Biology Chapter: Blood Functions and Properties

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Questions and Answers

What is the average volume of blood in a normal adult?

5 L (correct)

3 L

9 L

7 L

What color is venous blood, and what does this indicate?

Clear; indicates low oxygen levels

Dark red; indicates low carbon dioxide levels

Scarlet red; indicates high oxygen levels

Purple red; indicates carbon dioxide presence (correct)

What percentage of plasma is composed of water?

92% (correct)

70%

95%

80%

Which of the following is NOT a function of blood?

Generating cellular energy Signup and view all the answers

What is the normal pH level of blood under typical conditions?

7.4 Signup and view all the answers

Which type of blood cells are primarily involved in the immune response?

Leukocytes (WBC) Signup and view all the answers

What primarily contributes to the viscosity of blood?

Number of erythrocytes Signup and view all the answers

Which of the following substances are considered constituents of plasma?

Hormones, electrolytes, nutrients Signup and view all the answers

What characteristic distinguishes deoxyhemoglobin from oxyhemoglobin?

Deoxyhemoglobin gives veins a bluish tint. Signup and view all the answers

What is the average normal hemoglobin content in blood?

14 to 16 g/dL Signup and view all the answers

What is a primary function of leukocytes?

Act as a defense mechanism and provide immunity Signup and view all the answers

Which type of hemoglobin replaces fetal hemoglobin after birth?

HbA Signup and view all the answers

How are granulocytes characterized?

Lobed nuclei and presence of granules Signup and view all the answers

What condition is indicated by an increase in white blood cell count?

Leukocytosis Signup and view all the answers

What is the lifespan of thrombocytes (platelets)?

10 days Signup and view all the answers

What is one of the primary functions of plasma proteins?

Clotting Signup and view all the answers

How many main blood groups exist?

4 Signup and view all the answers

Which group of plasma proteins is responsible for maintaining osmotic pressure?

Albumins Signup and view all the answers

What distinguishes serum from plasma?

Absence of fibrinogen Signup and view all the answers

Which of the following statements about erythrocytes is true?

They contain hemoglobin for gas transport. Signup and view all the answers

What is the primary role of globulins in the blood?

Transport fats and fat-soluble vitamins Signup and view all the answers

Why are platelets considered formed elements in blood?

They play a role in clotting. Signup and view all the answers

How are red blood cells characterized?

They are flexible, biconcave disks. Signup and view all the answers

What is the form of hemoglobin called when it binds with oxygen?

Oxyhemoglobin Signup and view all the answers

Study Notes

Blood

Blood is a specialized body fluid that circulates throughout the body.
It carries oxygen, carbon dioxide, nutrients, hormones, and other substances.

Properties of Blood

Arterial blood is scarlet red due to its high oxygen content.
Venous blood is purple red due to its higher carbon dioxide content.
The average blood volume in an adult is 5 liters.
Blood is alkaline with a pH of 7.4.
The specific gravity of blood is 1.052 to 1.061.
Blood is five times more viscous than water due to red blood cells and plasma proteins.

Functions of Blood

Distribution and transport: Delivers oxygen and nutrients to the body.
Maintenance of body temperature: Absorbs and distributes metabolic heat.
Regulation and maintenance of normal pH: Buffers maintain pH and water content of cells.
Protection: Carries immune system components to prevent infection.

Composition of Blood

Blood is composed of cells and plasma.
Cells: Erythrocytes (RBC), Leukocytes (WBC), Platelets, Plasma proteins
Plasma: Liquid part of blood containing water, organic and inorganic substances.

Plasma

Composed of 92% water, 7% plasma proteins, and less than 1% other materials.
Functions: Transports nutrients and gases, regulates fluid and electrolyte balance, helps maintain stable pH.

Serum

Serum is plasma without plasma proteins.

Plasma Proteins

Albumins: Maintain osmotic pressure and transport hormones and fatty acids.
Globulins: Transport iron, fats, and fat-soluble vitamins. Gamma globulins function as antibodies.
Fibrinogen: Involved in clotting.

Formed Elements

All blood cells are formed elements, including erythrocytes, leukocytes, and platelets.
Synthesized in bone marrow.
Erythrocytes are synthesized in the marrow of flat bones (skull, vertebrae, ribs, breastbone, and pelvis) in adults.

Erythrocytes (RBC)

Carry hemoglobin (Hb), which comprises about 1/3 of the RBC's total weight.
An adult male has 5-6 million RBCs/mm3, while women and children have 4.5-5 million RBCs/mm3.
RBCs are tiny, flexible, and biconcave disks.
They lack a nucleus and other organelles.
RBCs have a lifespan of 120 days.
Function: Transport oxygen and carbon dioxide.

Hemoglobin (Hb)

Hb is the oxygen-carrying component of RBCs.
Hb binds reversibly to oxygen.
Two forms:
- Oxyhemoglobin: Hb bound to oxygen, gives blood bright red color.
- Deoxyhemoglobin: Hb without oxygen, has a dark red color.
Hb is composed of 4 globin molecules, each containing a heme group.

Leukocytes (WBC)

Represent only ~1% of total blood volume.
Synthesized in bone marrow.
Differences from RBCs:
- Contain a nucleus and organelles
- Do not contain hemoglobin
- Move in and out of blood vessels with amoeboid motion (Diapedesis)
Function: Defense mechanism and immunity.

Leukocytes (WBC) - Groups

Granulocytes: Contain lobed nuclei and cytoplasmic granules, short lifespan (~12 hours).
Agranulocytes: Contain spherical or oval nuclei, lack cytoplasmic granules, long lifespan (greater than 12 hours).

White Blood Cell Count

Total leukocyte count is 4,000 - 10,000/cu mm.
Leukocytosis: Increased WBC count.
Leukopenia: Decreased WBC count.
Life span: 12–20 days.

Platelets (Thrombocytes)

Anucleate cell fragments formed from megakaryocytes.
Megakaryocytes are derived from stem cells in bone marrow.
Platelets have a lifespan of about 10 days.
Contain cytoplasmic granules filled with enzymes.
Function: Stop bleeding through the formation of platelet plugs and blood clotting.

Blood Groups (Types)

There are four main blood groups: A, B, AB, and O.

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Description

This quiz explores the properties, functions, and composition of blood in the human body. Learn about arterial and venous blood characteristics, the role of blood in temperature regulation, and its crucial functions in maintaining health. Test your knowledge of this essential biological fluid.