Interactive lab

Five activities

Every activity uses real chapter content and keeps your progress in both study modes. Each also appears inside the topic where it helps most.

Centerpiece

Set severity, duration and tissue; predict the state; restore oxygen before or after the threshold.

In context: 1.4 Reversible and irreversible injury →

Centerpiece · Injury simulator

Set the injury, then restore oxygen

You choose how far oxygen delivery falls, for how long, and in which tissue. Predict the state the cell reaches, run it, then predict what restoring oxygen does first. Cell on a Clock shows one fixed timeline; here the outcome depends on the conditions you set.
Teaching schematicBefore the insultNa⁺/K⁺ pumpNucleusRough ERMitochondrion
  1. Normal
  2. Reversible injury
  3. Recovery
  4. Irreversible injury

Conceptual model. Duration is counted in steps, not minutes, and one teaching threshold stands in for a transition that in real tissue depends on the organ, collateral flow and how complete the ischemia is. The lecture gives no time values for it.

1 · Conditions

Course presets

The lecture's hypoxia summary: swelling is potentially reversible with restoration of O₂. (L1 p. 17)

Oxygen delivery

Steps are conceptual, not minutes.

Tissue
2 · Predict, then run

Hold these conditions. What state is the cell in at the end, before any oxygen is restored?

  • Rescue a cell: restore oxygen before the threshold (not yet)
  • Lose a cell: restore oxygen after the threshold (not yet)

No runs yet.

Read the morphology

Three original questions on what each state looks like. They describe schematic findings, not scored specimens.

Question 1

An electron micrograph of a renal tubular cell taken after a short period of low blood pressure shows surface blebs, a dilated endoplasmic reticulum with detached ribosomes and swollen mitochondria. The plasma membrane is continuous all the way round.

Which state of the simulator does this cell match, and why?

Question 2

A second cell from the same kidney shows the same swelling, and in addition large amorphous densities inside the mitochondria, gaps in the plasma membrane and a small, dark, shrunken nucleus.

Which finding places this cell beyond recovery?

Question 3

Several hours after a coronary artery is occluded, cardiac troponin becomes measurable in a patient's blood.

Which structural change in the simulator explains this laboratory finding?

Lecture and simulation cases on this mechanism

Source: L1 Cell injury.pdf, pp. 6, 16–19; mechanisms checked against Robbins Basic Pathology, ch. 1.

Timeline

Predict, scrub and compare reflow.

In context: 1.4 Reversible and irreversible injury →

Core activity · Cell on a Clock

Cell on a Clock

Predict what happens first when oxygen stops arriving, then scrub through the injury and compare what restoring flow does early versus late.
Teaching schematicHealthy cellNa⁺/K⁺ pumpNucleusRough ERMitochondrion

Oxygen delivery to this cell is about to fall. What is the first relevant downstream change?

Commit to a prediction before you watch. Your answer stays hidden until you check it.

Causal chains

Fill the missing step; events versus mechanisms.

In context: 1.4, 1.5, 1.7 →

Core activity · The Missing Arrow

The Missing Arrow

Complete the causal chain. Place the missing step by dragging a card onto a gap, or tap a card and then tap the gap. Some gaps need an event; others need the mechanism that links one event to the next.

A myocyte downstream of a blocked coronary artery. Complete the chain from lost oxygen to irreversible damage.

Two gaps ask for a mechanism, the link that explains how one event causes the next. Don't put an event there.

  1. Oxygen delivery to the myocyte stops
  2. complex IV has no electron acceptor
  5. Sodium accumulates inside the cell
  7. Cell and organelles swell (reversible)
  8. if ischemia persists, Ca²⁺ pumps fail and membranes leak
  10. phospholipases, proteases, mitochondrial permeability pore
  11. Membrane and mitochondrial damage: irreversible injury

Cards

Tap or drag a card. Placing a used card moves it.

Look-alikes

Find the shared feature, then the separating clue.

In context: 1.2, 1.4, 1.7, 1.8 →

Core activity · Almost Twins

Almost Twins

Two look-alikes side by side. Decide what they share, then pick the clue that separates them and say why it works.

Look-alike A

Hypertrophied myocyte

Left ventricle in long-standing hypertension (schematic).
  • Larger cell
  • Extra volume is protein and organelles: more myofilaments and mitochondria
  • Rough ER studded with ribosomes
  • Built by spending ATP on gene activation and protein synthesis

Step 1 · What they share

What do these two cells share?

Select every feature that both show.

Case reasoning

Change one fact and decide whether the answer moves.

In context: 1.6 Necrosis and infarction →

Core activity · One Fact Changes

One Fact Changes

Answer a case and name the decisive clue. Then exactly one fact changes. Decide whether the answer moves, and why.

1 · The original case

A 70-year-old woman with atrial fibrillation stopped her anticoagulant. An embolus lodged in a branch of her left anterior descending coronary artery. She died four days later. At autopsy the territory of the occluded vessel was examined microscopically.

What does the infarcted tissue most likely show?

Which fact decided it?