Go over Flashcards
A 55-year-old woman with a history of hypertension and smoking is brought to the Emergency Department with sudden onset of severe headache and vomiting. Subsequent investigations reveal a subarachnoid haemorrhage.
What is the most likely aetiology?
a) cerebral contusion
b) rupture of berry aneurysm
c) rupture of cerebral microaneurysms
d) rupture of middle meningeal artery
e) tear in veins crossing subdural space
What do the others cause?
b) rupture of berry aneurysm
cerebral contusion = bruising of the brain due to trauma
rupture of cerebral microaneurysms - intracerebral haemorrhage
rupture of middle meningeal artery - extradural haemorrhage (lucid period after initial unconsciousness)
tear in veins crossing subdural space - subdural haemorrhage
A 22-year-old man has profound bilateral hearing loss. He is unable to follow the spoken word but can communicate fluently using sign language. His condition, which is classed as sensorineuronal rather than conductive hearing loss, was acquired when he underwent antibiotic treatment in infancy.
What is the most likely location of the damage to his auditory system?
a) cochlear nerve
b) primary auditory cortex
c) spiral organ of the cochlea
d) tympanic membrane
e) Wernicke’s cortical language area
c) spiral organ of the cochlea
associated with ototoxicity from antibiotics
hair cells wuld be sensitive to toxic chemicals and therefore damaged, and they are found in the cochlea
A 52-year-old woman has a 12-year history of Meniere’s disease, characterised by occasional episodes of tinnitus, vertigo, nausea and vomiting. The disease has caused a progressive loss of hair cells from all parts of her inner ear, and she has suffered a gradual loss of hearing. However, between episodes she has no vestibular problems.
What is the most likely explanation for the episodic nature of her vestibular symptoms?
a) Area postrema is capable of marked adaptation to changes in sensory input
b) Cerebellum can compensate for permanent changes in the vestibular signal
c) Hair cells in the inner ear belong to the auditory and not the vestibular system
d) Loss of vestibular hair cells reduces input to the nucleus tractus solitarius
e) Vestibular signals are sent to the “anti-toxin circuitry” only when the cells are dying
b) cerebellum can compensate for permanent changes in the vestibular signal
The vestibular signals are used to control eye movements, and need to remain precisely accurate even in the face of changes in the system
the output is fed through the cerebellum, where long-term changes in synaptic strength can recalibrate the system as needed
A 24-year-old woman is brought to the emergency department after being knocked off her bicycle following an accident. She is in significant pain with a suspected injury to her right shoulder and arm and is prescribed morphine.
What does morphine inhibit to reduce pain neurotransmission?
a) Ca2+ channels
b) GABA receptors
c) K+ channels
d) Mu receptors
e) Na+ channels
d) Mu receptors
morphine acts on mu receptors on GABAergic neurons to cause disnihibition. The prevention of the inhibition of dopamine release causes a surge of dopamine.
furthermore, it can act on orbitofrontal cortex (OFC), periacqueductal grey (PAG) and spinal cord to stimulate the descending pain modulation pathway
A 25-year-old man volunteers for a clinical trial of a new drug. The drug is lipophilic and administered intravenously.
What best describes the property of a lipophilic drug?
a) A large volume of distribution
b) A short half-life
d) Low bioavailability
e) Poor permeability at the blood-brain barrier
Lipophilic drugs tend to have a large volume of distribution. This is because they readily cross cell membranes and accumulate in fatty tissues and other lipid-rich areas of the body. As a result, they are not confined to the vascular space but are distributed extensively throughout the body, leading to a high volume of distribution.
A chemist creates a new analgesic drug which is absorbed into the body better than a previous drug.
An increase in what property is most likely to be associated with this change?
a) Absorption in the stomach
b) Concentration difference
c) Lipid solubility
d) Molecular weight
e) Polar groups
c) lipid solubility
absorption of drugs requires them to cross layers of cells with semi-permeable lipophilic membranes (most absorption occurs through cells - transcellular)
*absorption in the stomach is incorrect because mort absorption occus in the small intestine
An 88-year-old man presents with sudden onset leg pain to the Emergency Department (ED). He has a background of ischaemic heart disease and peripheral vascular disease and the ED doctor is concerned about acute limb ischaemia
Which symptoms or signs would best support a diagnosis of acute limb ischaemia?
a) Pallor
b) Pink discolouration
c) Prominent veins
d) Pulsus paradoxus
e) Pruritus
And what is pruritus?
a) pallor
acute limb ischaemia is caused by sudden decrease in blood supply to the limb which compromises its viability
pruritus - itchy sensation of the skin due to e.g. skin condition/rash or a systemic illness such as liver disease
A 17-year-old woman presents to the Emergency Department following a horse-riding accident. She sustains a fracture of the surgical neck of humerus.
What structure is most at risk in a surgical neck fracture?
a) Axillary nerve
b) Brachial plexus
c) Musculocutaneous nerve
d) Radial nerve
e) Ulnar nerve
a) axillary nerve
axillary nerve wraps around the surgical neck of the humerus posteriorly
the radial nerve travels along the posterior aspect of the shaft of the humerus.
A 36-year-old woman is due for surgery on their left knee having sustained a sporting injury. The anaesthetist in charge is required to perform a nerve block to the adductor canal.
What nerve will most likely be affected by the nerve block?
a) Femoral nerve
b) Genitofemoral nerve
c) Obturator nerve
d) Saphenous nerve
e) Sural nerve
and Describe the adductor canal
d) sapphenous nerve
the adductor canal is a passageway between the anterior and posterior compartments of the thigh
it contains the femoral nerve, femoral vein and the sapphenous vein - a branch of the femoral nerve
as the sapphenous vein exits the adductor canal it becomes the popliteal vein
borders of the adductor canal:
laterally - vastus medialis
anteromedially - sartorius
posteriorly - adductor longus and adductor magnus
A 37-year-old woman presented with small flat areas of altered colour to the skin of her lips. The lesions were less than 1cm in diameter and had a smooth flat surface.
What term most appropriately describes these lesions?
a) Macule
b) Nodule
c) Papule
d) Plaque
e) Vesicle
a) macule
smooth and relatively flat
papule is raised and <5mm
nodule is raised and larger
plaque is raised and thickened
vesicle is raised and fluid filled ‘bubble’, smaller than a blister
A 55-year-old woman is admitted with severe pins and needles in both hands, associated with a perception of breathlessness and confusion. She has felt unwell, with other nonspecific symptoms including muscle cramps, since a thyroidectomy operation 3 weeks previously.
Initial blood tests results:
adjusted calcium
1.6 mmol/l (2.2 - 2.6)
phosphate
1.8 mmol/l (0.8 - 1.5)
What is the most likely cause of her signs and symptoms?
a) Hypoparathyroidism
b) Lung cancer
c) Osteoporosis
d) Renal failure
e) Vitamin D deficiency
a) hypoparathyroidism
hypoparathyroidism is characterised by low PTH which causes low Calcium and high Phosphate
PTH increases calcium by:
- stimulating osteoblasts to produce more M-CSF and RANKL to stimulate osteoclasts to increase bone resorption and Ca release into blood
- stimulates more Ca reabsorption in the DCT of kidney
PTH decreases phosphate by
- stimulating less phosphate reabsorption into the PCT of the kidney, therefore causing more phosphate excretion
therefore, less PTH following thyroidectomy has the opposite effect
furthermore, hypoparathyroidism has characteristic symptoms of pins and needles, confusion and breathlessness
A 38-year-old woman has symptoms of malaise, aches and pains and weight loss. She is found to have a high calcium: 4.1 mmol/l (normal range 2.2-2.6 mmol/l). Her urea and electrolytes, albumin and full blood count are normal.
What further biochemical test is the most appropriate to perform?
a) Ionized ‘free’ calcium in serum
b) Serum alkaline phosphatase
c) Serum calcitonin
d) Serum IGF-1
e) Serum parathyroid hormone
e) serum parathyroid hormone
determining whether PTH is high or low with the hypercalcaemia will help determine its cause
A 78-year-old woman is seen in a vascular clinic for leg claudication. She is examined by the consultant, who palpates for all the patient’s lower limb pulses.
What location best describes where the dorsalis pedis pulse is palpated?
a) Anterior to the lateral malleolus
b) Between the heads of the gastrocnemius muscle
c) Lateral to the extensor hallucis longus tendon
d) Medial to the extensor pollicis brevis tendon
e) Posterior to the medial malleolus
lateral to the extensor hallucis longus tendon
A 60-year-old man who presents to his General Practitioner with left knee pain and swelling is given a referral for an X-ray. On review of his X-ray a diagnosis of osteoarthritis is suspected. He has a past medical history of knee surgery at age of 20-years, as a result of knee injury while playing rugby.
What combination of findings on plain x-rays best explains the suspected diagnosis?
a) Calcium deposits, subchondral fracture, joint effusion
b) Joint effusion, osteopenia, erosions
c) Narrowed joint space, erosions, calcium deposits
d) Narrowed joint space, osteophytes, subchondral sclerosis
d) narrowed joint space, osteophytes, subchondral sclerosis
narrowed joint space: due to cartilage degradation
oseteophytes: bony outgrowths in the joint margins due to chronic mechanical stress and joint instability
subchondral sclerosis: increased bone density in the subchondral bone because the bone has had to repair often and the cartilage doesn’t fully repair each time
A 2-year-old child is found to have inefficient phagocytic cell function. Laboratory tests confirm a diagnosis of chronic granulomatous disease.
What component of the phagocytosis pathway is most likely affected in this patient?
a) Chemokine-dependent migration
b) Complement-dependent opsonisation
c) Lysosomal-dependent killing
d) NADPH-dependent killing
e) TLR-dependent recognition
And what does Chediak-Higashi cause?
d) NADPH-dependent killing
Chediak-Higashi causes defective phagosome-lysosome fusion
