NR-283 Pathophysiology - Set 3 - Part 3

Correct Answer: Hemothorax with blood in the pleural space

Blood layering in the pleural space blocks sound transmission, so percussion is dull and breath sounds fade. Losing that blood from the circulation explains the low pressure, fast pulse and cool skin. Option a is incorrect because air trapped against the chest wall gives a hyperresonant drum like note on percussion. Percussion is the finding that separates these two injuries at the bedside. Option b is incorrect because a free floating rib segment declares itself by moving inward on inspiration and outward on expiration. That visible paradox is missing from this description entirely. Option d is incorrect because bruised lung tissue shows up as patchy infiltrate with worsening hypoxemia over a day or two, and it does not by itself produce shock or a dull percussion note.

Correct Answer: Alveolar dead space, wasted ventilation

Ventilation without perfusion is dead space. Emphysema destroys the septa and the capillaries running through them, so these enlarged spaces still take in air while having no blood available for exchange. Option a is incorrect because an anatomic shunt routes venous blood around the alveoli entirely, adding desaturated blood to the arterial side. Emphysema does the reverse by losing the vessels rather than bypassing them. Option c is incorrect because a low ratio means air delivery has fallen while blood flow continues, which is the picture in chronic bronchitis. Here the airflow is preserved and the circulation is gone. Option d is incorrect because diffusion limitation requires blood on the far side of a barrier that is too thick or too small. Loss of the capillary bed removes the blood, not just the surface.

Correct Answer: A long standing cigarette smoking habit

Smoking is the single most powerful modifiable contributor to atherosclerosis, injuring endothelium, oxidizing lipid, lowering protective lipoprotein, and activating platelets. Risk falls substantially within one to two years of quitting, so the behavior is worth targeting. Option a is incorrect because inherited susceptibility cannot be altered by any behavior change. A relative with premature disease raises the client's baseline risk and guides how aggressively other factors are treated. Option b is incorrect because years lived accumulate regardless of treatment, placing age firmly in the non modifiable column. Risk does climb steeply after middle life, but nothing the client does will reverse that clock. Option d is incorrect because sex is fixed at birth and sits alongside age and heredity among the unchangeable factors. Men do carry higher early risk, yet that observation offers no target for intervention.

Correct Answer: Normal troponin with ST depression during pain

Stable angina is reversible ischemia from a fixed stenosis, so no myocytes die and troponin stays normal. During the episode the tracing typically shows ST depression or T wave inversion that resolves as the pain settles. Option a is incorrect because a rising troponin with sustained ST elevation means a fully occluded vessel and transmural necrosis. Pain that stops within minutes of rest is incompatible with an artery that stayed closed. Option b is incorrect because pathologic Q waves are the electrical footprint of dead muscle, and they persist for life. This client has predictable, brief, exertional symptoms with no evidence of completed necrosis. Option c is incorrect because sustained ST elevation with normal markers does not match a demand driven syndrome. Transient elevation that fully reverses points instead toward coronary spasm occurring at rest, usually overnight.

Correct Answer: The injury happened several days ago

Troponin stays elevated for roughly seven to fourteen days after myocyte death, while creatine kinase MB clears within two to three days. Elevated troponin with a normalized MB fraction therefore dates the injury to several days earlier. Option a is incorrect because fresh necrosis would push the MB fraction up as well, since it rises about four hours in and peaks near the first day. A normal value argues against ongoing damage. Option c is incorrect because troponin does not leave the myocyte unless the cell membrane has failed. A raised level is proof that muscle died, even though the event is now well behind the client. Option d is incorrect because troponin is the marker specific to cardiac muscle; myoglobin is the one that skeletal injury releases. Confusing the two reverses the whole reason troponin became the diagnostic standard.

Correct Answer: Aspiration of gastric contents into dependent segments

Impaired swallowing plus supine feeding lets oropharyngeal and gastric material enter the airway, and gravity carries it down the more vertical right main bronchus into the right lower lobe. Option b is incorrect because blood borne seeding scatters multiple small nodular lesions through both lungs, usually in clients with endocarditis or an infected catheter, not one lobe in a client who is being fed. Option c is incorrect because reactivation of walled off tubercle bacilli favors the apical and posterior upper lobes, develops over weeks with night sweats and weight loss, and follows immune suppression rather than feeding. Option d is incorrect because viral spread produces a diffuse illness with systemic symptoms and scattered interstitial change on imaging. A single dependent lobe consolidating in a client with dysphagia points to inhaled material.

Correct Answer: Rising pleural pressure compressing the great veins

Air enters the pleural space through a one way flap and cannot leave, so pressure climbs above atmospheric. The mediastinum shifts, the great veins kink, venous return drops and cardiac output collapses. Option a is incorrect because arterial bleeding into the chest would give dullness to percussion over blood rather than the hyperresonant note of trapped air, and it would flatten the neck veins. Option b is incorrect because a pump that suddenly stops squeezing backs blood into the lungs and produces crackles with frothy sputum. Here the ventricle is simply not being filled. Option c is incorrect because pain driven vasodilation warms the skin and empties the neck veins, the reverse of what is seen. Engorged veins point to a mechanical block on filling.

Correct Answer: Compensatory shock with pressure still being defended

Baroreceptor driven sympathetic outflow raises the rate, respiration blows off acid, and blood is diverted from the kidney. Pressure holds because compensation is working, which makes this the window where reversal is still possible. Option a is incorrect because a steady pressure proves only that compensation has not yet failed. Blood pressure is defended until roughly a third of the circulating volume is gone, so it lags far behind the trouble. Option b is incorrect because the refractory stage brings unresponsive hypotension, mottled cold skin and failure of several organ systems at once. This client still holds a normal pressure and remains salvageable. Option d is incorrect because pain and worry do not shut down urine production. Falling output signals that renal blood flow has been sacrificed to protect the brain and heart, which is a perfusion failure.

Correct Answer: Hemoglobin releases oxygen more readily to cells

A rightward shift lowers hemoglobin affinity, so oxygen comes off more easily where heat, acid and carbon dioxide are highest. That is exactly the tissue doing the most metabolic work. Option b is incorrect because tighter binding describes a leftward shift, driven by cold, alkalosis, low levels of the red cell phosphate, stored blood and carbon monoxide. Fever and acid push the opposite direction. Option c is incorrect because a higher saturation at the same oxygen tension is the graphic signature of a left shift, where the curve sits above its normal position. The right shift lowers saturation at every tension. Option d is incorrect because falling delivery with a reassuring saturation belongs to carbon monoxide poisoning and hypothermia, both of which hold oxygen on the molecule. Here the tissues receive more oxygen, not less.

Correct Answer: Small cell carcinoma arising near the hilum

Small cell tumors grow from neuroendocrine cells in the central airways, almost always in smokers, and they spread widely very early. That behavior is why treatment is chemotherapy and radiation rather than resection. Option a is incorrect because glandular tumors sit out at the lung periphery, are the commonest type in people who never smoked, and grow from mucus producing cells rather than neuroendocrine ones. Option c is incorrect because squamous lesions also sit centrally and cause hemoptysis, yet they follow squamous change in bronchial lining, tend to hollow out, and lack the neuroendocrine origin described. Option d is incorrect because mesothelioma grows from the pleural lining after asbestos exposure and encases the lung as a rind. It is not a bronchial tumor and has no link to tobacco.