Components of the circulatory system.

Which of the following NOT a component of the circulatory system?

• Heart.

• Veins.

• Arteries.

• Villi.

Answer explanation

The villi is a structure which is present in the intestine. The villi is involved in the absorption of nutrients and minerals from the digestive system.

What is the difference between oxygenated and deoxygenated blood?

• Oxygenated blood is blood that is red in color and deoxygenated blood is blood that is blue in color.

• Oxygenated blood is blood that is blue in color and deoxygenated blood is blood that is red in color.

• Oxygenated blood is blood that carries mostly carbon dioxide and deoxygenated blood is blood that carries mostly oxygen.

• Oxygenated blood is blood that carries mostly oxygen and deoxygenated blood is blood that carries mostly carbon dioxide.

Answer explanation

Oxygenated blood refers to the blood that has been exposed to oxygen in the lungs. Deoxygenated blood refers to the blood that has a low oxygen saturation relative to blood leaving the lungs.

What is the function of the blood?

• Blood is involved in carry out excretion

• Blood is involved in the process of creating heat.

• Blood is involved in the process of metabolism.

• Blood is involved in transport of products of excretion.

Answer explanation

The blood is an important complex fluid which is primordial proper functioning of the human body.

Which of the following describes an artery?

• The arteries are the thick blood vessels that deliver oxygen-rich blood from the heart to the tissues of the body. Exception to pulmonary artery.

• The arteries are the thin blood vessels that deliver oxygen-rich blood from the heart to the tissues of the body. Exception to pulmonary artery.

• The arteries are the thick blood vessels that deliver oxygen-rich blood from the heart to the tissues of the body.

• The arteries are the thin blood vessels that deliver oxygen-rich blood from the heart to the tissues of the body.

Answer explanation

The arteries are the thick muscularized blood vessels which carries blood at high pressure. All arteries have small lumen and no semi-lunar valves which helps to absorb the high pressure of blood pumped out of the heart.

Which of the following describes a vein?

• The veins are the thick blood vessels that transport oxygen-rich blood from the heart to the tissues of the body. Exception to pulmonary vein.

• The veins are the thin blood vessels that transport deoxygenated blood from all parts of the body back to the heart . Exception to pulmonary vein.

• The veins are the thick blood vessels that transport oxygenated blood from all parts of the body back to the heart . Exception to pulmonary vein.

• The veins are the thin blood vessels that transport oxygenated blood from all parts of the body back to the heart . Exception to pulmonary vein.

Answer explanation

Veins are thin muscularized blood vessels which have large lumen. They carry blood at a low pressure which is mostly deoxygenated except for pulmonary vein which takes oxygenated blood from the lungs to the heart.

Which of the following describes a capillary?

• A capillary is a large tube which is involved in transfer of substances and gases.

• A capillary is a small tube which is involved in transfer of substances and gases.

• A capillary is a large tube which is involved in transfer of only substances.

• A capillary is a small tube which is involved in transfer of only gases.

Answer explanation

Capillaries are the smallest blood vessels in the circulatory system. They are involved mainly in the transfer of substances and in gas exchange.

Describe the differences in function between arteries, veins and capillaries.

Answer explanation

You are required to relate the structure of each blood vessels to their respective function.

Explain why the blood vessels forms a close network and how it does blood flows throughout the closed network of blood vessels in human.

Answer explanation

The blood vessels are divided into 3 main groups. Arteries, veins and capillaries. The different blood vessels are linked by smaller blood vessels for example; arteries are divided into smaller blood vessels called arterioles which divides further to form capillaries. Moreover, capillaries are joined together to form a larger blood vessel called venules which regroups to form veins this forms a closed circuit or network as blood is not allowed to escape from the walls of the blood vessels nor to a sink.. The blood travels through this closed network from the main artery Aorta from the heart to the rest of the body and comes back to the heart which describes the systemic circulation. On the other hand, blood flows from the heart to the lungs by the pulmonary artery and back to the heart by the pulmonary vein which forms the pulmonary circulation. These two types of circulation forms the double circulation of the human circulatory system.