condition called ................

Answer 50

pernicious anemia or megaloblastic anemia (macrocytic anemia).

Question 51

in Vitamin B12 deficiency Neurological disorders are due to .............................

Answer 51

progressive demyelination of nervous tissue

Question 52

pernicious anemia.......................................................

Answer 52

 Large immature erythrocytes

Question 53

...................... is the site for blood cells production.

Answer 53

Bone marrow

Question 54

....................... is the most essential regulator of RBC production and erythropoietin

Answer 54

Tissue hypoxia

Question 55

.............. is the principle stimulus for RBCs production in low O2 states,

Answer 55

Erythropoietin hormone

Question 56

..................of Erythropoietin hormone comes from the kidneys

Answer 56

85-90%

Question 57

Anemia occurs in ...................................

Answer 57

kidney diseases

Question 58

High altitude, lung diseases, anemia, poor blood flow and relative lack of oxygen in athletes lead to..............and stimulate...................................

Answer 58

hypoxia | erythropoietin hormone secretion

Question 59

..................... forms the heme part of Hb

Answer 59

Iron

Question 60

iron is absorbed from the intestine helped by ................

Answer 60

gastric

Question 61

HCL and Vitamin c is carried as ...............

Answer 61

transferrin

Question 62

HCL and Vitamin c is stored as ..........and..............

Answer 62

ferritin and hemosiderin.

Question 63

Vitamin B12 absorption depends on the presence of the............. secreted from the parietal cells in the stomach.

Answer 63

intrinsic factor

Question 64

................. is important for myelin sheath production

Answer 64

Vitamin B12

Question 65

Healthy bone marrow and normal liver and kidneys are essential for ............................

Answer 65

erythropoiesis