3.3.4.1: Blood vessels and tissue fluid

Front

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

Back

To carry blood away from the heart

Answer explanation

The primary function of arteries is to carry blood away from the heart, delivering oxygen-rich blood to various parts of the body. This distinguishes them from veins, which carry blood towards the heart.

Front

Which structural feature of arteries helps them withstand high pressure?

Back

Thick muscular walls

Answer explanation

Arteries have thick muscular walls that allow them to withstand high pressure from the blood pumped by the heart. This structural feature provides strength and elasticity, enabling arteries to maintain their shape and function effectively.

Front

What is the main function of arterioles in the circulatory system?

Back

To regulate blood flow to capillaries

Answer explanation

The main function of arterioles is to regulate blood flow to capillaries. They control the amount of blood that enters the capillary beds, thus influencing nutrient and gas exchange in tissues.

Front

How do veins differ structurally from arteries?

Back

Veins have valves

Answer explanation

Veins differ from arteries primarily by having valves, which prevent backflow of blood. This is crucial as veins carry deoxygenated blood back to the heart, often against gravity, unlike arteries that have thicker walls and carry oxygenated blood.

Front

What is the primary role of capillaries in the circulatory system?

Back

To exchange gases, nutrients, and waste products

Answer explanation

The primary role of capillaries is to facilitate the exchange of gases, nutrients, and waste products between blood and tissues, making this option the correct choice.

Front

Why are capillary walls only one cell thick?

Back

To allow rapid diffusion of substances

Answer explanation

Capillary walls are only one cell thick to allow rapid diffusion of substances, such as oxygen and nutrients, between blood and surrounding tissues. This thin structure facilitates efficient exchange, which is crucial for cellular function.

Front

What is the significance of capillary beds in the circulatory system?

Back

They provide a large surface area for exchange

Answer explanation

Capillary beds are crucial as they provide a large surface area for exchange of gases, nutrients, and waste between blood and tissues, facilitating efficient cellular function.

Front

What is tissue fluid, and how is it formed?

Back

A fluid that surrounds cells, formed by filtration from capillaries

Answer explanation

Tissue fluid is a fluid that surrounds cells, formed by the filtration of blood plasma through capillary walls. This process allows nutrients and oxygen to reach cells while removing waste products.

Front

How does tissue fluid return to the circulatory system?

Back

Through the lymphatic system

Answer explanation

Tissue fluid returns to the circulatory system primarily through the lymphatic system. The lymphatic vessels collect excess tissue fluid, which is then transported back into the bloodstream, ensuring fluid balance in the body.

Front

What role do valves in veins play in the circulatory system?

Back

They prevent backflow of blood

Answer explanation

Valves in veins play a crucial role by preventing backflow of blood, ensuring that it flows in one direction towards the heart. This is essential for maintaining efficient circulation, especially in the lower extremities.