hllj/quesmed huggingface dataset:
Which of the following options best describes what happens in the distal tubule of the nephron during urine formation?

Options:
explanation: Modification of urine does occur via the movement of ions within the distal tubule, it occurs via the following mechanism: Na<sup>+</sup> and Cl<sup>-</sup> are actively reabsorbed from the tubular fluid in exchange for K<sup>+</sup> and H<sup>+</sup> which are secreted into the tubular fluid.
name: There is no movement of ions within the distal tubule
label: e
answer: no
explanation: This is switched around, the correct exchange of ions is: Na<sup>+</sup> and Cl<sup>-</sup> are actively reabsorbed from the distal tubule, in exchange for K<sup>+</sup> and H<sup>+</sup> which are secreted into the tubule.
name: Na<sup>+</sup>and Cl<sup>-</sup> are secreted from the tubular fluid in exchange for K<sup>+</sup> and H<sup>+</sup>, which are actively reabsorbed into the tubular fluid
label: c
answer: no
explanation: It is Cl<sup>-</sup> which is actively reabsorbed from the tubular fluid alongside Na<sup>+</sup> in exchange for K<sup>+</sup> and H<sup>+</sup>, not Ca<sup>2+</sup>.
name: Ca<sup>2+</sup> and Na<sup>+</sup> are actively reabsorbed from the tubular fluid in exchange for K<sup>+</sup> and H<sup>+</sup>, which are secreted into the tubular fluid
label: d
answer: no
explanation: The distal tubule performs modification of urine prior to the final modification in the collecting duct. Na<sup>+</sup> and Cl<sup>-</sup> are exchanged for K<sup>+</sup> or H<sup>+</sup> throughout the distal tubule.
name: Na<sup>+</sup> and Cl<sup>-</sup> are actively reabsorbed from the tubular fluid in exchange for K<sup>+</sup> and H<sup>+</sup>, which are secreted into the tubular fluid
label: a
answer: yes
explanation: The distal tubule performs modification of urine prior to the final modification in the collecting duct. However, the correct exchange of ions is the following: Na<sup>+</sup> and Cl<sup>-</sup> are exchanged for K<sup>+</sup> or H<sup>+</sup> throughout the distal tubule.
name: K<sup>+</sup> and Cl<sup>-</sup> are actively reabsorbed from the tubular fluid in exchange for Na<sup>+</sup> and H<sup>+</sup>, which are secreted into the tubular fluid
label: b
answer: no

Correct answer: a
Which of the following options best describes the mechanism of action of thiazide diuretics?

Options:
explanation: This mechanism would lead to an increase in Na<sup>+</sup> reabsorption, and so would cause decreased water excretion (diuresis). Instead, thiazide-diuretics act in the distal tubule to inhibit the apical Na<sup>+</sup>/Cl<sup>-</sup>co-transporter. This leads to less Na<sup>+</sup> reabsorption from the tubule, thus leading to moderately increased Na<sup>+</sup> excretion with increased water excretion. This is diuresis.
name: Activates the apical Na<sup>+</sup>/Cl<sup>-</sup> co-transporter in the distal tubule
label: b
answer: no
explanation: Thiazide diuretics act in the distal tubule to inhibit the apical Na<sup>+</sup>/Cl<sup>-</sup> co-transporter. This leads to less Na<sup>+</sup> reabsorption, thus leading to moderately increased Na<sup>+</sup> excretion with increased water excretion. This is diuresis.
name: Inhibits the apical Na<sup>+</sup>/Cl<sup>-</sup> co-transporter in the distal tubule
label: a
answer: yes
explanation: This is the mechanism of certain K<sup>+</sup>-sparing diuretics (e.g. spironolactone) which antagonise aldosterone receptors to then reduce Na<sup>+</sup> channel formation. This means that less Na<sup>+</sup> can be reabsorbed from the tubule - therefore causing greater Na<sup>+</sup> and water excretion. Meanwhile, thiazide-diuretics act in the distal tubule to inhibit the apical Na<sup>+</sup>/Cl<sup>-</sup> co-transporter. This leads to less Na<sup>+</sup> reabsorption from the tubule, thus leading to moderately increased Na<sup>+</sup> excretion with increased water excretion. This is diuresis.
name: Aldosterone receptor antagonist
label: c
answer: no
explanation: This is the action of the weak K<sup>+</sup> sparing diuretics triamterene and amiloride. This mechanism leads to the inhibition of Na<sup>+</sup> reabsorption and decrease of K<sup>+</sup> excretion. Meanwhile, thiazide-diuretics act in the distal tubule to inhibit the apical Na<sup>+</sup>/Cl<sup>-</sup> co-transporter. This leads to less Na<sup>+</sup> reabsorption from the tubule, thus leading to moderately increased Na<sup>+</sup> excretion with increased water excretion. This is diuresis.
name: Blocks the luminal Na<sup>+</sup> channel in the distal tubule
label: d
answer: no
explanation: This is the mechanism of carbonic anhydrase Inhibitors e.g. acetazolamide, which are early examples of weak diuretics, and are not often used for diuresis. Thiazide-diuretics, however, act in the distal tubule and inhibit the apical Na<sup>+</sup>/Cl<sup>-</sup> co-transporter. This leads to less Na<sup>+</sup> reabsorption from the tubule, thus leading to moderately increased Na<sup>+</sup> excretion with increased water excretion. This is diuresis.
name: Blocks NaHCO<sub>3</sub> reabsorption in the proximal tubule
label: e
answer: no

Correct answer: a
A 20-year-old male with a known anxiety disorder presents with shortness of breath and the feeling of pins and needles in his fingers. A venous blood gas (VBG) is carried out.

Given his likely diagnosis, what is the VBG most likely to show?

Options:
explanation: Given this patient's past medical history and symptoms, he is likely experiencing a panic attack which would lead to hyperventilation. This would result in him exhaling excessive CO~2~, thus causing decreased CO~2~, which would cause his pH to increase into an alkalosis. This would be seen via a raised pH and decreased PaCO~2~.
name: Respiratory alkalosis
label: a
answer: yes
explanation: Given this patient's past medical history and symptoms, it is unlikely that the cause of his symptoms is metabolic. Instead, he is most likely to be experiencing a panic attack which is causing hyperventilation and leading to exhalation of excessive CO~2~. This decreased CO~2~ would push his pH to increase into an alkalosis, not an acidosis, giving him a respiratory alkalosis overall.
name: Metabolic acidosis
label: b
answer: no
explanation: Given this patient's past medical history and symptoms, it is likely that the cause of his symptoms is respiratory - specifically a panic attack causing hyperventilation and leading to exhalation of excessive CO~2~. However, this decreased CO~2~ would push his pH to increase into an alkalosis, not an acidosis, giving him a respiratory alkalosis overall.
name: Respiratory acidosis
label: c
answer: no
explanation: Given this patient's past medical history and symptoms, it is unlikely that the cause of his symptoms is metabolic. Instead, he is most likely to be experiencing a panic attack which is causing hyperventilation and leading to exhalation of excessive CO~2~. This decreased CO~2~ would push his pH to increase into an alkalosis, giving him a respiratory alkalosis overall.
name: Mixed respiratory and metabolic alkalosis
label: e
answer: no
explanation: Given this patient's past medical history and symptoms, it is unlikely that the cause of his symptoms is metabolic. Instead, he is most likely to be experiencing a panic attack which is causing hyperventilation and leading to exhalation of excessive CO~2~. This decreased CO~2~ would push his pH to increase into an alkalosis, giving him a respiratory alkalosis overall.
name: Metabolic alkalosis
label: d
answer: no

Correct answer: a
A 60-year-old female presents with a one-week history of diarrhoea and nausea, and a two-day history of reduced urine output. On examination, she is clinically dehydrated and has a BP of 84/60. She is normally well with no past medical history. Her blood results are as follows:


||||
|---------------------------|:-------:|--------------------|
|Sodium|151 mmol/L|135 - 145|
|Potassium|6.2 mmol/L|3.5 - 5.3|
|Urea|28 mmol/L|2.5 - 7.8|
|Creatinine|660 µmol/L|60 - 120|
|Fasting Glucose|6.2 mmol/L|<6.1|



Which of the following is the most likely diagnosis?

Options:
explanation: The raised creatinine is most likely to have occurred over the last week as she was previously well. Additionally, the fall in urine output for more than eight hours also indicates an AKI. There is no past medical history to indicate a diabetic or drug cause. One week of diarrhoea and nausea indicates possible gastroenteritis causing dehydration, resulting in AKI.
name: Acute Kidney Injury (AKI) secondary to gastroenteritis
label: a
answer: yes
explanation: T2DM is more likely than T1DM given this patient's age. However, this would usually lead to CKD (chronic kidney injury), which would not fit with the one-week history of this patient's symptoms. Instead, a more acute cause e.g. gastroenteritis causing dehydration and AKI is more likely.
name: Type 2 Diabetes Mellitus (T2DM)
label: d
answer: no
explanation: CKD is unlikely given the length of time of the symptoms and the fact that this patient was previously well. The signs of clinical dehydration, and hypotension, both indicate that this patient has lost substantial amounts of fluid due to her diarrhoea - which given the one-week history, likely has an infective cause. This means the most likely diagnosis is AKI secondary to gastroenteritis.
name: Chronic Kidney Disease (CKD)
label: b
answer: no
explanation: T1DM is unlikely given the age of this patient, as we would have expected this to have already been diagnosed in childhood, or early adulthood at the latest. Dehydration due to gastroenteritis, causing an AKI is much more likely.
name: Type 1 Diabetes Mellitus (T1DM)
label: c
answer: no
explanation: Whilst sepsis is a risk for this patient given her likely infection, it is not possible to say if she is septic without further investigations (blood cultures etc.). However, it is possible to say that she is suffering with an AKI. This is likely due to gastroenteritis given her one-week history of gastrointestinal symptoms.
name: Sepsis
label: e
answer: no

Correct answer: a
A 20-year-old female presents to the emergency department after being hit with a cricket ball on the side of her head 20 minutes ago. She reports worsening vomiting, headache, and confusion. A CT scan is performed and shows a haemorrhage.

Where is this haemorrhage most likely to be located?

Options:
explanation: Subarachnoid haemorrhage is associated with sudden onset "thunderclap" headache after the rupture of an artery or berry aneurysm in the cerebral arterial circle (circle of Willis). It can be associated with age, trauma, hypertension and connective tissue disorders such as Marfan's or Elhers Dhanlos Syndrome.
name: Within the subarachnoid space
label: c
answer: no
explanation: Intraparenchymal/intracerebral haemorrhage occurs with rupture to the cerebral veins which causes sudden onset neurological deficits. It is often associated with hypertension.
name: Within the brain parenchyma
label: d
answer: no
explanation: Subdural haemorrhage often presents with a slow gradual deterioration. It can be after trauma and is associated with risk factors such as age, alcoholism, and hypertension.
name: Between the dura mater and arachnoid mater
label: b
answer: no
explanation: Dense connective tissue lacerations to the scalp will cause profuse bleeding from this area. They may require suturing or glue to prevent bleeding.
name: Within the dense connective tissue of the scalp
label: e
answer: no
explanation: Trauma to the pterion region of the skull can rupture the middle meningeal artery (MMA), which will cause an extradural haemorrhage above the dura mater and beneath the skull.
name: Between the skull and dura mater
label: a
answer: yes

Correct answer: a
What changes occur in the post-synaptic neuron in order to sustain late-phase long-term potentiation (LTP)?

Options:
explanation: This is required in early-phase LTP before late-phase LTP occurs. Activation of NMDA receptors allows calcium influx. NMDA receptors are activated once a post-synaptic neuron is already depolarised.
name: Activation of NMDA receptors in the post-synaptic neuron
label: c
answer: no
explanation: Nitric oxide diffuses into the presynaptic terminal to cause more glutamate to be released.
name: Nitric oxide signalling
label: e
answer: no
explanation: This is required in early-phase LTP before late-phase LTP occurs. These changes result in more excitatory post-synaptic potentials (EPSPs), enhanching neuron depolarisation.
name: Phosphorylation and insertion of AMPA receptors in the post-synaptic neuron
label: b
answer: no
explanation: This is required in early-phase LTP before late-phase LTP occurs. Calcium entry activates CaMKII, which can now insert and phosphorylate AMPA receptors.
name: Calcium ion entry through NMDA receptors
label: d
answer: no
explanation: This question is asking specifically about the late phase of LTP in the post-synaptic neuron.

Calcium-activated signal transduction activates new protein synthesis, recruiting new proteins to the synapse to cause morphological changes. These changes last for hours, days and months in late-phase LTP. Early phase LTP lasts minutes to an hour and is explained through the other options.
name: Protein synthesis and morphological changes
label: a
answer: yes

Correct answer: a
Serotonin is synthesised from which amino acid?

Options:
explanation: Tyrosine is used to synthesise various neurotransmitters, such as dopamine, adrenaline, and noradrenaline.
name: Tyrosine
label: b
answer: no
explanation: Serotonin is synthesised from tryptophan.
name: Tryptophan
label: a
answer: yes
explanation: Glutamate and GABA are both synthesised from Glutamine.
name: Glutamine
label: d
answer: no
explanation: Nitric oxide is synthesised from arginine. Nitric oxide is a retrograde neurotransmitter (travels from the pre-synaptic neuron to act on the pre-synaptic neuron).
name: Arginine
label: c
answer: no
explanation: At NMDA receptors, glycine is required for NMDA receptor activation. Glycine is also an inhibitory neurotransmitter in the spinal cord.
name: Glycine
label: e
answer: no

Correct answer: a
During an action potential, movement of which ion is responsible for repolarisation?

Options:
explanation: As the neuron returns back to resting potential, K+ is actively transported out (not in) through the Na+/K+ ATPase.
name: K+ in
label: c
answer: no
explanation: Action potentials open voltage-gated calcium channels at the axon terminal. This allows Ca2+ to diffuse in, which causes vesicle fusion at the synapse and neurotransmitter release.
name: Ca2+ in
label: e
answer: no
explanation: Na+ diffuses in during depolarization, so the membrane potential becomes more positive.
name: Na+ in
label: b
answer: no
explanation: K+ diffuses out of the neuron during repolarization, making the membrane potential more negative.
name: K+ out
label: a
answer: yes
explanation: As the neuron returns back to resting potential, Na+ is actively transported through the Na+/K+ ATPase.
name: Na+ out
label: d
answer: no

Correct answer: a
Which signal is sent from the globus pallidus external in the basal ganglia, and to where?

Options:
explanation: The cortex sends excitatory signals to the striatum in both direct and indirect pathways. The striatum sends signals to either globus pallidus internal or external.
name: Excitatory to the striatum
label: b
answer: no
explanation: The thalamus sends excitatory signals to the cortex in both pathways.
name: Inhibitory to the cortex
label: d
answer: no
explanation: The globus pallidus internus sends inhibitory signals to the thalamus in both pathways.
name: Inhibitory to the thalamus
label: c
answer: no
explanation: This is part of the indirect pathway. The subthalamic nucleus sends excitatory signals to here.
name: Excitatory to the globus pallidus internal
label: e
answer: no
explanation: This is part of the indirect pathway to withhold movement.
name: Inhibitory to the subthalamic nucleus
label: a
answer: yes

Correct answer: a
What cranial nerve is responsible for transmitting sour sense to the brain when the tip of the tongue licks a lemon?

Options:
explanation: The vagus nerve (CN X) has many functions in the body, but does not provide sensation to the tongue.
name: Vagus nerve
label: d
answer: no
explanation: The glossopharyngeal nerve (CN IX) innervates the posterior one-third of the tongue for taste and sensation.
name: Glossopharyngeal nerve
label: b
answer: no
explanation: The lingual nerve is a branch of the mandibular nerve (CN V3). It provides sensation to the anterior two-thirds of the tongue.
name: Lingual nerve
label: e
answer: no
explanation: The hypoglossal nerve (CN XII) innervates all the muscles of the tongue, apart from palatoglossus.
name: Hypoglossal nerve
label: c
answer: no
explanation: The facial nerve (CN VII) innervates taste in the anterior two-thirds of the tongue. The tongue's innervation can be divided between the anterior two-thirds and the posterior one-third. Different cranial nerves provide either taste (special sense) or general sensation in these regions.
name: Facial nerve
label: a
answer: yes

Correct answer: a
What drug is the first-line treatment of Parkinson's disease?

Options:
explanation: Monoamine oxidase inhibitors (MAO-Is) are part of the treatment of Parkinson's disease. They reduce the breakdown of monoamine neurotransmitters (such as dopamine).
name: Monoamine oxidase inhibitors
label: b
answer: no
explanation: This is a recent non-drug treatment for Parkinson's disease. There are different targets in the brain depending on the symptoms experienced.
name: Deep brain stimulation
label: d
answer: no
explanation: Anticholinergics were the first-line drug treatment for Parkinson's disease in the past. They help treat tremor, but have many side effects, such as cognitive decline.
name: Anticholinergics
label: c
answer: no
explanation: Entacapone is an additional treatment with levodopa. It reduces the peripheral metabolism of L-dopa, increasing efficacy. However, it worsens side effects.
name: Entacapone
label: e
answer: no
explanation: Parkison's disease involves the destruction of dopaminergic neurons in the substantia nigra, reducing dopamine transmission in the brain. Levodopa aims to replace dopamine and is the gold-standard treatment in Parkinson's disease.
name: Levodopa
label: a
answer: yes

Correct answer: a
Pain described as a "dull ache"  is transmitted through which nerve fibre?

Options:
explanation: These fibres are thinly myelinated and have a medium diameter. They are involved in light touch, temperature and nociception (pain). However, this pain is felt immediately after the injury. This pain is well-localised and often described as a sharp pain.
name: A delta
label: c
answer: no
explanation: These nerves are small and unmyelinated. This results in very slow transmission, so pain may be felt some time after the initial injury (second pain). This pain is also poorly localised, meaning it is felt in a wider area and more generally.
name: C fibres
label: a
answer: yes
explanation: These fibres are myelinated and have a large diameter. They are involved in light touch and proprioception.
name: A alpha fibres
label: b
answer: no
explanation: These fibres are myelinated and have a large diameter. They are involved in light touch and proprioception.
name: A beta
label: d
answer: no
explanation: Efferent nerve fibres exit the spinal cord and travel to effector sites (e.g. skeletal muscle). They do not perceive pain.
name: Efferent nerve fibres
label: e
answer: no

Correct answer: a
Which glial cell is responsible for myelinating neurons in the peripheral nervous system (PNS)?

Options:
explanation: Satellite cells perform the same role as astrocytes, but instead work in the PNS.
name: Satellite cell
label: e
answer: no
explanation: Astrocytes support neuronal development and influence the blood-brain barrier in the CNS.
name: Astrocyte
label: c
answer: no
explanation: These produce and maintain myelin in the PNS. One axon is wrapped per Schwann cell.
name: Schwann cell
label: a
answer: yes
explanation: Microglia are immune cells in the CNS. They engulf microbes and debris and, like other immune cells, originate from the mesoderm.
name: Microglial cell
label: d
answer: no
explanation: These produce and maintain myelin, but in the central nervous system (CNS) instead. One oligodendrocyte myelinates multiple axons from different neurons, unlike Schwann cells.
name: Oligodendrocyte
label: b
answer: no

Correct answer: a
A patient with epilepsy describes their seizures. They can happen at any time of day. During their seizures, they have visual hallucinations, are often scared, and experience deja vu.

Which type of seizure is this?

Options:
explanation: Atonic seizures occur suddenly with the muslces losing tone and becoming limp.
name: Atonic
label: e
answer: no
explanation: Absence seizures are short and abrupt. They can happen multiple times a day, and patients report memory loss during their seizures.
name: Absence
label: c
answer: no
explanation: This is the commonest form of primary generalized epilepsy. It starts in childhood and features early-morning jerks.
name: Juvenile myoclonic epilepsy
label: d
answer: no
explanation: Focal onset seizures start in one region of the brain. In this case, the sensory symptoms suggest they start in the temporal lobe (the most common lobe for focal onset seizures). Focal seizures may spread to the whole brain, becoming a secondary generalized seizure. However, this patient does not describe this.
name: Focal onset
label: a
answer: yes
explanation: These seizures happen with sudden onset as electrical dischargers spread over the whole brain. Patients experience continuous muscle spasm (tonic phase), rhythmic jerking (clonic phase), and drowsiness/ confusion/ pain/ headache afterwards (post-ictal phase).
name: Primary generalized
label: b
answer: no

Correct answer: a
A 35-year-old male had a traumatic brain injury three weeks ago. He is still unresponsive to voice and pain. However, he does have pupillary reflexes, as well as a sleep/wake cycle.

How can his state of consciousness best be described?

Options:
explanation: Patients in a coma are unresponsive to external stimuli and do not show basic reflexes. Coma is often reversible. However, it may progress to vegetative states, minimally conscious states, or even death.
name: Coma
label: e
answer: no
explanation: As this patient is unresponsive but shows arousal in his sleep-wake cycle, he is in a vegetative state. These patients are unresponsive and do not show voluntary responses to their environment. Reflexes are variably preserved.
name: Continuing vegetative state
label: a
answer: yes
explanation: This is similar to a vegetative state. However, some higher cortical function remains, such as movement to command, reaching, or visual tracking.
name: Minimally conscious state
label: d
answer: no
explanation: This is irreversible damage to the brainstem. As such, no reflexes are present.
name: Brainstem death
label: c
answer: no
explanation: Patients are conscious (arousable and aware), but cannot respond. Their vertical eye movements are often present. They do not have any reflexes due to damage to the pons in the brain.
name: Locked-in syndrome
label: b
answer: no

Correct answer: a