The human body has 3 main types of blood vessels:

1. Arteries:

• thick-walled blood vessels that carry oxygenated blood away from the heart and distribute it to various organs and tissues
• muscular and elastic structure that allows them to withstand the high pressure generated by the heart’s pumping
• largest artery is the aorta

2. Veins:

• blood vessels that carry deoxygenated blood back to the heart from the organs and tissues
• thinner walls and less muscular tissue
• valves prevent the backward flow of blood and facilitate the return of blood against gravity
• major veins are the inferior vena cava and the superior vena cava

3. Capillaries:

• smallest and most numerous blood vessels in the body
  
• connect arteries and veins and facilitate the exchange of oxygen, nutrients, and waste products between blood and surrounding tissues
  
• walls are incredibly thin, consisting of a single layer of cells to allow for diffusion

• This reply was modified 3 months, 1 week ago by  Kasvi Methi. Reason: formatting