(EDAPT WEEK 2)
Anatomy & Physiology III course with a lab
,Hematological Disorders
Anemia
Questions
1. MCV is the index that measures the average size of RBCs
2. Hereditary spherocytosis is a microcytic anemia characterized by hyperchromic RBCs
3. Anemia can be caused by impaired RBC production, excessive blood loss, and increased RBC
production
4. Bradycardia is not characteristic of anemia; tachycardia is present due to hypoxemia
Definition
Hematological disorder characterized by a
reduction in the total number of circulating
RBCs and/or a decrease in hemoglobin (Hb)
amount or function
Capacity of blood to transport oxygen to the
tissues is reduced
Etiology
Excessive blood loss
o Acute
Trauma, surgery, postpartum
hemorrhage
o Chronic
GI bleed, cancer
Decreased RBC production
o Abnormal proliferation or differentiation of stem cells
Aplastic anemia
o Defective DNA synthesis in erythroblasts
Vitamin B12 deficiency, folate deficiency
o Defective Hb synthesis
Defective heme synthesis
Iron deficiency anemia
Defective globin chains
Hemoglobinopathies (including sickle cell anemia), thalassemia
Unknown or multiple mechanisms
Sideroblastic anemia
Increased RBC destruction (hemolysis)
o Abnormal Hb
Sickle cell anemia, thalassemia
o Enzyme deficiencies
Glucose-6-phosphage dehydrogenase (G6PD)
o Membrane disorders
Spherocytosis, paroxysmal nocturnal hemoglobinuria
Any combination of the three
Clinical Manifestations of Anemia
Decreased tissue oxygenation from anemia can manifest as signs and symptoms of the following:
Severe fatigue, pallor, weakness, dyspnea, dizziness
↓RBC level will ↓ blood volume, activating the renin-angiotensin-aldosterone (RAAS) system, which
promotes fluid retention and movement of interstitial fluid into the capillaries. This will result in
↑plasma volume and dilute plasma. The dilute blood flows faster, which creates a hyperdynamic state.
This “stresses” the cardiac system and can result in tachycardia or even heart failure.
, Anemia Classification
Anemias can be classified according to the size (-cytic) of the RBCs:
Microcytic anemia (MCV <80fL) describes RBCs that are small
Normocytic anemia (MCV 80-99fL) describes RBCs that are normal in size
Macrocytic anemia (MCV >100fL) describes RBCs that are large
Microcytic (MCV <80 fl) Normocytic (MCV 80-99 fL) Macrocytic (MCV >100 fL)
Thalassemia G6PD deficiency B12 deficiency (pernicious
Anemia of chronic disease Paroxysmal nocturnal anemia)
Iron deficiency hemoglobinuria Folate deficiency
(Lead poisoning) Posthemorrhagic anemia
Sideroblastic Aplastic anemia
*remember TAILS
Anemias can also be classified according to the color (-chromic) of the RBCs:
Hypochromic anemia (↓ MCHC) RBCs with less hemoglobin than normal, RBC pale in color
Normochromic anemia (normal MCHC) RBCs that have a normal amount of hemoglobin
Hyperchromic anemia (↑ MCHC) RBCs with more hemoglobin than normal, RBC dark in color
Hypochromic (↓MCHC) Normochromic Hyperchromic (↑ MCHC)
Pale RBC with ↓ hgb Normal hgb Dark RBC with ↑ hgb
Iron deficiency Anemia of chronic disease Hereditary spherocytosis
Sideroblastic Posthemorrhagic anemia
Thalassemia
Questions
1. Which of the following symptoms reflect decreased tissue oxygenation as an effect of anemia?
a. Dyspnea, dizziness, weakness
2. Which of the following is a type of macrocytic anemia?
a. Vitamin B-12 deficiency
3. The terms normocytic, microcytic, and macrocytic characterizes red blood cells by their:
a. Size
4. Identification of the type of anemia involves an examination of the size of the RBC only
a. False; determining both size and color of the RBCs is an important step in identifying the
type and source of the anemia
Microcytic Anemias
Questions
1. The treatment of iron deficiency anemia includes:
a. Iron supplementation
2. Which of the following anemias can be categorized as microcytic-hypochromic? (SATA)
a. Sideroblastic anemia, iron deficiency anemia, anemia of inflammation and chronic
disease
3. Which of the following would indicate that the patient’s iron stores are depleted?
a. Ferritin level (low ferritin level)
4. The most common type of anemia is
a. Iron deficiency anemia
Iron Deficiency Anemia
Microcytic (↓MCV) and hypochromic (↓MCHC)
Most common type of anemia, affecting almost 20% of the world population
Most common problem contributing to this is the insufficient amount of iron availability
Pathophysiology