Circulatory system 🫀

• What does the heart do?

  It pumps blood around the body.
• What are the three types of blood vessels?

  The three types of blood vessels are arteries, veins, and capillaries.
• What do arteries do?

  Carry oxygenated blood away from the heart.
• What are the adaptations of the artery?

  -strong, thick walls to withstand high pressure of blood flow.

  -elastic walls for smooth blood flow.

  -thin lumen
• What do capillaries do?

  Arteries break into capillaries. They take nutrients and oxygen to cells and take waste products away.
• What are the adaptations of capillaries?

  -tiny and narrow with a fine network to squeeze into gaps in between cells.

  -thin one cell thick walls which increases rate of diffusion by decreasing distance.

  -permeable walls so substances can easily diffuse in and out.

  -good blood supply

  -narrow lumen
• What do veins do?

  Capillaries join up to form veins. They return deoxygenated blood back to the heart.
• What are the adaptations of the veins?

  -thin walls since blood is at a lower pressure

  -wide lumen to help blood flow

  -valves to stop the backflow of blood (valves open and close to keep blood flowing in right direction)