Hematopoeisis

Question 1

Anemia

Answer 1

A decrease in the amount of RBCs or hemoglobin in the blood

Can also be defined as a lowered ability for blood to carry oxygen

Question 2

Slow onset anemia symptoms

Answer 2

Feeling tired
Weakness
Shortness of breath
Poor ability for exercise

Question 3

Rapid onset anemia symptoms

Answer 3

Confusion
Feeling like you’re going to pass out
Increased thirst

Question 4

Most anemias are due to deficiencies of what?

Answer 4

Iron (most common)
Vitamin B12
Folic Acid

Question 5

Heme biosynthesis

Answer 5

Mainly in the liver and bone marrow
Pathway involves mitochondrial and cytoplasmic enzymes
The last stem involves incorporation of Fe++

Question 6

Iron is a ‘one-way element’ - what does this mean?

Answer 6

Very little of it is excreted (0.5mg-1.0mg/day)

Question 7

T/F - Any type of bleeding (including menstrual flow) will cause loss of iron from the body

Answer 7

True

Question 8

T/F - Only the upper layers of skin cells contain iron

Answer 8

False - all skin cells contain iron

Question 9

What forms of iron are absorbed?

Answer 9

Free ferrous ion (Fe++)

Heme iron

Question 10

How is iron transported in the plasma?

Answer 10

It is transported by binding to transferrin

Question 11

What form is iron stored in? Where is it stored?

Answer 11

Stored as ferritin in macrophages of the liver spleen and bone
And parenchyal liver cells

Question 12

How is iron deficiency anemia treated?

Answer 12

Oral or parenteral iron preparation

Oral iron corrects the anemia just as rapidly as parenteral in most cases if iron absorption from the GI tract is normal

Question 13

Folic acid and Vitamin B12 are necessary for what?

Answer 13

DNA synthesis - Hematopoeisis is especially sensitive

Question 14

Anemias resulting from an insufficiency of vitamin B12 usually reflect what?

Answer 14

An absorption malady

Question 15

What are some causes of B12 deficiency?

Answer 15

B12 deficiency in food (

Question 16

How is vitamin B12 absorbed?

Answer 16

Combines with intrinsic factor (IF) forminga complex that resists digestion by GI tract enzymes
This complex is absorbed at the terminal ileum by pinocytosis
B12 is then transported to the liver for storage

Question 17

What can deficiencies of Vitamin B12 cause?

Answer 17

Macrocytic anemia due to failure of maturation of RBCs

Neurological manifestations because the vitamin is also needed for the myelination of nerves

Question 18

What is the most common cause of adult B12 deficiency

Answer 18

Loss of ability to absorb B12

• may be due to loss of IF
• may be due to other conditions that decrease production of gastric acid - which also plays a role in absorption of B12 from foods

Question 19

What are the two types of Macrocytic anemia?

Answer 19

1) Cobalamin (B12 deficiency)

2) Folic acid deficiency

Question 20

What can be causes of Folic acid deficiency?

Answer 20

Poor nutrition (Anorexia)
Malabsorption of small bowel
ETOH
Hemodialysis

Question 21

Sickle-cell disease

Answer 21

Aka Sickle Cell Anemia
Hereditary blood disorder characterized by an abnormality in the oxygen-carrying protein hemoglobin
Leads to a propensity for the cells to assume an abnormal, rigid, sickle-like shape under certain circumstances

Question 22

What causes the actual anemia associated with Sickle-cell disease?

Answer 22

The destruction of the blood cells because of their shape

Bone marrow attempts to compensate by creating new RBCs, but cannot match the rate of destruction

Question 23

How long do normal RBCs function?

How long do Sickled cells funciton?

Answer 23

Normal = 90-120 days
Sickle = 10-20 days

Question 24

How can you treat sickle cell disease?

Answer 24

With treatment, people can now live to age 50+ (previously 20-40 yrs)
Can do a bone marrow transplant in severe cases, but it’s risky (5-10% mortality rate) and success is mild (85%)

Question 25

Erythropoeitin (EPO)

Answer 25

Glycoprotein hormone that controls erythropoiesis, or RBC production
It is a cytokine for erythrocyte precursors in the bone marrow
Can be used as a therapeutic agent to treat anemia resulting form chronic kidney disease, inflammator bowel disease, and myelodysplasia from the treatment of cancer

Question 26

Where is Erythropoeitin (EPO) synthesized, and why?

Answer 26

Produced in the kidney and is inducible by low oxygen or hypoxia?

Question 27

Granulocyte-colony stimulating factor (GCSF)
or
Colony stimulating factor 3 (CSF 3)

Answer 27

Glycoprotein that stimulates the bone marrow to produce granulocytes and stem cells and release them into the blood stream

Question 28

Granulocyte-macrophage colony stimulating factor (GM-CSF)
or
Colony stimulating factor 2 (CSF 2)

Answer 28

Monomeric glycoprotein secreted by macrophages, T cells, mast cells, endothelial cells and fibroblasts that functions as a cytokine

Question 29

G-CSF and GM-CSF are used for what?

Answer 29

Used to treat chemotherapy induced neutropenia (low neutrophil count)

Question 30

IL-11

Answer 30

Multifunctional cytokine isolated form bone-marrow-derived stromal cells
Key regulator of multiple events in hematopoeisis
Has been demonstrated to improve platelet recovery after chemotherapy-induced thrombocytopenia (loss of platelets)

Question 31

Why do we give a shit about all of this?

Answer 31

Dentist might be the first health professional to observe symptoms of anemia in a patient because these symptoms might precede decreases such as a decline in Hb
Anemia might be a sign of serious hematopoietic disorder such as cancer, malnutrition, or drug toxicity