SBA style medsoc exam 2022

Question 1

Which of the following does not develop from the paramesonephric ducts in the absence of testosterone?
f. Upper 2/3 of the vagina
g. Lower 1/3 of the vagina
h. Fallopian tubes
i. Uterus
j. Cervix

Answer 1

Answer - B.
- In the absence of testosterone, the Wolffian duct degenerates and the lower 1/3 vagina and female external genitalia on the body surface develop from the urogenital sinus.
- In the absence of Mullerian-inhibiting factor, the paramesonephric (Mullerian) ducts do not degenerate and instead develop into the uterus, cervix, fallopian tubes and uterus and upper 2/3 of the vagina.

Question 2

3. A 2-year-old girl presents to the paediatric clinic due to delayed walking. On examination, you observe that both legs have increased tone and hyperreflexia but there is no muscle wasting. Where is the site of the lesion?
   a. Medulla oblongata
   b. Lower motor neuron
   c. Upper motor neuron
   d. Neuromuscular junction
   e. Pons

Answer 2

Answer - C.
The patient’s symptoms point towards an UMN lesion picture.
UMN-
pathway- starts from cereberal cortex to cranial nerve nuclei in brain and anterior horns in spinal cord.
type of paralysis- hyperflexia
deep tendon reflex- hyperrflexia
muscle tone- hypertonic
muscle mass- muscle maintained (except disuse atrophy)
fasicculations- absent
clonus- present
bambinski sign- positive - toes up

LMN- opposite
path- motor pathway from anterior horn cell via peripheral nerve to the motor end plate

Question 3

4. Which of the following statements about lung defence mechanisms is true?
   a. Respiratory epithelium consists of non-keratinised stratified squamous epithelium
   b. Receptors for the cough reflex are in the nasopharynx and oropharynx
   c. Alveolar macrophages make up only 7% of pulmonary macrophages
   d. Innate immunity requires prior exposure to pathogens
   e. Particles that adhere to the mucus on the respiratory epithelium are swept into the
   pharynx by the mucociliary escalator

Answer 3

Answer - E.
Respiratory epithelium consists of ciliated pseudostratified columnar epithelium. Receptors for the cough reflex are in the larynx, trachea and bronchi. Alveolar macrophages actually make up the opposing percentage – 93%. Innate immunity doesn’t require prior exposure!

Question 4

5. Which of the following would lead to a rise in GFR?
   a. Blood loss
   b. Dehydration
   c. Increased dietary protein intake
   d. Chronic kidney disease
   e. Low blood pressure

Answer 4

Answer - C.
- Raised GFR can be caused by a build up pressure in the glomerulus from constricted efferent or dilated afferent arterioles. High dietary proteins can lead to afferent arteriole dilation.
- All other options lead to decreased GFR which through constricting the afferent or dilating the efferent arteriole, which leads to reduced fluid pressure in the glomerulus.

Question 5

6. What compensatory mechanism occurs in respiratory acidosis?
   a. The pH decrease stimulates lung chemoreceptors → enhanced respiration → a fall
   in CO2 → less acidity → increases pH.
   b. The pH increase inhibits lung chemoreceptors → reduced respiration → increase in
   CO2 → more acidity → decreases pH.
   c. The pH decrease stimulates the kidneys to increase H+ secretion and release more
   HCO3- into the plasma, increasing the pH
   d. The pH increase stimulates the kidneys to decrease H+ secretion, which leads to H+
   retention, decreasing the pH.
   e. No compensatory mechanism occurs.

Answer 5

Answer - C.
- In respiratory acidosis, the lungs fail to get rid of CO2 resulting in a decrease in blood pH as CO2 builds up. To compensate this renal compensation occurs where the kidneys increase H+ secretion in the form of ammonium (NH4+) and also release more HCO3- which increases pH as a result of the use of the ammonium buffer.
- A - respiratory compensation in metabolic acidosis - B - respiratory compensation in metabolic alkalosis - D - renal compensation in respiratory alkalosis

Question 6

7. A 30-year-old woman was admitted in A&E after a car accident. She was crossing the road when she was hit by a car’s bumper which made a forceful impact with her leg, resulting in a foot drop. Which of the following nerves have been damaged?
   a. Median nerve
   b. Pudendal nerve
   c. Saphenous nerve
   d. Median plantar nerve
   e. Common peroneal nerve

Answer 6

Answer - E.
E is correct. The common peroneal nerve supplies sensation and motor function of the lower leg (dorsiflexion and foot eversion) so compression will cause a foot drop. Median and pudendal nerve are not located in the leg. Compression of the median nerve would cause carpal tunnel syndrome (tingling in the hands and atrophy of thenar muscles).

Question 7

9. What molecule is secreted from the zona glomerulosa in the adrenal gland? a. Mineralocorticoids
   b. Glucocorticoids
   c. Androgens
   d. Adrenaline e. Cholesterol

Answer 7

Answer - A.
- Mineralocorticoids are produced from the zona glomerulosa e.g aldosterone
- Glucocorticoids are produced from the zona fasciculata e.g., cortisol
- Androgens are produced from the zona reticularis
- Adrenaline produced in the adrenal medulla, along with noradrenaline
- Cholesterol - precursor for all corticosteroids. Synthesis takes place in the cytoplasm and in the endoplasmic reticulum

Question 8

10. Which of the following is false with regards to thyroid hormones?
    a. TRH is released by the hypothalamus
    b. TSH and TRH actions are inhibited through a negative feedback loop
    c. In the bloodstream T3 and T4 bind to Thyroxine-Binding Globulin
    d. T4 is converted to T3 in peripheral tissues by 5’-deiodinase
    e. TSH also decreases protein synthesis in thyroid follicular cells

Answer 8

Answer - E.
- TSH increases protein synthesis in thyroid follicular cells. It also increases the DNA replication, cell division and the amount of rough endoplasmic reticulum

Question 9

14. Which of the following is false regarding type 2 pneumocytes?
    a. They are fewer in number than type 1 pneumocytes
    b. They secrete surfactant
    c. They occupy a minority of the alveolar surface area
    d. Their cytoplasm is rich in mitochondria, smooth and rough endoplasmic reticulum
    e. They generally first detectable between the 24th and 28th week of gestation

Answer 9

Answer - A.
Whilst type 2 pneumocytes are larger than type 1 pneumocytes, there are more in number. Their function is to secrete surfactant and they begin doing this between the 24th and 28th weeks of gestation, which carries important implications for the ability of premature babies to breathe unassisted. Since they produce surfactant, a complex mixture of phospholipids, carbohydrates and proteins, they have abundant mitochondria, smooth and rough endoplasmic reticulum.

Question 10

16. A patient has had a stroke and they have lost control of speech, this makes you suspect that Broca’s area has been impaired. Which artery supplies blood to Broca’s area?
    a. Anterior cerebral artery
    b. Middle cerebral artery
    c. Posterior cerebral artery
    d. Anterior inferior cerebellar artery
    e. Basilar artery

Answer 10

Answer - B.
Broca’s is supplied by the MCA. The ACA supplies the medial cortex of the brain (within the sagittal sulcus). The PCS supplies the occipital lobe. The anterior cerebellar artery supplies the cerebellum and pons. The basilar artery supplies the posterior circulation

Question 11

17. A patient is having difficulties coordinating movement and balance. Which area of the brain is most likely to have the lesion.
    a. Frontal lobe
    b. Parietal lobe
    c. Occipital lobe
    d. Temporal lobe
    e. Cerebellum

( what is the mnemonic for its dysfunction)

Answer 11

Answer - E.
The cerebellum is responsible for coordination and balance. There is a mnemonic for
cerebellar dysfunction: DANISH.
Dysdiadochokinesia Ataxia
Nystagmus Intention tremor Slurred speech Hypotonia

Question 12

18. Huntington’s disease is an autosomal dominant genetic condition which can affect successive generations earlier and more severely as it is passed on from one generation to the next. Which of the following term best matches this description?
    a. Penetrance b. Expressivity c. Anticipation d. Lyonisation e. Genotype

Answer 12

Answer - C.
- Anticipation (option C) – genetic disorders such as Huntington’s disease can affect successive generations earlier and more severely due to the expansion of unstable triplet repeat sequences.
- Penetrance (option A) – the percentage of individuals with a specific genotype showing the expected phenotype.
- Expressivity (option B) – the degree to which a phenotype is expressed by individuals who have a particular phenotype, not everyone with the same phenotype displays the same symptoms and same severity of symptoms.
- Lyonization (option D) – one of the X chromosomes in females is inactivated during early embryogenesis.
- Genotype (option E) – genetic constitution of an organism.

Question 13

20. Emily is a 7 year old girl who attends the general practice with her Mother. She describes feeling short of breath, especially when running. Her mother also says she can hear Emily coughing throughout the night. The GP suspects asthma and refers her for spirometry. Which statement is false?
    a. Asthma is an obstructive condition
    b. Obstructive conditions have an FEV1/FVC < 0.7
    c. The average FVC is 4.5L
    d. FVC is the same as total lung capacity
    e. FVC = inspiratory reserve volume + tidal volume + expiratory reserve volume

Answer 13

Answer - D.
FVC is the maximal volume that can be exhaled after maximum inspiration. Total lung capacity is the entire volume of the lungs (you can’t exhale all of it, there will always be residual volume

Question 14

22. A patient is brought into A&E following a head trauma. When the doctor shines a torch onto the patient’s eyes, he notices that there is absent pupil constriction. Which cranial nerve is responsible for this parasympathetic response?
    a. Abducens nerve
    b. Ophthalmic nerve
    c. Oculomotor nerve
    d. Optic nerve
    e. Trochlear nerve

Answer 14

Answer - C.
C is correct. Oculomotor nerve innervates the sphincter muscle responsible for parasympathetic response of pupil constriction. The other parasympathetic nerves are facial, glossopharyngeal and Vagus nerves (1973).
A is incorrect as it innervates the lateral rectus to stimulate abduction of the eye.
B is incorrect as it is a branch of the trigeminal nerve that provides sensation to the superior part of the face.
D is responsible for vision.
E is responsible for somatic innervation of the superior oblique muscle.

Question 15

27. Forced vital capacity consists of which lung volumes?
    a. Inspiratory reserve volume + expiratory reserve volume
    b. Inspiratory reserve volume + tidal volume + expiratory reserve volume
    c. Tidal volume + inspiratory reserve volume
    d. Expiratory reserve volume + residual volume
    e. Sum of all volumes

Answer 15

Answer - B.
A is an incorrect answer as it does not represent any type of lung capacity. C represents inspiratory capacity, D represents functional residual capacity and E represents total lung capacity.

Question 16

preload

Answer 16

: the volume of blood in the ventricles just before contraction (EDV), so its same as volume of blood in each ventricle at the end of diastole

Question 17

afterload

Answer 17

the pressure against which the heart must work to eject blood in systole

Question 18

compliance

Answer 18

how easily a chamber of the heart expands when it is filled with blood (C= ∆V / ∆P)

Question 19

reisistance

Answer 19

a force that must be overcome to push blood through the circulatory system.

Question 20

30. What is the correct effect of increased cortisol effect on female hormones?
    a. Increase in progesterone, decrease in oestrogen
    b. Increase in progesterone, increase in oestrogen
    c. Decrease in progesterone, decrease in oestrogen
    d. Decrease in progesterone, increase in oestrogen
    e. It has no effect on progesterone or oestrogen

Answer 20

Answer - C.
- High cortisol levels inhibit the gonadotropin releasing hormone (GnRH) leading to decreased progesterone and oestrogen in females. It can lead to reduced decreased sperm count, ovulation and sexual activity in both sexes.

Question 21

33. Which of the following statements regarding DNA replication is true?
    a. DNA ligase joins okazaki fragments together
    b. DNA helicase relieves/prevents supercoiling of DNA
    c. DNA is made in the 3’ to 5’ direction
    d. Topoisomerase breaks hydrophobic interactions between strand
    e. A primer is a short nucleic acid sequence which is added on after DNA has been
    synthesised

Answer 21

Answer - A.
- Option A is the only statement that is correct.
- Option B is incorrect – DNA helicase breaks hydrogen bonds between DNA strands. - Option C is incorrect – DNA is made in the 5’ to 3’ direction.
- Option D is incorrect – Topoisomerase prevents/relieves supercoiling.
- Option E is incorrect – A primer is a short nucleic acid sequence, usually RNA, which provides a starting point for DNA synthesis.

Question 22

35. In the acinar organisation of the liver parenchyma, the corners of each acinus consists of what?
    a. Hepatic venules
    b. Portal tracts
    c. Either portal tracts or hepatic venules
    d. Hepatic arterioles
    e. Portal venules.

Answer 22

Answer - C.
Either portal tracts or hepatic venules. There are two ways of organising the parenchyma of the liver, both of these ways are artificial and do not represent divisions within the microanatomy. In the lobule organisation there is a central venule and 6 corners which each consist of a portal tract, making a hexagon. In the acinar organisation there are 4 corners, two of which are hepatic venules and the other two are portal tracts, making a diamond shape.

Question 23

36. How many calories are there per unit of alcohol?
    a. 46 kcal
    b. 56 kcal
    c. 64 kcal
    d. 75 kcal
    e. 78 kcal

Answer 23

answer - C.
There are 7 kcal per gram of alcohol, one unit = 10ml (8g) of pure alcohol. 7 x 8 = 56 kcal
per unit of alcohol.

Question 24

38. Where is oestrogen secreted in the luteal phase of menstruation?
    a. Corpus luteum
    b. Antrum
    c. Granulosa cells
    d. Theca cells
    e. Granulosa and theca cells

Answer 24

Answer - A.
- Corpus luteum synthesises oestrogen and progesterone in the luteal phase
- The antrum is a fluid filled space formed from granulosa cell secretions. Granulosa
and theca cells - work together to synthesise oestrogen in the follicular phase

Question 25

39. Which of the following macronutrients is the most energy dense? a. Protein
    b. Alcohol
    c. Carbohydrates d. Fats
    e. Fibre

Answer 25

Answer - D.
- Protein (Option A) - 4kcal/g
- Alcohol (Option B) - 7kcal/g

• Carbohydrates (Option C) - 4kcal/g
• Fats (Option D) - 9kcal/g - correct answer)
• Fibre (Option E) - 2kcal/g

Question 26

40. Clara is a 5ft 10 15-year-old girl who presents to her GP with a goitre, weight loss, heat intolerance and diarrhoea. Her GP suspects hyperthyroidism. She also tells her GP she has been feeling quite stressed and anxious about her upcoming exams. Which of the following factors of Clara’s would be least likely to contribute to an increase in basal metabolic rate (BMR)?
    a. Female
    b. 15 years old
    c. Hyperthyroidism
    d. Feeling stressed
    e. Tall

Answer 26

Answer - A.
- Factors that contribute to increased BMR include being male, younger age (option B), hyperthyroidism (option C), feeling stressed (option D) and increased height (E).
- Females (option A) usually have a lower BMR than males so this is the correct answer.

Question 27

41. What is a phase I reaction in liver detoxification?
    a. The removal of molecules of hydrogen to make the metabolite more soluble
    b. The addition of OH groups to make the metabolite more soluble
    c. Reactions that expose an OH group on the metabolite to make it more soluble
    d. The addition of glucuronate to make the metabolite more soluble
    e. The removal of glucuronate to make the metabolite less soluble

Answer 27

Answer - C.
Phase one reactions in the liver aim to make molecules more soluble. This can be either be by adding OH molecules or by removal of NH or CH groups which leave behind an OH group.
The addition of glucuronate (glucuronidation) is a phase II reaction.

Question 28

44. Which molecule is permeable through phospholipid bilayer? a. Na+
    b. K+
    c. Glucose d. Urea
    e. H+

Answer 28

Answer - D.
- Urea (option D) and other small uncharged polar molecules such as water and ethanol and permeable and can pass directly through the phospholipid bilayer. Hydrophobic molecules such as oxygen, carbon dioxide and nitrogen are also permeable through the phospholipid bilayer.
- Ions such as Na+ (option A), K+ (option B) and H+ (option E), as well as large uncharged polar molecules such as glucose (option C) are not permeable and require ion channels or carrier proteins to allow them to move through the phospholipid bilayer.

Question 29

46. A 23 year old man is brought into the emergency department via ambulance. He has been in a road traffic accident and his lung has collapsed (pneumothorax). This means his lungs are not inflating equally like they normally would. What is the name of the gaps in between alveoli that allow the lungs to inflate equally?
    a. Pores of Cajal
    b. Pores of Kohn
    c. Pores of Reinke
    d. Pores of Clara
    e. Pores of equalisation

Answer 29

Answer - B.
Pores of Kohn are small communication pathways between alveoli, providing a collateral
pathway to reduce resistance and allow equal inflation of the alveoli.
Interstitial cells (not pores) of Cajal are essentially the pacemaker cells of the GI tract smooth muscle, which generate slow electrical waves causing peristalsis in gastrointestinal smooth muscle.
Reinke crystalloids are rod-shaped structures that lie in the cytoplasm of Leydig cells of the testis.
Clara cells are nonciliated bronchiolar secretory cells in the airway - prioritise type I / II pneumocytes over learning this!

Question 30

50. Which of the following is a type of lung receptor? a. Tear
    b. Irritant
    c. Juxta-arterial d. Chemical
    e. Pneumocytic

Answer 30

answer - B.
The main 3 lung receptors are stretch, irritant and juxtapulmonary capillary (J).

Question 31

51. Which of the following is NOT a function of the liver?
    a. Stores vitamin C
    b. Detoxifies drugs
    c. Produces bile
    d. Produces albumin
    e. Stores vitamin K

Answer 31

Answer - A.
The liver cannot store vitamin C as it is a water-soluble vitamin. The body cannot store vitamin C anywhere because of this. The liver plays an important role in the metabolism and detoxification of drugs or medicines through Phase I and Phase II reactions. The liver is responsible for the production and recycling of bile. One of the most abundant plasma proteins is produced by the liver, Albumin. The liver does store vitamin K which is a fat soluble vitamin.

Question 32

53. A 30-year-old man is stabbed in the back causing a hemi section of the spinal cord at T5. What signs would you expect to see?
    a. Ipsilateral loss of temperature, fine touch and vibration and spastic paresis
    b. Ipsilateral loss of temperature, contralateral loss of fine touch and vibration ipsilateral
    spastic paresis
    c. Contralateral loss of temperature, ipsilateral loss of fine touch and vibration,
    contralateral spastic paresis
    d. Contralateral loss of temperature, fine touch and vibration and spastic paresis
    e. Contralateral loss of pain and temperature, ipsilateral loss of deep touch and
    vibration, ipsilateral spastic paresis

Answer 32

Answer - E.
This is Brown-Sequard syndrome. Pain and temperature are carried in the lateral spinothalamic tract which decussates at the spinal level it enters so the hemisection of the spinal cord will result in contralateral loss of these functions. The corticospinal tract (which carries motor function) and DCML (which carries fine touch, vibration and proprioception) decussate above the spinal cord so hemi section will result in ipsilateral loss of these function

Question 33

55. What is the action of Cholecystokinin (CCK)?
    a. It stimulates the release of acid in the stomach
    b. It stimulates the pancreas to release digestive enzymes
    c. It causes the duodenum to contract aiding with peristalsis
    d. It causes the contraction of the stomach to speed up transit of food
    e. It causes the release of bile from the liver

Answer 33

Answer - B.
CCK causes the release of Digestive enzymes from the pancreas. It also causes the gallbladder to contract pushing bile into the duodenum at the same time. Gastrin causes the
increased production of acid in the stomach. The other functions are not directly controlled by a hormone.

Question 34

56. Red blood cells have a lifespan of around 120 days in healthy adults. In order to preserve some of their building blocks, the body recycles old red blood cells by breaking them down. Which of these transforms conjugated bilirubin into urobilinogen?
    a. Macrophages
    b. Heme oxygenase
    c. Biliverdin oxygenase
    d. Glucuronyltransferase
    e. Colonic bacteria

Answer 34

Answer - E.
Bilirubin metabolism is as follows:
Haemoglobin → iron + biliverdin (via heme oxygenase)
Biliverdin → unconjugated bilirubin (via biliverdin reductase)
Unconjugated bilirubin → conjugated bilirubin (via UGT - uridine glucuronyl transferase) Conjugated bilirubin → urobilinogen (via colonic bacteria) → stercobilin / urobilin / back to circulation

Question 35

57. A 28 year old woman is on the labour ward about to give birth to her first child, after 35 weeks in utero. Which of the following embryonic germ layers is correctly matched up to a structure it will become?
    a. Endoderm → sweat glands
    b. Endoderm → urogenital system
    c. Mesoderm → the muscular walls of the bowel
    d. Ectoderm → thyroid gland
    e. Ectoderm → liver

Answer 35

Answer - C.
The sweat glands arise from the ectoderm.
The urogenital system is derived from the mesoderm. The thyroid and liver are both derived from endoderm.

Question 36

58. What is the purpose of the glucose alanine cycle?
    a. To transport glucose from the muscles to the Liver
    b. To transport ammonium from the liver to the muscles
    c. To transport ammonium from the muscles to the liver
    d. To transport glucose from the liver to the muscles
    e. To transport urea from the muscles to the liver

Answer 36

Answer - C.
The glucose alanine cycle uses the glucose in the blood to form pyruvate in the muscles through glycolysis. The pyruvate reacts with Glutamate to form alpha-ketoglutarate and alanine. The alanine travels in the blood to the liver where it reacts with alpha-ketoglutarate to form glutamate and pyruvate again. The glutamate can then be processed into urea through the urea cycle and be excreted in the bile. This therefore transports Ammonium from the muscles to the liver to be excreted.

Question 37

60. Which of the following ECG leads show the inferior view of the heart?
    a. V1, V2
    b. V3, V4
    c. I, aVL, V5, V6
    d. II, III, aVF
    e. V1,V2,V3,V4

Answer 37

Answer - D.
V1, V2 → give septal/medial view
V3, V4 → give anterior view
I, aVL, V5, V6 → give lateral view
II, III, aVF → give inferior view
V1, V2 , V3, V4 → septal, medial and anterior views combined

Question 38

61. Raised central venous pressure and severe pulmonary hypertension are signs of?
    a. Right-side heart failure
    b. Left-side heart failure
    c. Biventricular failure
    d. Korotkoff sounds
    e. Acute myocardial infarction

Answer 38

Answer - B.
A → Right-sided heart failure may be caused by pulmonary hypertension, due to the right atrium having to work harder against the pressure in the lungs.
B → Pulmonary oedema in the presence of normal central venous pressure, or pulmonary hypertension may be signs of left-side heart failure
C→ Biventricular failure → shortness of breath, severe peripheral oedema and ascites after a heart attack can indicate biventricular failure
D→ Korotkoff sounds → Turbulent flow produces this sound, therefore turbulent arterial blood flow caused the first korotkoff sound
E → Signs of acute MI may be ST elevation.

Question 39

62. Which part of the heart does the right coronary artery (RCA) supply?
    a. The right ventricle and the apex of the heart
    b. Posterior 1⁄3 of the interventricular septum and AV node
    c. Right atrium (RA) and the right ventricle (RV)
    d. Anterior 2⁄3 of the interventricular septum and R & L ventricle
    e. Left ventricle

Answer 39

Answer - C.
A → Right ventricle and the apex of the heart → is supplied by right marginal artery
B → Posterior 1⁄3 of the interventricular septum and AV node → is supplied by posterior interventricular artery (PIA)
C → Right atrium (RA) and the right ventricle (RV) → is supplied by right coronary artery D → Anterior 2⁄3 of the interventricular septum and R & L ventricle →is supplied by the left anterior descending (LAD) artery
E → Left ventricle → is supplied by left marginal artery

Question 40

63. Which of the following statements about glycogenolysis are true?
    a. The liver produces the hormone that stimulates glycogenolysis
    b. The hepatocytes hydrolyse glycogen in response to insulin
    c. The hepatocytes hydrolyse glycogen in response to glucagon
    d. The hepatocytes release glucose using vesicles
    e. The liver senses blood glucose levels and initiates glycogenolysis.

Answer 40

Answer - C.
The liver does not produce the hormones involved in glucose regulation; it is the pancreas. Insulin causes glucose uptake and storage in the liver rather than hydrolysis of glycogen which would release more glucose. The liver doesn’t use vesicles for the release of glucose; it would pass through glucose transport protein channels and the pancreas is responsible for monitoring changes in blood glucose.

Question 41

66. Which of the following cell types generate spontaneous action potentials?
    a. Skeletal muscle cells
    b. Neurones
    c. Cardiomyocytes
    d. Fibroblasts
    e. Endothelial Cells

Answer 41

Answer - C.
Cardiomyocytes have the properties of automaticity, conductivity, and contractility. The sinoatrial node and atrioventricular node can spontaneously generate action potentials but depolarise at different rates, this acts as the pacemaker system of the heart. This is vital in situations where one part fails e.g. the SAN fails the heart can continue to beat albeit at a lower rate. Neurons and skeletal cells require stimuli to generate action potentials. Fibroblast contraction is caused by shearing forces or cytokine stimulation. Under normal conditions endothelial cells should not contract and can’t generate action potentials.

Question 42

69. During what part of the menstrual cycle does ischemic necrosis of the functional endometrium occur?
    a. Day 1-4
    b. Day 4-14
    c. Day 14-16
    d. Day 16-25
    e. Day 25-28

Answer 42

Answer - A.
Day 1-4, it is this necrosis which causes menses. Day 1-4 is the menses, day 5-16 is the proliferative phase, ovulation occurs at day 14-16 and days 25-28 are the premenstrual phase. These figures are all averages and variation can be wide.

Question 43

71. Which of the following statements regarding peripheral chemoreceptors is true?
    a. Peripheral chemoreceptors are responsible for 60% of respiratory control
    b. Peripheral chemoreceptors are stimulated by an increase in H + concentration in the
    CSF
    c. Peripheral chemoreceptors are most sensitive to pCO2 change
    d. Peripheral chemoreceptors are located in the medulla oblongata
    e. Afferent impulses from peripheral chemoreceptors are carried by the
    glossopharyngeal and vagus nerves

Answer 43

Answer - E.
The answers for A-D are true of central chemoreceptors rather than peripheral. Peripheral chemoreceptors are found in the carotid and aortic bodies and are most sensitive to pO 2 change.

Question 44

72. A 30-year-old woman was discharged from hospital 2 days ago after sustaining a head injury. Since then, she has noticed difficulty going down stairs as she says that she can’t see where she’s going. Her husband has also told her that she has started to tilt her head to the left which she was unaware of. What is the most likely diagnosis?
    a. Abducens nerve palsy
    b. Extraocular muscle impingement
    c. Oculomotor nerve palsy
    d. Trochlear nerve palsy
    e. Facial nerve palsy

Answer 44

Answer - D.
D is correct. It presents with vertical diplopia which is double vision when looking down and a head tilt. A is incorrect because damage to the abducens nerve would cause inability to abduct the affected eye. C is incorrect because it would present with a down and out eye, ptosis (droopy eyelid) and dilated pupils. E is incorrect because damage to the facial nerve would present with change in taste and reduced ability to make facial expressions.

Question 45

73. A 42 year old woman attends A&E with severe pain in her right upper quadrant. After investigation of her biliary tract and gallbladder she is diagnosed with gallstones. What type of epithelium lines the gallbladder?
    a. Simple columnar
    b. Simple columnar with poorly developed brush border
    c. Simple squamous
    d. Pseudostratified columnar with goblet cells
    e. Simple columnar with crypts

Answer 45

Answer - B.
Simple columnar cells generally line glandular tissue. Simple squamous epithelium lines abrasive areas such as the mouth, vagina and rectum. D is respiratory epithelium and E lines the intestines.

Question 46

74. A 57-year-old man presents to A&E complaining of sudden onset visual disturbance. Examination of his eyes reveals a field defect in the right upper quadrant of both his eyes. Where is the anatomical location of the lesion affecting vision?
    a. Left inferior optic radiation
    b. Left optic tract
    c. Left superior optic radiation
    d. Right optic tract
    e. Right optic nerve

Answer 46

Answer - A.
The patient is suffering from right superior homonymous quadrantanopia. This is caused by lesion of the contralateral inferior optic radiation in the temporal lobe (Meyer’s loop).
B would lead to a right homonymous hemianopia.
C would lead to right inferior quadrantanopia (Baum’s loop).
D would lead to left homonymous hemianopia. E would lead to right monocular vision loss.
It is worth learning your visual field defects and corresponding lesions!

Question 47

75. Which of the following is not a component of bile?
    a. Cholesterol
    b. Bile salts
    c. Bile pigments
    d. Triglycerides
    e. Lecithin (a phospholipid)

Answer 47

Answer - D.
Cholesterol is excreted with bile whilst also being used to make bile salts. Bile pigments are from the breakdown of haemoglobin and lecithin is another component of the bile. Triglycerides are not part of bile.

Question 48

76. You are observing a cholecystectomy (a gallbladder removal). The consultant inserts his finger in the space behind the hepatoduodenal ligament. What is the name of this space?
    a. Hepatoduodenal recess
    b. Anterior recess of the liver
    c. Lesser omentum
    d. Epiploic foramen of Winslow
    e. Retroperitoneal cavity.

Answer 48

Answer - D.
The epiploic foramen of Winslow is a passage between the greater sac and the lesser sac.
The hepatoduodenal ligament lies at the free border of the lesser omentum.

Question 49

78. A 34 year old lady is being seen by her general practitioner. She complains of weight gain, increased appetite and feeling cold all the time. She has thyroid function test which reveals she has hypothyroidism. What is the name given to the structure that unites the right and left lobes of the thyroid?
    a. Follicle
    b. Thyroid tree
    c. Larynx
    d. Isthmus
    e. Parathyroid

Answer 49

Answer - D.
The isthmus is the structure that unites the two lobes of the thyroid.

Question 50

80. What is the embryological origin of the gallbladder?
    a. Hindgut
    b. Lateral mesoderm
    c. Mid gut
    d. Ectoderm
    e. Foregut

Answer 50

Answer - E.
The foregut forms the Trachea, Lungs and respiratory tract, oesophagus, stomach, liver, gallbladder bile ducts and the first half of the duodenum. The midgut forms the second half of the duodenum up to the proximal 2/3 of the transverse colon. The hindgut forms the distal 1/3 of the transverse colon up to the anus. The lateral mesoderm is involved in the formation of the Kidneys and bladder and the ectoderm is responsible for the skin and nervous system.

Question 51

87. Which of the following enzymes involved in Vitamin D metabolism is found in the kidneys?
    a. 24-hydroxylase
    b. 1-alpha-hydroxylase
    c. 25-hydroxyvitamin D
    d. 1,25-dihydroxyvitamin-D3
    e. 25-hydroxylase

Answer 51

Answer - B.
1-alpha hydroxylase is the enzyme within the kidney that converts 25-hydroxyvitamin-D3 to
1,25-dihydroxyvitamin-D3.

Question 52

88. A mother presents to the GP with their 3 year old son who previously was diagnosed with Prader–Willi syndrome. They are worried after reading that in childhood these patients develop insatiable hunger (hyperphagia) and wanted to know more. Which of the following hormones signals satiety following meals in humans?
    a. Ghrelin
    b. Motilin
    c. Peptide YY
    d. Cholecystokinin
    e. Leptin

Answer 52

Answer - D.
Whilst leptin and CCK both help signal satiety, CCK is released by I cells after meals to immediately signal. Leptin is made by adipocytes and is involved in long-term regulation of body weight. Ghrelin, released by pancreatic enteroendocrine cells, has the antagonistic effect and signals hunger. Motilin, released by Mo cells of the small intestine, stimulates gastric motility. Peptide YY, released by L cells of the mucosa, inhibits gastric mobility to allow greater water and electrolyte absorption in the colon.

Question 53

90. Which of the following ion channels maintain action potentials in the sinoatrial and atrioventricular nodes?
    a. T type Ca2+ channels
    b. L type Ca2+ channels
    c. Na+ uniporter
    d. Funny Na+ channels
    e. Ryanodine receptor 2

Answer 53

Answer - B.
L type Ca2+ channels are used in maintaining action potentials whereas T type are used in initiating them in the SAN and AVN. Think of it as T for trigger and L for long to remember. Na+ uniporters drive depolarisation in the cardiac cycle. Funny channels open when voltage is more negative after the end of a previous action potential, causing a slow efflux of K+ and slow influx of Na+. This contributes to the pacemaker potential in the SAN. Ryanodine receptor 2 are sarcoplasmic reticulum receptors that sense a Ca2+ influx and cause the release of Ca2+ from the sarcoplasmic reticulum. This is what is known as calcium-induced calcium release.