Chapter 5: The Circulatory System

What is the primary function of the arteries?

To relax and contract to maintain blood pressure
To pump blood from the lungs to the body
To control the diameter of blood vessels
To carry blood away from the heart to the body (correct)

What is the role of the smooth muscle in the walls of the arteries?

To contract and relax to pump blood through the body
To maintain the elasticity of the artery walls
To regulate blood flow by controlling the diameter of the arteries (correct)
To allow for the expansion of the artery walls when blood is pumped into them

What is the function of the elastic fibers in the walls of the arteries?

To regulate blood flow to the organs
To maintain the shape of the arteries
To allow the arteries to stretch and recoil in response to changes in blood volume (correct)
To pump blood through the body

What is the purpose of the process of vasoconstriction in the arteries?

To reduce the diameter of the arteries and decrease blood flow to an organ (D) Signup and view all the answers

How do the arterioles differ from the larger arteries?

Arterioles, like the larger arteries, have smooth muscle in their walls that can regulate blood flow (D) Signup and view all the answers

What is the purpose of the process of vasodilation in the arteries?

To increase blood flow to an organ (A) Signup and view all the answers

What is the relationship between the aorta and the pulmonary artery?

The aorta carries blood from the left ventricle to the body, while the pulmonary artery carries blood from the right ventricle to the lungs (B) Signup and view all the answers

What is the main function of the circulatory system?

To transport nutrients and oxygen to cells throughout the body (C) Signup and view all the answers

Which muscle is responsible for regulating blood flow through the capillaries?

Smooth muscle (A) Signup and view all the answers

Why are the walls of veins thinner than the walls of arteries?

Veins have a lower blood pressure, so their walls do not need to be as thick and elastic (C) Signup and view all the answers

What is the primary purpose of the increased blood flow through the muscle tissues during exercise?

To increase oxygen and nutrient supply (C) Signup and view all the answers

What is the purpose of the valves in veins?

To prevent the backflow of blood in the veins (B) Signup and view all the answers

How do the diameters of arteries and veins differ?

The diameter of arteries and veins varies depending on their location in the body (D) Signup and view all the answers

What is the role of vasodilators in the regulation of blood flow during exercise?

They dilate the arterioles to increase blood flow (A) Signup and view all the answers

What is the relationship between the blood pressure in arteries and veins?

Blood pressure is higher in arteries than in veins (A) Signup and view all the answers

How does the release of heat energy during cellular respiration in the muscle cells affect blood flow?

It increases blood flow to the muscles (B) Signup and view all the answers

What is the role of the thick muscle layer in the structure of an artery?

It allows the artery to expand and contract (D) Signup and view all the answers

How do red blood cells move through the capillaries?

Red blood cells can only move through the capillaries in single file (B) Signup and view all the answers

What is the key difference between the walls of arteries and veins?

Arteries have thicker, more muscular walls than veins (B) Signup and view all the answers

What is the function of the valves in the veins?

They prevent the backflow of blood (C) Signup and view all the answers

What is the primary purpose of the capillary web surrounding the muscle cells?

To distribute oxygen and nutrients (C) Signup and view all the answers

What is the main form in which carbon dioxide is transported in the blood plasma?

As bicarbonate ions (D) Signup and view all the answers

In the lungs, how does carbon dioxide leave the blood and enter the alveoli?

Through breakdown of carbonic acid (C) Signup and view all the answers

Which ions are formed when carbonic acid ionizes in the blood plasma?

Hydrogen ions and bicarbonate ions (D) Signup and view all the answers

What is the primary function of carbaminohaemoglobin in the circulatory system?

Transporting carbon dioxide (B) Signup and view all the answers

Which part of the body is surrounded by a dense network of capillaries where carbon dioxide diffuses out of the blood?

Alveoli in the lungs (D) Signup and view all the answers

What happens to carbonic acid under enzyme action in the alveoli?

It breaks down into water and carbon dioxide (B) Signup and view all the answers

Which component of blood accounts for 22% of transporting carbon dioxide?

Combined with haemoglobin (A) Signup and view all the answers

What is the main source of nutrients that are transported in the blood plasma?

Obtained from consumed food (A) Signup and view all the answers

How does most of the carbon dioxide react with water during transportation in the body?

To create carbonic acid (C) Signup and view all the answers

Which organelle plays a critical role in facilitating the exchange of carbon dioxide and oxygen in the circulatory system?

Alveoli (B) Signup and view all the answers

What is the primary function of the blood vessels discussed in the text?

To deliver oxygen and nutrients to cells and remove their wastes (A) Signup and view all the answers

What is the key difference between arteries and veins, as described in the text?

Arteries carry blood towards the heart, while veins carry blood away from the heart (A) Signup and view all the answers

How does the body accommodate changes in the oxygen and nutrient requirements of cells?

By both a and b (A) Signup and view all the answers

What is the name of the sequence of events that occurs in one complete beat of the heart?

The cardiac cycle (D) Signup and view all the answers

What is the pumping phase of the cardiac cycle, when the heart muscle contracts?

Systole (A) Signup and view all the answers

Which of the following statements about the differences between arteries and veins is NOT correct, according to the text?

Arteries have valves, while veins do not (B) Signup and view all the answers

What is the primary role of the blood, according to the text?

To deliver oxygen and nutrients to cells and carry away their wastes (D) Signup and view all the answers