NR-283 Pathophysiology - Set 3 - Part 2

Correct Answer: The oral mucosa and the tongue

Central cyanosis reflects arterial desaturation and shows in warm, well perfused mucous membranes. The tongue and oral mucosa are dependable in every skin tone, while peripheral sites can look blue from cold alone. Option a is incorrect because nail beds discolor whenever flow through the digits slows, which happens with cold or vasoconstriction in a client whose arterial saturation is perfectly adequate. That finding is peripheral, not central. Option b is incorrect because ears and the nose sit at the far end of the circulation and cool quickly, so they turn dusky from sluggish flow with increased extraction rather than from arterial desaturation. Option c is incorrect because chest skin carries pigment that masks color change, and cyanosis is judged by capillary blood rather than by epidermis. Palms and soles serve better when mucous membranes cannot be seen.

Correct Answer: The high oxygen tension favoring this aerobic organism

Tubercle bacilli are strict aerobes, and the apical and posterior upper lobe segments carry the highest oxygen tension in the lung. Reactivating organisms multiply best there and hollow out cavities. Option b is incorrect because gravity sends most pulmonary blood flow to the bases in an upright person, so perfusion is actually lowest at the apices where reactivation disease concentrates. Option c is incorrect because lymphatic clearance is not what selects the site. Primary infection lands in the well ventilated lower and middle zones, and the shift upward on reactivation tracks oxygen availability. Option d is incorrect because membrane thickness is uniform across healthy lung and governs diffusion rather than bacterial growth. Where an organism thrives depends on its metabolic needs, not on how thin the barrier is.

Correct Answer: Shunt, perfusion without any ventilation

Blood keeps flowing past alveoli that hold no air, so it returns to the left heart still unoxygenated. Added oxygen never reaches those units, which is why raising the concentration fails. Option a is incorrect because dead space describes alveoli that receive air but no blood, so there is nothing for the gas to exchange with. That pattern usually improves once supplemental oxygen is applied. Option b is incorrect because a thickened membrane slows transfer through an alveolus that is still open and still ventilated. Fibrosis behaves that way, and its hypoxemia does respond when inspired oxygen is raised. Option d is incorrect because depressed drive would raise carbon dioxide across the whole lung rather than leave one lobe airless. The collapsed lobe here points to a local airway blockage instead.

Correct Answer: A viral upper respiratory infection

Viral infection of the upper airway is the commonest precipitant of childhood exacerbations, with rhinovirus and respiratory syncytial virus leading. Irritant receptors fire, inflammation intensifies, and the hyperresponsive airway narrows sharply. Option b is incorrect because weather fronts matter mainly through the cold dry air they bring, which is a lesser and less consistent trigger. Pressure itself does not act on bronchial smooth muscle. Option c is incorrect because indoor carbon dioxide levels in an ordinary classroom stay far too low to provoke bronchospasm. Dust mites, animal dander and tobacco smoke carried on clothing are the genuine indoor culprits. Option d is incorrect because sunlight has no role in the list of recognized precipitants. Exercise, cold air, aspirin, strong odors, stress and reflux appear on that list, and none of them involves light.

Correct Answer: "Leftover organisms can trigger antibodies that later attack the heart valves."

Rheumatic fever is immune mediated. Antibodies raised against streptococcal M protein cross react with valve tissue weeks after the throat clears, so eradicating every organism is what prevents the later carditis. Option a is incorrect because pneumonia is not the feared sequel of untreated pharyngitis. The complication that shapes this teaching is delayed valve damage appearing two to four weeks after the throat infection. Option b is incorrect because the organism is long gone from the body by the time carditis appears. Damage comes from cross reacting antibodies and T cells, not from bacteria burrowing into leaflets. Option c is incorrect because resistance is a genuine concern generally, yet group A streptococcus has stayed reliably sensitive to penicillin. Completing therapy here is aimed squarely at preventing an immune mediated sequel.

Correct Answer: Viral inflammation and injury of the myocardium

Myocarditis follows a viral prodrome by days to weeks. Direct injury plus the immune attack on infected myocytes releases troponin and creates electrical instability, so it mimics infarction in a young person with normal coronaries. Option a is incorrect because infarction demands an occluded coronary artery, and this client's vessels were clean on angiography. Without obstruction there is no ischemic territory to explain the troponin release. Option c is incorrect because rheumatic disease follows a sore throat rather than an influenza like illness, and it announces itself with migratory joint pain, rash and a new murmur. None of that appears here. Option d is incorrect because that genetic disorder produces exertional syncope and a murmur that grows louder with standing or straining. It also carries no viral prodrome and does not typically raise troponin.

Correct Answer: Obstructed right ventricular outflow limiting left sided filling

The clot blocks the outflow path of the right ventricle, which cannot generate high pressure acutely. It dilates, the septum bows leftward, left ventricular filling falls, and obstructive shock follows. Option a is incorrect because fluid moving into alveoli describes pulmonary edema, which would fill the lungs with crackles and frothy secretions. The neck veins here are distended by a pressure barrier, not by lost volume. Option b is incorrect because a failing left ventricle backs blood into the lungs first, giving crackles and pink froth before systemic congestion appears. Here the obstruction sits upstream of the left heart entirely. Option c is incorrect because widespread vasodilation describes distributive shock from sepsis or anaphylaxis, where the skin is warm and neck veins are flat. This client is cold with engorged veins.

Correct Answer: Systemic vascular resistance falls in one and rises in the other

Mediators in sepsis dilate the vessels, so resistance collapses and warm blood reaches the skin. Hemorrhage instead triggers intense sympathetic vasoconstriction, which shunts flow away from the skin and leaves it cold and moist. Option b is incorrect because thermoregulatory failure describes poikilothermia after a high spinal cord injury. Septic warmth comes from blood redirected to dilated cutaneous vessels, not from a broken thermostat. Option c is incorrect because hemoglobin level governs oxygen carrying capacity and pallor, not the warmth of the skin. A profoundly anemic client whose vessels are dilated would still feel warm to touch. Option d is incorrect because sweat glands stay structurally intact during sepsis. Dryness there simply reflects the absence of the sympathetic surge that makes a hemorrhaging client diaphoretic, so no gland damage is involved.

Correct Answer: The first has emphysema, the second bronchitis

Alveolar destruction with lost recoil produces the thin, pink, pursed lip breather with a barrel chest. Airway centered mucus disease produces the cyanotic, edematous cougher who retains carbon dioxide early. Option a is incorrect because the labels sit the wrong way round. Pursed lips and a barrel chest come from destroyed elastic tissue, while copious sputum with right sided fluid overload comes from inflamed mucus filled airways. Option c is incorrect because emphysema does not generate copious daily sputum or early cyanosis, and gas exchange holds up until very late. The second client shows exactly what emphysema does not produce. Option d is incorrect because chronic bronchitis rarely wastes a client down to a barrel chested pursed lip breather with acceptable gases. Retention of carbon dioxide and weight gain define that column instead.

Correct Answer: Intimal tear splitting the layers of the aorta

Aortic dissection begins when the intima tears and blood forces its way into the media, creating a false lumen. The propagating tear explains tearing pain and unequal arm pressures as branch vessels are compromised. Option a is incorrect because an abdominal aortic aneurysm usually sits silent until it ruptures, and then the pain is abdominal or flank with hypotension and a pulsatile mass. Arm pressures stay equal. Option b is incorrect because berry aneurysms sit at the circle of Willis, and rupture floods the subarachnoid space. Clients describe the worst headache of their life, not interscapular pain with pulse differences. Option d is incorrect because a false aneurysm follows a puncture or anastomotic leak and is walled off by surrounding tissue and clot. This client had no vascular procedure and no local swelling.

Correct Answer: A faulty chloride channel dehydrating the airway surface

The defective transporter cannot secrete chloride, and sodium is over absorbed instead. Water follows the sodium inward, the thin fluid layer around the cilia dries out, and secretions become too viscous to clear. Option b is incorrect because loss of an antiprotease shield is the story in alpha one antitrypsin deficiency, where unopposed elastase digests alveolar walls. That produces early emphysema, not sticky mucus in the bronchi. Option c is incorrect because cystic fibrosis is inherited rather than autoimmune, and no antibody attacks the epithelium. The cilia in this child are structurally normal and simply cannot budge secretions that thick. Option d is incorrect because mast cell crowding drives allergic bronchospasm and belongs to the immediate phase of asthma. Nothing about a salt transport failure depends on histamine release from those cells.

Correct Answer: Pressure cannot be felt, so dosing must be daily

Hypertension is called the silent killer because arterioles carry no pain receptors and a wall thickening slowly generates no sensation. Damage proceeds while the client feels well, so treatment is taken on schedule rather than by symptom. Option a is incorrect because headaches arise from countless causes and correlate poorly with any given reading. Early morning headache shows up only in severe or long standing disease, far too late to steer daily decisions. Option b is incorrect because most clients feel entirely well while the left ventricle thickens and the glomeruli scar. The first perceptible event is often a stroke or an infarct rather than a warning sensation. Option c is incorrect because a normal reading on therapy means the drug is working, not that the disease resolved. Stopping abruptly invites rebound elevation and can precipitate angina or a crisis.

Correct Answer: Secondary bacterial pneumonia after epithelial damage

Influenza strips ciliated epithelium and disables the mucociliary escalator, leaving the lung open to staphylococci and pneumococci. The classic clue is a client who recovers and then suddenly worsens. Option a is incorrect because drift refers to small yearly mutations that force annual reformulation of the vaccine. It explains seasonal epidemics across a population, not a purulent relapse inside one client. Option b is incorrect because a drug reaction would bring rash, eosinophilia or organ inflammation rather than purulent sputum with a focal shadow on the chest film pointing to bacteria in one region. Option d is incorrect because scarring takes weeks to months and shows as progressive stiffness with a dry cough. Fibrosis does not announce itself with sudden fever and thick purulent secretions.

Correct Answer: Macrophages engulfed oxidized lipid through scavenger receptors

Oxidized low density lipoprotein crosses injured endothelium and is taken up by macrophages through unregulated scavenger receptors. With no feedback to stop the uptake, the cells fill with fat droplets and become foam cells. Option a is incorrect because collagen secretion by migrated smooth muscle cells builds the fibrous cap of a mature plaque, a much later step. A fatty streak contains no organized fibrous tissue yet. Option c is incorrect because platelet adhesion requires a breach that exposes subendothelial collagen to flowing blood. That belongs to the ruptured, complicated lesion, and it produces thrombus rather than lipid laden cells. Option d is incorrect because the cap over an atheroma is built by smooth muscle cells that migrate in from the media, not by fibroblasts. Cap formation also comes long after the streak appears.

Correct Answer: Loss of the atrial kick reducing ventricular filling

Fibrillating atria quiver instead of contracting, so the final push that tops off the ventricle is gone. A stiff chamber depends on that contribution, and a fast rate steals filling time as well. Option b is incorrect because a silent sinus node would let a slower junctional or ventricular escape rhythm take over. That produces bradycardia with regular complexes, not the fast chaotic pattern described. Option c is incorrect because a torn papillary muscle follows infarction and floods the lungs within minutes through severe mitral leak. No ischemic event preceded this episode, and the trigger named was a rhythm change. Option d is incorrect because infranodal block strands the ventricles on a slow wide escape beat, giving syncope and profound bradycardia. Atrial fibrillation conducts irregularly through the node rather than stopping there.

Correct Answer: Renin rises, angiotensin narrows vessels, aldosterone holds sodium

Reduced renal perfusion triggers renin release, which converts angiotensinogen toward angiotensin two. That peptide constricts arterioles and drives aldosterone secretion, so sodium and water are retained. Resistance and volume both climb, and pressure rises. Option a is incorrect because low perfusion at the kidney stimulates renin rather than suppressing it. Falling angiotensin with dilated vessels would drop the pressure, which is the opposite of what a narrowed renal artery produces. Option b is incorrect because angiotensin two stimulates the adrenal cortex to pour out aldosterone, so the hormone climbs. Sodium is then held back in the distal tubule, expanding volume instead of contracting it. Option c is incorrect because natriuretic peptides act as a brake on this system, released when the atria and ventricles are stretched by volume overload. They oppose the pressure rise here rather than causing it.

Correct Answer: Mycoplasma pneumoniae producing interstitial inflammation

The gradual onset, dry cough, prominent headache and myalgia, and imaging that outruns the physical findings in a young person in shared housing all point to Mycoplasma, an atypical pathogen. Option a is incorrect because pneumococcal disease begins abruptly with shaking chills, high fever, rust colored sputum and a dense lobar shadow that matches the dullness and bronchial sounds found on examination. Option c is incorrect because Klebsiella typically strikes debilitated adults with alcohol use disorder, producing thick red currant jelly sputum and destructive upper lobe disease rather than a mild illness in a healthy student. Option d is incorrect because Pseudomonas is a hospital organism that infects ventilated or chronically ill clients. Nothing in this history places the student in a healthcare setting where such resistant bacteria circulate.

Correct Answer: Stagnant blood in the atrial appendage forms clots

Without organized contraction, blood pools in the left atrial appendage. Stasis, an injured atrial lining and a clot prone local milieu satisfy Virchow's triad inside the heart, and the resulting thrombus can embolize to the brain. Option a is incorrect because rhythm drugs such as amiodarone alter conduction and repolarization without touching the clotting cascade. Anticoagulants are added precisely because those agents leave thrombus risk untouched. Option b is incorrect because beta blockers and calcium channel blockers slow conduction through the node and do not scar arterial walls. The danger in this rhythm sits inside the left atrium, not in the arteries. Option d is incorrect because consumption of clotting factors describes disseminated intravascular coagulation, a different disorder entirely. Clients in this rhythm clot too readily rather than bleeding, which is why thinning the blood helps them.

Correct Answer: Ectopic antidiuretic hormone secreted by tumor cells

Small cell tumors release antidiuretic hormone without feedback control, so the kidney retains free water. Sodium is diluted, the urine stays concentrated, volume looks normal, and confusion follows the falling sodium. Option b is incorrect because that peptide mimics parathyroid hormone and drives calcium out of bone, raising serum calcium. It belongs to squamous tumors and would not pull the sodium level down. Option c is incorrect because antibodies against those channels block acetylcholine release and cause proximal weakness that improves with repeated effort. Muscle strength, not water balance, is what suffers in that syndrome. Option d is incorrect because excess cortisol production raises glucose and blood pressure while dropping potassium, and it wastes muscle. Sodium tends to rise in that setting rather than fall to a dangerous level.

Correct Answer: It creates back pressure that splints airways open

Elastin loss removes the radial pull that normally holds small airways open, so they collapse during exhalation and trap air. Pursed lips raise pressure inside the airway and keep the passage open longer. Option a is incorrect because muscle strength is built through conditioning and rehabilitation over weeks, not through the shape of the lips. A hyperinflated chest actually flattens the diaphragm and weakens its pull. Option b is incorrect because surfactant comes from type two alveolar cells and its output is not altered by breathing technique. Slow exhalation changes pressure in the airway, leaving cellular secretion untouched. Option c is incorrect because the destroyed alveolar walls cannot be regrown, and surface area lost to emphysema stays lost. Pursed lip breathing improves emptying of air, not the size of the exchange membrane.