Human Blood Functions and Composition

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Questions and Answers

What is one of the primary functions of blood?

Protection from infections only

Transportation of hormones and medications to the cells (correct)

Production of red blood cells exclusively

Storage of oxygen in the lungs

What component of blood comprises the majority?

Leukocytes

Formed elements

Platelets

Plasma (correct)

Which plasma protein is primarily responsible for maintaining osmotic pressure in blood?

Fibrinogen

Albumin (correct)

Globulins

Prothrombin

Which element is essential for erythropoiesis?

Iron Signup and view all the answers

What is the lifespan of red blood cells (RBCs) in the human body?

120 days Signup and view all the answers

Which type of leukocyte is most abundant in the blood?

Neutrophils Signup and view all the answers

What does the term 'erythropoiesis' refer to?

The production of red blood cells Signup and view all the answers

Which of the following is NOT a function of blood?

Production of antibodies only Signup and view all the answers

What is the life span of a platelet?

10 days Signup and view all the answers

What role does the spleen play when there is a hemorrhage?

Contracts to release stored blood Signup and view all the answers

Which factor contributes to the increased risk for thrombosis in aging individuals?

Increased coagulation Signup and view all the answers

Which condition is caused by bone marrow suppression?

Aplastic anemia Signup and view all the answers

What nutrient is essential for building red blood cells and is primarily found in red meats?

Vitamin B12 Signup and view all the answers

Which of the following is a common cause of anemia due to hemorrhage?

Surgical blood loss Signup and view all the answers

What is one common nutrient associated with the production of red blood cells found in leafy green vegetables?

Folic acid Signup and view all the answers

Which group has the highest incidence of sickle cell disease?

African Americans Signup and view all the answers

Which population is most likely to have a higher prevalence of pernicious anemia?

Scandinavian descent Signup and view all the answers

Which sign is a better indicator of anemia?

Pale conjunctiva of the eye Signup and view all the answers

What condition is characterized by brittle and spoon-shaped nails?

Mild anemia Signup and view all the answers

What can cause blood dyscrasias?

Drugs and toxic substances Signup and view all the answers

In which case might a patient experience dyspnea on exertion?

Mild anemia (Hb 11 to 13 g/dL) Signup and view all the answers

Which symptom is not commonly associated with anemia?

Frequent urination Signup and view all the answers

What is a potential effect of bone marrow failure?

Excessive bleeding Signup and view all the answers

Which is not a classification of anemia according to its cause?

Anemia from iron deficiency Signup and view all the answers

What is the primary function of neutrophils in the immune response?

Engulfing and destroying bacteria through phagocytosis Signup and view all the answers

What percentage of white blood cells do eosinophils typically compose?

1% to 3% Signup and view all the answers

Which type of white blood cell is responsible for the cell-mediated immune response?

T lymphocytes Signup and view all the answers

What triggers the production of more neutrophils?

Infections in the body Signup and view all the answers

What is the lifespan of leukocytes in the human body?

13 to 20 days Signup and view all the answers

What do basophils primarily release in response to allergens?

Histamine Signup and view all the answers

Granulocytes are primarily produced in which type of bone marrow?

Red bone marrow Signup and view all the answers

Which cells transform into macrophages that help eliminate foreign substances from the body?

Monocytes Signup and view all the answers

Study Notes

Blood Functions

Transports vital substances to cells: water, oxygen, nutrients, hormones, enzymes, medications
Removes waste products: carbon dioxide and other waste
Regulates fluid volume, electrolyte balance, pH, body temperature
Provides clotting factors for hemostasis

Blood Composition

Formed elements (45%): erythrocytes (red blood cells), platelets, leukocytes (white blood cells)
- Leukocytes: neutrophils (54-62%), lymphocytes (25-33%), monocytes (3-7%), eosinophils (1-3%), basophils (0-1%)
Plasma (55%):
- Proteins (7%): albumin (54%), globulins (38%), fibrinogen (4%), prothrombin (1%)
- Water (91%)
- Other solutes (2%): ions, nutrients, waste products, gases, regulatory substances

Plasma Protein Functions

Albumin: maintains osmotic pressure, preventing fluid leakage into tissues
Alpha and beta globulins: transport drugs and lipids
Gamma globulins: act as antibodies
Fibrinogen: essential for blood clot formation

Blood Cell Production

Stem cells in bone marrow produce blood cells through erythropoiesis
Kidney produces erythropoietin, stimulating red blood cell production by bone marrow
Erythropoiesis requires iron, vitamins B12, C, E, folic acid, and amino acids (obtained from proteins)

Red Blood Cell Functions

Erythrocytes contain hemoglobin: carries oxygen to cells, removes CO2
Blood types: A, B, AB, O
Normal RBC count: 4.2 to 6.2 million/mm3 (varies by gender)
Normal hemoglobin level: 12 to 18 g/dL (varies by gender)
Reduced RBCs or hemoglobin levels decrease oxygen transport
RBC lifespan: approximately 120 days
Spleen and liver remove old and damaged RBCs

White Blood Cell Functions

First line of defense against microbial agents
Normal WBC count: 4500 to 11,000/mm3
WBC lifespan: 13 to 20 days
Migrate from bone marrow to tissues through bloodstream
Divided into granulocytes (with granules) and agranulocytes (without granules)
Granulocytes: neutrophils, eosinophils, basophils
- Neutrophils: engulf and destroy bacteria (phagocytosis)
- Eosinophils: detoxify foreign proteins, increase during allergic reactions and parasitic infections
- Basophils: release histamine, prevent clotting in small blood vessels
Agranulocytes: lymphocytes and monocytes
- Lymphocytes: produced in bone marrow and lymphatic tissue, B cells and T cells
  - B cells: differentiate into plasma cells, produce immunoglobulins (humoral immune response)
  - T cells: killer cells, fight antigens (cell-mediated immune response)
- Monocytes: differentiate into macrophages (phagocytes) in tissues, fight infection and remove foreign substances

Platelets and Their Function

Prevent bleeding by promoting clotting
Fibrin strands attach to aggregated platelets to form clots
Adhere to damaged surfaces, clump together
Platelet lifespan: approximately 10 days

Lymphatic System Interaction

Spleen: filters blood, removes pathogens, old blood cells, and debris, produces lymphocytes
Spleen acts as a blood reservoir, releasing stored blood during hemorrhage
Lymph vessels collect fluid and proteins from tissues, return them to bloodstream
Lymph nodes filter leukocytes and cell debris before lymph returns to bloodstream

Hematologic Changes with Aging

Decreased plasma volume after age 60
Reduced bone marrow activity, slower cellular production
Increased coagulation: higher risk of thrombosis in coronary and cerebral arteries

Causes of Hematologic Disorders

Genetic disorders: hemophilia, sickle cell disease, agranulocytosis
Hemorrhage (anemia): surgical blood loss, childbirth, spontaneous abortion, trauma, gastrointestinal bleed
Anemia: iron deficiency, folic acid deficiency, megaloblastic anemia, chronic blood loss, aplastic anemia
Hemolysis: blood transfusion reaction, genetic types of anemia
Bone marrow suppression: antineoplastic agents, radiation treatment, exposure to ionizing radiation, toxic chemicals, bone marrow suppressing drugs
Bone marrow proliferation or abnormality: leukemia

Nutrients for Red Blood Cell Production (Erythropoiesis)

Vitamin B12: red meat, especially liver
Folic acid: green leafy vegetables, liver, meat, fish, legumes, whole grains
Iron: liver and muscle meats, eggs, dried fruits, legumes, dark green leafy vegetables, whole-grain bread and cereals, potatoes
Vitamin C: citrus fruits, green leafy vegetables, strawberries, cantaloupe

Cultural Cues for Genetic Hematologic Tendencies

African Americans: highest incidence of sickle cell disease
Scandinavian and African Americans: higher prevalence of pernicious anemia
Middle Eastern: genetic predisposition to thalassemia
Whites: higher incidence of leukemia, followed by Hispanics

Physical Assessment

Head and Neck: conjunctiva and sclera color, gums, oral mucous membranes, tongue, enlarged cervical lymph nodes
Skin: color (pallor), fingernails (brittle, spoon-shaped), ecchymosis, petechiae, jaundice, hair (dry, brittle, thinning)
Chest and Abdomen: rapid respirations, shortness of breath, swollen lymph nodes, rapid pulse, widened pulse pressure, epigastric tenderness, abdominal distention
Extremities: swollen or painful joints (hemarthrosis), pulse quality, skin color
Urine and Stool: signs of blood

Excessive bleeding
Excessive clotting
Fatigue
Anorexia
Pain
Infection
Bone marrow failure

Anemia

Insufficient functional red blood cells or hemoglobin to meet tissue oxygen demands
Classifications: blood loss, failure in blood cell production, destruction of red blood cells
Mild anemia (Hb 11 to 13 g/dL): mild headache, palpitations, dyspnea on exertion
Moderate anemia (Hb 8 to 10 g/dL): brittle nails, sore tongue, pallor, chronic fatigue, headache, dizziness
Severe anemia (Hb less than 8 g/dL): severe symptoms, requiring blood transfusions

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Description

Explore the vital roles of blood in the human body with this quiz focusing on its functions, composition, and the significance of different blood proteins. Test your understanding of how blood transports substances, regulates bodily functions, and assists in clotting. Perfect for biology students or anyone interested in human physiology.