| Course | NSG 120 Nursing Pathophysiology |
|---|---|
| Unit | Unit 1 |
| Paper type | Disease process summary |
| Length | About 900 words, 6 pages |
| Format | APA 7 student paper |
| School | Herzing University |
| Program | BSN |
| Updated | October 2026 |
Free sample paper for NSG 120 Unit 1
Trading Cilia for Toughness: Squamous Metaplasia of the Airway Lining in a Long-Term Smoker, and Where the Adaptation Stops Protecting
Student Name
Department of Nursing, Herzing University
NSG 120: Nursing Pathophysiology
Instructor Name
January 16, 2026
Trading Cilia for Toughness: Squamous Metaplasia of the Airway Lining in a Long-Term Smoker, and Where the Adaptation Stops Protecting
The Stressor and the Tissue Meeting It
The composite patient is a 52-year-old man who works as a warehouse supervisor and has smoked about a pack of cigarettes a day since he was 17. He has no diagnosis relevant to this summary. What matters is that for 35 years the lining of his large airways, the trachea and bronchi, has been exposed many times a day to hot smoke carrying irritant gases and particles.
Under normal conditions this lining is a pseudostratified ciliated columnar epithelium. In plain terms, it is a single layer of tall cells, many of them carrying cilia, hair-like projections that beat in coordinated waves, with mucus-producing goblet cells scattered among them. The mucus traps particles and microbes, and the cilia sweep that mucus up toward the throat, where it is swallowed or coughed out. This system, called the mucociliary escalator, is the airway's main cleaning mechanism. It is also delicate: the ciliated cells are easily damaged by heat and chemicals.
The Adaptive Response: Metaplasia
The adaptation this tissue makes is called metaplasia: one kind of fully developed cell is replaced by a different fully developed kind that is better able to withstand the stress. A classmate could say it like this: the airway swaps its fragile, specialized cells for tougher, plainer ones. In the smoker's bronchi, patches of ciliated columnar cells are replaced by stratified squamous epithelium, several layers of flat cells similar to the lining of the mouth or esophagus. The change does not happen because a mature ciliated cell turns into a squamous cell. Instead, the basal stem cells of the airway, under repeated injury and chemical signals, begin producing squamous cells rather than columnar ones (Rogers, 2023).
The squamous layer is protective in one narrow sense: it tolerates irritation far better than the ciliated lining did. Alongside it, the number of goblet cells and the size of the submucosal glands usually increase, so more mucus is produced. That is also an adaptation, since more mucus traps more particles.
Where Adaptation Stops Protecting
The boundary this unit is built around falls in two places, and it helps to keep them separate.
The first is a cost built into the adaptation itself. Squamous cells have no cilia. Where metaplasia has occurred, the escalator has stopped working, while mucus production has gone up. Smoking also damages the cilia on the columnar cells that remain, shortening them and slowing their beat (Tilley et al., 2015). The result is more mucus and less ability to move it. At this stage, nothing in the cells is injured in the sense the course uses; the metaplastic cells are healthy squamous cells doing what squamous cells do. But the tissue as a whole now protects the lung less well. This is where the adaptation gives out as a defense, even though it has not yet caused injury.
The second place is where adaptation gives way to disordered growth. With continued exposure, some metaplastic areas develop dysplasia: cells that vary in size and shape, have enlarged and irregular nuclei, and lose their orderly layering. Dysplasia is no longer an adaptation. It is an abnormal change that can progress to cancer. A landmark autopsy study of bronchial epithelium found that changes such as loss of cilia, basal cell hyperplasia, and atypical cells were far more common in smokers than in nonsmokers and increased with the amount smoked (Auerbach et al., 1961).
Metaplasia itself is considered reversible. If the stressor is removed, the airway can gradually return to a ciliated columnar lining. Dysplasia may also regress, but the further along the change, the less reliably it does. Reversibility is therefore the practical line between an adaptation and something worse.
What a Nurse Would See or Record
Each finding below is attached to the step above that explains it.
A productive cough, worse on waking, with gray or clear sputum: more mucus from enlarged glands and goblet cells, and no escalator to clear it overnight, so it is coughed out in the morning.
Frequent chest colds that last longer than those of his coworkers: trapped mucus and slowed clearance give microbes more time in the airway.
Crackles or rhonchi that change after coughing: mucus sitting in the larger airways and shifting when it is coughed.
A smoking history recorded in pack-years, here 35: the dose of the stressor, which matters because the changes grow with exposure.
None of these findings shows metaplasia directly. Metaplasia is a tissue finding seen under a microscope. The findings are the consequences of the adaptation's cost, which is why they appear in this summary and why no diagnosis does.
Readings Checked
The description of airway epithelium and metaplasia follows the course pathophysiology text (Rogers, 2023). The effects of smoke on cilia follow Tilley et al. (2015). The historical evidence for the progression from metaplasia to atypical changes follows Auerbach et al. (1961). Texts place the boundary between adaptation and injury slightly differently: some treat metaplasia as the last protective adaptation and dysplasia as the first abnormal change, while others describe the loss of ciliary clearance itself as an early form of injury to the tissue. This summary uses the first placement for the cells and records the second as the point where the tissue stops protecting the lung.
References
Auerbach, O., Stout, A. P., Hammond, E. C., & Garfinkel, L. (1961). Changes in bronchial epithelium in relation to cigarette smoking and in relation to lung cancer. New England Journal of Medicine, 265(6), 253-267. https://doi.org/10.1056/NEJM196108102650601
Rogers, J. L. (Ed.). (2023). McCance & Huether's pathophysiology: The biologic basis for disease in adults and children (9th ed.). Elsevier.
Tilley, A. E., Walters, M. S., Shaykhiev, R., & Crystal, R. G. (2015). Cilia dysfunction in lung disease. Annual Review of Physiology, 77, 379-406. https://doi.org/10.1146/annurev-physiol-021014-071931
NSG 120 Unit 1 instructions, in plain terms
Unit 1 asks you to summarize a disease process at the cellular level and connect it to what a nurse would observe. Expect to describe the stressor and tissue, explain the adaptive response, show where adaptation stops protecting and link findings to mechanisms. Many versions ask whether you can write this without hospital experience; you can, using the course text and a composite patient. Check whether your section wants a real condition or allows a process studied on its own. Keep the explanation in plain language with the key terms defined. Each finding should be attached to the step that causes it, rather than listed separately. Cite the course pathophysiology text and at least one primary or review source. Keep the patient composite and unidentifiable. A diagram is optional but can help the reader follow the sequence. Stay within the length your section sets.
Inside the NSG 120 Unit 1 example
The summary opens with the patient and the stressor, linking smoking history to the airway lining. The adaptation section defines metaplasia and explains why squamous cells resist smoke better while losing cilia and mucus function. The boundary section is the summary's core, separating two points where protection ends: loss of clearance, which causes infections and cough, and progression toward dysplasia, which is the step toward cancer. The findings section lists observations, such as a productive morning cough and frequent chest infections, each tied to a mechanism above. The readings section names the sources used. The structure keeps cause and finding together, which is what the unit asks students to practice. Plain language with defined terms makes the summary readable for a classmate who has not studied the topic yet.
Where the points sit in the NSG 120 Unit 1 rubric
Herzing's rubric for a disease process summary usually covers accuracy of the cellular mechanism, explanation of adaptation, identification of where adaptation fails, the link between mechanisms and findings, sources and writing. Accuracy of the mechanism draws the closest reading, since graders check terms such as metaplasia and dysplasia carefully. Adaptation points reward a clear explanation of why the change helps at first. Failure criteria look for the point where protection ends. Finding points go to observations tied to the step that causes them. Sources should include the course text. Plain language with defined terms helps the writing score. A logical sequence from stressor to finding is often credited. Patient privacy is expected. Rogers's McCance and Huether text and Auerbach's study belong in the APA 7 list.
NSG 120 Unit 1 help: mistakes that cost points
Disease summaries in Unit 1 often slip by defining terms without explaining the sequence from stressor to finding. Another frequent problem is confusing metaplasia with dysplasia, which changes the meaning of the boundary. Students often list findings without linking each to a mechanism. The point where adaptation stops protecting is missing. Sources are limited to websites. Jargon is used without definitions. The patient is described too vaguely to anchor the summary. The paper drifts into treatment, which the unit does not ask for. Diagrams, if used, are unlabeled. Finally, attach each finding to its cause, because graders reward a summary where a reader can trace every observation back to a specific step in the process.
Get a NSG 120 Unit 1 example written to your instructions
Send the Unit 1 instructions and the rubric from your NSG 120 classroom, and tell us which stressor the assignment starts from. We write a custom example that names the stressor concretely, keeps adaptation ahead of injury, marks where protection ends and attaches every finding to a step. First custom sample free, back in 24 to 48 hours.
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NSG 120 Unit 1 questions, answered
I have never worked in a hospital. Can I still write this?
Yes, and the unit is built on the assumption that you have not. Nothing in the summary asks you to have seen the process happen; it asks you to explain it and to say what a nurse would then be watching for. The composite patient exists precisely so you can describe findings without borrowing anybody from a placement site.
Does the summary need a real condition, or can the process stand alone?
Most sections want the process anchored to a condition, since the findings only make sense once the tissue is named. What the summary should avoid is letting the condition carry the explanation. Two paragraphs of definition and one sentence of mechanism tends to score poorly, while a modest condition traced properly through to observable findings usually reads well.
What do I do when my textbook and my lecture disagree?
Write down both and say which one the summary follows and why. Course materials place some boundaries differently, and a paper that shows it noticed reads as more careful than one asserting a single line. Check the reading list your section supplies before you commit, and cite the source you actually used rather than the one you remember.
Where can I find a free NSG 120 Unit 1 sample paper?
The full NSG 120 Unit 1 squamous metaplasia summary is free on this page, from the stressor to where adaptation stops and the findings it explains. A summary of a different adaptation can be written on request.
What is squamous metaplasia in smokers?
It is the replacement of the airway's ciliated cells with tougher squamous cells in response to smoke. The change resists irritation but loses mucus clearance, and it can progress toward dysplasia, as this sample explains.