B3.2 Transport

Which type of blood vessel is highly branched and has thin walls to maximize the exchange of substances between blood and the environment?

• Arteries

• Capillaries

• Veins

• Aorta

Answer explanation

Capillaries are highly branched and have thin walls, allowing for efficient exchange of substances between blood and surrounding tissues, unlike arteries and veins which have thicker walls.

Which of the following features distinguishes arteries from veins when observed under a microscope?

• Presence of valves

• Thickness of the wall

• Irregular shape

• Smaller diameter

Answer explanation

The thickness of the wall is a key feature that distinguishes arteries from veins. Arteries have thicker walls to withstand higher pressure from blood flow, while veins have thinner walls and often contain valves to prevent backflow.

What is the primary function of arteries?

• To return blood to the heart

• To filter waste products from the blood

• To transport blood away from the heart

• To exchange gases with the environment

Answer explanation

The primary function of arteries is to transport blood away from the heart, delivering oxygen and nutrients to tissues. This distinguishes them from veins, which return blood to the heart.

Which component of arterial walls helps them withstand high blood pressure?

• Valves

• Elastic tissue and muscle

• Thin endothelium

• Fenestrations

Answer explanation

Elastic tissue and muscle in arterial walls allow them to stretch and recoil, helping them withstand the high pressure of blood flow. This structural feature is crucial for maintaining blood circulation effectively.

Which pulse point is commonly used to measure heart rate using fingertips?

• Femoral

• Carotid or radial

• Brachial

• Popliteal

Answer explanation

The carotid and radial pulse points are easily accessible with fingertips, making them the most common sites for measuring heart rate. The femoral, brachial, and popliteal points are less commonly used for this purpose.

What is the primary function of veins?

• To deliver oxygen to tissues

• To carry blood away from the heart

• To return blood back to the heart

• To regulate blood pressure

Answer explanation

The primary function of veins is to return blood back to the heart. Unlike arteries, which carry blood away from the heart, veins are responsible for transporting deoxygenated blood from the tissues back to the heart.

Which adaptation helps prevent the backflow of blood in veins?

• Thick muscular walls

• Narrow lumen

• Valves

• High blood pressure

Answer explanation

Valves in veins are crucial adaptations that prevent the backflow of blood, ensuring it flows towards the heart. Unlike arteries, veins have lower pressure, making valves essential for maintaining proper circulation.

What is the term for the blockage of coronary arteries?

• Atherosclerosis

• Occlusion

• Stroke

• Angina

Answer explanation

The blockage of coronary arteries is referred to as 'occlusion'. Atherosclerosis is a condition that can lead to occlusion, while stroke and angina are related but distinct medical issues.

What statistical measure can be used to assess the strength of the relationship between two variables, such as coronary artery occlusion and heart rate?

• Mean

• Standard deviation

• Correlation coefficient

• T-test

Answer explanation

The correlation coefficient measures the strength and direction of the relationship between two variables, making it the appropriate choice for assessing the link between coronary artery occlusion and heart rate.

What is the process by which water is transported from the roots to the leaves of plants?

• Photosynthesis

• Respiration

• Transpiration

• Osmosis

Answer explanation

Transpiration is the process where water is absorbed by plant roots and transported through the xylem to the leaves, where it evaporates into the atmosphere. This process is crucial for nutrient transport and temperature regulation.