Summary
Blood flow, a critical aspect of cardiovascular physiology, refers to the movement of blood through the circulatory system, delivering oxygen and nutrients to tissues and organs while removing waste products. This flow is driven primarily by the pumping action of the heart and is regulated by various physiological mechanisms to ensure adequate perfusion of tissues.
This overview begins with major steps found in blood circulation throughout the cardiovascular system. Remember this process is continuous allowing the:
1) maintenance of cell-level metabolism by the transportation of nutrients, hormones, metabolic wastes, O2 and CO2 throughout the body; 2) regulation of pH, osmotic pressure and temperature of the whole body; 3) protection from microbial and mechanical harms
Tracing Blood Flow
There are main functional units:
A. Right heart consisting of both the Right atrium and Right ventricle
B. Left heart consisting of both the Left atrium and Left ventricle.
From each lung, you can trace blood being transported to the Left atrium via four pulmonary veins, which contain high O2 and low CO2 concentration. Blood flows from the Left atrium through the Left atrioventricular valve (also called Mitral valve or Bicuspid valve) reaching the Left ventricle. (Because the Left ventricle is the chamber that pumps blood from the heart, it is the most muscular and powerful of the four chambers). From the Left ventricle, blood is then pumped through the aorta to supply all systemic tissues:
- Cerebral Â
- Coronary heart
- Splanchnic Â
- Renal system
- MusculoskeletalÂ
- Skin
Arteries split into arterioles, capillaries, draining into venules and then veins drains into either the Superior vena cava, Inferior vena cava, or Coronary sinus,  opening into the right atrium.
Blood from the head and neck region is drained by the Superior vena cava. Blood from the peripheral system is drained by the inferior vena cava. Blood from the heart is drained by the coronary sinus. Subsequently, all drain into the right atrium.
From the Right atrium, the deoxygenated blood (with decrease in O2 concentration, and increase in CO2 concentration) is pumped into the Right ventricle through the Right Atrium ventricular valve, also called Tricuspid valve. Finally, from the Right ventricle, blood is pumped through pulmonary arteries back to the lungs.