Chapter 13_1 flashcards

Question 1

Red Blood Cell (RBC) / Erythrocyte: Main Function

Answer 1

Deliver oxygen to the body’s tissues via hemoglobin (Hgb).

Question 2

Anemia: General Definition

Answer 2

A condition of insufficient delivery of oxygen to tissues due to an inadequate number of mature, healthy RBCs, or deficient Hgb.

Question 3

Polycythemia: General Definition

Answer 3

A disorder characterized by overproliferation of blood cells in the bone marrow (primary) or specifically RBCs (secondary).

Question 4

Hematopoiesis: Definition

Answer 4

The process by which all blood cells (RBCs, WBCs, platelets) are formed in the bone marrow.

Question 5

Erythropoiesis: Definition & Stimulus

Answer 5

The specific series of steps in the bone marrow leading to mature RBC synthesis. Major stimulus: Hypoxia, sensed by kidneys, which release erythropoietin (EPO).

Question 6

Erythropoietin (EPO): Source & Function

Answer 6

Hormone released by the kidneys in response to hypoxia; stimulates bone marrow to synthesize RBCs.

Question 7

Reticulocyte: Definition & Significance

Answer 7

An immature RBC. Reticulocyte count reflects bone marrow activity; high count (reticulocytosis) indicates rapid RBC production (e.g., due to blood loss or hemolysis); low count indicates poor RBC production.

Question 8

Substances Needed for Healthy RBC Production (Box 13.1)

Answer 8

Protein, Iron, Vitamin B12, Folic acid, Healthy bone marrow, Healthy kidney (for EPO).

Question 9

Hemoglobin (Hgb): Composition

Answer 9

Composed of heme (iron + porphyrin) and globin (polypeptide chains).

Question 10

Porphyrin Breakdown Products

Answer 10

Porphyrin -> Biliverdin (green, colors bile/feces/ecchymoses) -> Bilirubin (yellow, constituent of bile).

Question 11

Hyperbilirubinemia & Jaundice (Icterus)

Answer 11

Hyperbilirubinemia: Accumulation of bilirubin in bloodstream (e.g., from high RBC breakdown). Jaundice: Yellow staining of skin and sclera due to bilirubin adherence to elastin.

Question 12

RBC Characteristics

Answer 12

Biconcave disc shape (large surface area for diffusion), no nucleus (more room for Hgb), flexible, lifespan ~120 days.

Question 13

Spleen’s Role with RBCs

Answer 13

‘Graveyard of RBCs’; removes aged, lysed, and dead RBCs. Recycles components. Splenomegaly can occur with high RBC breakdown.

Question 14

Oxygen Transport by Hgb

Answer 14

~95% of O2 travels attached to Hgb. Hgb has four iron atoms, each can carry one oxygen molecule.

Question 15

Hemoglobin Types: Hgb A vs. Hgb F

Answer 15

Hgb A: Normal adult Hgb (2 alpha, 2 beta chains). Hgb F: Fetal Hgb (until ~6 months old), has higher oxygen affinity (facilitates placental O2 transfer).

Question 16

Hemoglobinopathy: Definition

Answer 16

Inherited disorder of Hgb structure due to genetic mutation (e.g., Sickle Cell Anemia - Hgb S).

Question 17

Iron Metabolism: Absorption & Transport

Answer 17

Absorbed in duodenum/upper jejunum. Transported by transferrin protein in bloodstream.

Question 18

Total Iron Binding Capacity (TIBC)

Answer 18

Represents iron bound to transferrin and other sites; indicates available binding sites for iron.

Question 19

Iron Storage

Answer 19

Stored as ferritin complexes, mainly in bone marrow, liver (primary reserve), and spleen.

Question 20

Factors Influencing Iron Absorption

Answer 20

Increased by: Citrate, Vitamin C, decreasing iron stores, hypoxia, erythropoietic activity. Decreased by: Tannates (tea).

Question 21

Oxyhemoglobin Dissociation Curve: Purpose

Answer 21

Represents the relationship between partial pressure of oxygen (PO2) and Hgb’s affinity for oxygen. Shows how Hgb loads/unloads O2.

Question 22

Oxyhemoglobin Curve: Shift to the Right (Decreased Affinity)

Answer 22

Causes: Increased CO2, fever, increased 2,3-DPG, decreased pH (acidosis). Hgb gives up O2 more easily to tissues.

Question 23

Oxyhemoglobin Curve: Shift to the Left (Increased Affinity)

Answer 23

Causes: Decreased CO2, hypothermia, decreased 2,3-DPG, increased pH (alkalosis). Hgb holds O2 more tightly.

Question 24

Bohr Effect

Answer 24

Effect of pH on Hgb’s oxygen affinity: Low pH (acidosis) -> Hgb binds O2 less strongly (releases to tissues). High pH (alkalosis) -> Hgb binds O2 more tightly.

Question 25

Haldane Effect

Answer 25

High O2 concentration -> Hgb binds O2 tightly, displacing CO2. Deoxygenated Hgb has free sites for CO2 binding.

Question 26

2,3 Diphosphoglycerate (2,3 DPG)

Answer 26

Organic phosphate in RBCs; reduces Hgb's affinity for O2, aiding O2 unloading to tissues.

Question 27

Impact of Anemia on Oxygen Delivery

Answer 27

Even with 100% O2 saturation, if Hgb is low (anemia), oxygen delivery to tissues will be inadequate, causing cellular hypoxia.

Question 28

Carbon Monoxide (CO) Poisoning Mechanism

Answer 28

Hgb has much greater affinity for CO than for O2. CO displaces O2 from Hgb, leading to deoxygenated state and potential fatality.

Question 29

Blood Types: Agglutinogens

Answer 29

Specific antigens on RBC surface (Type A and Type B).

Question 30

ABO Blood Group System

Answer 30

Categorizes blood into types A, B, AB, and O based on presence/absence of A and B agglutinogens.

Question 31

Rh Factor (D Antigen)

Answer 31

Another antigen on RBC surface. Present = Rh positive (Rh+); Absent = Rh negative (Rh-).

Question 32

Blood Type Antibodies

Answer 32

Individuals develop antibodies against blood antigens NOT present on their own RBCs (e.g., Type A blood has anti-B antibodies).

Question 33

Universal Donor / Universal Recipient

Answer 33

Universal Donor: Type O negative (no A, B, or RhD antigens on RBCs). Universal Recipient: Type AB positive (has A, B, and RhD antigens; no anti-A, anti-B, or anti-RhD antibodies).

Question 34

Transfusion Reaction: Basic Mechanism

Answer 34

Occurs if recipient's antibodies attack antigens on donor's transfused RBCs, causing hemolysis.

Question 35

WHO Definition of Anemia

Answer 35

Hgb level lower than 13 g/dL in men and lower than 12 g/dL in women.

Question 36

Complete Blood Count (CBC): Key RBC Parameters (Table 13-2)

Answer 36

Hgb, Hct, Total RBC count, Mean Corpuscular Volume (MCV), Mean Corpuscular Hemoglobin (MCH), Mean Corpuscular Hemoglobin Concentration (MCHC), RBC Distribution Width (RDW).

Question 37

Normal Hgb Values (Approximate)

Answer 37

Men: 13-18 gm/dL. Women: 12-16 gm/dL. (Females & African American males often 1-2g lower than European American males).

Question 38

Normal Hct Values (Approximate)

Answer 38

Men: 45%-52%. Women: 37%-48%.

Question 39

Mean Corpuscular Volume (MCV): Definition & Interpretation

Answer 39

Volume of one RBC (size). Normal: 80-100 fL. Microcytic (<80), Normocytic (80-100), Macrocytic/Megaloblastic (>100).

Question 40

MCH / MCHC: Definition & Interpretation

Answer 40

MCH: Average Hgb amount per RBC (27-32 pg). MCHC: Average Hgb concentration in a volume of RBCs (32%-36%). Low values indicate pale (hypochromic) cells.

Question 41

Normocytic Normochromic (NCNC) Anemia

Answer 41

RBCs are normal size and color. Common cause: Acute blood loss.

Question 42

Microcytic Hypochromic Anemia

Answer 42

RBCs are small and pale. Common cause: Iron deficiency.

Question 43

Macrocytic (Megaloblastic) Anemia

Answer 43

RBCs are abnormally large. Common causes: Vitamin B12 deficiency, Folic acid deficiency.

Question 44

Platelets: Normal Value (CBC)

Answer 44

90,000 to 450,000 platelets per microliter.

Question 45

Reticulocyte Count: Normal Value & Significance in Anemia

Answer 45

Normal: ~1% of total RBCs. Increased with anemia suggests accelerated destruction/loss of RBCs with active bone marrow response.

Question 46

Physiological Response to Acute Blood Loss

Answer 46

Sudden drop in O2 carrying capacity & intravascular volume -> hypoxia & hypovolemia. Triggers sympathetic nervous system (tachycardia, vasoconstriction), RAAS activation, ADH release. EPO release stimulates marrow.

Question 47

Physiological Response to Chronic Blood Loss

Answer 47

Slow RBC loss. Body initially replaces volume, but nutrient stores (iron, B12, folic acid) become depleted. Leads to deficient erythropoiesis, typically iron-deficiency anemia.

Question 48

Diagnosis of Anemia: General History Key Points

Answer 48

Medications, diet/nutrition, GI symptoms (stool color, history of ulcers/IBD), menstrual history (menorrhagia), past medical history (kidney disease, chronic disorders), family history (inherited anemias), social habits (alcohol).

Question 49

Common Signs & Symptoms of Anemia (General - Box 13-2)

Answer 49

Pallor (skin, conjunctiva, nailbeds, buccal mucosa), excessive fatigue, weakness, shortness of breath (esp. with activity), exercise intolerance, palpitations (tachycardia), chest pain, dizziness/faintness, headache. Nutritional anemias: glossitis, cheilitis, koilonychia, pica.

Question 50

Diagnosis of Anemia: Physical Exam Findings

Answer 50

Vital signs (tachypnea, tachycardia). Pallor. Jaundice (hemolytic anemia). Splenomegaly (hemolytic anemia). Hair loss, koilonychia (spoon nails), cheilitis (cracked mouth corners), glossitis (smooth, swollen red tongue) in chronic/nutritional anemias.

Question 51

Basic Diagnostic Tests for Anemia

Answer 51

CBC with differential, peripheral blood smear (RBC size, shape, color). Bone marrow aspiration/biopsy if diagnosis is difficult.

Question 52

Treatment of Anemia: General Approach

Answer 52

Varies by cause. Transfusion often for significant blood loss or very low Hgb (e.g., <7 g/dL).

Question 53

Causes of Anemia (Broad Categories)

Answer 53

1. Decreased RBC Mass (Acute/Chronic Blood Loss, Hemolysis) 2. Lack of Sufficient RBC Synthesis (Nutritional Deficiencies, Bone Marrow Failure) 3. Hemoglobinopathies (Abnormal Hgb Structure)