hllj/quesmed huggingface dataset:
A 35 year old male attends an endocrinology clinic with one month of polyuria, nocturia and polydipsia. He has a diagnosis of bipolar affective disorder but has been stable for several years on lithium. A water deprivation test diagnoses nephrogenic diabetes insipidus.

Which of the following structures has developed resistance to anti-diuretic hormone (ADH)?

Options:
explanation: ADH acts upon the collecting duct, rather than the proximal convoluted tubule. Nephrogenic diabetes insipidus does not involve ADH resistance of the proximal convoluted tubule, making this answer incorrect.
name: The proximal convoluted tubule
label: e
answer: no
explanation: ADH is synthesised, stored and released from the **posterior** pituitary gland not the anterior. Furthermore, this question describes a case of **nephrogenic** diabetes insipidus and thus the pituitary gland is unaffected.
name: Anterior pituitary gland
label: b
answer: no
explanation: ADH acts upon the collecting duct, rather than the renal glomerulus. Nephrogenic diabetes insipidus does not involve ADH resistance of the glomerulus, making this answer incorrect.
name: The glomerulus of the nephron
label: d
answer: no
explanation: The posterior pituitary gland is responsible for the synthesis, storage and release of ADH. In **cranial** diabetes insipidus, there is a lack of ADH secretion. However, this question features **nephrogenic** diabetes insipidus and therefore this answer is incorrect.
name: Posterior pituitary gland
label: c
answer: no
explanation: Nephrogenic diabetes insipidus is a condition in which the kidney fails to respond to ADH. This can be caused by a multitude of factors, however, the likely cause in this vignette is lithium which is being used as a mood stabiliser for this patient's bipolar affective disorder. ADH acts on the distal convoluted tubule and collecting ducts of the nephron, which increases the presence of aquaporin-2 channels allowing for water reabsorption.
name: The collecting ducts of the nephron
label: a
answer: yes

Correct answer: a
A 32 year old male attends his GP surgery to discuss the results of a recent semen analysis. The analysis shows hypospermia. The patient wishes to know more about the process by which a sperm cell can fertilise an oocyte.

Which of the following processes ensures only a single sperm cell fertilises an oocyte?

Options:
explanation: This release of proteolytic enzymes is key to digesting the zona pellucida. However, it plays no role in the polyspermy block and therefore is incorrect.
name: Release of Proteolytic enzymes from the sperm's acrosome
label: c
answer: no
explanation: This is present on the capacitated sperm cell head and is responsible for dissolving the connection between the cumulus-oocyte complex, which is necessary for sperm to penetrate the oocyte. However, it plays no role in the polyspermy block and is therefore incorrect.
name: Hyaluronidase of the sperm cell head
label: e
answer: no
explanation: This is the final maturation process for sperm and is necessary for fertilisation. However, it plays no role in the polyspermy block and is therefore incorrect.
name: Sperm capacitation
label: d
answer: no
explanation: Release of Ca2+ from the smooth endoplasmic reticulum is known as the cortical reaction and causes intracellular Ca2+ to rise, preventing polyspermy. This rise in Ca2+ stimulates a sequence of processes which hardens the membrane of the oocyte to prevent penetration of further sperm cells.
name: Release of Ca2+ from the smooth endoplasmic reticulum
label: a
answer: yes
explanation: Potassium ions are not involved in the polyspermy block and therefore this answer is incorrect.
name: Release of K+ from the smooth endoplasmic reticulum
label: b
answer: no

Correct answer: a
A 19 year old female comes to her GP to discuss contraceptive options. After discussion, she decides that she would like to try the combined oral contraceptive pill (COCP).

Which of the following describes the mechanism of action of this drug?

Options:
explanation: The combined oral contraceptive pill thickens cervical mucus. This makes it harder for sperm to reach the oocyte and therefore gives its contraceptive properties.
name: Thinning of the cervical mucus
label: c
answer: no
explanation: This is incorrect as the combined oral contraceptive pill is not used in patients who have sperm cells, or who produce semen. The COCP contains both oestrogen and progesterone. This in turn inhibits the release of FSH and LH through negative feedback, as well as causing thickening of the cervical mucus which makes it more difficult for sperm to penetrate. It also inhibits endometrial proliferation, which prevents implantation.
name: Reduces the number of sperm cells in semen
label: e
answer: no
explanation: Endometrial proliferation is part of the normal physiological process of the menstrual cycle to facilitate implantation of the oocyte to the endometrium and therefore fertilisation. The high levels of oestrogen and progesterone inhibit this process preventing implantation and therefore fertilisation of the oocyte.
name: Inducing endometrial proliferation
label: d
answer: no
explanation: The COCP contains both oestrogen and progesterone. This in turn inhibits the release of FSH and LH through negative feedback, as well as causing thickening of the cervical mucus which makes it more difficult for sperm to penetrate the uterus. It also inhibits endometrial proliferation, which prevents implantation. Thickening of the cervical mucus therefore correctly describes a component of the mechanism of action of the COCP.
name: Thickening of the cervical mucus
label: a
answer: yes
explanation: The combined oral contraceptive pill contains oestrogen and progesterone. It actually reduces levels of FSH and LH, which inhibits ovulation.
name: High LH and FSH levels inhibit oestrogen and progesterone levels
label: b
answer: no

Correct answer: a
A 20 year old woman receives a new diagnosis of Ehlers-Danlos syndrome. Her GP explains that this is an autosomal dominant condition.

Which of the following is true of autosomal dominant conditions?

Options:
explanation: This is incorrect. There are times when a person will be the first person in their family to have the specific mutation (de novo). This can occur due to a sporadic mutation.
name: There is always a family history of autosomal dominant disorders
label: d
answer: no
explanation: This is incorrect. If one parent carries the abnormal allele of an autosomal dominant condition, the chance of a child inheriting the allele and becoming a carrier is 50%. If Aa is the affected parent and aa is the unaffected parent: Aa, Aa, aa and aa are the possible allele combinations. 2 out of 4 of these are affected and therefore the chance is 50%.
name: There is 100% chance of a child inheriting an autosomal dominant condition if only one parent carries the gene
label: c
answer: no
explanation: This is incorrect. Males and females are equally affected. This statement would be true of x-linked recessive conditions; as males only have one x chromosome, if they inherit a pathogenic variant of x-linked recessive condition then they will be affected.
name: Only males can be affected
label: e
answer: no
explanation: This is correct. In autosomal dominant conditions, only one copy of the gene is needed for the individual to be symptomatic. This means that any patient with the abnormal allele will always be both a carrier and a sufferer. It also means that only one parent has to be a sufferer to pass on the condition.
name: Only one abnormal copy of a gene is needed for an individual to be symptomatic
label: a
answer: yes
explanation: This is incorrect. In autosomal dominant conditions, if one parent carries the faulty gene there is a 50% chance that their offspring will inherit it, and in turn become symptomatic.
name: Both parents must have a copy of the abnormal gene for the child to be symptomatic
label: b
answer: no

Correct answer: a
A 32 year old female patient presents to her GP with concerns about her pregnancy. She is currently 22 weeks pregnant and has had all of her routine checks without issue. However, she is concerned because a friend gave birth prematurely and the baby had to have "help to breathe". She is keen to learn more about foetal lung development.

Which of the following stages of lung development is the foetus still yet to undergo?

Options:
explanation: After 26 weeks the developing lungs enter the terminal sac stage. This is where the alveoli develop, comprised of type 1 pneumocytes (which are simple squamous epithelial cells) and type 2 pneumocytes (which are cuboidal cells that produce surfactant). As the foetus in the clinical vignette is only at 22 weeks gestation, its lungs are yet to have developed alveoli.
name: Development of the alveoli
label: a
answer: yes
explanation: Formation of the respiratory diverticulum occurs during the embryonic stage of lung development at 3-6 weeks gestation. The respiratory diverticulum forms in the foregut endoderm. As the foetus in this question is at 22 weeks gestation they will have undergone this stage, making this option incorrect.
name: Formation of the respiratory diverticulum
label: c
answer: no
explanation: The development of the bronchial tree occurs in the pseudoglandular stage of lung development. This occurs between 8-16 weeks gestation and involves multiple differentiations of the bronchial buds to form a primitive bronchial tree. As the foetus in this question is at 22 weeks gestation they will have undergone this stage and thus have developed a bronchial tree, making this option incorrect.
name: Development of the bronchial tree
label: b
answer: no
explanation: Formation of parietal and visceral pleura occurs during the embryonic stage of lung development from around 5 weeks gestation. The pleura is developed from the mesoderm. As the foetus in this question is at 22 weeks gestation they will have undergone this stage, making this option incorrect.
name: Formation of parietal and visceral pleura
label: d
answer: no
explanation: The mesoderm is one of the germ cell layers of the embryoblast. Following implantation the primitive streak appears in the epiblast and helps form new layers: firstly the endoderm and then the mesoderm, leaving the original layer of hypoblast cells (now known as the ectoderm). This occurs around weeks 2-3 of gestation. As the foetus in this question is at 22 weeks gestation they will have already undergone formation of the mesoderm, making this option incorrect.
name: Formation of the mesoderm
label: e
answer: no

Correct answer: a
A newborn boy is examined on the labour ward following an instrumental vaginal delivery.  The baby was born at 35 weeks gestation, weighing 5 pounds 9 ounces. On examination of the heart sounds a continuous 'machine whirring' murmur is identified across all areas of the chest.

Which of the following best describes the function of the foetal circulatory structure that has remained potent in this patient?

Options:
explanation: This is incorrect. This describes the role of the umbilical vein. This structure is closed after birth and becomes the round ligament of the liver. It can reopen later in life, for example in severe liver cirrhosis. However, it is not associated with a continuous 'machine' murmur and is therefore not the single best answer in this case.
name: Delivery of oxygenated blood from placenta to foetus
label: d
answer: no
explanation: This is correct. The baby in the vignette has a patent ductus arteriosus, as indicated by the continuous 'machine whirring' murmur heard on examination. A machine whirring murmur heard across the cardiac cycle is characteristic of patent ductus arteriosus. In foetal circulation the ductus arteriosus connects the pulmonary artery and the aorta, allowing blood from the right ventricle to bypass the pulmonary artery (and so bypass the inactive lungs) and instead pass around the rest of the body via the aorta.
name: Allow blood to bypass the lungs
label: a
answer: yes
explanation: This is incorrect. This describes the role of the umbilical artery which after birth becomes two parts; one becomes the median umbilical ligament and another remains open as part of the internal iliac artery. It is not associated with a continuous 'machine' murmur and is therefore not the single best answer.
name: Delivery of deoxygenated blood from fetus to placenta
label: e
answer: no
explanation: This is incorrect. This describes the role of the foramen ovale. This allows oxygenated blood from the placenta to pass from the right to the left atrium. It is a relatively common cause of a murmur on auscultation of the newborn heart. However, a patent foramen ovale causes a soft ejection systolic murmur heard best at the upper left sternal border, rather than a continuous 'machine' murmur. This is therefore not the single best answer.
name: Allow oxygenated blood can move from the right to left atrium
label: c
answer: no
explanation: This is incorrect. This describes the function of the ductus venosus, which allows blood from the placenta to bypass the liver, which in foetal physiology is not as active. A patent ductus venosus is uncommon and would not cause a continuous 'machine' murmur, so this is not the single best answer.
name: Allow blood to bypass the liver
label: b
answer: no

Correct answer: a
A 39 year old male presents to the GP surgery after a back injury sustained by picking up a heavy box at work. He experienced sudden, severe pain in his lower back with shooting pains down the back of his legs. Since the incident he has been unsteady on his feet tripping over multiple times. 
The patient enters the consultation room with a high-stepping gait. On examination there is sensory loss over the dorsum of his left foot. Dorsiflexion, inversion and eversion of the foot are significantly weaker on the left compared to the right side, however, all reflexes of the upper and lower limbs are intact.
Which of the following structures is most likely implicated in the patient's presentation

Options:
explanation: This answer is incorrect. Whilst a common peroneal nerve lesion can give rise to foot drop, sensory loss and pain, this patient's presentation is not wholly in keeping with a common peroneal nerve lesion. The impairment of inversion (a tibial nerve function), is indicative of an L5 radiculopathy rather than a common peroneal nerve lesion.
name: L3
label: d
answer: no
explanation: This is incorrect. The dermatome of L4 supplies the anterior aspect of the knee and medial malleolus, rather than the dorsum of the foot. Furthermore, the patella reflex is commonly disrupted in L4 lesions, whereas this patient demonstrated normal reflexes. L4 is therefore not the most likely location of the lesion in this case.
name: L4
label: c
answer: no
explanation: This answer is incorrect. Whilst a common peroneal nerve lesion can give rise to foot drop, sensory loss and pain, this patient's presentation is not wholly in keeping with a common peroneal nerve lesion. The impairment of inversion (a tibial nerve function), is indicative of an L5 radiculopathy rather than a common peroneal nerve lesion.
name: Common peroneal nerve
label: b
answer: no
explanation: This is correct. This vignette is characteristic of an L5 radiculopathy. The patient demonstrates clinical signs of foot drop, including a loss of dorsiflexion and a high stepping gate. The back pain and history of heavy lifting is suggestive of a disc herniation causing sciatica-like shooting pain, while the dermatomal loss of sensation on the dorsum of the foot makes an L5 lesion most likely. Limb reflexes are intact in L5 lesions.
name: L5
label: a
answer: yes
explanation: This is incorrect. Tibial nerve damage is characterised by weakness of foot plantarflexion and sensory loss over the plantar surface of the foot, rather than the dorsum. The tibial nerve is therefore not the most likely location of the lesion in this case. Another point to note is that the tibial nerve is a deep structure and is therefore not often injured through mechanical trauma.
name: Tibial nerve
label: e
answer: no

Correct answer: a

L5
A newborn baby is examined by the on-call paediatrician following an instrumental vaginal delivery. The baby was born at 39 weeks gestation and weighs 7 pounds 3 ounces. On examination, the baby's right shoulder rests in adduction while the right elbow is fixed in extension. The right forearm is pronated and wrist is flexed.

Which of the following nerve roots have been damaged in this patient?

Options:
explanation: This is incorrect. The infant in this vignette shows signs of Erb's palsy, which is caused by C5-C6 nerve root damage. C8-T1 are the nerve roots affected in Klumpke's palsy not Erb's palsy. This predominantly affects the nerves of the T1 root, ulnar and medial and presents with a clawed hand appearance.
name: C8-T1
label: d
answer: no
explanation: This is incorrect. The infant in this vignette shows signs of Erb's palsy, which is caused by C5-C6 nerve root damage. C3-C4 are unaffected by Erb's palsy, making this option incorrect. C3-C4 is also not part of the brachial plexus and therefore would not give rise to the clinical features described here.
name: C3-C4
label: b
answer: no
explanation: This is incorrect. The infant in this vignette shows signs of Erb's palsy, which is caused by C5-C6 nerve root damage. By contrast, T2-T3 nerve roots are not part of the brachial plexus. Therefore any damage to these roots would not give rise to the clinical presentation seen in this case.
name: T2-T3
label: e
answer: no
explanation: This is correct. The patient in the vignette demonstrates the waiter's tip sign which is characteristic of Erb's palsy. This involves damage to the nerve roots C5-C6. Being born via an instrumental vaginal delivery is a risk factor for Erb's palsy. Individuals with Erb's palsy also show dermatomal sensory loss in the C5-6 distribution.
name: C5-C6
label: a
answer: yes
explanation: This is incorrect. The infant in this vignette shows signs of Erb's palsy, which is caused by C5-C6 nerve root damage. C7-C8 are unaffected by Erb's palsy, making this option incorrect. C7-C8 damage would also not give rise to the clinical signs in the vignette as the waiter's tip sign is seen due to the musculocutaneous and axillary nerves being affected.
name: C7-C8
label: c
answer: no

Correct answer: a
A 25 year old male patient presents to A&E after a cricket ball hits him in the right elbow during a match. On examination, there is marked tenderness at the right medial epicondyle. There is also weakness of wrist flexion and thumb adduction on the right side compared to the left, as well as a sensory deficit in the medial one-and-a-half digits of the right hand.

Which of the following nerves is most likely to be damaged?

Options:
explanation: This is incorrect. The musculocutaneous nerve is responsible for elbow flexion and supination, not wrist flexion or thumb adduction. Furthermore, the sensory distribution of the musculocutaneous nerve is to the lateral part of the forearm, not the medial one-and-a-half fingers. The pattern of deficits seen in this patient is therefore most in keeping with an ulnar nerve lesion.
name: Mucsculocutaneous nerve
label: b
answer: no
explanation: This is incorrect. The radial nerve is responsible for forearm, wrist, finger and thumb extension, not wrist flexion or thumb adduction. Furthermore, the sensory distribution of the radial nerve is to the dorsal aspect of the thumb, index and middle finger, as well as the lateral side of the ring finger. The pattern of deficits seen in this patient is therefore most in keeping with an ulnar nerve lesion.
name: Radial nerve
label: d
answer: no
explanation: This is correct. This vignette is strongly suggestive of an ulnar nerve injury. Fracture to the medial epicondyle is a common cause of ulnar nerve injury, and this is suggested by the tenderness of the medial epicondyle on a background of recent trauma. The patient also demonstrates weakness in wrist flexion and thumb adduction; both functions of the ulnar nerve. Furthermore, the patient shows a sensory deficit in the medial one-and-a-half digits of the right hand, which is supplied by the ulnar nerve.
name: Ulnar nerve
label: a
answer: yes
explanation: This is incorrect. The median nerve is responsible for motor actions of the LOAF (flexor pollicis brevis, opponens pollicis, abductor pollicis brevis and lateral two lumbricals) muscles of the hand, including but not limited to little finger abduction and flexion. It is not responsible for wrist flexion or thumb adduction. Furthermore, the sensory distribution is to the lateral three-and-a-half fingers rather than the medial one-and-a-half fingers. The pattern of deficits seen in this patient is therefore most in keeping with an ulnar nerve lesion.
name: Median nerve
label: e
answer: no
explanation: This is incorrect. The axillary nerve is responsible for shoulder abduction, not wrist flexion or thumb adduction. Furthermore, the sensory distribution of the axillary nerve is the inferior region of the deltoid muscle, not the medial one-and-a-half fingers. The pattern of deficits seen in this patient is therefore most in keeping with an ulnar nerve lesion.
name: Axillary nerve
label: c
answer: no

Correct answer: a
A 44 year old woman presents to the GP with pain in both of her hands. The pain has been present for the last month and is worse in the morning; her hands feel very stiff all morning but later improve with movement. She is otherwise fit and well, and had no other medical conditions and no recent infections. She has been taking paracetamol for the pain to limited effect but has no regular medications.

On examinatio,n she has tender, red, swollen metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints bilaterally. All other joints are unremarkable. Her observations are all within normal limits.

Which of the following is the most likely underlying diagnosis?

Options:
explanation: This is correct. There are several signs of symptoms in this case that are characteristic of rheumatoid arthritis. Prolonged morning stiffness (>30 minutes) that improves throughout the day is a characteristic of inflammatory pain such as in rheumatoid arthritis. It typically features bilateral involvement of the small joints of the hand, and is more common in women, with typical age of onset between the ages 40-60 years old.
name: Rheumatoid arthritis
label: a
answer: yes
explanation: This is incorrect. Reactive arthritis is an inflammatory arthritis that typically occurs in the four weeks following an infection. It is also usually a monoarthritis, most commonly affecting the large joints of the lower limbs. Rheumatoid arthritis is therefore more likely in this case.
name: Reactive arthritis
label: c
answer: no
explanation: This is incorrect. There are a few features of this case that make osteoarthritis less likely. Firstly, the patient is below the typical age of onset for osteoarthritis. The presence of morning stiffness that improves with activity, and involvement of the small rather than large, weight-bearing joints, is also indicative of an inflammatory arthritis such as rheumatoid arthritis.
name: Osteoarthritis
label: b
answer: no
explanation: This is incorrect. Septic arthritis typically presents with an acutely painful, hot, swollen monoarthritis. Patients tend to be systemically unwell. The timeframe, multiple small joint involvement and normal observations seen in this case mean that rheumatoid arthritis is a more likely underlying diagnosis.
name: Septic arthritis
label: d
answer: no
explanation: This is incorrect. Psoriatic arthritis shares many characteristics with rheumatoid arthritis and with this case. However, there are key differences. Psoriatic arthritis typically involves personal or family history of psoriasis, often including nail changes or dactylitis. These features are not mentioned in this case, making rheumatoid arthritis a more likely underlying diagnosis.
name: Psoriatic arthritis
label: e
answer: no

Correct answer: a