Anatomy & Physiology

Centrifuged blood sample showing golden plasma, a thin buffy coat and red blood cells in a clinical laboratory.

Blood: What Is Actually Moving Around the Circu...

A blood sample can produce dozens of separate results, but they all come from the same circulating tissue. Follow plasma, blood cells and volume changes from the tube back to...

Blood: What Is Actually Moving Around the Circu...

A blood sample can produce dozens of separate results, but they all come from the same circulating tissue. Follow plasma, blood cells and volume changes from the tube back to...

Cutaway model of a human long bone showing cancellous bone, red bone marrow, yellow marrow and marrow blood vessels.

Bone Marrow: Where Blood Cells Are Made

Bone marrow is where blood-cell production begins. Learn how haematopoietic stem cells produce erythrocytes, leucocytes and platelets, how the marrow responds to demand, and what happens when production fails.

Bone Marrow: Where Blood Cells Are Made

Bone marrow is where blood-cell production begins. Learn how haematopoietic stem cells produce erythrocytes, leucocytes and platelets, how the marrow responds to demand, and what happens when production fails.

Medical illustration of the brain with a magnified cerebral capillary showing endothelial cells, tight junctions, astrocyte processes and a pericyte forming the blood-brain barrier.

The Blood-Brain Barrier: How Does the Brain Con...

How does the blood-brain barrier protect the brain? Learn how cerebral capillaries, tight junctions, astrocytes and selective transport control what moves from blood into brain tissue.

The Blood-Brain Barrier: How Does the Brain Con...

How does the blood-brain barrier protect the brain? Learn how cerebral capillaries, tight junctions, astrocytes and selective transport control what moves from blood into brain tissue.

Anatomical heart model showing the cardiac electrical conduction pathway beside an ECG trace, illustrating how electrical activity in the heart produces the ECG waveform.

The Heart’s Electrical Conduction System: From ...

Follow one heartbeat from the sinoatrial node through the atria, atrioventricular node and His–Purkinje system, then use that physiology to understand the P wave, PR interval, QRS complex, T wave...

The Heart’s Electrical Conduction System: From ...

Follow one heartbeat from the sinoatrial node through the atria, atrioventricular node and His–Purkinje system, then use that physiology to understand the P wave, PR interval, QRS complex, T wave...

Cellular illustration of B cells, T cells and antibody production in immune memory

How the Immune System Remembers Infection: B Ce...

Follow an infection from first exposure to immune memory: antigen presentation, clonal selection, B cells, T cells, antibodies and why vaccination creates a prepared immune response.

How the Immune System Remembers Infection: B Ce...

Follow an infection from first exposure to immune memory: antigen presentation, clonal selection, B cells, T cells, antibodies and why vaccination creates a prepared immune response.

Anatomical stomach illustration showing interstitial cells of Cajal and gastric electrical activity

The Stomach’s Pacemaker: How Interstitial Cells...

A mechanism-first UK student nurse guide to interstitial cells of Cajal, gastric slow waves and how coordinated stomach motility connects with symptoms such as early satiety, nausea and vomiting in...

The Stomach’s Pacemaker: How Interstitial Cells...

A mechanism-first UK student nurse guide to interstitial cells of Cajal, gastric slow waves and how coordinated stomach motility connects with symptoms such as early satiety, nausea and vomiting in...