The Cardiac Cycle
Posted inMedicine

The Cardiac Cycle

The cycle begins with the atria (the two upper chambers) filling with blood. On the right side, blood comes from the body through the superior and inferior vena cava. On the left side, blood arrives from the lungs via the pulmonary veins
Renin–Angiotensin–Aldosterone System (RAAS)
Posted inMedicine

Renin–Angiotensin–Aldosterone System (RAAS)

The JG cells detect crisis through three eyes: Baroreceptor eye → senses renal arterial pressure. Chemoreceptor eye (Macula densa) → monitors sodium chloride in distal tubule. Nerve eye → listens to sympathetic nerves releasing norepinephrine. When all scream “low!”, they release Renin. Note that Renin is not a hormone — it’s an enzyme. It cleaves angiotensinogen into action.