Across
- 5. carry blood towards the heart.
- 6. a thin membrane that lines the inside of the heart.
- 8. carry blood away from the heart.
- 10. a strong muscular wall that divides the heart into a left and right half.
- 11. a watery yellow fluid.
Down
- 1. the exchange of substances occurs between them and cells.
- 2. small biconcave discs that do not contain nuclei.
- 3. two bottom chambers.
- 4. the kind of blood the left side of the heart contains.
- 7. flat discs that do not contain nuclei.
- 9. two upper chambers.
- 12. are bigger than erythrocytes but do not have a fixed shape but do have a nucleus.