Cell Injury Part 1 Flashcards

Flashcards covering the fundamental concepts, mechanisms, and cellular changes associated with cell injury, specifically focusing on hypoxia and reversible cell injury.

What is the most common cause of cell injury?

Hypoxia

What is the most common cause of hypoxia?

Ischemia

Which cell type is most sensitive to hypoxia, and what is the duration of its sensitivity?

Neurons/brain tissue ($3-5\,\text{mins}$)

Which cell type is most resistant to hypoxia, and how long can it withstand it?

Fibroblasts (can withstand up to $60\,\text{minutes}$)

What is the first change observed in cell injury?

Mitochondrial dysfunction

In reversible cell injury, what leads to lactic acid production and an acidic pH?

Anaerobic glycolysis resulting from decreased ATP levels

What effect does an acidic pH have on the nucleus during reversible cell injury?

Nuclear chromatin clumping

What occurs when ribosomes detach from the Rough Endoplasmic Reticulum during cell injury?

Protein synthesis goes down

What is the normal ion exchange ratio of the $Na^{+}\text{-}K^{+}\text{ ATPase}$ pump?

$3$ sodium ($Na^{+}$) ions go out, and $2$ potassium ($K^{+}$) ions come in

What is the consequence of $Na^{+}\text{-}K^{+}\text{ ATPase}$ pump failure during cell injury?

$Na^{+}$ stays inside the cell, causing water influx and cellular swelling, known as hydropic change

What are myelin figures primarily composed of?

Myelin figures comprise phospholipid $>>>$ calcium

Where are myelin figures observed in terms of cell injury types?

They are seen in reversible cell injury (few) and irreversible cell injury (more enhanced)

How do myelin figures appear under electron microscopy?

Lamellated concretions