How does blood reach literally every cell in the body? There can’t be capillaries between every single cell when capillaries are also made of cells…. can there?

Question

How does this work?

In: 4868

Answer 1

Osmosis. So the reason skin infections can be hard ti treat is because the skin doesn’t have direct blood supply. Capillaries run throughout the skin and are surrounded by interstitial fluid. This fluid picks up things it’s low in such as oxygen and that’s then taken up by the cells. Sane in reverse for co2 but other waste products remain in the fluid, this fluid is moved around the body and replenished by the lymphatic system, similar to capillaries and blood vessels but instead of being pumped by the heart, your bodies skeletal movements work to pump it around. That’s why lower mobility = increased swelling, especially of lower limbs. The fluid is transported the lymph nodes around the body to be cleaned up. You can get cancer in a lymph node and unfortunately it’s often bad news, the lymphatic system will often spread the cancer around your body making it super hard to treat.

Edit to add; as peeps have pointed out, the oxygen and co2 exchange is diffusion not osmosis 🙂 my senior school biology teacher would be laughing at me rn lol