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HS 323 study materials
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HS 323 practice questions

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Question 1Foundations of health sciences practice and professional standards

A patient's blood pressure is recorded as 118/76 mmHg. According to standard blood pressure classification for adults, how should this reading be categorized?

  1. Elevated
  2. Normal Correct answer.
  3. Stage 1 hypertension
  4. Stage 2 hypertension

Explanation

Adult blood pressure classification holds that a systolic value below 120 mmHg together with a diastolic value below 80 mmHg is normal. A reading of 118/76 therefore falls within the normal range on both components.

Question 2Foundations of health sciences practice and professional standards

A health sciences professional is told to apply the principle of beneficence when planning care. Which action best demonstrates this principle?

  1. Actively promoting the patient's welfare and well-being Correct answer.
  2. Distributing limited resources equally among all patients
  3. Documenting a patient's refusal of treatment accurately
  4. Allowing the patient to make an informed choice without pressure

Explanation

Beneficence obligates the professional to act in ways that promote the patient's good and welfare. It is a positive duty to advance well-being, distinct from duties to avoid harm, to be fair, or to respect autonomy.

Question 3Foundations of health sciences practice and professional standards

A researcher wants to test whether a new hand-hygiene protocol reduces hospital-acquired infection rates. Which study design provides the strongest evidence for a causal claim?

  1. A single-site descriptive study
  2. A randomized controlled trial Correct answer.
  3. A cross-sectional survey of staff attitudes
  4. A retrospective case series

Explanation

Randomized controlled trials reduce selection bias and confounding by allocating participants by chance, which supports causal inference. Observational and descriptive designs can suggest associations but cannot establish causation as strongly.

Question 4Foundations of health sciences practice and professional standards

Which organization publishes the global reference classification of diseases, injuries, and causes of death used for health statistics?

  1. National Institutes of Health
  2. World Health Organization Correct answer.
  3. Joint Commission
  4. Centers for Disease Control and Prevention

Explanation

The World Health Organization maintains the International Classification of Diseases, the global standard for morbidity and mortality coding. Other bodies produce national guidance or accreditation standards but do not own this international classification.

Question 5Foundations of health sciences practice and professional standards

A colleague repeatedly arrives late for shared clinical shifts, leaving others to cover duties. Which professional standard is most directly breached?

  1. Confidentiality
  2. Accountability Correct answer.
  3. Informed consent
  4. Cultural competence

Explanation

Accountability means accepting responsibility for one's commitments and the consequences of one's actions, including reliable attendance and coverage of assigned duties. Chronic lateness shifts the burden to colleagues and breaches that duty.

Question 6Foundations of health sciences practice and professional standards

Which term describes a health care professional's legal duty to keep patient information private and disclose it only as authorized?

  1. Veracity
  2. Confidentiality Correct answer.
  3. Nonmaleficence
  4. Fidelity

Explanation

Confidentiality is the duty to protect patient information from unauthorized disclosure. It is grounded in both ethics and law and permits disclosure only with authorization or where the law requires it.

Question 7Foundations of health sciences practice and professional standards

During a sterile procedure, a clinician notices that a sterile glove has touched the edge of a non-sterile drape. What is the correct immediate action?

  1. Wipe the glove with an alcohol swab and proceed
  2. Replace the contaminated glove before continuing Correct answer.
  3. Ask the patient to confirm the glove looks clean
  4. Continue, because only the glove cuff was contaminated

Explanation

Any contact between a sterile field and a non-sterile surface breaks sterility, and the contaminated item must be replaced. Continuing would place the patient at risk of infection.

Question 8Foundations of health sciences practice and professional standards

Which of the following best describes the purpose of informed consent before a procedure?

  1. To protect the clinician from legal liability
  2. To confirm the patient has read the hospital brochure
  3. To ensure the patient authorizes care after understanding risks and alternatives Correct answer.
  4. To document that the patient agreed to the fee schedule

Explanation

Informed consent is an ethical and legal process ensuring the patient voluntarily authorizes care after receiving adequate information about risks, benefits, and alternatives. Its primary purpose is protecting patient autonomy, not shielding the clinician.

Question 9Foundations of health sciences practice and professional standards

A patient with limited English proficiency is being consented for surgery. Which approach best meets professional standards?

  1. Use a qualified medical interpreter and provide translated materials Correct answer.
  2. Have the patient sign first and explain afterward
  3. Use the patient's adult child to interpret the discussion
  4. Speak more slowly and loudly in English

Explanation

Professional standards require meaningful communication, which for limited-English patients means a qualified interpreter and translated materials. Relying on family members risks errors and conflicts of interest.

Question 10Foundations of health sciences practice and professional standards

A clinician is uncertain whether a specific disclosure of patient information is permitted. Which action reflects appropriate professional judgment?

  1. Consult the organization's privacy officer or legal counsel before disclosing Correct answer.
  2. Disclose the information and apologize later if challenged
  3. Withhold all information permanently regardless of legal requirements
  4. Ask a colleague in the hallway for an informal opinion

Explanation

When a disclosure decision is unclear, the professional standard is to use organizational resources such as the privacy officer or legal counsel before acting. This balances patient protection with legal obligations.

Question 11Foundations of health sciences practice and professional standards

A team is reviewing an incident in which a medication error reached a patient. Which approach best reflects a just-culture response?

  1. Require the reporter to identify colleagues who witnessed the event
  2. Suppress the report to avoid reputational damage
  3. Focus on system factors while holding individuals accountable for reckless behavior Correct answer.
  4. Discipline the individual who administered the medication without further review

Explanation

A just culture distinguishes honest error from reckless behavior, examining system contributors while retaining individual accountability for intentional or reckless acts. This encourages reporting and supports learning.

Question 12Foundations of health sciences practice and professional standards

Which statement correctly describes the relationship between a profession's scope of practice and its code of ethics?

  1. The code of ethics overrides licensure law whenever the two conflict
  2. Scope of practice defines legally permitted activities, while the code of ethics guides conduct within those activities Correct answer.
  3. Scope of practice applies only to physicians, while the code applies to all staff
  4. Scope of practice and the code of ethics are identical documents with the same legal force

Explanation

Scope of practice is defined in law and regulation and sets the boundaries of permitted activity, whereas the code of ethics articulates professional values and conduct expectations. The two are complementary but distinct.

Question 13Foundations of health sciences practice and professional standards

A health sciences student is asked to calculate the sensitivity of a screening test. Which definition is correct?

  1. The proportion of people without disease who test negative
  2. The proportion of positive tests that are truly diseased
  3. The proportion of all tested people who are diseased
  4. The proportion of people with disease who test positive Correct answer.

Explanation

Sensitivity is the probability of a positive test among those who truly have the disease, calculated as true positives divided by all diseased individuals. It reflects the test's ability to detect disease.

Question 14Foundations of health sciences practice and professional standards

A clinician suspects that a patient's symptoms are caused by an adverse drug reaction. Which action should be taken in addition to adjusting care?

  1. Report the reaction to the national pharmacovigilance system Correct answer.
  2. Wait for a second patient to experience the same reaction
  3. Publish the case on social media to warn the public
  4. Record it only in the patient's chart and take no further action

Explanation

Suspected adverse drug reactions should be reported to the national pharmacovigilance authority so that signals can be detected across populations. Chart documentation alone does not contribute to system-level surveillance.

Question 15Foundations of health sciences practice and professional standards

According to standard precautions, how should a health care worker treat a patient's blood and body fluids when the patient's infection status is unknown?

  1. Apply precautions only for patients with visible bleeding
  2. Use gloves only when the patient requests them
  3. Treat all blood and body fluids as potentially infectious Correct answer.
  4. Apply precautions only after laboratory confirmation

Explanation

Standard precautions require treating all blood and body fluids as potentially infectious regardless of known diagnosis. This protects workers and patients when infection status is unknown or undisclosed.

Question 16Foundations of health sciences practice and professional standards

A patient declines a recommended treatment after a thorough discussion. What is the most appropriate professional response?

  1. Transfer the patient to another clinician immediately
  2. Respect the decision, document the discussion, and continue to offer support Correct answer.
  3. Proceed with treatment because the clinician knows best
  4. Ask a family member to sign consent on the patient's behalf

Explanation

A competent patient has the right to refuse treatment, and the professional must respect that decision while documenting the discussion and maintaining the care relationship. Coercion or substitution of consent is inappropriate.

Question 17Foundations of health sciences practice and professional standards

Which measure is the most appropriate way to reduce the risk of transmitting pathogens via a clinician's hands between patients?

  1. Performing hand hygiene at the recommended moments of patient contact Correct answer.
  2. Relying on alcohol-based sanitizer only after visible soiling
  3. Wearing the same gloves for consecutive patients
  4. Changing gloves once per shift

Explanation

Hand hygiene at the World Health Organization's recommended moments is the single most effective measure for interrupting transmission between patients. Gloves are not a substitute for hand hygiene.

Question 18Foundations of health sciences practice and professional standards

A team member notices that a colleague appears impaired during a shift. Which action aligns with professional duty?

  1. Report the concern through the appropriate channel so patient safety is protected Correct answer.
  2. Document the concern and wait until the next scheduled review
  3. Confront the colleague publicly in front of patients
  4. Ignore the behavior to avoid conflict

Explanation

Professionals have a duty to protect patients by reporting suspected impairment through designated channels so that evaluation and support can occur promptly. Silence or delay risks harm.

Question 19Foundations of health sciences practice and professional standards

Which statement best describes the role of evidence-based practice in health sciences?

  1. It requires every decision to be supported by a randomized trial
  2. It relies solely on expert opinion and tradition
  3. It integrates the best available research with clinical expertise and patient values Correct answer.
  4. It excludes patient preferences from clinical decisions

Explanation

Evidence-based practice combines the best available research evidence, clinician expertise, and patient preferences and values. It is a triad, not reliance on any single element.

Question 20Foundations of health sciences practice and professional standards

A patient's record contains a documented allergy to penicillin. A prescriber orders a penicillin-class antibiotic. What is the most appropriate action?

  1. Clarify the order with the prescriber before administration Correct answer.
  2. Record the order without action
  3. Substitute a different antibiotic independently
  4. Administer the drug and monitor closely

Explanation

A documented allergy is a safety flag, and the professional should clarify the order with the prescriber before any administration. Independent substitution exceeds the professional's role in most settings.

Question 21Foundations of health sciences practice and professional standards

A researcher plans to enroll human participants and intends to publish the results. Which requirement is fundamental before enrollment begins?

  1. Obtaining a commercial sponsor's marketing approval
  2. Obtaining approval from an institutional review board or research ethics committee Correct answer.
  3. Registering a domain name for the study website
  4. Securing a journal acceptance letter in advance

Explanation

Research involving human participants requires prospective review and approval by an institutional review board or research ethics committee. This safeguards participants' rights and welfare before any enrollment.

Question 22Foundations of health sciences practice and professional standards

A screening program is evaluated and found to have high sensitivity but low specificity. What is the most likely consequence for the population screened?

  1. Many people without disease will be falsely reassured
  2. Many people without disease will test positive and require follow-up Correct answer.
  3. The test will accurately identify all healthy individuals
  4. Few people with disease will be missed and no follow-up will be needed

Explanation

Low specificity means the test produces many false positives among people without disease, generating unnecessary follow-up and anxiety. High sensitivity reduces false negatives but does not offset the false-positive burden.

Question 23Foundations of health sciences practice and professional standards

A clinician is asked to participate in a study where participation could influence care for their own patients. Which conflict-of-interest management approach is most appropriate?

  1. Disclose the conflict and recuse from decisions where it could bias care Correct answer.
  2. Delegate all care decisions to the study sponsor
  3. Proceed without disclosure because the clinician's judgment is reliable
  4. Ask patients to waive any concerns in writing

Explanation

Conflicts of interest are managed through transparency and, where needed, recusal from decisions that could be biased. Disclosure alone may be insufficient when the conflict directly affects patient care.

Question 24Foundations of health sciences practice and professional standards

A quality-improvement team finds that error rates differ by shift but not by individual clinician. Which interpretation is most defensible?

  1. A single clinician on one shift is responsible for all errors
  2. The variation is random and should be ignored
  3. System-level factors such as staffing or workload on different shifts likely contribute Correct answer.
  4. The finding proves the measurement tool is invalid

Explanation

When variation tracks shifts rather than individuals, system factors such as staffing levels, workload, and handoff patterns are plausible contributors. This pattern argues for system-level intervention rather than individual blame.

Question 25Foundations of health sciences practice and professional standards

A new diagnostic test is evaluated in a population with very low disease prevalence. Compared with a high-prevalence setting, how will positive predictive value most likely change, assuming sensitivity and specificity are unchanged?

  1. Positive predictive value will increase
  2. Positive predictive value will remain identical
  3. Positive predictive value will decrease Correct answer.
  4. Positive predictive value will equal sensitivity

Explanation

Positive predictive value depends on prevalence as well as sensitivity and specificity. As prevalence falls, a larger share of positive results come from healthy people, so positive predictive value decreases.

Question 26Foundations of health sciences practice and professional standards

A health sciences trainee is asked to describe the primary purpose of a professional code of ethics for a regulated health profession. Which statement best captures that purpose?

  1. It establishes the minimum legal penalties for malpractice claims.
  2. It guarantees that every clinical encounter will have a favorable outcome.
  3. It replaces the need for informed consent in routine procedures.
  4. It guides professional conduct and decision-making beyond what law alone requires. Correct answer.

Explanation

A professional code of ethics articulates the values, duties, and standards of conduct expected of members, often exceeding legal minimums. It informs judgment in situations where laws are silent or ambiguous, and it supports public trust. Codes do not set legal penalties, guarantee outcomes, or substitute for consent processes.

Question 27Foundations of health sciences practice and professional standards

A clinician is documenting a telephone encounter in the electronic health record. Which documentation practice best aligns with professional record-keeping standards?

  1. Using vague phrases such as 'patient doing fine' to save time.
  2. Recording only the final diagnosis to keep the record concise.
  3. Including the date, time, content of the discussion, and the clinician's name and credentials. Correct answer.
  4. Backdating the note to match the time of the patient's call.

Explanation

Professional documentation standards require entries to be timely, accurate, complete, and attributable. A telephone note should capture when the encounter occurred, what was discussed, what was decided, and who documented it. Vague summaries, diagnosis-only notes, and backdating undermine the record's reliability and legal defensibility.

Question 28Foundations of health sciences practice and professional standards

A patient with capacity tells a nurse that they do not want their adult daughter to know any details of their care. Later, the daughter calls and asks for an update. What is the nurse's most appropriate response?

  1. Provide full details because the daughter is immediate family.
  2. Ask the daughter to come in person so information can be shared privately.
  3. Confirm the patient's admission and general condition but withhold specifics.
  4. Decline to share any information and explain that the patient has not authorized disclosure. Correct answer.

Explanation

Confidentiality is owed to the patient, and a patient with capacity may restrict disclosure even to family. The nurse should decline to share information and explain that the patient controls what is disclosed. Confirming admission or sharing details without authorization would breach confidentiality.

Question 29Foundations of health sciences practice and professional standards

A hospital committee is revising its policy on accepting gifts from vendors. Which principle should guide the policy to best protect professional integrity?

  1. Vendor gifts are acceptable because they reduce operating costs for the hospital.
  2. Only gifts that could reasonably influence clinical judgment should be restricted.
  3. Gifts should be prohibited or tightly limited to avoid even the appearance of influence on clinical decisions. Correct answer.
  4. Gifts of any value are acceptable if disclosed to a supervisor.

Explanation

Professional standards generally require avoiding conflicts of interest and the appearance of impropriety, not only proven influence. Policies therefore tend to prohibit or sharply limit gifts that could bias judgment. Relying on disclosure alone or on a subjective influence test leaves integrity vulnerable.

Question 30Foundations of health sciences practice and professional standards

A clinician is asked to serve on a committee that sets formulary policy for a drug manufactured by a company in which the clinician holds significant stock. Which action best manages the conflict of interest?

  1. Sell the stock after the committee has completed its work.
  2. Participate fully but mention the stock holding once at the start of each meeting.
  3. Continue to participate because the clinician's clinical expertise outweighs any financial interest.
  4. Recuse from deliberations and decisions involving that manufacturer's products and disclose the financial interest. Correct answer.

Explanation

A significant financial interest in an affected company creates a conflict that should be disclosed and managed by recusal from related decisions. Disclosure alone does not neutralize the risk of biased judgment, and timing a sale after decisions are made does not address the conflict during the decision.

Question 31Anatomy, physiology, and pathophysiology

Which formed element of blood is primarily responsible for oxygen transport from the lungs to peripheral tissues?

  1. Neutrophil
  2. Erythrocyte Correct answer.
  3. Lymphocyte
  4. Platelet

Explanation

Erythrocytes are packed with hemoglobin, and each heme group binds oxygen reversibly in the pulmonary capillaries and releases it in tissues with lower partial pressure of oxygen. Platelets support hemostasis, whereas neutrophils and lymphocytes are leukocytes dedicated to immune defense.

Question 32Anatomy, physiology, and pathophysiology

A patient's ECG shows a prolonged PR interval with a consistent 1:1 relationship between every P wave and every QRS complex. Which conduction abnormality does this represent?

  1. Premature ventricular contraction
  2. Atrial fibrillation
  3. First-degree atrioventricular block Correct answer.
  4. Third-degree atrioventricular block

Explanation

First-degree AV block is defined by a PR interval longer than 0.20 seconds while every atrial impulse still conducts to the ventricles. Because conduction is merely slowed rather than dropped or dissociated, each P wave is followed by a QRS.

Question 33Anatomy, physiology, and pathophysiology

In the nephron, in which segment does the majority of filtered sodium and water reabsorption occur?

  1. Thin descending limb of the loop of Henle
  2. Proximal convoluted tubule Correct answer.
  3. Collecting duct
  4. Distal convoluted tubule

Explanation

Roughly two-thirds of filtered sodium and water is reclaimed in the proximal convoluted tubule, driven by basolateral sodium-potassium ATPase and apical cotransporters. Downstream segments fine-tune the remaining fraction under hormonal control rather than performing bulk reabsorption.

Question 34Anatomy, physiology, and pathophysiology

Which change in the alveolar-capillary membrane is the most direct cause of impaired gas diffusion in pulmonary fibrosis?

  1. Excess surfactant inactivation
  2. Increased pulmonary blood volume
  3. Bronchial smooth muscle constriction
  4. Thickening of the alveolar septa Correct answer.

Explanation

Fibrotic deposition thickens the alveolar interstitium, increasing diffusion distance so that oxygen equilibration between alveolus and capillary is impaired. Bronchoconstriction alters airflow, surfactant loss promotes alveolar collapse, and blood volume changes affect perfusion rather than membrane thickness.

Question 35Anatomy, physiology, and pathophysiology

A hormone released from the posterior pituitary acts primarily to increase water permeability in the collecting duct. Which hormone is it?

  1. Antidiuretic hormone Correct answer.
  2. Parathyroid hormone
  3. Atrial natriuretic peptide
  4. Aldosterone

Explanation

Antidiuretic hormone, also called vasopressin, is stored and released by the posterior pituitary and inserts aquaporin-2 channels into collecting duct principal cells. This concentrates urine and expands free water retention when plasma osmolality rises.

Question 36Anatomy, physiology, and pathophysiology

During an acute inflammatory response, which vascular change occurs earliest at the site of injury?

  1. Arteriolar vasodilation with increased capillary permeability Correct answer.
  2. Sustained vasoconstriction of the entire capillary bed
  3. Permanent loss of endothelial cell junctions
  4. Immediate thrombosis of the supplying artery

Explanation

The earliest vascular event in acute inflammation is transient arteriolar vasodilation, producing heat and redness, followed by increased permeability that allows protein-rich exudate to escape. This sequence creates the classic swelling and pain of inflammation.

Question 37Anatomy, physiology, and pathophysiology

Which structure of the central nervous system is the primary regulator of body temperature, thirst, and pituitary hormone release?

  1. Thalamus
  2. Medulla oblongata
  3. Cerebellum
  4. Hypothalamus Correct answer.

Explanation

The hypothalamus integrates autonomic, endocrine, and behavioral responses to maintain homeostasis, including thermoregulation, water balance, and control of the anterior pituitary via releasing hormones. Its role as a homeostatic control center distinguishes it from the other regions listed.

Question 38Anatomy, physiology, and pathophysiology

A patient with chronic obstructive pulmonary disease retains carbon dioxide. Which acid-base disturbance is expected on arterial blood gas analysis?

  1. Respiratory acidosis Correct answer.
  2. Respiratory alkalosis
  3. Metabolic alkalosis
  4. Metabolic acidosis with respiratory compensation

Explanation

Alveolar hypoventilation in COPD impairs carbon dioxide elimination, raising arterial partial pressure of carbon dioxide and lowering pH, which defines respiratory acidosis. Renal bicarbonate retention develops later as metabolic compensation but does not change the primary label.

Question 39Anatomy, physiology, and pathophysiology

Which immunoglobulin class is the first antibody produced in a primary humoral immune response and is also the largest?

  1. IgM Correct answer.
  2. IgE
  3. IgA
  4. IgG

Explanation

IgM is a pentameric antibody that appears earliest in a primary response and is efficient at complement activation because of its multiple antigen-binding sites. IgG dominates secondary responses, IgA protects mucosal surfaces, and IgE mediates allergic reactions.

Question 40Anatomy, physiology, and pathophysiology

In a patient with left-sided heart failure, which mechanism most directly explains the development of pulmonary edema?

  1. Lymphatic obstruction in the mediastinum
  2. Reduced plasma oncotic pressure from protein loss
  3. Increased alveolar surface tension from surfactant deficiency
  4. Elevated pulmonary capillary hydrostatic pressure Correct answer.

Explanation

Left ventricular failure raises pressure in the left atrium and pulmonary veins, transmitting elevated hydrostatic pressure to pulmonary capillaries and forcing fluid into the interstitium and alveoli. This cardiogenic mechanism differs from oncotic, lymphatic, or surfactant-related causes of edema.

Question 41Anatomy, physiology, and pathophysiology

Which part of the cardiac conduction system normally sets the resting heart rate by generating impulses at the highest intrinsic rate?

  1. Sinoatrial node Correct answer.
  2. Atrioventricular node
  3. Bundle of His
  4. Purkinje fibers

Explanation

The sinoatrial node has the steepest spontaneous phase 4 depolarization and therefore the highest intrinsic firing rate, normally 60 to 100 beats per minute, making it the dominant pacemaker. Lower pacemakers fire more slowly and are normally overdriven.

Question 42Anatomy, physiology, and pathophysiology

Which lung volume or capacity cannot be measured by simple spirometry alone?

  1. Inspiratory reserve volume
  2. Tidal volume
  3. Vital capacity
  4. Residual volume Correct answer.

Explanation

Residual volume is the air remaining in the lungs after maximal exhalation and cannot be exhaled, so spirometry cannot measure it directly; plethysmography or gas dilution is required. Tidal volume, inspiratory reserve volume, and vital capacity are all obtainable from a forced spirometry maneuver.

Question 43Anatomy, physiology, and pathophysiology

A patient with type 1 diabetes misses insulin doses and develops hyperglycemia, ketonemia, and metabolic acidosis. Which process best explains the ketone production?

  1. Excessive glycogen synthesis in the liver
  2. Hepatic fatty acid oxidation driven by insulin deficiency Correct answer.
  3. Enhanced lipogenesis in adipose tissue
  4. Increased glucose uptake by skeletal muscle

Explanation

Without insulin, adipose lipolysis releases free fatty acids that the liver oxidizes to acetyl coenzyme A faster than the citric acid cycle can use it, shunting carbon into ketone bodies. The resulting ketoacidosis lowers blood pH and produces the clinical picture of diabetic ketoacidosis.

Question 44Anatomy, physiology, and pathophysiology

Which cranial nerve carries parasympathetic fibers that slow the heart rate?

  1. Oculomotor nerve
  2. Facial nerve
  3. Glossopharyngeal nerve
  4. Vagus nerve Correct answer.

Explanation

The vagus nerve, cranial nerve X, supplies parasympathetic fibers to the sinoatrial and atrioventricular nodes, releasing acetylcholine that reduces the rate of spontaneous depolarization. This vagal tone is the principal brake on resting heart rate.

Question 45Anatomy, physiology, and pathophysiology

Which type of hypersensitivity reaction underlies anaphylaxis after a bee sting?

  1. Type III immune complex hypersensitivity
  2. Type IV delayed hypersensitivity
  3. Type I immediate hypersensitivity Correct answer.
  4. Type II antibody-mediated hypersensitivity

Explanation

Anaphylaxis is a type I reaction in which allergen cross-linking of IgE on mast cells triggers rapid release of histamine and other mediators, producing bronchoconstriction and vasodilation within minutes. The other types proceed through different effector mechanisms and time courses.

Question 46Anatomy, physiology, and pathophysiology

Which transport process moves glucose across the intestinal epithelium against its concentration gradient?

  1. Pinocytosis of luminal fluid
  2. Facilitated diffusion through GLUT2 on the apical membrane
  3. Simple diffusion through the lipid bilayer
  4. Secondary active transport via sodium-glucose cotransport Correct answer.

Explanation

The sodium-glucose cotransporter on the apical membrane uses the inward sodium gradient maintained by basolateral sodium-potassium ATPase to move glucose uphill. Glucose then exits the basolateral side by facilitated diffusion through GLUT2.

Question 47Anatomy, physiology, and pathophysiology

Which cell type secretes hydrochloric acid in the gastric mucosa?

  1. Parietal cell Correct answer.
  2. Chief cell
  3. Mucous neck cell
  4. G cell

Explanation

Parietal cells secrete hydrochloric acid through the hydrogen-potassium ATPase pump after stimulation by histamine, gastrin, and acetylcholine. Chief cells release pepsinogen, G cells release gastrin, and mucous cells provide protective mucus.

Question 48Anatomy, physiology, and pathophysiology

A patient has a lesion of the upper motor neuron pathway. Which finding is most consistent with this pattern?

  1. Loss of reflex activity in the affected limb
  2. Fasciculations in the affected muscle
  3. Hyperreflexia with increased muscle tone Correct answer.
  4. Flaccid paralysis with marked muscle atrophy

Explanation

Upper motor neuron lesions remove descending inhibition and produce spasticity, hyperreflexia, and a positive Babinski sign, often with minimal atrophy. Lower motor neuron lesions instead cause flaccidity, atrophy, fasciculations, and areflexia.

Question 49Anatomy, physiology, and pathophysiology

Which factor most strongly increases the oxygen unloading from hemoglobin at the tissue level?

  1. A fall in body temperature
  2. A rise in blood pH to alkalosis
  3. A fall in erythrocyte 2,3-diphosphoglycerate
  4. A rise in tissue carbon dioxide and hydrogen ion concentration Correct answer.

Explanation

The Bohr effect describes the rightward shift of the oxygen-hemoglobin dissociation curve when carbon dioxide and hydrogen ions accumulate in active tissues. This reduces hemoglobin's affinity for oxygen and enhances oxygen delivery where metabolism is highest.

Question 50Anatomy, physiology, and pathophysiology

Which component of the cardiac cycle corresponds to the period when the ventricles are contracting but no blood is leaving because all valves are closed?

  1. Isovolumetric contraction Correct answer.
  2. Atrial systole
  3. Isovolumetric relaxation
  4. Ventricular ejection

Explanation

Isovolumetric contraction begins when the atrioventricular valves close at the start of systole and ends when ventricular pressure exceeds aortic and pulmonary pressure, opening the semilunar valves. Ventricular volume is constant during this interval, so no blood moves.