Formative Exam: Knowledge Gaps

Question 1

What it comes to risk factors in disease what does an environmental factor mean?

Answer 1

Anything that is not genetic

Question 2

What is a chemoreceptor?

Answer 2

Nerve receptors that sense changes in the chemical composition of the blood

Question 3

How does PCO2 affect breathing?

Answer 3

Chemoreceptors pick up changes in PCO2 in the blood, if this increases breathing is increased to expell CO2

Question 4

What is the first line if investigation into COPD

Answer 4

Spirometry

This is where the measures the strength of your exhalation

Question 5

What is the main function of protein kinases?

Answer 5

Add phosphate groups to proteins

Question 6

What is the purpose of phosphorylation?

Answer 6

Phosphorylation of amino acids changes how they form into proteins and therefore the structure of the protein. The structure of the protein defines the function of the protein.

Question 7

What polymerises amino acids?

Answer 7

Ribosomes

Question 8

A 60 year old man visits his GP for a health check. He has a history of lower
back pain.
His blood pressure is 140/85 mmHg and BMI 30.
He is given advice about weight loss.
What is the correct advice to give the patient about exercise?

Answer 8

Aim for at least 150 minutes per week of moderate intensity activity

The current (2021) UK guidelines are for patient to have at least 150 minutes of moderate intensity exercise
(cycling, swimming, walking) or 75 minutes of vigorous intensity such as running. This level of exercise can be done
independent of his BP (which is not raised) and BMI (which is).

Question 9

Which is the most accurate description of the structure of tropocollagen?

Answer 9

Three left hand helix polypeptide strands twisted into a super helix

Item notes: A single collagen molecule, tropocollagen, is approximately 300 nm long and 1.5 nm in diameter, and it is
made up of three polypeptide strands (called alpha peptides, each of which has the conformation of a left-handed helix.
These three left-handed helices are twisted together into a right-handed triple helix or “super helix”, a cooperative
quaternary structure stabilized by many hydrogen bonds.

Question 10

Which neurotransmitter is released by motor neurons at the neuromuscular
junction?

Answer 10

Acetylcholine

Question 11

What constituent of peripheral nerves communicates information from the
periphery to the central nervous system?

Answer 11

Afferent axons

Question 12

What is the difference between afferent and efferent nerves?

Answer 12

Afferent nerves take sensory information to the CNS (they sense hence they are affected by stuff hence afferent)

Efferent nerves take information fromt he CNS to the muscles (they effect stuff hence efferent)

Question 13

Infarction vs Ischaemia

ST elevation or depression?

Answer 13

ST elevation is symptomatic of an infarction, ST depression is symptomatic of ischaemia

HINT: The seriousness of an infarction is elevated

Question 14

Antigen vs Antibody

Answer 14

• Antigen is the protein structure that defines something (e.g. lateral flow tests are antigen tests which means they look for antigens (protein structure) belonging to the covid virus)
• Antibodies locate and attack antigens

Question 15

An 86 year old man developed sudden onset of left sided weakness 5 hours earlier.
His BP is 159/92 mmHg. He has weakness of left arm and leg with dysarthria.
Investigations:
CT scan brain: no evidence of haemorrhage

What drug should be given in this case?

Answer 15

Aspirin

I said warfarin as both prevent clotting however perhaps warfarin is better for long term prevention

Question 16

A 65 year old man has pain and swelling at his right first metatarsophalangeal joint.
Which ascending spinal pathway will transmit the pain signal to the cerebral cortex?

Answer 16

Correct answer: Left spinothalamic tract

Item notes: Pain signal is produced by nociceptors these enter the right side of the spinal cord (first order neurone)
whic then synapse with a second order neurome which crosses the spinal cord and ascends via the spinothalamic tract

Question 17

An 8 year old child has a history of fragility fractures of both arms, short stature and blue sclerae.
A diagnosis of osteogenesis is suspected.
Which is the most likely pathogenesis of this condition?

Answer 17

Correct answer: Mutations in genes for collagen type I

Item notes: Osteogenesis imperfecta is most commonly caused by mutations in genes encoding the alpha 1 and alpha 2
chains of type I collagen