Pathoma: Chapter 1. Cell Adaption & Injury – Medical School Pathology Summary, Notes, Practice Test Questions and Answers

In this easy-to-understand lesson, we summarize important notes from Pathoma’s Chapter 1. Cell Adaption and Injury. This lesson also includes main summary, note points, practice exam/test questions, and answers for fellow medical school students learning pathology. Happy learning!

Pathoma: Chapter 1. Cell Adaption & Injury – Medical School Pathology Summary and Notes

Hyperplasia vs Hypertrophy

Hypertrophy = involves gene activation, protein synthesis, and production of organelles

Hypertrophy = SIZE CHANGE

Hyperplasia = Number of cells CHANGE

Example of Hypertrophy = Cardiac hypertrophy

Example of Hyperplasia = Benign prostate hyperplasia (BPH)

What is an example of where hyperplasia CANNOT progress to cancer?

Answer: BPH or benign prostate hyperplasia (note: it has benign in it! so cannot become cancer)

Benign hyperplasia (Ex: BPH) vs Pathologic Hyperplasia

Pathologic Hyperplasia Examples: 1) Endometrial hyperplasia –> that can progress to dysplasia and cancer

What’s the mechanism by which cellular components are degraded?

Answer: Autophagy

Decrease in cell size occurs via: 1) ubiquitin proteosome degradation of cytoskeleton or 2) autophagy of cellular components

What type of epithelium is present in Barrett’s esophagus?

Answer: Columnar mucinous non-ciliated epithelium (A healthy esophagus is supposed to have squamous epithelium –> but barret’s = columnar epithelium)

What is Metaplasia?

Metaplasia = reprogramming of stem cells, REVERSIBLE with removal of the stressor

Example of metaplasia = GERD (because it is reversible once treated)

Is metaplasia reversible?

Answer: yes!

What is the mechanism of action of metaplasia?

Answer: Reprogramming of stem cells

Example of Metaplasia not predisposing to cancer? –> Apocrine metaplasia (Associated with fibrocystic changes of breast)

Can Metaplasia progress to dysplasia and cancer?

Answer: yes, metaplasia can progress to dysplasia and cancer. Examples include Barrett esophagus. EXCEPT apocrine metaplasia.

Corneal metaplasia = from lack of vitamin A

What is dysplasia?

Dysplasia = reversible with alleviation of inciting stress

If stress persists, dysplasia progresses to carcinoma

Carcinoma = Cancer = Irreversible

What is hypoplasia?

Hypoplasia = decrease of number of cells (lack of cells in an organ or tissue)–> Streak ovary in Turner syndrome

Hypoxia = low oxygen delivery to issue

Ischemia = decreased blood flow through an organ

In Budd-Chiari syndrome, there is a thrombosis of <<<HEPATIC VEIN>>>>

What is the most common cause of Budd-Chiari syndrome?

Answer: Polycythemia vera

Hypoxemia vs Methemoglobinemia

Hypoxemia = Low partial pressure of O2 in blood

The earliest sign of carbon monoxide poisoning is…

Answer: Headache; other classic findings == cherry red appearance of skin , can lead to coma and death

Oxygen can only bind hemoglobin if the iron is in the Fe{{c7::2}}+ state

Methemoglobinemia = Iron in heme is oxidized to Fe3+ –> which cannot bind O2

PaO2 normal // SaO2 decreased

Why are newborns particularly vulnerable to methemoglobinemia?

Answer: Low methemoglobin reductase activity}}

Chocolate-colored blood suggests:


Treatment for methemoglobinemia = IV methylene blue

MOA of IV Methylene blue = helps reduce Fe3+ back to –> Fe2+

What happens to the GI absorptive surface are in the setting of ischemia?

Answer: Decreases

Initial phase of injury is reversible

-Hallmark = cellular swelling

-Leads to loss of microvilli, membrane blebbing, and swelling of RER

The decrease in protein synthesis which occurs during reversible cellular injury is due to:

Answer: RER swelling ⇒ Ribosome detachment}}

The hallmark of irreversible cellular injury is:

Answer: Membrane damage}}

Where is the electron transport chain located?

Answer: Inner mitochondrial membrane}}

In the setting of irreversible cellular injury, proteolytic enzymes are released from the:

Answer: :Lysosomes}}

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