respiration key words Crossword

This printable crossword puzzle on the topic of Human Body Systems has 10 clues. Answers range from 5 to 20 letters long. This crossword is also available to download as a Microsoft Word document or a PDF.

glucose from food reacts with oxygen to produce energy
air sacs in the lungs where gaseous exchange happens
chemical reactions that release energy without oxygen
Anaerobic respiration
small blood vessels with thin walls, which carry blood between the arteries and veins
breathing out air from the lungs
breathing air into the lungs
by product of anaerobic respiration, causes aching muscles
cells in the blood which carry oxygen around the body
blood vessels that carry blood towards the heart