Blood Physiology and Constituents Quiz

Blood Physiology

• Blood Classification: Blood is classified as connective tissue. It comprises cells suspended in a liquid matrix (plasma).
• Average Blood Volume: The average human body contains 4-5 liters of blood, varying with body size and gender.
• Blood Functions (Exclusions): Blood transports oxygen and nutrients, regulates body temperature, and protects against infection. It does not produce hormones.
• Normal Blood pH: The normal pH range for blood is 7.35-7.45.
• Oxygen Binding Protein: Hemoglobin is the oxygen-carrying protein within red blood cells.

Blood Constituents

• Plasma Percentage: Plasma constitutes approximately 55% of total blood volume.
• Formed Elements: The three formed elements of blood are red blood cells (RBCs), white blood cells (WBCs), and platelets.
• RBC Production: Red bone marrow is the site of red blood cell production (hematopoiesis).
• RBC Percentage: Red blood cells account for approximately 99.1% of formed elements.
• RBC Lifespan: Red blood cells typically survive for about 120 days.

Leukocytes & Platelets

• Most Abundant WBC: Neutrophils are the most abundant type of white blood cells (50-80%), acting as the primary responders to infections.
• Allergic Responses: Basophils are responsible for triggering allergic reactions by releasing histamine.
• Platelet Function: Platelets (thrombocytes) are crucial for blood clot formation, preventing excessive bleeding.

Hemostasis & Blood Tests

• First Step in Clot Formation: Vasoconstriction (narrowing of blood vessels) is the first step in blood clot formation.
• INR Measurement: International Normalized Ratio (INR) measures blood clotting time.
• Blood Clotting Vitamin: Vitamin K is essential for producing clotting factors.
• Fibrin Breakdown: The enzyme plasmin breaks down fibrin clots to prevent excessive clotting.
• High Hematocrit: A high hematocrit often signifies dehydration, as there's less plasma relative to red blood cells.