13. The oesophagus.
14. The thyroid gland.
15. The thymus gland or sweetbread.
16. The large vein, vena cava, which conveys the blood from the brain and upper body into the heart.
17-25. Lymph nodes; 17, of the neck; 25, of the abdomen.
18. Cross section of the arch of the aorta or main artery of the body after it leaves the heart.
19. The sternum or breast bone.
20. The cavity of the heart.
21. The liver.
22. The descending aorta at the back of the abdominal cavity.