Circulatory System Functions and Structures

Dr. Mike explains the circulatory system, focusing on blood circulation and vessels. He covers the systemic and pulmonary circulations, the distribution of blood in the body, and the roles of different blood vessels. Arteries are elastic vessels that handle high pressure, while arterioles regulate blood flow with smooth muscle. Capillaries are the site of nutrient and gas exchange. Venules and veins act as capacitance vessels, holding most of the body's blood. The video emphasizes the importance of each vessel type in maintaining efficient circulation.

What is one of the primary functions of the circulatory system?

• To store energy

• To deliver nutrients and remove waste

• To regulate body temperature

• To produce blood cells

Which of the following is NOT a substance delivered by the circulatory system?

• Glucose

• Hormones

• Carbon dioxide

• Oxygen

What is the systemic circulation responsible for?

• Delivering blood to the lungs

• Delivering blood to the tissues of the body

• Removing waste from the kidneys

• Regulating body temperature

Approximately what percentage of blood is distributed to the brain at rest?

• 5%

• 25%

• 15%

• 20%

What type of vessel carries blood away from the heart?

• Veins

• Arteries

• Venules

• Capillaries

Why do arteries need to have a lot of elastic tissue?

• To store blood

• To regulate body temperature

• To stretch and snap back under pressure

• To produce blood cells

What is the primary function of arterioles?

• To regulate blood flow to tissues

• To store blood

• To exchange gases

• To remove waste

Which nervous system influences the smooth muscle in arterioles?

• Parasympathetic nervous system

• Sympathetic nervous system

• Central nervous system

• Somatic nervous system

What is the main function of capillaries?

• To store blood

• To exchange nutrients and waste

• To produce hormones

• To regulate blood pressure

What percentage of blood is typically found in veins and venules at any one moment?

• 7%

• 13%

• 64%

• 9%