Anemia

Question 1

Anemia is a group of diseases characterized by a decrease in what?

Answer 1

• hemoglobin
• RBCs
• both

Question 2

Anemia may occur as what?

Answer 2

• a primary disease
• secondary to another pathology
• nutritional deficiency

Question 3

Describe a RBC and its components

Answer 3

• biconcave discoid shaped cell
• no nucleus, no mitochondria
• cell membrane - function
• hemoglobin - function

Question 4

RBCs use glucose to produce (…) via glycolysis

Answer 4

ATP

Question 5

A RBC membrane must provide for mechanical strength as well as (…) and (…) and is reversible b/c it needs to squeeze through capillaries that are smaller than diameter of RBC and pass from splenic cords to splenic sinus?

Answer 5

deformability and elasticity

Question 6

• The RBC membrane is a lipid envelope composed of many (…) and (…)
• Lipids maintain a (…), meaning certain phospholipids always face (…) or (…)
• This requires energy (…) to maintain orientation

Answer 6

• phospholipids and cholesterol
• sidedness; outside or inside
• glucose

Question 7

What are long fibrous proteins found on the inner aspect of the RBC membrane, have alpha and beta components, is the most abundant protein of the cytoskeleton, and forms a backbone of the RBC membrane?

Answer 7

spectrin

Question 8

What provides for much of the elasticity and flexibility of the RBC?

Answer 8

spectrin

Question 9

What makes up 5% of the RBC membrane proteins, is a mixture of a few different proteins, and connects spectrins to the transmembrane proteins (band 3)?

Answer 9

ankyrin

Question 10

What RBC protein is a major integral (transmembrane) protein of the RBC membrane and has multiple roles as an anion exchanger (HCO3) and structural support?

Answer 10

band 3

Question 11

• What is the function of a RBC?
• What is the key protein that makes up 1/3 of RBC content?
• Hemoglobin is a tetrameric protein made up of what globin chains?
• Each globin chain is complexed with 1 (…) with 1 (…)
• Therefore, each hemoglobin protein carries (…) iron molecules

Answer 11

• oxygen transport through body
• hemoglobin
• 2 alpha and 2 beta globin chains
• heme group; iron molecule
• 4 iron molecules

Question 12

• What is the major form of hemoglobin in adults?
• What is the major form of hemoglobin in the fetus?

Answer 12

• HbA
• HbF

Question 13

• Where does erythropoiesis occur?
• What is the primary regulatory hormone of RBC production?
• What is the physological stimulus for RBC production?
• What type of cells produce and release EPO when decreased oxygen is sensed?

Answer 13

• red bone marrow
• erythropoietin (EPO)
• hypoxia
• peritubular renal cells (kidney)

Question 14

Production of mature and function RBCs require what?

Answer 14

• B12
• folic acid
• iron

Question 15

• What is the normal lifespan of RBCs?
• What are RBCs typically destroyed by?
• RBCs lack a (…) and (…) therefore, there is no new protein production and must rely on glycolysis

Answer 15

• 120 days
• spleen by macrophages
• nucleus and mitochondria

Question 16

In the body, as ATP production decreases, changes in membrane integrity of the RBC occurs and it becomes more (…). The membrane proteins cluster/aggregate and (…) recognize senescent RBCs and (…) occurs

Answer 16

• spherical
• macrophages
• phagocytosis

Question 17

Pertaining to anemia:
- there is a decrease of (…) below normal values
- results in decreased (…) carrying capacity of the body resulting in (…)

Answer 17

• functional RBCs
• O2; tissue hypoxia

Question 18

• What describes variations in RBC size?
• What describes variations in RBC shape?

Answer 18

• anisocytosis
• poikilocytosis

Question 19

A patient has low Hb and low MCV, what is the likely diagnosis?

Answer 19

microcytic anemia caused by iron deficiency

Question 19

A patient has low Hb and high MCV, what is the likely diagnosis?

Answer 19

macrocytic anemia caused by B12 and/or folate deficiency

Question 19

A patient has a low Hb and a normal MCV, what is the likely diagnosis?

Answer 19

normocytic anemia that could be many causes such as CKD, malignancy, blood loss, bone marrow failure, hemolysis

Question 20

What are some signs/findings in patients with more advanced anemia?

Answer 20

• splenomegaly
• koilonychia (concaved, thin nails)

Question 21

What are different mechanisms of anemia?

Answer 21

1. blood loss
2. increased destruction
3. decreased production

Question 22

• Anemia due to blood loss from trauma is due to a rapid shift of fluid from (…) space to (…) resulting in hemodilution and lowering hematocrit
• There is an increased response of (…), therefore there will be an increased production of (…)
• Other blood loss mechanisms leading to anemia can be due to what?

Answer 22

• interstitial space to vasculature
• EPO; reticulocytes
• heavy menses, blood donations, GI ulcers (may result in iron deficiency anemia)

Question 23

What are the general features of increased destruction of RBCs (hemolytic)?

Answer 23

- premature destruction of RBC - increased EPO and increased erythropoiesis - accumulation of Hb breakdown products as RBC are destroyed

Question 24

- Extravascular increased destruction of RBCs predominately occurs by phagocytes in what places? - What are some clinical features of this?

Answer 24

- spleen, bone marrow, and liver - anemia, splenomegaly, jaundice

Question 25

- Intravascular increased destruction of RBCs is less common and can be due to (...) - What can cause intravascular RBC destruction? - What are some of the clinical presentations of this?

Answer 25

- mechanical injury - parasites (malaria), complement fixation, exogenous toxins in blood - anemia, hemoglobinemia, hemoglobinuria, and jaundice **but no splenomegaly**

Question 26

- How is sickle cell disease inherited? - This is due to a genetic defect in what hemoglobin chain? - Deoxygenation of (...) leads to (...) and forms aggregates, producing a "sickle" shape of the RBC

Answer 26

- autosomal recessive - beta chain - HbS; polymerization

Question 27

- Initially the sickling process in sickle cell anemia is (...) so once HbS is (...), it re-obtains normal shape - Sickle cell anemia is a (...) problem; once deoxygenated in tissue obtains the sickle shape again, it can cause (...)

Answer 27

- reversible; oxygenated - microvascular problem; vaso-occlusion

Question 28

Sickle cell anemia has a single base substitution where (...) replaces (...)

Answer 28

valine replaces glucamic acid