What type of blood do arteries transport?

• Deoxygenated blood

• Oxygenated blood

• Mixed blood

• Nutrient-rich blood

Answer explanation

Arteries primarily transport oxygenated blood away from the heart to the body's tissues. The only exception is the pulmonary arteries, which carry deoxygenated blood to the lungs. Therefore, the correct answer is oxygenated blood.

Which feature allows arteries to handle high pressure?

• Valves

• Thick walls

• Thin walls

• Large diameter

Answer explanation

Arteries have thick walls made of muscle and elastic tissue, allowing them to withstand and regulate the high pressure of blood pumped from the heart. This structural feature is crucial for maintaining proper circulation.

What is the main function of veins?

• Transport oxygenated blood to the body

• Carry deoxygenated blood back to the heart

• Exchange nutrients and waste

• Store blood

Answer explanation

Veins primarily function to carry deoxygenated blood back to the heart, which is essential for the circulation process. This distinguishes them from arteries, which transport oxygenated blood away from the heart.

What prevents blood from flowing backward in veins?

• Thick walls

• Elastic fibers

• Valves

• High pressure

Answer explanation

Valves in veins prevent blood from flowing backward by closing when blood tries to move in the reverse direction. This mechanism is crucial for maintaining proper circulation, especially against gravity.

What is the primary characteristic of capillaries?

• Thick walls

• One cell thick

• Large diameter

• High pressure

Answer explanation

The primary characteristic of capillaries is that they are one cell thick. This thinness allows for efficient exchange of gases, nutrients, and waste between blood and tissues, distinguishing them from other blood vessels.

How do capillaries assist in nutrient exchange?

• By having thick walls

• By being one cell thick

• By having valves

• By being elastic

Answer explanation

Capillaries assist in nutrient exchange by being one cell thick, which allows for easy diffusion of nutrients and waste products between blood and surrounding tissues.

What type of blood vessel has the smallest diameter?

• Arteries

• Veins

• Capillaries

• Aorta

Answer explanation

Capillaries have the smallest diameter among blood vessels, allowing for the exchange of oxygen, carbon dioxide, and nutrients at the cellular level. They are narrower than arteries and veins.

Which blood vessel type is not as strong as arteries?

• Capillaries

• Veins

• Aorta

• Arterioles

Answer explanation

Veins are not as strong as arteries because they have thinner walls and lower pressure. Unlike arteries, which carry blood away from the heart under high pressure, veins return blood to the heart at a lower pressure.

What allows arteries to expand and contract?

• Valves

• Elastic fibers

• Thick walls

• Small diameter

Answer explanation

Elastic fibers in the walls of arteries allow them to expand and contract with each heartbeat, accommodating changes in blood pressure. This elasticity is crucial for maintaining proper blood flow.

What is the role of capillaries in the circulatory system?

• Transport blood under high pressure

• Exchange nutrients and oxygen with tissues

• Prevent blood from flowing backward

• Store blood

Answer explanation

Capillaries are tiny blood vessels that facilitate the exchange of nutrients and oxygen with tissues. They connect arteries and veins, allowing for the delivery of essential substances and the removal of waste products.