Which are the three primary types of blood vessels?

Which are the three primary types of blood vessels?

• A. Arteries, veins, and capillaries
• B. Arteries, lymphatics, and capillaries
• C. Arteries, veins, and lymphatics
• D. Veins, arteries, and nerves

Answer: (A)

The main idea here is how the blood is conveyed through the body's vessels. The three primary types are arteries, veins, and capillaries. Arteries carry blood away from the heart and have thick, muscular walls to withstand high pressure; they usually transport oxygen-rich blood in the systemic circulation (with pulmonary arteries carrying oxygen-poor blood to the lungs). Veins return blood toward the heart and have thinner walls with valves to prevent backflow, carrying oxygen-poor blood in the systemic circuit (with pulmonary veins carrying oxygen-rich blood from the lungs). Capillaries are the smallest vessels, with ultra-thin walls that allow gas, nutrient, and waste exchange between blood and tissues. Lymphatics and nerves aren’t blood vessels. Lymphatic vessels are part of the immune/lymphatic system and transport lymph, not blood. Nerves are part of the nervous system. So the combination that represents the true blood vessel types is arteries, veins, and capillaries.

The main idea here is how the blood is conveyed through the body's vessels. The three primary types are arteries, veins, and capillaries. Arteries carry blood away from the heart and have thick, muscular walls to withstand high pressure; they usually transport oxygen-rich blood in the systemic circulation (with pulmonary arteries carrying oxygen-poor blood to the lungs). Veins return blood toward the heart and have thinner walls with valves to prevent backflow, carrying oxygen-poor blood in the systemic circuit (with pulmonary veins carrying oxygen-rich blood from the lungs). Capillaries are the smallest vessels, with ultra-thin walls that allow gas, nutrient, and waste exchange between blood and tissues.

Lymphatics and nerves aren’t blood vessels. Lymphatic vessels are part of the immune/lymphatic system and transport lymph, not blood. Nerves are part of the nervous system. So the combination that represents the true blood vessel types is arteries, veins, and capillaries.