Medicine » The Learning Hub

Laminar Flow

Laminar flow is the smooth, organized movement of blood in layers inside a vessel. Instead of swirling or mixing randomly, the blood glides forward in neat “sheets.” The layer at the center moves the fastest, while the layers closer to the vessel wall move slower because of friction.

Medicine

Margination of Cells

When there is injury or infection, your body widens the blood vessels in that area to allow more blood flow. But ironically, widening the vessels actually slows down the flow. When there is injury or infection, your body widens the blood vessels in that area to allow more blood flow. But ironically, widening the vessels actually slows down the flow.

Medicine

Mesangial Cell Signaling

To understand Mesangial Cell Signaling, imagine each kidney nephron like a tiny water-treatment factory. Inside the glomerulus (the filter), we have three important workers: StructureFunctionEndothelial cellsLet plasma through but block…

Medicine

Plasma Proteins

Plasma proteins are large organic molecules found in the plasma part of the blood. They are mainly synthesized by: The liver (majority) The plasma cells (lymphocytes) — especially immunoglobulins

Medicine

The Wiggers Diagram

The Wiggers Diagram is a classic graph in physiology that represents all the events of the cardiac cycle in one picture. It combines: Electrical activity (ECG) Pressure changes (atria, ventricles, aorta) Volume changes (in the ventricles) Heart sounds (phonocardiogram: S1, S2, etc.) This is why it looks so complicated—because everything is happening at once. But if we follow it layer by layer, it makes sense.

Medicine

Inflammation – An Easy Guide

Inflammation is the body’s protective response to injury, infection, or irritation. Its goal is simple: Eliminate the cause of injury (like microbes or toxins). Clear out damaged tissue. Start repair. It is not always harmful — it’s a survival mechanism. But when excessive or uncontrolled, inflammation itself can cause disease.

Medicine

Cardiopulmonary Anastomosis – A Simple Guide

In medicine, anastomosis means a connection or joining between two tubular structures. In the cardiovascular system, it usually refers to the joining of blood vessels that allows alternate routes for blood flow. So, cardiopulmonary anastomosis = the vascular connections between the heart and the lungs that ensure continuous blood supply and oxygen exchange, even if one route is blocked or compromised.

Medicine

Hypoxic Pulmonary Vasoconstriction

In most of the body, when tissues are low on oxygen, blood vessels open up (dilate) to bring more oxygen. But in the lungs, the opposite happens: low oxygen makes small arteries narrow (constrict). Why? Because the lung’s job is to match airflow (ventilation) with blood flow (perfusion). If one area of the lung isn’t getting air, it makes no sense to send blood there — that blood would leave still “blue” and waste circulation.

Medicine

Ultrafiltration — A simplified Concept

Fluid movement across a semipermeable membrane is driven by opposing forces: hydrostatic pressure (push) and oncotic pressure (pull due to proteins). The generalized Starling equation describes fluid flux (Jv): Jv = Kf × [ (Pc - Pi) - σ(πc - πi) ]

Medicine

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