The video explains the circulatory system, highlighting its functions: transportation, regulation, and protection. It covers the components of blood and lymph, the structure of blood vessels, and the heart's role in circulation. The video also distinguishes between open and closed circulatory systems, and describes single and double circulation in animals.

What are the three main functions of the circulatory system?

• Transportation, regulation, and protection

• Digestion, absorption, and excretion

• Protection, absorption, and excretion

• Respiration, circulation, and digestion

Which of the following is NOT a component of blood?

• Leukocytes

• Thrombocytes

• Erythrocytes

• Hemolymph

What is the primary function of lymph in the body?

• Regulate body temperature

• Carry nutrients

• Transport oxygen

• Defend against pathogens

Which type of blood vessel carries oxygenated blood away from the heart?

• Venules

• Capillaries

• Arteries

• Veins

How many chambers does a fish's heart have?

• Three

• Two

• Four

• Five

In which type of circulatory system is blood always enclosed within vessels?

• Open circulatory system

• Closed circulatory system

• Single circulation

• Double circulation

What type of circulation involves blood flowing through the heart twice during one complete cycle?

• Pulmonary circulation

• Systemic circulation

• Double circulation

• Single circulation