How to use these physiology practice questions
These physiology practice questions use a single-best-answer format. They cover mechanisms rather than isolated definitions: pressure gradients, transport, feedback, clearance, membrane potentials and acid–base compensation.
Answer each question before reading its explanation. For every incorrect answer, identify whether the problem was a missing fact, a confused mechanism, or a calculation error. That distinction matters: a fact gap needs a card, while a mechanism error needs another question using the same relationship.
The questions are arranged across major areas of physiology. They are suitable for biomedical science revision, but the exact wording, weighting and question format of a particular course or examination should be checked against its official syllabus or course guide.
Question 1 — cardiac physiology
This tests the relationship between ventricular pressure, valve movement and the phases of the cardiac cycle. In MySummaries, a question screen can mark the answer immediately and explain the key mechanism.
During the isovolumetric contraction phase of the left ventricular cardiac cycle, which change occurs?
Both valves are closed during isovolumetric contraction. Ventricular muscle is generating tension, so left ventricular pressure rises, but no blood enters or leaves and volume remains constant. The strongest distractor is that the aortic valve is open: it opens only when ventricular pressure exceeds aortic pressure, starting ejection.
The useful rule is to ask which side of each valve has the greater pressure. The mitral valve closes when left ventricular pressure exceeds left atrial pressure. The aortic valve then opens when left ventricular pressure exceeds aortic pressure.
Question 2 — renal physiology
This question tests clearance and the difference between filtration, secretion and reabsorption.
A substance is freely filtered at the glomerulus and is neither reabsorbed nor secreted by the renal tubules. Its renal clearance is expected to be equal to which measurement?
A freely filtered substance that is neither reabsorbed nor secreted has a clearance equal to the glomerular filtration rate. Inulin approximates this experimentally. The strongest distractor is renal plasma flow: para-aminohippurate clearance approximates effective renal plasma flow because it is filtered and strongly secreted, not because all filtered substances have this clearance.
For calculations, keep the definition visible: clearance is the virtual volume of plasma completely cleared of a substance per unit time. If a substance is reabsorbed, its clearance is less than GFR; if it is secreted, its clearance is greater than GFR.
Question 3 — respiratory physiology
This tests alveolar ventilation rather than simply minute ventilation. Dead space must be removed from the volume reaching gas exchange surfaces.
A person has a respiratory rate of 12 breaths/min, a tidal volume of 500 mL and a physiological dead space of 150 mL. What is the approximate alveolar ventilation?
Alveolar ventilation = respiratory rate × (tidal volume − dead space): 12 × (500 − 150) mL/min = 4,200 mL/min, or 4.2 L/min. The strongest distractor is 6.0 L/min, which is minute ventilation and includes the 150 mL of air ventilating dead space on each breath.
The calculation is more useful than memorising the two terms. A rapid, shallow breathing pattern can produce a reasonable minute ventilation while reducing alveolar ventilation because a larger proportion of each breath occupies dead space.
Question 4 — acid–base physiology
This question tests the primary disturbance and the expected direction of compensation.
A patient has a blood pH of 7.25, a bicarbonate concentration of 15 mmol/L and a low arterial carbon dioxide tension. Which interpretation is most appropriate?
The low bicarbonate identifies a primary metabolic acidosis. The low carbon dioxide indicates increased ventilation, which is the expected respiratory compensation. The strongest distractor is respiratory alkalosis: in a primary respiratory alkalosis, carbon dioxide is low first and bicarbonate falls as renal compensation develops; the question's markedly reduced bicarbonate and acidotic pH support metabolic acidosis.
A practical sequence is: decide whether the pH is acidotic or alkalotic, identify which variable points in that direction, then assess whether the other variable is compensating. Compensation does not normally return the pH fully to the reference range.
Question 5 — endocrine physiology
This tests negative feedback in the hypothalamic–pituitary–thyroid axis.
Which hormone pattern is most consistent with primary hypothyroidism caused by failure of the thyroid gland?
A failing thyroid produces too little thyroxine. Reduced negative feedback allows hypothalamic thyrotropin-releasing hormone and pituitary thyroid-stimulating hormone to rise, so the characteristic pattern is low thyroxine with high TSH. The strongest distractor is low thyroxine with low TSH, which suggests a pituitary or hypothalamic cause rather than primary thyroid failure.
When a feedback question feels difficult, locate the failed organ first. Then predict the downstream hormone and use negative feedback to predict the upstream hormone. This prevents memorising four hormone patterns as unrelated pairs.
Question 6 — neurophysiology
This question tests the ionic basis of the resting membrane potential and the effect of changing extracellular potassium.
What is the immediate effect of increasing extracellular potassium concentration on a typical neuron's resting membrane potential?
Increasing extracellular potassium reduces the outward potassium concentration gradient. The potassium equilibrium potential becomes less negative, and the resting membrane potential generally depolarises. The strongest distractor is hyperpolarisation: that would be expected with a larger outward potassium gradient, such as reduced extracellular potassium, not increased extracellular potassium.
The membrane potential is not identical to the equilibrium potential of every ion. At rest, potassium conductance is usually dominant, so changes in the potassium gradient have a particularly strong immediate effect.
Question 7 — muscle physiology
This tests excitation–contraction coupling in skeletal muscle.
In skeletal muscle, what is the direct role of calcium released from the sarcoplasmic reticulum?
Calcium binds troponin C, causing a conformational change that moves tropomyosin and exposes myosin-binding sites on actin. ATP is then required for cross-bridge cycling. The strongest distractor is calcium binding directly to myosin: that describes neither the principal skeletal muscle regulatory mechanism nor the role of troponin.
Separate the sequence into electrical and mechanical steps: an action potential travels along the sarcolemma and T-tubules, calcium is released, troponin changes conformation, and actin–myosin cycling produces force.
Question 8 — gastrointestinal physiology
This question tests the stimulus and action of secretin.
Acidic chyme entering the duodenum most directly stimulates secretion of which hormone, and what is its main effect?
Acid in the duodenum stimulates S cells to release secretin. Secretin promotes bicarbonate-rich pancreatic and biliary secretion, helping neutralise the acid. The strongest distractor is gastrin: gastrin is associated mainly with gastric acid secretion and gastric mucosal activity, not the principal response to acid entering the duodenum.
For gastrointestinal hormones, link each hormone to its trigger, target and effect. This is more reliable than learning a single action without knowing when the hormone is released.
Question 9 — autonomic physiology
This tests receptor location and the second-messenger pathway responsible for a common cardiovascular response.
Activation of beta-1 adrenoceptors in cardiac pacemaker cells most directly produces which effect?
Beta-1 receptors are Gs-coupled. Their activation increases adenylate cyclase activity and cyclic AMP, increasing inward currents during phase 4 and therefore increasing heart rate. The strongest distractor is reduced calcium entry: beta-1 activation increases calcium handling and supports positive chronotropy and inotropy.
A useful autonomic answer has three linked parts: receptor, G protein or ion channel, and physiological effect. If one link is missing, the answer may sound plausible but will not explain the direction of the response.
Question 10 — haemostasis
This tests the distinction between platelet plug formation and fibrin stabilisation.
Which interaction is most important for platelet adhesion to exposed subendothelial collagen at an injured vessel?
Von Willebrand factor binds exposed collagen and platelet glycoprotein Ib, helping platelets adhere under shear. Glycoprotein IIb/IIIa binding fibrinogen is mainly important for platelet aggregation between activated platelets. That is the strongest distractor because it is also a platelet interaction, but it describes aggregation rather than initial adhesion.
Keep primary haemostasis and secondary haemostasis separate. Platelets form the initial plug; the coagulation cascade generates thrombin, which converts fibrinogen to fibrin and stabilises that plug.
Review the result, not just the score
After answering the ten questions, classify each error. A calculation error should lead to another worked calculation. A mechanism error should lead to a short explanation in your own words. A forgotten value or receptor should become a compact flashcard with one answer only.
A weak-area view is more useful than a total percentage because it shows where another question is most likely to change your performance.
If the same concept is missed twice, reduce it to the smallest useful prompt rather than rereading a whole chapter. The remediation tray might contain a question such as this:
You lost this mark twice: a substance has a clearance below GFR when it is reabsorbed, secreted, or neither?
Return to that prompt until you can answer it and explain why. Then attempt a new question that changes the numbers or clinical context, so you test the principle rather than recognising the original wording.
How MySummaries helps
MySummaries can turn your physiology notes into a revision board, generate single-fact flashcards, write further practice papers, mark responses against your own material, and place repeated errors in a remediation queue. Use the questions above as a diagnostic starting point, then build the next set around the sections where your marks are lowest.