Identify structures 1,2,3 ,4 from the given diagram.

(b) Fill in the blanks . The poorly oxygenated blood comes from the body parts and poured into (1) and then pumped into (2) from which, through (3) artery to lungs. Then from lungs oxygenated blood enters into (4) through pulmonary (5). Then pumped into (6) from this the oxygenated blood passes through (7) to the body except lungs.

Explanation

(a) (1) Tunica externa , 2. Tunica media, 3. Elastic membrane of Tunica interna, 4. Endothelium
(b)(1) Right atrium, 2. Right ventricle 3. Pulmonary artery , 4. Left atrium, 5 Vein , 6. Left ventricle , 7 Systemic aorta