Question 1

A LONG-TERM SMOKER'S BRONCHIAL LINING CHANGES FROM CILIATED COLUMNAR CELLS TO STRATIFIED SQUAMOUS CELLS. WHICH ADAPTATION IS THIS?

Accepted Answer

METAPLASIA. One mature cell type has been swapped for a tougher one that copes better with smoke. The trade-off is lost cilia and mucus clearance, and the change can reverse if the person stops smoking.

Question 2

A WEIGHTLIFTER'S THIGH MUSCLES GROW BIGGER OVER A YEAR, BUT THE NUMBER OF MUSCLE FIBRES STAYS THE SAME. WHAT EXPLAINS THE GROWTH?

Accepted Answer

EACH CELL MAKING MORE PROTEIN AND GETTING LARGER. Adult skeletal muscle fibres barely divide, so extra workload is met by building more contractile protein inside existing fibres. Bigger cells make a bigger muscle, which is hypertrophy.

Question 3

A HEART MUSCLE CELL LOSES ITS OXYGEN SUPPLY AND ATP STARTS TO FALL. WHAT IS THE EARLIEST CHANGE YOU WOULD SEE?

Accepted Answer

THE CELL SWELLS WITH WATER. Without ATP the sodium-potassium pump stops, sodium stays inside and water follows it in by osmosis. Swelling comes first and is still reversible; nuclear breakup and membrane rupture come later.

Question 4

WHICH FINDING TELLS YOU AN INJURED CELL HAS PASSED THE POINT OF NO RETURN?

Accepted Answer

SEVERE DAMAGE TO THE PLASMA AND LYSOSOMAL MEMBRANES. Blebs, fat droplets and swollen organelles can all recover once oxygen returns. When the outer and lysosomal membranes fail, enzymes leak and digest the cell, so death follows whatever happens next.

Question 5

A PATIENT DIES THREE DAYS AFTER A HEART ATTACK. UNDER THE MICROSCOPE THE DEAD HEART MUSCLE STILL SHOWS THE OUTLINES OF ITS CELLS. WHICH PATTERN IS THIS?

Accepted Answer

COAGULATIVE NECROSIS. Ischemia in a solid organ like the heart denatures the cell's own enzymes along with its structural proteins, so the dead tissue keeps its ghost-like outline for days before white cells clear it.

Question 6

A STROKE CUTS OFF BLOOD TO PART OF THE BRAIN. WEEKS LATER THE DEAD AREA HAS BECOME A FLUID-FILLED CAVITY. WHY?

Accepted Answer

BRAIN TISSUE UNDERGOES LIQUEFACTIVE NECROSIS. Ischemic death in the brain is digested into soft liquid instead of keeping its shape. Brain tissue has very little collagen framework to hold dead cells in place, and their enzymes break them down.

Question 7

A CHEST X-RAY SHOWS A LUNG LESION FROM TUBERCULOSIS. A BIOPSY OF ITS CENTER LOOKS WHITE, CRUMBLY AND CHEESE-LIKE. WHICH TYPE OF CELL DEATH IS THIS?

Accepted Answer

CASEOUS NECROSIS. Tuberculosis provokes a granuloma, and the dead tissue at its core turns friable and white. The name comes from the Latin for cheese, which is exactly how it looks to the naked eye.

Question 8

IN ACUTE PANCREATITIS, CHALKY WHITE SPOTS APPEAR IN THE FAT AROUND THE PANCREAS. WHAT CAUSES THEM?

Accepted Answer

ESCAPED LIPASES SPLIT FAT AND THE FATTY ACIDS BIND CALCIUM. Leaked pancreatic enzymes break triglycerides into fatty acids, which then react with calcium to form soap-like deposits. That process, called saponification, is what leaves the chalky spots.

Question 9

WHY DOES APOPTOSIS USUALLY CAUSE NO INFLAMMATION, WHILE NECROSIS DOES?

Accepted Answer

APOPTOTIC CELLS ARE PACKAGED AND EATEN BEFORE THEIR CONTENTS LEAK. A dying apoptotic cell breaks into sealed fragments that macrophages swallow whole. In necrosis the membrane bursts and spills its contents into the tissue, and those leaked molecules call in white cells.

Question 10

A SPRAINED ANKLE PUFFS UP WITHIN AN HOUR. WHAT CAUSES MOST OF THE SWELLING?

Accepted Answer

LEAKY SMALL VESSELS LETTING PROTEIN-RICH FLUID INTO THE TISSUE. Mediators such as histamine open gaps between the endothelial cells of venules. Plasma and its proteins escape, and the protein drags more water out with it, so the tissue swells fast.

Question 11

THE SKIN AROUND AN INFECTED CUT IS RED AND HOT. WHICH CHANGE IN THE BLOOD VESSELS CAUSES BOTH SIGNS?

Accepted Answer

DILATION OF ARTERIOLES INCREASING BLOOD FLOW. Widened arterioles push more warm blood from the body's core into the area. Extra blood near the surface looks red and feels hot, which is why redness and heat appear together.

Question 12

A WOUND BECOMES INFECTED WITH BACTERIA. WHICH WHITE BLOOD CELL WILL DOMINATE THE SITE DURING THE FIRST 24 HOURS?

Accepted Answer

NEUTROPHILS. Neutrophils are plentiful in the blood, respond fastest to chemical signals and stick to vessel walls quickly, so they arrive first. Macrophages and lymphocytes take over if the problem lasts for days.

Question 13

A PATIENT TAKES IBUPROFEN FOR A SWOLLEN, PAINFUL KNEE. WHICH STEP OF INFLAMMATION DOES THE DRUG BLOCK?

Accepted Answer

PROSTAGLANDIN SYNTHESIS BY CYCLOOXYGENASE. Ibuprofen inhibits the cyclooxygenase enzymes, so less arachidonic acid is turned into prostaglandins. Fewer prostaglandins means less pain, less vasodilation and a lower fever.

Question 14

A PATIENT WITH PNEUMONIA HAS A FEVER, A HIGH WHITE CELL COUNT AND A RAISED C-REACTIVE PROTEIN. WHICH MEDIATORS DRIVE THESE WHOLE-BODY EFFECTS?

Accepted Answer

IL-1, TNF AND IL-6. These cytokines travel in the blood: they reset the hypothalamic thermostat, tell the marrow to release more leukocytes and push the liver to make acute-phase proteins. Histamine acts mainly at the local site.

Question 15

A PATIENT'S CALF MUSCLES SHRINK AFTER SIX WEEKS IN A LEG CAST. THIS ADAPTATION IS CALLED ___.

Accepted Answer

ATROPHY. Unused muscle cells break down some of their own structural proteins and get smaller. The muscle usually rebuilds once the cast comes off and the leg is loaded again.

Question 16

AN OLDER MAN'S PROSTATE ENLARGES BECAUSE ITS GLANDULAR CELLS MULTIPLY. THIS IS CALLED HORMONE-DRIVEN ___.

Accepted Answer

HYPERPLASIA. Benign prostatic enlargement comes from more cells, not bigger ones, under the influence of androgens. Prostate cells can still divide, so number rather than size goes up.

Question 17

FREE RADICALS ATTACK THE DOUBLE BONDS IN MEMBRANE FATS IN A CHAIN REACTION CALLED LIPID ___.

Accepted Answer

PEROXIDATION. One radical steals an electron from a fatty acid, which then attacks its neighbour, and so on along the membrane. The membrane becomes leaky and the cell loses control of what enters it.

Question 18

BLOOD FLOW IS RESTORED TO A BLOCKED CORONARY ARTERY, BUT SOME HEART CELLS GET WORSE. THIS IS REPERFUSION ___.

Accepted Answer

INJURY. Returning oxygen meets damaged mitochondria and produces a burst of free radicals, while calcium floods in and white cells arrive. Cells that were still salvageable can be pushed over the edge.

Question 19

A DIABETIC PATIENT'S TOE LOSES ITS BLOOD SUPPLY AND TURNS BLACK, SHRIVELLED AND HARD. THIS IS ___ GANGRENE.

Accepted Answer

DRY. Without infection, the dead tissue simply dries out and mummifies. If bacteria invade, the tissue liquefies and swells instead, which is called wet gangrene and is far more dangerous.

Question 20

SECONDS AFTER A BEE STING, A RED WHEAL APPEARS BECAUSE ___ CELLS RELEASE HISTAMINE.

Accepted Answer

MAST. Mast cells sit near small blood vessels in the skin with histamine already stored in granules. They can empty those granules almost instantly, which is why the wheal appears so fast.

Question 21

NEUTROPHILS CRAWL OUT OF A VENULE AND HEAD STRAIGHT FOR INVADING BACTERIA. THIS GUIDED MOVEMENT IS ___.

Accepted Answer

CHEMOTAXIS. Bacterial peptides, complement fragments and chemokines form a concentration gradient. Receptors on the neutrophil sense which side is stronger and steer the cell toward the source.

Question 22

BACTERIA COATED WITH ANTIBODY ARE SWALLOWED BY MACROPHAGES MUCH FASTER. THE COATING PROCESS IS CALLED ___.

Accepted Answer

OPSONIZATION. The coating gives phagocytes something to grip: their receptors bind the antibody's tail, so the bacterium is held tight and engulfed far more efficiently than a bare one.

Cellular Injury and Inflammation