Human Blood and Blood Circulation

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Questions and Answers

What is the approximate volume of blood in an average adult?

10 liters

5 liters (correct)

2 liters

7 liters

What is the main function of albumins in plasma?

Clotting

Lipid transport

Osmotic pressure maintenance (correct)

Immunity

What is the pH range of oxygen-rich blood?

7.35-7.45 (correct)

7.0-7.5

6.5-7.5

7.5-8.5

What is the lifespan of erythrocytes?

120 days Signup and view all the answers

What is the function of leukocytes in the blood?

Protection against foreign substances Signup and view all the answers

What is the percentage of water in plasma?

90% Signup and view all the answers

What is the name of the staining method used in blood smear analysis?

May-Grunwald-Giemsa staining Signup and view all the answers

What is the term for variations in RBC size?

Anisocytosis Signup and view all the answers

What is the function of hemoglobin in erythrocytes?

Transport of oxygen Signup and view all the answers

What is the percentage of erythrocytes in the hematocrit of men?

40-50% Signup and view all the answers

What is the primary function of neutrophils?

To actively phagocytose foreign substances Signup and view all the answers

What is the role of eosinophils in the body?

To migrate to sites of allergic reactions and parasitic infections Signup and view all the answers

What type of granules are found in basophils?

Granules containing histamine, heparin, and serotonin Signup and view all the answers

What is the function of B cells in the immune system?

To differentiate into plasma cells and produce antibodies Signup and view all the answers

What is the origin of platelets in the body?

Fragments of megakaryocytes Signup and view all the answers

What is the function of α-granules in platelets?

To contain fibrinogen and PDGF Signup and view all the answers

What is the primary function of the bone marrow?

To produce stem cells for other tissues Signup and view all the answers

What is the characteristic of megakaryocytes?

Azurophilic granules with polyploid nuclei Signup and view all the answers

What type of leukocytes are most numerous in the body?

Neutrophils Signup and view all the answers

What is the role of monocytes in the body?

To become macrophages in connective tissue Signup and view all the answers

Study Notes

Blood Characteristics

Oxygen-rich blood is brightly red, while oxygen-poor blood is darkly red.
pH of blood must remain between 7.35-7.45 (slightly alkaline).
Temperature of blood is slightly higher than body temperature.
Average adult has about 5 liters of blood (~7-8% of body weight).
There are approximately 1 billion red blood cells in two to three drops of blood.

Functions of Blood

Transports gases (O₂, CO₂), nutrients, waste products, processed molecules (e.g., proteins), and regulatory molecules (hormones).
Regulates pH and osmosis.
Maintains body temperature.
Protects against foreign substances.
Forms clots.

Blood Components

Hematocrit measures the volume of packed erythrocytes per unit of blood (40-50% for men, 35-45% for women).
Composition of blood: plasma (55%), cells (45%).
Erythrocytes (RBCs), leukocytes (WBCs), and platelets make up the formed elements of blood.

Plasma

Composed of water (90%), proteins (8%), albumins (58%), globulins (38%), clotting proteins (4%), and inorganic salts (0.9%).
Types of plasma proteins include albumins (osmotic pressure maintenance), globulins (lipid transport, immunity), and fibrinogen (clotting).

Erythrocytes (RBCs)

Specializations: biconcave shape, no nucleus, contain hemoglobin.
Lifespan: approximately 120 days.
Functions: transports oxygen from lungs to tissues and carbon dioxide from tissues to lungs.
Surface antigens: blood groups A, B, AB, O.
Hemoglobin structure: 4 polypeptide molecules (CO₂ transport), 4 heme molecules (O₂ transport).
Types of hemoglobin: oxyhemoglobin (Hb carrying O₂), carbaminohemoglobin (Hb carrying CO₂).

Leukocytes (WBCs)

Much fewer in number compared to RBCs.
Defense against disease.
Types: granulocytes (neutrophils, eosinophils, basophils) and agranulocytes (lymphocytes, monocytes).
Neutrophils: most numerous, multilobed nucleus, active phagocytes.
Eosinophils: migrate to sites of allergic reactions, inflammation, and parasitic infection.
Basophils: initiators of the inflammatory process.
Lymphocytes: types include B cells (humoral immunity), T cells (cellular immunity), and natural killer cells (attack cancerous and virally infected cells).
Monocytes: become macrophages in connective tissue, phagocytosis, produce cytokines, and present antigens.

Platelets (Thrombocytes)

Origin: fragmentation of megakaryocytes.
Function: promotes clotting and prevents blood loss.
Structure: hyalomere (transparent, peripheral zone), granulomere (central zone with granules).
Granule types: α-granules (contains fibrinogen, PDGF), δ-granules (contains calcium, ADP, ATP), λ-granules (contains hydrolytic enzymes).

Bone Marrow

Types: red bone marrow (hematogenous) and yellow bone marrow (rich in adipose cells).
Structure: composed of stroma, hematopoietic cords, and sinusoidal capillaries.
Function: source of stem cells for other tissues.
Megakaryocytes: precursors for platelets, exhibit polyploid nuclei with azurophilic granules.

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Description

Learn about the physical characteristics, functions, and composition of human blood. Understand the pH, temperature, and volume of blood, as well as its role in transporting gases, nutrients, and waste products.