Sheep heart

1. right atrium
2. right ventricle
3. left atrium 
4. left ventricle
5. rigt/left auricles 
6. precava 
7. postcava 
8. pulmonary trunk 
9. aorta 
10. pulmonary veins
11. innominate or brachiocephalic artery 
12. left sublclavian artery
13. ligamentum arteriosum
14. coronary arteries 
15. apex 
16. interventricular septum
17. bicuspid valve 
18. chordae tendineae 
19. papillary muscles 
20. trabeculae carnae 
21. aortic semilunar valve