Circulatory System Functions and Structures

This video explores the circulatory system's blood vessels: arteries, capillaries, and veins. It explains how each vessel's structure relates to its function. Arteries carry high-pressure blood from the heart, requiring strong, elastic walls. Capillaries facilitate nutrient and gas exchange with tissues, having thin, permeable walls. Veins return low-pressure blood to the heart, equipped with valves to prevent backflow. The video also demonstrates calculating blood flow rate through the aorta.

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

• To filter waste products from the blood

• To carry blood away from the heart

• To exchange nutrients with tissues

• To carry blood back to the heart

What is the main function of the circulatory system?

• To digest food

• To transport blood throughout the body

• To produce hormones

• To store energy

Why do arteries need to be both strong and elastic?

• To withstand high blood pressures

• To filter blood

• To store oxygen

• To transport nutrients

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

• To carry blood back to the heart

• To exchange substances with cells

• To carry blood away from the heart

• To store blood

How thick are the walls of capillaries?

• Three cell layers thick

• Multiple cell layers thick

• A single cell thick

• Two cell layers thick

What is the significance of the large total cross-sectional area of capillaries?

• It stores more blood

• It decreases blood pressure and slows blood flow

• It filters blood more efficiently

• It increases blood pressure

What feature of veins prevents blood from flowing backwards?

• Smooth muscle

• Elastic fibers

• Valves

• Thick walls

Why do veins have relatively thin walls?

• To filter blood

• To store more blood

• To increase blood pressure

• Because the blood they carry is at low pressure

What is the formula to calculate the rate of blood flow?

• Volume of blood plus time

• Volume of blood multiplied by time

• Time divided by volume of blood

• Volume of blood divided by time

If 2500 ml of blood passes through the aorta in 8 minutes, what is the rate of blood flow?

• 312 ml/min

• 320 ml/min

• 315 ml/min

• 325 ml/min