Practice Questions from Weekly Quizes

Question 1

Which component of the cell membrane prevents the membrane from becoming too rigid?

1. Cholesterol
2. Sphingomyelin
3. Phosphatidyl serine
4. Transmembrane ion pores
5. Transmembrane cell surface receptors

Answer 1

1. Cholesterol

This is found within the phospholipid bilayer and helps to maintain the fluidity of the membrane. It helps to prevent the membrane from becoming too rigid or too fluid, allowing it to function optimally.

Question 2

The following is a simple diagram of an important homeostatic endocrine loop known as the renin-angiotensin-aldosterone system (RAAS). Various drugs target this system.

When the blood pressure is low the kidney releases renin. This converts angiotensinogen to angiotensin I which is converted by angiotensin converting enzyme (ACE) to angiotensin II (AG II). AGII causes arteries to constrict and by becoming narrower they raise blood pressure. AG II also stimulates release of aldosterone. Aldosterone acts back on the kidney causing the kidney to retain salt and water, which will further raise blood pressure.

Hypertension is a very common condition and one of the main classes of treatment are angiotensin converting enzyme inhibitors (ACE inhibitors) which will lower blood pressure.

Using your knowledge of homeostasis what would be the effect of an ACE inhibitor on the other parts of this feedback loop.

1. Increased aldosterone and increased angiotensinogen
2. Reduced aldosterone and increased renin
3. Increased aldosterone and reduced renin
4. No effect on any components
5. Reduced renin and increased aldosterone

Answer 2

2. Reduced aldosterone and increased renin

The reduced AG II will lead to lower aldosterone levels, which will reduce salt and water retention. AGII will also lower blood pressure which will lead to increased renin. This will be trying to re-establish the original homeostatic position by increasing AG II and aldosterone.

Question 3

How does oxygen get into the cell?

1. Protein co-transporter with glucose
2. Diffusion
3. Protein uniporter
4. Protein anti-porter with carbon dioxide
5. Protein active transporter with glucose

Answer 3

2. Diffusion

Question 4

A 62 year old woman has three months of occasional central chest pain. These episodes mostly occur when she walks uphill, especially into the wind. The pain lasts about 5 minutes and goes away when she rests. She is an ex-smoker. She has hypertension and takes amlodipine.
Her pulse is 68 bpm and blood pressure 149/96 mmHg.
What is the most likely diagnosis?

1. Angina
2. Non-ST elevation myocardial infraction
3. Aortic dissection
4. Pneumothorax
5. Pleurisy

Answer 4

1. Angina

This is the typical presentation of angina. The patient likely has atheroma in her coronary arteries which reduces the ability to increase blood supply when she exerts herself.

Question 5

How does glucose get into a kidney epithelial cell?

1. Diffusion across the membrane
2. Sodium-glucose co-transporter
3. Lysosomal membrane uptake
4. Potassium-glucose anti-porter
5. Glucose-ATP co-transporter

Answer 5

2. Sodium-glucose co-transporter

Question 6

The following an image from a CT scan abdomen.

Match each arrow to the correct anatomical description.

Spleen
Right kidney
Abdominal aorta
Intestine
Liver

Answer 6

• A – liver
• B – Abdominal aorta
• C – Intestine
• D – spleen
• E – right kidney

Question 7

A 44 year old woman is confused and drowsy following an abdominal operation. She has received intravenous morphine.
Her temperature is 36.4°C, pulse 88 bpm, blood pressure 118/72 mmHg and respiratory rate 8 breaths per minute. Her tongue has a blue-grey discolouration (see image)

What is the cause of the discolouration of the tongue?

1. Decreased extracellular partial pressure of of oxygen
2. Increased deoxygenated haemoglobin
3. Increased plasma bicarbonate
4. Decreased haemoglobin concentration
5. Increased dissolved carbon dioxide

Answer 7

2. Increased deoxygenated haemoglobin

The patient has the clinical sign of cyanosis. This is due to increased deoxyhaemoglobin concentration and associated hypoxaemia. Although tissue oxygen levels are also low they are not the direct cause of the colour discolouration. The affinity of haemoglobin for haemoglobin is unlikely to have undergone any change. Although carbon dioxide concentration is increased it does not cause the colour change. In this patient the respiratory drive is most likely to have been reduced by morphine leading to hypoxaemia. Although the fingers can often show cyanosis this is harder to detect in patient with darker skin, hence the importance of looking at the tongue. The oxygen saturation monitor is the best way to measure this at the bedside.

Question 8

This shows an X-ray of a normal right shoulder.

Match the arrow for each part to the correct bone description.

Humeral head
Humeral shaft
Scapula
Clavicle
Glenoid

Answer 8

A – Humeral head
B – Clavicle
C – Glenoid
D – scapula
E – Humeral shaft

Question 9

A 70 year old woman has tiredness and reduced exercise capacity. She has lost weight over the last three months.
Her oxygen saturation is 96% breathing air. Her cardiovascular and respiratory examination are normal.
Investigations-Blood test
Haemoglobin 88 g/L (115-165)
What is the best explanation for her reduced oxygen capacity?

1. Reduced cardiac output
2. Reduced carbon dioxide transport from tissues
3. Increased carbon dioxide in the lungs
4. Reduced oxygen delivery to tissues
5. Reduced respiratory muscle effort

Answer 9

4. Reduced oxygen delivery to tissues

Oxygen is transported bound to iron in the haem ring of haemoglobin. It picks up oxygen at the alveolar capillary interface and transports it to tissues where it dissociates. This patient has a low haemoglobin. This is known as anaemia. Haemoglobin still functions normally but there is insufficient amounts of haemoglobin to transport sufficient oxygen especially when demand increases.

Question 10

A 70 year old woman has 12 months of worsening breathlessness on exertion. She struggles to walk up hills and has to stop at least twice when she walks to the shop, which is about 1 km away. She has an occasional cough bringing up a small amount of white sputum. She has hypertension. She is an ex-smoker and she smoked 20 cigarettes per day for 50 years (this is a 50 pack year smoking history).
Her blood pressure is 128/85 mmHg. Her chest and cardiovascular examination is normal.
Investigations:
Forced expiratory volume in 1 sec (FEV1)/Forced vital capacity (FVC) ratio: 50% (normal >75%)
What is the most likely diagnosis?

1. Asthma
2. Chronic obstructive pulmonary disease
3. Lung cancer
4. Heart failure
5. Anaemia

Answer 10

2. Chronic obstructive pulmonary disease

This is typical history of chronic obstructive pulmonary disease with progressive breathlessness in someone with a previous smoking history. Heart failure is another possibility although there are no other specific features for this diagnosis. The FEV1/FVC ratio is used to make this diagnosis. The following link gives an outline for spirometry: https://www.blf.org.uk/support-for-you/breathing-tests/spirometry-and-reversibility

Question 11

What mechanism is the major contributor to transport of carbon dioxide from peripheral tissues to the lungs?
1. Dissolved carbon dioxide in plasma
2. Bound the iron in haem ring
3. Bound to amine groups in globin chain
4. Bound to albumin
5. Dissolved in plasma as bicarbonate

Answer 11

5. Dissolved in plasma as bicarbonate

Carbon dioxide is transported in three ways:
A small amount is directly dissolved in plasma
A more significant component is bound to amine groups on amino acids on polypeptide chains such as globin and albumin.
Most is carried in the form of bicarbonate as CO2 dissolves in plasma. This process is catalysed by carbonic anhydrase in red blood cells. This is also why carbon dioxide plays an important role in acid base regulation.

Question 12

What process best describes the release of neurotransmitter into the synaptic cleft?

1. Direct pre-synaptic to post synaptic membrane contact
2. Lipophilic diffusion
3. Release of neurotransmitter through voltage gated channels
4. Active transport of neurotransmitter via ATP dependent channel
5. Vesicle membrane fusion

Answer 12

5. Vesicle membrane fusion

Neurotransmitters are contained in the pre-synaptic terminal in vesicles. The action potential causes entry of calcium which promotes fusion of vesicles with the membrane and exocytosis of neurotransmitter.

Question 13

An 85 year old man has three days of worsening back pain and difficulty walking. He has a history of prostate cancer.
He has weakness of hip flexion and knee extension with brisk reflexes.

MR scan spine:

Which structure highlighted by the arrow is abnormal?

1. Thoracic rib
2. Rhomboid major
3. Transverse process
4. Spinal cord
5. Vertebral body

Answer 13

5. Vertebral body

The MR scan shows an abnormal T7 vertebra, most likely due to a deposit of metastatic cancer. He has clinical and radiological evidence of compression of the spinal cord.

Question 14

A 71 year old woman has six months of intermittent dull left hip pain. The pain is worse towards the end of the day and also occurs when she gets up from a seated position. She has some stiffness in the hip in the morning which lasts for around 10 minutes.
Her temperature is 36.5°C. She has discomfort on active and passive flexion and internal rotation of the left hip. Her BMI is 26.

She is given oral paracetamol as analgesia.
What other treatment is indicated?

1. Exercise regime
2. Oral calcium and vitamin D supplements
3. Glucocorticoid injection of left hip joint
4. Oral dihydrocodeine
5. Topical ibuprofen

Answer 14

1. Exercise regime

The clinical diagnosis is of left hip osteoarthritis. Pain relief with oral paracetamol is recommended. It is also important recommend an exercise regime to improve muscle strength. Topical non-steroidal anti-inflammatory drugs are used on hands and knee but penetration to hip is unlikely. You would not use a weak opiate such as dihydrocodeine. Injections of glucocorticoid are not used on the hips. There is no evidence that vitamin D and calcium supplements help.

Question 15

A 25 year old man is involved in a road traffic collision.
His hands feel cool with a capillary refill time of 6 seconds. His pulse is 120 bpm and blood pressure 90/60 mmHg.
Which neurotransmitter is responsible at the end organ for the cold hands and tachycardia?

1. Acetylcholine
2. Dopamine
3. Noradrenaline
4. Histamine
5. Adenosine

Answer 15

3. Noradrenaline

This patient has hypovolaemia due to haemorrhage. This activates baroreceptors due to low blood pressure which in turn activates the sympathetic nervous system. Release of noradrenaline causes an increased heart rate and constriction of blood vessels both designed to increase blood pressure and maintain perfusion of critical organs.

Question 16

The spinal cord extends from the foramen magnum to the level of which vertebral bodies?

1. T10/T11
2. L1/L2
3. L3/L4
4. L5/S1
5. S2/S3

Answer 16

2. L1/L2

The spinal cord ends as the conus medullaris at L1/L2 level.

Question 17

The following is a diagram of the an action potential.

What process happens at point A?

1. Opening of stimulus-gated sodium channels
2. Closure of voltage-gated potassium channels
3. Activation of sodium-potassium ATP pump
4. Opening of voltage-gated sodium channels
5. Opening of stimulus-gated potassium channels

Answer 17

4. Opening of voltage-gated sodium channels

The action potential involves the initial entry of sodium by stimulus or ligand gated sodium channels and once the threshold potential is reached voltage gated sodium channels open leading to rapid sodium entry into the cell and depolarization. This is then transmitted along the neurone.

Question 18

The plasma membrane of a neurone has a resting membrane potential of -70 mV.
What is the main mechanism by which this is maintained?

1. Increased intracellular chloride anions
2. Increased intracellular bicarbonate ions
3. Increased extracellular potasssium ions
4. Sequestration of calcium ions in the sarcoplasmic reticulum
5. Increased extracellular sodium ions

Answer 18

5. Increased extracellular sodium ions

There are more cations on the outside of the membrane primarily sodium (Na+). There is an active sodium-potassium pump (ATP dependent) that pumps out 3 sodium ions to 2 potassium, which results in net positive charge outside so a negative potential across the membrane.

Question 19

A 65 year old woman has sudden onset of weakness of her right arm and leg and inability to speak 3 hours ago. She has hypertension and type 2 diabetes mellitus.
Her blood pressure is 169/90 mmHg. She has flaccid weakness of her right arm and leg, drooping of the lower right half of her face and is unable to speak. She is unable to swallow a teaspoon of water without choking.

MR scan brain:

Which blood vessel is most likely to be occluded?

1. Right external carotid artery
2. Left internal carotid artery
3. Left anterior cerebral artery
4. Right Vertebral artery
5. Basilar artery

Answer 19

2. Left internal carotid artery

The patient has an acute stroke with evidence of ischaemia/infarction of the parietal lobe. This will involve occlusion of the left internal carotid artery and probably left middle cerebral artery.

Question 20

What is the function of the nerves myelin sheath?

1. Optimise oxygen transfer to neurones
2. Regulate extracellular electrolyte composition
3. Prevent synaptic connections between neurones
4. Enable unidirectional transmission of action potential
5. Speed up transmission of the action potential

Answer 20

5. Speed up transmission of the action potential

Myelin forms a sheath around the neurones with gaps known as the nodes of Ranier. The electrical changes of the synapse can only occur at these areas so an action potential at one node triggers an action potential at the next one. This is called saltatory conduction with the action potential leaping from one node to the next.

Question 21

Which cell is responsible for the synthesis of proteoglycans and collagen in cartilage?

1. Chondrocyte
2. Fibroblast
3. Mast cells
4. Osteoblast
5. Osteoclast

Answer 21

1. Chondrocyte

Chondrocytes produce collagen and proteoglycans that comprose critical components of cartilage.

Question 22

A 55 year old woman as admitted following a fall. Her left wrist is painful and deformed.
X-ray (see image).

Which bone is fractured?
1. Radius
2. Scaphoid
3. Trapezoid
4. First metacarpal
5. Ulna

Answer 22

1. Radius

This is a Colles fracture of the radius.

Question 23

Match the label to each component of the shoulder anatomy.

Glenohumeral ligament
Coracoclavicular ligament
Coracoacromial ligament
Coracohumeral ligament

Answer 23

A-Coracoacromial ligament
B-Coracohumeral ligament
C-Glenohumeral ligament
D-Coracoclavicular ligament

Question 24

An 80 year old woman has a fall and fractures her right neck of femur. She has a right hip arthroplasty and makes a good functional recovery. She is taking paracetamol as required for analgesia. She has hypertension and takes amlodipine.
What is the most appropriate change to her treatment on discharge?

1. Stop amlodipine
2. Start ibuprofen
3. Start hormone replacement therapy
4. Start alendronic acid
5. No change in treatment

Answer 24

4. Start alendronic acid

This woman has a fragility fracture and should be started on a bisphosphonate to reduce the risk of further fractures. She does not need an assessment of her bone mineral density before starting this.

Question 25

A 70 year old man has two years of increasing bilateral knee pain. The pain is worse at the end of the day and occasionally wakes him at night. His knees feel stif first thing in the morning but has imp[roved by the time he has taken a shower..
He has swelling of both knees with crepitus on passive flexion. There is no effusion. his BMI is 27.
He is using topical ibuprofen gel with some effect.
What is the most appropriate management?

1. Arrange MR scan both knees
2. Arrange X-rays both knees
3. Recommend active lifestyle and weight loss
4. Change topical ibuprofen to oral ibuprofen
5. Start oral glucosamine

Answer 25

3. Recommend active lifestyle and weight loss

The patient has a clinical diagnosis of osteoarthitis. The main management should focus on maintaing an active lifestyle and losing weight. Imaging investigations are not required.

Question 26

What most abundant amino acids in collagen type 1?
1. Glycine, proline, hydroxyproline
2. Alanine, lysine, valine
3. Cysteine and glycine
4. Leucine, threonine and arginine
5. Serine, valine and tyrosine

Answer 26

1. Glycine, proline, hydroxyproline

The primary amino acid sequence of collagen is either glycine-proline-X or glycine-X-hydroxyproline, where X is one of 17 amino acids.

Question 27

A 65 year old woman is seen in the Emergency Department following a fall. She has pain in both hips.
Pelvis X-ray (see image)

What surgical procedure has she had on the left hip?

1. Dynamic hip screw
2. Hip hemiarthroplasty
3. Hip resurfacing
4. Hip osteotomy
5. Total hip arthroplasty

Answer 27

5. Total hip arthroplasty

The X-ray shows a total hip arthroplasty which is the most effective surgery for hip osteoarthritis.

Question 28

A 55 year old woman has six months of painful swelling of the joints of her hands, elbows and wrists. She has hypertension and a previous stroke. She smokes 10 cigarettes per day and drinks 30 units of alcohol per week. She does not take any exercise. Her medication includes clopidogrel, atorvastatin and lisinopril.
She has swelling and tenderness of the metacarpophalangeal joints in both hands and at the wrists.
Investigations
Anti-cyclic citrinullated peptide antobodies 120 U/mL (< 10)

What feature of her history is most likely to have contributed to the development of this presentation?

1. Atorvastatin
2. Alcohol intake
3. Lack of exercise
4. Previous stroke
5. Smoking history

Answer 28

5. Smoking history

The patient has rheumatoid arthritis. Smoking is a significant risk factor for the development of this disease.

Question 29

A 47 year old man has a 12 month history of rheumatoid arthritis. He is taking oral methotrexate, hydroxychloroquine and naproxen. He continues to have symptoms and signs of active arthritis and synovitis in his hands.
Additional biologic treatment is planned.
What is the most likely mechanism of this additional treatment?

1. Increase interleukin-1 activity
2. Increase interleukin-10 activity
3. Inhibit tumour necrosis factor-α
4. Inhibit endothelial cell growth
5. Reduce circulating white blood cells

Answer 29

3. Inhibit tumour necrosis factor-α

The patient has active rheumatoid arthritis which has not responded to intial diseae modifying anti-rheumatic drugs. The next step is either to add anti-TNF or anti-IL-6 biological treatment. Treatment guidelines can be found here:

https://pathways.nice.org.uk/pathways/rheumatoid-arthritis#path=view%3A/pathways/rheumatoid-arthritis/drug-treatment-for-rheumatoid-arthritis.xml&content=view-node%3Anodes-initial-treatment

Anti-TNF and anti-IL-6 are antibodies designed to decrease inflammatory response

Question 30

A 60 year old man develops sudden pain in his left heel while playing tennis.
There is tenderness and swelling over the left heel with a defect palpable in the Achilles tendon.
Which further assessment is most likely to help confirm the diagnosis?
1. Check for tenderness over medial and lateral malleoli
2. Test eversion and inversion against resistance
3. Test dorsiflexion against resistance
4. Ask patient Stand on left leg with eyes closed for 15 seconds
5. Squeeze the patient’s left calf with the left knee resting at 90°C on a chair

Answer 30

5. Squeeze the patient’s left calf with the left knee resting at 90°C on a chair

This is most likely an Achilles tendon rupture. The best bedside test is to squeeze the calf while the knee is resting on chair. If the foot does not plantarflex then this will confirm the diagnosis. This is known as Thompson test.