At which point, the pulmonary artery is different from the pulmonary vein:
1. Its lumen is broad
2. Its wall is thick
3. It has valves
4. It does not possess endothelium
Systemic heart refers to:
1. | The heart that contracts under stimulation from the nervous system |
2. | Left auricle and left ventricle in higher vertebrates |
3. | Entire heart in lower vertebrates |
4. | The two ventricles together in humans |