Chapter 5: Circulatory System and Blood Composition

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What is the main function of the circulatory system?

Regulating body temperature

Absorbing oxygen

transport oxygen, nutrients, hormones, and other essential substances to cells throughout the body and to remove waste products, such as carbon dioxide and metabolic byproducts, from those cells (correct)

Producing red blood cells

Which organs are responsible for absorbing nutrients from the environment?

Heart

Kidneys

Digestive system (correct)

Respiratory system

What is one of the functions of blood as highlighted in the text?

Producing antibodies against infections

Producing hormones for cell growth

Absorbing toxins from the environment

Maintaining ion concentration of the body fluids (correct)

Why is blood considered important in maintaining the internal environment of the body?

To distribute heat and maintain body temperature Signup and view all the answers

Which statement accurately describes a function of blood clotting?

Preventing blood loss when vessels are damaged Signup and view all the answers

How does blood help in protecting against diseases?

By defending against disease-causing micro-organisms Signup and view all the answers

What happens to oxyhaemoglobin when the oxygen concentration is relatively low?

It breaks down into haemoglobin and oxygen. Signup and view all the answers

Why is the blood in the arteries (excluding the pulmonary arteries) bright red?

Due to the high proportion of oxyhaemoglobin. Signup and view all the answers

What is the color of haemoglobin?

Purplish Signup and view all the answers

Why is deoxygenated blood in the veins (excluding pulmonary veins) dark red?

Due to a high proportion of deoxygenated haemoglobin Signup and view all the answers

Where does oxygen diffuse after red blood cells release it in the capillaries?

Into the tissue fluid and then into the cells Signup and view all the answers

What characterizes oxygenated blood?

Bright red color Signup and view all the answers

What is the primary function of erythrocytes (red blood cells)?

To transport oxygen from the lungs to the body's cells Signup and view all the answers

What is the approximate percentage of red blood cells in the total blood volume?

41% Signup and view all the answers

What is the term used to describe the percentage of red blood cells in the total blood volume?

Hematocrit Signup and view all the answers

What is the primary function of plasma, the liquid component of blood?

To transport cells, nutrients, wastes, hormones, proteins, and antibodies throughout the body Signup and view all the answers

What is the approximate percentage of plasma in the total blood volume?

55% Signup and view all the answers

Why do red blood cells lack a nucleus?

All of the above Signup and view all the answers

What is the main function of basophils in the body?

Production of heparin and histamine to defend against parasites and bacteria Signup and view all the answers

Which type of lymphocyte is involved in antibody-mediated immunity?

B-lymphocytes Signup and view all the answers

What percentage of the blood volume is made up of the formed elements?

45% Signup and view all the answers

Which of the following is a characteristic of the granulocytes?

Lobed nucleus and granular cytoplasm Signup and view all the answers

What is the main component of plasma?

Water Signup and view all the answers

What is the primary function of leucocytes?

To remove dead or injured cells and invading microorganisms Signup and view all the answers

Which of the following statements about erythrocytes is false?

They have a nucleus Signup and view all the answers

What is the approximate lifespan of erythrocytes?

120 days Signup and view all the answers

Where are platelets (thrombocytes) formed?

In the red bone marrow Signup and view all the answers

How do the sizes of platelets and erythrocytes compare?

Platelets are about one-third the size of erythrocytes Signup and view all the answers

What is the primary function of platelets (thrombocytes)?

To facilitate normal blood clotting Signup and view all the answers