mock SAQ

Question 1

Hyponatraemia is a lack of which ion?

Answer 1

Na+ ions

Question 2

What is the typical fluid volume distribution in the interstitial compartment and intracellular compartment in a 70kg male?

Answer 2

• Intracellular =28L/66%
• Interstitial = 11/26%
• 70kg man has 42L of fluid, this is split into compartments
• Intracellular = 28L
• Extracellular = 14L > interstitial = 11L & blood/plasma = 3L

Question 3

What is a method of genetic testing in pregnancy?

Answer 3

Chorionic villus sampling OR amniocentesis

Question 4

Between which chambers of the heart is the foramen ovale located?

Answer 4

Between the right & left atria

Question 5

Define penetrance in genetics

Answer 5

Proportion of people with a gene/genotype who show the expected phenotype

Question 6

Where does haematopoiesis occur in an adult and where does it occur in a foetus?

Answer 6

Adult = axial bone marrow
Foetus = yolk sac, liver or spleen

Question 7

State the structural differences of foetal haemoglobin compared to adult haemoglobin

Answer 7

Foetal = 2 alpha & 2 gamma chains 
Adult = 2 alpha & 2 beta

Question 8

Why does the haematocrit not change following a major trauma in which a lot of blood is lost?

Answer 8

Haematocrit is the ratio of red blood cells to blood volume, this does not change because the ratio is unaffected by blood loss because you’re losing the same ratio of RBCs to blood volume

Question 9

Define FEV1 & FVC

Answer 9

FEV1 = forced expiratory volume in the first second of expiration
FVC = forced vital capacity. It is the measurement of lung size (in litres) and represents the volume of air that can be forcefully exhaled (omitting the residual volume)

Question 10

Name a method that can be used to measure total lung capacity

Answer 10

Gas dilution or total body plethysmography (body box)

Question 11

A gentleman’s FVC is below 80% of the predicted value for someone his age. What is this a sign of?

Answer 11

FVC <80% of predicted = airway restriction

Question 12

State the effects of ageing on lung function

Answer 12

Delayed response to hypercapnia/hypoxia, decreased FEV/FVC, impaired gas exchange, decreased immune function, change in shape of thorax, stiffening of thoracic cartilage in ribs, decrease in respiratory muscle mass, loss of elastic recoil

Question 13

What type of prevention is smoking cessation with regards to lung cancer?

Answer 13

Primary prevention

Question 14

What are the functions of parietal and enteroendocrine (G) cells?

Answer 14

Parietal cells = secrete HCl & secrete intrinsic factor
Enteroendocrine cells (G cells) = release gastrin

Question 15

Where in the stomach are you most likely Enteroendocrine (G) cells?

Answer 15

Antrum of the stomach

Question 16

Vitamin B12 is absorbed in the terminal ileum, what other vitamins are absorbed in the ileum?

Answer 16

vitamin A, vitamin D, vitamin E, vitamin K

They are all fat-soluble vitamins & once bound to intrinsic factor, vitamin B-12 is absorbed like a fat-soluble vitamin

Question 17

In a study, individuals were asked to fill out a questionnaire about their smoking habits. Data regarding their absences in the last 24 months has been obtained from their employer. What type of study design has been used?

Answer 17

A retrospective cohort study

Question 18

Define sensitivity and specificity, with regards to screening programmes

Answer 18

Sensitivity = probability of a person with the disease testing positive OR true positive/ total number of people screened 
Specificity = probability of a person without the disease testing negative OR true negative/ total number of people screened