Vocab

4. muscular, thick-walled part of a bird's stomach for grinding food, typically with grit.
8. the protein contained in red blood cells that is responsible for delivery of oxygen to the tissues
10. Any of the tubes forming part of the blood circulation system of the body, carrying in most cases oxygen depleted blood toward the heart
12. gland-produces hormones that regulate the body's metabolic rate, growth and development.
14. an organism that lives in or on an organism of another species (its host) and benefits by deriving nutrients at the other's expense.
15. Distribute oxygen rich blood to your body

1. part of the alimentary canal that connects the throat to the stomach
2. membranes-an epithelial tissue which secretes mucus, and lines many body cavities and tubular organs including the gut and respiratory passages.
3. part of the body's defense mechanism
5. a condition that develops when your blood produces a lower-than-normal amount of healthy red blood cells
6. deliver oxygen to the tissues in your body.
7. gland-the major endocrine gland.
9. the protein contained in red blood cells that is responsible for delivery of oxygen to the tissues
11. pouch in a bird's gullet where food is stored or prepared for digestion.: "the parent waxbill partially digests food in its crop".
13. pumps blood around your body as your heart beats