MCPHS PA Pathophys Exam 3 Hematopoietic & Lymphoid Systems

Question 1

Approx how many cells are produced by bone marrow every day?

Answer 1

100 billion making the Bone Marrow one of the most active organs in the body.

In adults most active marrow resides in the vertebrae, sternum, and ribs.

In children the marrow is more active in the long bones.

In fetus the spleen, liver, and lymphnode produce until birth.

Question 2

What is the composition of blood in the body?

Answer 2

Approx 5.5L

55% Plasma

7% proteins

91% water

2% other solutes

45% Formed Elements

<1% Platelets

<1% Leukocytes

>99% Erythrocytes

Question 3

What is Serum?

Answer 3

Part of blood which is similar in composition with plasma but excluding clotting factors of blood. (Plasma - Clotting factors = Serum)

Question 4

What are the Characteristics of RBCs?

Answer 4

Biconcave disk

No Nucleus

4-6 Million

120 day Life Span

Transport O2 and CO

Question 5

What are granulocytes?

Answer 5

Neutrophil

Eosinophil

Basophil

Question 6

What are Agranulocytes?

Answer 6

Monocyte

Lymphocyte

Question 7

What is Anemia?

Answer 7

A reduction in the Oxygen-transporting Capacity of blood resulting from a decrease in the red cell mass to subnormal levels.

Question 8

What is the pathogenesis of Anemia?

Answer 8

Decrease in RBC circulation causing Anemia which is a decrease in O2 carrying capacity which leads to Tissue Hypoxia.

Question 9

How does Anemia present?

Answer 9

Decreased Hematocrit (RBC/blood volume ratio)

Decreased Hemoglobin concentration

These correlate with the red cell mass except when there are changes in plasma volume caused by fluid retention or dehydration

Question 10

What are the most useful red cell indices in Anemia?

Answer 10

Mean cell volume: Avg. volume of a RBC (macro microcytic)

Mean cell hemoglobin: Avg. mass of Hb / RBC in picograms (Hyper hypochromic)

Mean cell hemoglobin concentration: Avg. concentration of hemoglobin in a given volume of packed red cells in g/dL

Question 11

What is the underlying mechanism of blood loss anemia?

Answer 11

Acutely: Trauma

Chronic: GI tract lesions, gynecologic disturbances

Question 12

What is the underlying mechanism of Intrinsic Hemolytic Anemias?

Answer 12

Heredity

Membrane abnormalities

Membrane skeleton proteins (Spherocytosis, elliptocytosis)

Membrane lipids (abetalipoproteinemia)

Enzyme deficiencies

Enzymes of PPP: G-6-PD, glutathione synthetase

Glycolytic enzymes: pyruvate kinase, hexokinase

Disorders of hemoglobin synthesis

Structurally abnormal globin synthesis (hemoglobinopathies): Sickle Cell Anemia, unstable hemoglobins

Structurally abnormal globin synthesis: Thalassemia Syndromes

Aquired

Membrane defect: Paroxysmal nocturnal hemoglobinuria

Question 13

What is the underlying mechanism of Extrinsic Hemolytic Anemias?

Answer 13

Antibody-mediated

Isohemagglutinins: Transfusion reactions, Rh disease of the newborn

Autoantibodies: Idiopathic (primary), drug associated, SLE

Mechanical trauma to red cells

Microangiopathic hemolytic anemias: TTP, DIC; Defective cardiac valves

Infections

Malaria

Question 14

What is the underlying mechanism of Impaired Red Cell Production?

Answer 14

Disturbed proliferation and differentiation of stem cells: Aplastic Anemia

Disturbed proliferation and Maturation of Erythroblasts

Defective DNA synthesis: Vitamin B12 and Folic acid deficiency

Anemia of renal failure (erythropoietin deficiency)

Anemia of chronic disease (iron sequestration, relative EPO deficiency)

Anemia of endocrine disorders

Defective hemoglobin synthesis

Deficient heme synthesis:irin deficiency, sideroblastic anemias

Deficient globin syunthesis: Thalassemias

Marrow replacement: Primary hematopoietic neoplasms

Marrow infiltration: Metastic neoplasms, granulomatous disease