eMRCS Physiology Flashcards
(112 cards)
1
Q
A 75 year old lady reports urinary incontinence when coughing and sneezing. She has had 2 children with no complications. She has no significant past medical history and is on no medications. What is the most appropriate initial management?
Trial of sacral neuromodulation Urodynamic studies Pelvic floor exercises for 3 months Bladder drill training for 6 weeks Administration of oxybutynin
A
Pelvic floor exercises for 3 months
A diagnosis of stress incontinence is obvious from the history, therefore there is no need for a bladder diary or urodynamic studies. Pelvic floor exercises would be the first line management.
2
Q
Which of the following is not directly affected by warfarin?
Protein C Factor II Factor VII Factor VIII Factor IX
A
Factor VIII
Warfarin affects synthesis of factors II, VII, IX, X and protein C.
3
Q
Which of the following is responsible for the release and synthesis of calcitonin?
Parathyroid glands Anterior pituitary Thyroid gland Posterior pituitary Adrenal glands
A
Thyroid
Calcitonin has the opposite effect of PTH and is released from the thyroid gland.
4
Q
A 24 year old man is injured in a road traffic accident. He becomes oliguric and his renal function deteriorates. Which of the options below would favor acute tubular necrosis over pre renal uraemia?
No response to IV fluids Urinary Na <20mmol/L Bland coloured urinary sediment Increased urine specific gravity None of the above
A
No response to IV fluids
In ATN, there is no response to IV fluids because the damage occurs from within the renal system rather than as a result of volume depletion.
5
Q
patient is seen in clinic complaining of abdominal pain. Routine bloods show:
Na 142 K 4.0 Cl- 104 Bicarb 19 Urea 7.0 Creatinine 112
What is the anion gap?
4 mmol/L 14 mmol/L 20 mmol/L 21 mmol/L 23 mmol/L
A
23 mmol/L
The anion gap may be calculated by using (Na + K) - (bicarb + Cl-)
= (142 + 4.0) - (104 + 19) = 23 mmol/L
A normal AG is 8-14mmol/L.
6
Q
A 44 year old lady presents with jaundice. Following a minor ward based surgical procedure she develops troublesome and persistent bleeding. Deficiency of which of the vitamins listed below is responsible?
Vitamin C Vitamin K Vitamin D Vitamin B Vitamin A
A
Vitamin K
Patients who are jaundiced usually have impaired absorption of vitamin K. This can result in loss of the vitamin K dependent clotting factors and troublesome bleeding.
7
Q
Cortisol is predominantly produced by which of the following?
Zona fasciculata of adrenal Zona glomerulosa Zona reticularis Adrenal medulla Posterior lobe of pituitary
A
Zona fasciculata
Relative glucocorticoid activity:
Hydrocortisone = 1
Prednisolone = 4
Dexamethasone = 25
Cortisol is 90% protein-bound, 10% active. Has a circadian rhythm (high in the mornings). Negative feedback via ACTH.
Actions: glycogenolysis, gluconeogenesis, protein catabolism, lipolysis, stress response, anti-inflammatory, decrease protein in bones, increase gastric acid, increase neutrophils/plt/RBCs, inhibit fibroblast activity
8
Q
A 22 year old man is undergoing a daycase excision of a sebaceous cyst. He is needle phobic and as the surgeon approaches with the needle the patient begins to hyperventilate. He soon develops circumoral parasthesia and muscular twitching. Which of the following is the most likely explanation for this event?
Temporal lobe epilepsy Reduction in ionised Ca levels Increase in ionised Ca levels Fall in serum PTH Rise in serum PTH
A
Reduction in ionised Ca levels
50% of plasma Ca is ionised. Hyperventilation will induce a state of alkalosis which will lower ionised plasma calcium levels.
9
Q
A 56 year old male presents to the acute surgical take with severe abdominal pain. He is normally fit and well. He has no malignancy. The biochemistry laboratory contacts the ward urgently, his corrected calcium result is 3.6 mmol/l. What is the medication of choice to treat this abnormality?
IV pamidronate Oral alendronate Dexamethasone Vitamin D Resonium salts
A
IV pamidronate
IV pamidronate is the drug of choice as it most effective and has long lasting effects. Calcitonin would need to be given with another agent, to ensure that the hypercalcaemia is treated once its short-term effects wear off.
IV zoledronate is preferred in scenarios associated with malignancy.
10
Q
An elderly lady who presented with weight loss and malabsorption was found to have amyloid of the small bowel. On presentation she was found to have osteomalacia and was hypocalcaemic. Over the past seven days she has received total parenteral nutrition with adequate calcium replacement. Despite this she remained hypocalcaemic. Deficiency of which of the following electrolytes is most likely to account for this process?
Mg K Na Phosphate None of the above
A
Magnesium
Patients with malabsorption may develop Mg deficiency. Although her TPN feeds may have contained Mg, it may not have been sufficient to correct her losses.
Mg is required for both PTH secretion and its action on target tissues. HypoMg may cause both hypoCa and render pts unresponsive to Tx with Ca and vit D supplementation.
Mg is the 4th most abundant cation in the body, contains 1000mmol, half in bone and half in muscle, soft tissues and ECF.
No one specific hormonal control of Mg, various hormones including PTH and aldosterone affect renal handling of Mg.
Mg and Ca also interact at cellular level. Decreased Mg will affect permeability of cell membranes to Ca, causing hyperexcitability.
Na, phosphate and K would not have this effect on serum Ca.
11
Q
Which of the following conditions is most likely to be associated with these arterial blood gas sample results:
pH 7.48 pO2 10.1 Bicarb 30 pCO2 4.5 Cl- 96
Resp alkalosis Met acidosis with normal AG Met alkalosis Met acidosis with increased AG T2RF
A
Metabolic alkalosis
These ABG results are classically seen in situations where there is metabolic alkalosis such as may occur following prolonged vomiting.
12
Q
Which of the conditions listed below is most likely to account for the following arterial blood gas result:
pH 7.49 pO2 8.5 Bicarb 22 pCO2 2.4 Cl- 12
A
Respiratory alkalosis
The hyperventilation results in decreased carbon dioxide levels, causing a respiratory alkalosis (non-compensated).
13
Q
A 34 year old woman from Chad presents with continuous dribbling incontinence after having her 2nd child. Apart from prolonged labour the woman denies any complications related to her pregnancies. She is normally fit and well. What is the most likely diagnosis?
Vesicovaginal fistula Stress urinary incontinence Overactive bladder syndrome Colovesical fistula Pudendal neuropathy
A
Vesicovaginal fistula
Vesicovaginal fistulae should be suspected in patients with CONTINUOUS DRIBBLING incontinence after prolonged labour and from an area with limited obstetric services.
14
Q
A 73 year old lady is diagnosed with hyperaldosteronism. From which of the following structures is aldosterone released?
Zona fasciculata Juxtaglomerular apparatus of kidney Zona reticularis Adrenal medulla Zona glomerulosa
A
Zona glomerulosa of adrenal cortex
Aldosterone serves to conserve Na and water.
It is a mineralocorticoid. Secretion is regulated by renin-angiotensin system, and by plasma levels of Na and K. It conserves Na by stimulating the reabsorption of Na in distal nephron in exchange for K.
Lack of aldosterone release will cause hyperK and hypoNa.
15
Q
Deficiency of which vitamin is most likely to explain the presentation of a 3 year old child with Rickets?
Vitamin C Vitamin B3 Vitamin D Vitamin A Vitamin E
A
Vitamin D
Vitamin D is needed to help mineralise bone. When this is deficient, mineralisation is inadequate and deformities may result.
16
Q
A 23 year old woman presents with severe headache, photophobia and neck stiffness. A lumbar puncture is undertaken and cerebrospinal fluid is sent for microscopy and culture. Culture shows a growth of Neisseria meningitidis. What is likely to be the predominant cell type in the cerebrospinal fluid?
Eosinophils Basophils Macrophages Lymphocytes Neutrophils
A
Neutrophils
In bacterial meningitis, neutrophils are typically present in the CSF. In viral meningitis, a lymphocytosis is said to predominate. Clinically, there can be overlap with a neutrophilia occurring in some cases of viral meningitis. In bacterial meningitis, the neutrophilia can be attenuated by the administration of antibiotics.
17
Q
Which of the arterial blood gas analyses shown below would most likely be seen with a patient who has a pulmonary embolus?
pH 7.64, pO2 10, pCO2 2.8, bicarb 20 pH 7.25, pO2 8.9, pCO2 3.2, bicarb 10 pH 7.20, pO2 6.2, pCO2 5.8, bicarb 27 pH 7.60, pO2 8.2, pCO2 5.8, bicarb 40 pH 7.50, pO2 7.2, pCO2 2.5, bicarb 24
A
pH 7.50, pO2 7.2, pCO2 2.5, bicarb 24
A combination of hypoxia and respiratory alkalosis should suggest a PE. The respiratory alkalosis is due to hyperventilatioAntin associated with the pulmonary embolism.
18
Q
A 33 year old female is admitted for varicose vein surgery. She is fit and well. After the procedure she is persistently bleeding. She is known to have menorrhagia. Investigations show a prolonged bleeding time and increased APTT. She has a normal PT and platelet count. What is the most likely cause?
Anti-phospholipid syndrome Haemophilia Factor V Leiden deficiency von Willebrand's disease Protein C and S deficiency
A
von Willebrand’s disease
Bleeding post-op, epistaxis and menorrhagia may indicate a diagnosis of vWD. Haemoarthroses are rare. The bleeding time is usually normal in haemophilia (X-linked) and vitamin K deficiency.
19
Q
A 43 year old man has a nasogastric tube inserted. The nurse takes a small aspirate of the fluid from the stomach and tests the pH of the aspirate. What is the normal intragastric pH?
0.5 2 4 5 6
A
pH 2
The intragastric pH is usually 2. Administration of PPIs can result in almost complete abolition of acidity.
20
Q
A 63 year old female is referred to the surgical clinic with an iron deficiency anaemia. Her past medical history includes a left hemi colectomy but no other co-morbidities. At what site is most dietary iron absorbed?
Stomach Duodenum Proximal ileum Distal ileum Colon
A
Duodenum
Iron is best absorbed from the PROXIMAL SMALL BOWEL (duodenum and jejunum) in the Fe 2+ state.
Iron is transported across the small bowel mucosa by a divalent membrane transporter protein (hence the improved absorption of Fe 2+). The intestinal cells typically store the bound iron as ferritin. Cells requiring iron will typically then absorb the complex as needed.
21
Q
Which arterial blood gas sample best represents widespread mesenteric infarction?
pH 7.64, pO2 10, pCO2 2.8, bicarb 20 pH 7.25, pO2 8.9, pCO2 3.2, bicarb 10 pH 7.20, pO2 6.2, pCO2 5.8, bicarb 27 pH 7.60, pO2 8.2, pCO2 5.8, bicarb 40 pH 7.45, pO2 7.2, pCO2 2.5, bicarb 24
A
pH 7.25, pO2 8.9, pCO2 3.2, bicarb 10
This is usually associated with acidosis, hyperventilation and reduction in bicarbonate.
22
Q
Which one of the following would cause a rise in the carbon monoxide transfer factor (TLCO)?
Emphysema PE Pulmonary haemorrhage Pneumonia Pulmonary fibrosis
A
Pulmonary haemorrhage
Transfer factor describes the RATE at which GAS will DIFFUSE FROM ALVEOLI TO BLOOD. CO is used to test the rate of diffusion. Results may be given as total gas transfer (TLCO) or that corrected for lung volume (transfer coefficient, KCO).
Where alveolar haemorrhage occurs the TLCO tends to increase due to the enhanced uptake of CO by intra-alveolar Hb.
23
Q
With which of the following blood products is iatrogenic septicaemia with a gram positive organism most likely?
Cryoprecipitate Platelets Packed red cells Factor VIII concentrate Factor IX concentrate
A
Platelets
PLATELETS are stored at room temperature and must be used soon after collection. This places them at increased risk of culturing gram POSITIVE organisms.
Iatrogenic infection with gram NEGATIVE organisms is more likely with PACKED RED CELLS as these are stored at 4 degrees.
Infections with blood products of this nature are both rare.
24
Q
A 56 year old lady reports incontinence mainly when walking the dog. A bladder diary is inconclusive. What is the most appropriate investigation?
IV urography Urodynamic studies Flexible cystoscopy Micturating cystourethrogram Rigid cystoscopy
A
Urodynamic studies
Urodynamic studies are indicated when there is diagnostic uncertainty or plans for surgery.
25
What is the most common cause of hypercalcaemia in the UK in hospitalised patients?
```
Thiazide use
Metastatic malignancy
Primary hyperPTH
Osteogenic sarcoma
Sarcoidosis
```
Metastatic malignancy
Metastatic cancer accounts for most cases of hypercalcaemia in HOSPITALISED patients.
In the COMMUNITY = primary hyperPTH
26
A 53 year old man has an arterial blood gas sample taken and the following results are obtained, he is breathing room air.
pH 7.49, pO2 8.5, bicarb 22, pCO2 2.4, Cl- <10
Which of the conditions listed below is most likely to account for these findings?
```
Resp alkalosis
T2RF
Met acidosis with increased anion gap
Met alkalosis
Met acidosis with normal anion gap
```
Respiratory alkalosis
The hyperventilation results in decreased CO2 levels, causing a respiratory alkalosis (non-compensated).
27
A 50 year old man has an arterial blood gas sample taken and the following results are obtained, he is breathing room air.
pH 7.20, pO2 7.5, bicarb 22, pCO2 8.1, Cl- 10
Which of the conditions listed below is most likely to account for these findings?
```
T1RF
Met alkalosis
Met acidosis with normal anion gap
Met acidosis with increased anion gap
T2RF
```
Type 2 respiratory failure
This is a sign of acute type 2 respiratory failure (non-compensated). This is the result of carbon dioxide retention.
28
A 69 year old man has been living in sheltered accommodation for many months, with inadequate nutrition notices that his night vision is becoming impaired. Deficiency of which vitamin is responsible?
```
Vitamin B3
Vitamin A
Vitamin C
Vitamin B12
Vitamin E
```
Vitamin A
Loss of vitamin A will result in impaired RHODOPSIN synthesis and results in POOR NIGHT VISION.
29
A 70 year old lady with metastatic breast cancer is admitted to hospital confused and acutely unwell, with nausea and vomiting. Her vital signs are within normal limits. What abnormality is most likely to contribute to her clinical condition?
```
HypoNa
HyperNa
HypoCa
HyperCa
HyperK
```
Hypercalcaemia
The commonest site of metastatic breast cancer is to a bony site (often the axial skeleton) and so hypercalcaemia is often present in those with metastatic disease who are acutely unwell.
30
Which of the blood gas results listed below is most likely to fit with a patient who has acute respiratory acidosis?
pH 7.57, pCO2 3.5, pO2 24.5 (FiO2 85%), bicarb 23.5, BE +1.8
pH 7.19, pCO2 10.2, pO2 16 (FiO2 85%), bicarb 23.8, BE -2.2
pH 7.14, pCO2 7.4, pO2 8.9 (FiO2 40%), bicarb 14, BE -10.6
pH 7.36, pCO2 7.3, pO2 8.9 (FiO2 40%), bicarb 30.2, BE +5.3
pH 7.32, pCO2 3.8, pO2 22.2 (FiO2 40%), bicarb 19.1, BE -7.9
pH 7.19, pCO2 10.2, pO2 16 (FiO2 85%), bicarb 23.8, BE -2.2
31
Which of the following is not linked to excess glucocorticoids?
```
Osteonecrosis
Osteoporosis
HypoK
HypoNa
Growth retardation in children
```
HypoNa
There are many adverse effects associated with excess glucocorticoids. Thinning of the skin, osteonecrosis and osteoporosis are all common.
Steroids are associated with retention of Na and water. K+ loss may occur and hypoK alkalosis has been reported.
32
A 55-year-old man with a history of type 2 diabetes mellitus, bipolar disorder and COPD has bloods taken during a pre operative assessment of an inguinal hernia repair:
Na 125, K 3.8, bicarb 24, urea 3.7, creatinine 92
Due to his smoking history, a CXR is ordered which is reported as normal. The Consultant asks you what is the most likely cause for the hypoNa?
```
Metformin
Lithium
Carbamazepine
Sodium valproate
Pioglitazone
```
Carbamazepine
SIADH - drug causes: carbamazepine, sulfonylureas, SSRIs, tricyclics
LITHIUM can cause diabetes insipidus but this is generally associated with a HIGH SODIUM. Lithium only tends to cause raised ADH levels following a severe overdosage.
33
A 38 year old lady presents with abdominal pain. On investigation, her serum calcium is found to be 3.5mmol/L. What is the most appropriate initial management?
```
IV bisphosphonates
Oral bisphosphonates
IV calcitonin
IV 0.9% NaCl
IV furosemide
```
IV 0.9% NaCl
The immediate treatment of hypercalcaemia involves IV fluid resuscitation. This may be complemented with the use of bisphosphonates and sometimes diuretics. However, fluids are administered first and because this question asks what the most appropriate initial treatment is, IV fluids are the most appropriate answer. Normal saline is usually preferred for this over dextrose-containing solutions.
34
A homeless 42 year old male had an emergency inguinal hernia repair 24 hours previously. He has a BMI of 15. He has been put on a nasogastric feeding regime of 35 kcal/kg/day with no additional medications. The nursing staff contact you as he has become confused and unsteady. On examination the patient is disorientated to place, has diplopia and nystagmus. What is the most likely diagnosis?
```
Cerebellar stroke
Acute dystonic reaction
Cerebrovascular accident
Parkinsonism
Wernicke's encephalopathy
```
Wernicke's encephalopathy
Triad of Wernicke's encephalopathy = acute confusion, ataxia, ophthalmoplegia
This patient has received a carbohydrate rich diet without any thiamine or vitamin B co strong replacement. This has led to Wernickes encephalopathy, which classically presents with confusion, ataxia and ophthalmoplegia. Characteristically it is associated with chronic alcoholism, however it is also known to occur post bariatric surgery.
35
A 22 year old lady presents with symptoms and signs of hyperthyroidism. Her diagnostic work up results in a diagnosis of Graves disease. Which of these statements best describes the pathophysiology of the condition?
Formation of IgG Abs to TSH receptors on thyroid gland
Formation of IgG Abs to TRH receptors on the anterior pituitary
Formation of IgM Abs to TSH receptors on thyroid gland
Formation of IgA Abs to TSH receptors on thyroid gland
Formation of IgM Abs to TRH receptors on the anterior pituitary
Formation of IgG Abs to TSH receptors on thyroid gland
Usually IgG antibodies are formed against the TSH receptors on the thyroid gland.
This is why the TSH level is often very low in Graves disease.
36
Which one of the following cells secretes the majority of tumour necrosis factor in humans?
```
Neutrophils
Macrophages
Natural killer cells
Killer T cells
Helper T cells
```
Macrophages
37
A 23 year old lady is persistently vomiting following a laparoscopic appendicectomy for a perforated gangrenous appendicitis. Imaging shows some dilated small bowel loops. What is the most appropriate course of action?
```
Insertion of a wide-bore NG tube
Insertion of a narrow-bore NG tube
Administration of IV cyclizine
Administration of metoclopramide
Arrange a laparotomy
```
Insertion of a wide-bore NG tube
This patient is likely to have a paralytic ileus and the administration of anti-emetic drugs in this situation achieves very little. It's important to decompress the stomach and this can be achieved with a wide bore nasogastric tube.
38
Which substance can be used to achieve the most accurate measurement of the glomerular filtration rate?
```
Glucose
Protein
Inulin
Creatinine
Para-amino hippuric acid (PAH)
```
Inulin
Creatinine declines with age due to decline in renal function and muscle mass. Glucose, protein (amino acids) and PAH are reabsorbed by the kidney.
39
Which of the following is least likely to be associated with hypercalcaemia?
```
Thiazides
Antacids
Coeliac disease
Sarcoidosis
Zollinger-Ellison syndrome
```
Coeliac disease
Causes of hyperCa (CHIMPANZEES):
```
Ca supplementation
HyperPTH
Iatrogenic (drugs: thiazides)
Milk alkali syndrome
Paget's disease of the bone
Acromegaly, Addison's disease
Neoplasia
Zollinger-Ellison syndrome (MEN type 1)
Excessive Vitamin D
Excessive Vitamin A
Sarcoidosis
```
40
Which of the substances below is derived primarily from the zona reticularis of the adrenal gland?
```
Mineralocorticoid hormones
Glucocorticoid hormones
Sex hormones
FSH
Vasopressin
```
Sex hormones
41
Which of the following treatments is not utilized in the treatment of overactive bladder syndrome?
```
Sacral neuromodulation
Botulinum toxin injections
Bladder drill
Oxybutynin
Colposuspension
```
Colposuspension
OAB is very common and 1st line Mx includes the use of ANTICHOLINERGICS and BLADDER DRILL whereby voiding is deferred.
Refractory cases can be treated with SNS or botulinum toxin injections.
A Burch COLPOSUSPENSION is used to treat STRESS urinary incontinence.
42
A 72-year-old woman is admitted to the acute surgical unit with profuse vomiting. Admission bloods show the following:
```
Na 131
K 2.2
Urea 3.1
Creatinine 56
Glucose 4.3
```
Which one of the following ECG features is most likely to be seen?
```
Short PR interval
Short QT interval
Flattened P waves
J waves
U waves
```
U waves
```
ECG features in hypoK:
U waves
Small/absent T waves (sometimes inverted)
Prolonged PR interval
Long QT interval
ST depression
```
(in hypoK, U have no Pot and no T, but a long PR and a long QT)
J waves are seen in hypothermia whilst delta waves are associated with Wolff Parkinson White syndrome.
43
What is the main component of colloid in the thyroid gland?
```
T3
T4
Thyroglobulin
Thyroxin-binding globulin
TSH
```
Thyroglobulin
It is a high molecular weight protein that acts as a storage form of thyroid hormones.
44
A man develops xerostomia. What proportion of salivary gland secretions is contributed by the parotid gland?
```
25%
50%
75%
80%
5%
```
25%
Parotid gland secretions account for around 25% of saliva. Most comes from the submandibular gland (70%).
45
Which of the following statements relating the fluid physiology of a physiologically normal 70 kg adult MALE is FALSE?
He will have more water per unit of body weight than a female of similar weight
Plasma will comprise 25% of his body weight
Interstitial fluid will account for up to 24% of body water
Approx 65% of total body water is intracellular
60% of his body weight is composed of water
FALSE = Plasma will comprise 25% of his body weight
The 60-40-20 rule of total body weight:
60% = water
40% = intracellular
20% = extracellular
Plasma typically accounts for 4-6% of body weight in healthy individuals.
Males typically have more water per unit weight than females, as females have a higher fat content.
46
Which of the following stimulates gastric acid secretion?
```
Cholecystokinin
Gastric inhibitory peptide
Secretin
Histamine
Somatostatin
```
Histamine
Histamine released from enterochromaffin-like cells then stimulate the parietal cells in paracrine manner to increase gastric acid production
GASTRIN = from G cells, STIMULATE gastric acid production
Pepsin = digest protein, secretion happens simultaneously with gastrin
SECRETIN = from mucosal cells in duodenum and jejunum, INHIBIT gastric acid, stimulate bile and pancreatic juice production
GIP (produced in response to fatty acids) = INHIBIT gastrin release and acid secretion from parietal cells
CCK = from mucosal cells in duodenum and jejunum (produced in response to fatty acids), INHIBIT acid secretion, gallbladder contraction, relaxation of sphincter of Oddi
Somatostatin = from D cells
47
A 56 year old man underwent a truncal vagotomy operation many years ago. The direct release of which of these hormones will be most affected as a result?
```
CCK
Secretin
Motilin
Glucose-dependent insulinotropic peptide
Gastrin
```
Gastrin
Motilin is released by the small bowel in response to alkaline contents in the duodenum/ jejunum and increases the migrating motor complexes in the small bowel.
CCK, secretin and GIP are all released in response to changes in the luminal contents.
Gastrin is released from G cells and whilst the luminal contents affect its release, it is also directly released in response to vagal stimuli.
48
Which of the following is NOT an effect of somatostatin?
```
Stimulates pancreatic acinar cells to release lipase
Decreases gastric acid secretion
Decreases gastrin release
Decreases pepsin secretion
Decreases glucagon release
```
Stimulate pancreatic acinar cells to release lipase
Somatostatin INHIBITS pancreatic enzyme secretion.
49
Which of the following is NOT an effect of cholecystokinin?
```
Causes gallbladder contraction
Increases rate of gastric emptying
Relaxes sphincter of Oddi
Stimulates pancreatic acinar cells
Trophic effect on pancreatic acinar cells
```
Increases rate of gastric emptying
CCK DECREASES rate of gastric emptying.
50
Which of the following statements are NOT typically true in hypokalaemia?
It may occur as a result of mechanical bowel prep
Chronic vomiting may increase renal K+ losses
It may be associated with aciduria
It may cause hypoNa
It often accompanies acidosis
FALSE = HypoK often accompanies acidosis.
K+ depletion occurs either through the GI tract or the kidney. Chronic vomiting is less prone to induce K+ loss than diarrhoea as gastric secretions contain less K+ than those in the lower GI tract.
If vomiting produces a metabolic alkalosis then renal K+ wasting may occur as K+ is excreted in preference to H+ ions. The converse may occur in K+ depletion resulting in acid urine.
Causes of hypoK with alkalosis = vomiting, diuretics, Cushing's, Conn's
Causes of hypoK with acidosis = diarrhoea, RTA, acetazolamide, partially treated DKA
51
Release of somatostatin from the pancreas will result in which of the following?
```
Decrease in pancreatic exocrine secretions
Contraction of gallbladder
Increase in rate of gastric emptying
Increased synthesis of growth hormone
Increased insulin release
```
Decrease in pancreatic exocrine secretions
Octreotide reduces exocrine pancreatic secretions so is used to treat high output pancreatic fistulae (though parenteral feeding is most effective).
Other uses include variceal bleeding and treatment of acromegaly.
Inhibits growth hormone and insulin release (when released from pancreas).
Somatostatin is also released by the hypothalamus causing a negative feedback response on growth hormone.
52
Which of the following does not cause an INCREASED anion gap acidosis?
```
Uraemia
Paraldehyde
DKA
Ethylene glycol
Acetazolamide
```
Acetazolamide
```
Causes of increased AG acidosis (MUDPLIES):
Methanol
Uraemia
DKA
Paraldehyde/phenformin
Iron
Lactic acidosis
Ethylene glycol
Salicylates
```
53
In a 70 Kg male, what proportion of total body fluid will be contributed by PLASMA?
```
50%
5%
35%
65%
25%
```
5%
54
A person is diagnosed with Conns syndrome. If the parotid gland secretions were assayed, what change (if any) will be noted?
```
Decreased K+
Decreased Na
Increased Na
K+ levels unchanged, Na levels increased
K+ levels increased, Na levels unchanged
```
Decreased Na
Aldosterone affects the parotid gland secretions and has the effect of conserving sodium (so salivary sodium reduced) and potassium secretion increased.
55
Which of the following does not cause a normal anion gap acidosis?
```
Pancreatic fistula
Acetazolamide
Uraemia
Ureteric diversion
Renal tubular acidosis
```
Uraemia
Uraemia will typically cause a high anion gap acidosis. It is one of the unmeasured anions.
56
A 52-year-old woman with a history of gastrectomy reports lethargy and a sore tongue. Blood tests are reported as follows:
Hb 107, MCV 121 fl, plt 177, WCC 5.4
What is the most likely cause?
```
Vitamin B12 deficiency
Vitamin C deficiency
Iron deficiency anaemia
Anaemia of chronic disease
Vitamin E deficiency
```
Vitamin B12 deficiency
A history of gastrectomy and a macrocytic anaemia should indicate a diagnosis of B12 deficiency.
57
Which of the following areas is predominantly concerned with thermoregulation?
```
Hypothalamus
Anterior pituitary
Cerebellum
Brainstem
Temporal lobe
```
Hypothalamus
The hypothalamus is primarily concerned with thermoregulation. It may relay to the cerebral cortex to induce behavioural adaptation to facilitate the thermoregulatory process.
58
Which of the following is not secreted by the parietal cells?
```
HCl
Mucus
Mg
Intrinsic factor
Ca
```
Mucus
Parietal cells = secrete HCl, Ca, Na, Mg, intrinsic factor
Chief cells = secrete pepsinogen
Surface mucosal cells = secrete mucus and bicarbonate
59
A 34 year old man presents with a peptic ulcer. Which of the following is responsible for the release of gastric acid?
```
Chief cells
Parietal cells
Brunner's glands
G cells
None of the above
```
Parietal cells
Parietal cells are responsible for the release of gastric acid.
G cells release gastrin.
Brunner's glands are found in the duodenum - they secrete alkaline fluid containing mucin, which protects the duodenal mucosa from the acidic stomach contents entering the duodenum.
60
Which of the following does not cause hyperkalaemia?
```
Haemolysis
Burns
Familial periodic paralysis
Type 4 renal tubular acidosis
Severe malnutrition
```
Severe malnutrition
Familial periodic paralysis has subtypes associated with hyper and hypokalaemia.
```
Causes of hyperK (MACHINE):
Medications - ACEi, NSAIDs
Acidosis - metabolic, resp
Cellular destruction - burns, traumatic injury
Hypoaldesteronism, haemolysis
Intake (excessive)
Nephrons - renal failure
Excretion - impaired
```
61
Which of the following is not a feature of normal cerebrospinal fluid?
It has a pressure of between 10-15mmHg
It usually contains a small amount of glucose
It may normally contain up to 5 RBC per mm3
It may normally contain up to 3 WBC per mm3
None of the above
It may normally contain up to 5 RBC per mm3
Normal CSF should NOT contain RBCs.
62
Which of the following inhibits gastric acid secretion?
```
Histamine
Nausea
Calcium
Parasympathetic vagal stimulation
Gastrin
```
Nausea
Nausea inhibits gastric secretion via higher cerebral activity and sympathetic innervation.
63
A 48 year old woman suffers blunt trauma to the head and develops respiratory compromise. As a result she develops hypercapnia. Which of the following effects is most likely to ensue?
Cerebral vasoconstriction
Cerebral vasodilation
Cerebral blood flow will remain unchanged
Shunting of blood to peripheral tissues will occur in preference to CNS perfusion
None of the above
Cerebral vasodilation
Hypercapnia will tend to produce cerebral vasodilation. This is of considerable importance in patients with cranial trauma as it may increase intracranial pressure.
64
A 22 year old man suffers a blunt head injury. He is drowsy and has a GCS of 7 on admission. Which of the following is the major determinant of cerebral blood flow in this situation?
```
Systemic BP
Mean arterial pressure
Intracranial pressure
Hypoxaemia
Acidosis
```
Intracranial pressure
Hypoxaemia and acidosis may both affect cerebral blood flow.
However, in traumatic situations, ICP increases are far more likely to occur especially when GCS is low. This will adversely affect cerebral blood flow.
65
A 45 year old man sustains a closed head injury. He is initially alert, however, his level of consciousness deteriorates on arrival at hospital. An intra cranial pressure monitor is inserted. What is the normal intracranial pressure?
```
35-45 mmHg
45-55 mmHg
<15 mmHg
25-35 mmHg
25-30 mmHg
```
<15 mmHg
The normal intracranial pressure is between 7 and 15 mm Hg. The brain can accommodate increases up to 24 mm Hg, thereafter clinical features will become evident.
66
Intracranial pressure is governed by the principles of the Monroe-Kellie doctrine. To which of the following does this concept not apply?
```
2 month old child
2 year old child
5 year old child
10 year old child
Adult
```
2 month old child
The Monroe-Kelly Doctrine assumes that the cranial cavity is a rigid box. In children with non-fused fontanelles this is not the case.
67
The blood-brain barrier is not highly permeable to which of the following?
```
CO2
Barbiturates
Glucose
Oxygen
Hydrogen ions
```
Hydrogen ions
The BBB is relatively impermeable to highly dissociated compounds.
68
Which of the following statements relating to cerebrospinal fluid is untrue?
The choroid plexus is only present in the lateral ventricles
Total CSF volume is 100-150mL
CSF pressure is usually 10-15mmHg
The cerebral aqueduct connects the third and fourth ventricles
The foramen of Luschka are paired and lie laterally in the fourth ventricle
False = The choroid plexus is only present in the lateral ventricles
The choroid plexus lies in ALL ventricles.
69
A 20 year old man is admitted to the intensive care unit with an isolated severe head injury. A CT scan shows multiple intracerebral bleeds but no midline shift. He is intubated and ventilated. His pupils are dilated and react sluggishly to light. His heart rate is 50 beats/minute blood pressure 170/110 mmHg and his respiratory rate is set at 10 breaths/minute. The rising blood pressure is likely to be caused by:
Aortic and carotid baroreceptor stimulation
Cortisol stimulation
Renin angiotensin stimulation
Sympathetic stimulation related to blood loss
Sympathetic stimulation related to increased ICP
Sympathetic stimulation related to increased ICP
The changes seen are the result of raised ICP, its rare for head injuries to cause sufficient blood loss to affect the circulating volume.
Increases in ICP results in stepwise activation of the SNS initially. This raises peripheral vascular resistance and results in HTN. Cardiac output is also increased. These haemodynamic changes are detected by aortic arch baroreceptors and this results in activation of the parasympathetic nervous system.
These parasympathetic effects comprise the second stage of the Cushing reflex.
The Cushing reflex is a serious development that indicates imminent coning or other terminal events if not resolved quickly.
70
In which space is a lumbar puncture performed?
```
Subdural space
Epidural space
Subarachnoid space
Extradural space
Intraventricular space
```
Subarachnoid space
CSF samples are normally obtained by inserting a needle between the L3-4 vertebrae. The tip of the needle lies in the subarachnoid space, the spinal cord terminates at L1 and is not at risk of injury.
Clinical evidence of raised ICP is a contraindication to lumbar puncture.
71
Which of the following is not classically seen in coning resulting from raised intra cranial pressure?
```
Coma
Hypotension
Unreactive mid-sized pupils
Cheyne-Stokes style respiratory efforts
Bradycardia
```
Hypotension
Cushing's triad = widening of pulse pressure, respiratory changes, bradycardia
Due to raised ICP, systemic HTN is usually seen. Compression of the respiratory centre will typically result in Cheyne-Stokes style respiration.
72
A healthy man has a blood pressure of 120/80 mmHg and an intracranial pressure of 17 mmHg. What is the approximate cerebral perfusion pressure?
```
103 mmHg
63 mmHg
83 mmHg
91 mmHg
76 mmHg
```
76mmHg
Cerebral perfusion pressure = MAP - ICP
CPP is defined as the net pressure gradient causing blood flow to the brain.
MAP = (2 x DBP + SBP)/3
Following trauma, the CPP has to be carefully controlled and this may require invasive monitoring of the ICP and MAP.
73
Via which structure does cerebrospinal fluid enter the subarachnoid space?
```
Cisterna magna
Cerebral aqueduct
Foramen of Luschka
Cisterna chyli
Arachnoid granulations
```
Foramen of Luschka
CSF leaves the 4th ventricle via the laterally placed foramen of Luschka and also via the midline foramen of Magendie.
74
A 5 year old boy presents with recurrent headaches. As part of his assessment he undergoes an MRI scan of his brain. This demonstrates enlargement of the lateral and third ventricles. Where is the most likely site of obstruction?
```
Foramen of Luschka
Foramen of Magendie
Foramen of Munro
Aqueduct of Sylvius
None of the above
```
Aqueduct of Sylvius
The CSF flows from the 3rd to the 4th ventricle via the Aqueduct of Sylvius.
75
Where is the vomiting centre located?
```
Medulla
Substantia nigra
Antrum of stomach
Pons
Midbrain
```
Medulla
```
ABCs of non-GI causes of vomiting:
Acute renal failure
Brain (Increased ICP)
Cardiac (Inferior MI)
DKA
Ears (labyrinthitis)
Foreign substances (Tylenol, theo, etc)
Glaucoma
Hyperemesis Gravidarum
Infections (pyelonephritis, meningitis)
```
76
Which of the following substances is released from the sympathetic nervous system to stimulate the adrenal medulla?
```
Noradrenaline
Acetylcholine
Substance P
Tyrosine
Arginine
```
Acetylcholine
In the autonomic nervous system, NA is the commonly used NT. However, in the adrenal medulla, ACh is released to stimulate adrenaline release.
77
A 22 year old lady receives intravenous morphine for acute abdominal pain. Which of the following best accounts for its analgesic properties?
Binding to δ opioid receptors in the brainstem
Binding to δ opioid receptors at peripheral nerve sites
Binding to beta opioid receptors within the CNS
Binding to alpha opioid receptors within the CNS
Binding to µ opioid receptors within the CNS
Binding to miu opioid receptors within the CNS
Morphine is a strong opioid mediated via 4 types of opioid receptors:
δ (CNS) = analgesic and antidepressant effects
k (mainly CNS) = analgesic and dissociative effects
µ (CNS and PNS) = analgesia, miosis, decreased gut motility
Nociceptin receptor (CNS) = Affect of appetite and tolerance to µ agonists.
Administered PO or IV. Its clinical effects stem from binding to these receptor sites within the CNS and GI tract. Unwanted SEs include nausea, constipation, respiratory depression and, if used long term, addiction.
78
A 47 year old lady is diagnosed as suffering from a phaeochromocytoma. From which of the following amino acids are catecholamines primarily derived?
```
Aspartime
Glutamine
Arginine
Tyrosine
Alanine
```
Tyrosine
Catecholamine hormones are derived from tyrosine, it is modified by a DOPA decarboxylase enzyme to become dopamine and thereafter via two further enzymic modifications to NA and finally adrenaline.
79
A 23 year old man is undergoing an inguinal hernia repair under local anaesthesia. The surgeon encounters a bleeding site which he manages with diathermy. About a minute or so later the patient complains that he is able to feel the burning pain of the heat at the operative site. Which of the following nerve fibres is responsible for the transmission of this signal?
```
A-alpha fibres
A-β fibres
B fibres
C fibres
None of the above
```
C fibres
SLOW transmission of mechanothermal stimuli is transmitted via C fibres.
A-γ fibres transmit information relating to motor proprioception
A-β fibres transmit touch and pressure
B fibres are autonomic fibres
80
A 23 year old man has taken an opiate overdose. Of the following structures, which will be most affected by opiates to produce a reduction in respiratory rate?
```
Carotid chemoreceptors
Central chemoreceptors
Medullary respiratory centre
Pneumotaxic centre
Juxtacapillary (J) receptors
```
Medullary respiratory centre
Opiates typically affect the medullary respiratory centre to depress respiratory activity.
81
Which receptor does noradrenaline mainly bind to?
```
Alpha-1 receptors
Alpha-2 receptors
Beta-1 receptors
Beta-2 receptors
G receptors
```
Alpha-1 receptors
NA is the precursor of adrenaline. It is a powerful α-1 stimulant (although it will increase myocardial contractility). Infusions will produce vasoconstriction and an increase in total peripheral resistance.
It is the inotrope of choice in septic shock.
82
Which opioid receptor does morphine attach to?
```
mu
alpha
sigma
beta
kappa
```
mu
Pethidine and other conventional opioids attach to this receptor.
Opioids combine to specific opiate receptors in the CNS (periaqueductal grey matter, limbic system, substantia gelatinosa)
Morphine attaches to mu1 receptors
83
A 34 year old man receives morphine following an appendicectomy. He develops constipation as a result. Which of the following best accounts for this process?
```
Stimulation of DOPA receptors
Inhibition of DOPA receptors
Stimulation of Mu receptors
Stimulation of serotonin release
Inhibition of serotonin release
```
Stimulation of Mu receptors
Constipation is a common SE of morphine treatment and stimulation of Mu receptors accounts for this process.
84
Which of the following drugs causes hyperkalaemia?
```
Heparin
Ciprofloxacin
Salbutamol
Levothyroxine
Codeine phosphate
```
Heparin
Both unfractionated and LMWH can cause hyperkalaemia. This is thought to be caused by inhibition of aldosterone secretion. Salbutamol is a recognised treatment for hyperkalaemia.
85
Which of the following best accounts for the mechanism of action of glucocorticoids?
Binding of cell wall receptors and intracellular tyrosine kinase activation
Binding of intracellular receptors that migrate to the nucleus to then affect gene transcription
Activation of transmembrane tyrosine kinase systems to affect intranuclear gene transcription
Induces post-translational modification of intracellular proteins
Direct binding of inflammatory cells inducing apoptosis
Binding of intracellular receptors (located on the nucleus) that migrate to the nucleus to then affect gene transcription
86
Which of the following inhibits the secretion of insulin?
```
Adrenaline
Lipids
Gastrin
Arginine
Vagal cholinergic activity
```
Adrenaline
Inhibition of insulin release: alpha adrenergic drugs, sympathetic nerves
87
The acute phase response to injury does not typically include:
```
Pyrexia
Decreased albumin
Hepatic sequestraion of cations
Increased transferrin
Increased serum amyloid A
```
Increased transferrin
```
The acute phase response includes:
Acute phase proteins
Reduction of transport proteins (albumin, transferrin)
Hepatic sequestration cations
Pyrexia
Neutrophil leukocytosis
Increased muscle proteolysis
Changes in vascular permeability
```
88
A 77 year old man presents to pre-operative clinic for a total knee replacement. He is on furosemide for hypertension. He is known to have multiple myeloma. He is found to have the following test results:
Na 120
Serum osmolality 280 (normal)
Urine osmolality normal
Urine Na normal
What is the most likely cause?
```
Pseudohyponatraemia
SIADH
Hypotonic hypovolaemic hyponatraemia
Psychogenic polydipsia
Hypertonic hypovolaemic hyponatraemia
```
Pseudohyponatraemia
Hyperlipidaemia and multiple myeloma are known to cause a pseudohyponatraemia, this is due to raised protein.
89
A 55 year old man undergoes a laparotomy and repair of incisional hernia. Which of the following hormones is least likely to be released in increased quantities following the procedure?
```
Insulin
ACTH
Glucocorticoids
Aldosterone
Growth hormone
```
Insulin
Insulin and thyroxine often have reduced levels of secretion in the post-op period.
This, coupled with increased glucocorticoid release may cause difficulty in management of diabetes in individuals with insulin resistance.
90
A 28 year old lady with hyperthyroidism is started on carbimazole to treat the condition. What is the main mechanism of action?
Inhibition of TSH
Increased degradation of T4 within thyroid colloid
Increased degradation of T3 within thyroid colloid
Inhibit release of T3 and T4 into circulation
Inhibition of thyroid peroxidase enzyme
Inhibition of thyroid peroxidase enzyme
Carbimazole is used to treat hyperthyroidism. Carbimazole is a pro-drug as after absorption it is converted to the active form, methimazole.
METHIMAZOLE prevents thyroid peroxidase enzyme from iodinating and coupling the tyrosine residues on thyroglobulin, hence reducing the production of the thyroid hormones T3 and T4.
Clinical effects take some months to occur as thyroid globulin stores remain for some time after treatment commences.
91
Which of these substances is not released from the islets of Langerhans?
```
Pancreatic polypeptide
Glucagon
Secretin
Somatostatin
Insulin
```
Secretin
Secretin is released from the mucosal cells (S cells) in the duodenum and jejunum.
92
Which of these substances related to thyroid function has its secretion inhibited by increased plasma T3 and T4?
```
T3
T4
Thyroglobulin
Tyroxin-binding globulin
Thyroid-stimulating hormone
```
Thyroid-stimulating hormone
TSH release is inhibited by negative feedback.
93
Which one of the following serum proteins is most likely to increase in a patient with severe sepsis?
```
Transferrin
Transthyretin
Ferritin
Albumin
Cortisol binding protein
```
Ferritin
Ferritin can be markedly increased during acute illness. The other parameters tend to decrease during an acute phase response.
94
A 16 year old girl develops pyelonephritis and is admitted in a state of septic shock. Which of the following is not typically seen in this condition?
```
Increased cardiac output
Increased systemic vascular resistance
Oliguria may occur
Systemic cytokine release
Tachycardia
```
Increased systemic vascular resistance
The SVR is reduced in sepsis. For this reason, a vasopressor e.g. NA may be used if hypotension and oliguria remain a concern despite administration of adequate amounts of IV fluids.
95
Which of the following drugs is least likely to cause SIADH?
```
Haloperidol
Carbamazepine
Amitriptyline
Cyclophosphamide
5-fluorouracil
```
5-fluorouracil
Drugs causing SIADH: ABCD
A nalgesics: opioids, NSAIDs
B arbiturates
C yclophosphamide/ Chlorpromazine/ Carbamazepine
D iuretic (thiazides)
96
A 63 year old man undergoes a laparotomy and small bowel resection. Twelve hours post operatively he is noted to have a decreased urine output. Which of the hormones listed below is most likely to be responsible?
```
Cortisol
Atrial natriuretic hormone
Vasopressin
Insulin
Glucagon
```
Vasopressin
Vasopressin is released in increased quantities following most operative procedures and will tend to cause WATER RETENTION. For this reason, excessive administration of IV fluids in an attempt to force a diuresis may cause fluid overload in post-op patients.
97
Which of the following statements is true of glucagon?
Glucagon is produced in response to hyperglycaemia
Released by beta cells
Inhibits gluconeogenesis
Produced in response to an increase in amino acids
Composed of 2 alpha polypeptide chains linked by hydrogen bonds
Produced in response to an increase in amino acids
Glucagon is a protein comprised of a SINGLE polypeptide chain.
Produced by ALPHA cells of pancreatic islets of Langerhans in response to HYPOGLYCAEMIA and RAISED AMINO ACIDS.
It increases plasma glucose and ketones.
98
What is the half life of insulin in the circulation of a normal healthy adult?
```
<30min
1-2 hours
2-3 hours
4-5 hours
>6 hours
```
<30min
Insulin is degraded by enzymes in the circulation. It typically has a half life of <30min. Abnormalities of the clearance of insulin may occur in T2DM.
99
A 34 year old lady has just undergone a parathyroidectomy for primary hyperparathyroidism. The operation is difficult and all 4 glands were explored. The wound was clean and dry at the conclusion of the procedure and a suction drain inserted. On the ward she becomes irritable and develops stridor. On examination, her neck is soft and the drain empty. Which of the following treatments should be tried initially?
```
Administration of IV calcium gluconate
Administration of IV lorazepam
Removal of skin closure on the ward
Direct laryngoscopy
Administration of calcichew D3 orally
```
Administration of IV calcium gluconate
Exploration of the parathyroid glands may result in impairment of the blood supply. Serum PTH levels can fall quickly and features of HYPOCALCAEMIA may ensue.
These include neuromuscular irritability and LARYNGOSPASM. Prompt administration of IV calcium gluconate can be lifesaving.
The absence of any neck swelling and no blood in the drain would go against a contained haematoma in the neck (which should be managed by removal of skin closure).
100
Which of the following drugs does not interfere with the laboratory analysis of serum cortisol levels?
```
Dexamethasone
Prednisolone
IV hydrocortisone
PO hydrocortisone
IM hydrocortisone
```
Dexamethasone
Prednisolone and its metabolites can chemically mimic cortisol in radio-immunoassay techniques of laboratory analysis.
Dexamethasone can be given as glucorticoid replacement during testing for Addison's or adrenal insufficiency as it does not interfere with cortisol levels.
E.g. if you have a patient with polymyalgia rheumatica and they are on long-term prednisolone, you can replace the prednisolone with dexamethasone to undertake a short synacthen test.
101
What are the most likely effects of the release of vasopressin from the pituitary?
Vasoconstriction of the afferent glomerular arteriole
Increased permeability of the mesangial cells to glucose
Reduced permeability of the inner medullary portion of the collecting duct to urea
Increased secretion of aldosterone from the macula densa
Increased water permeability of the distal tubule cells of the kidney
Increased water permeability of the distal tubule cells of the kidney
ADH (vasopressin) results in the insertion of aquaporin channels in apical membrane of the distal tubule and collecting ducts.
102
Which of the following stimulates prolactin release or action?
```
Leutinising hormone
Dopamine
Thyrotropin releasing hormone
Oestrogen
Follicle stimulating hormone
```
Thyrotropin releasing hormone
TRH stimulates prolactin release. Dopamine suppresses the release of prolactin.
103
A 54-year-old woman is admitted to the Surgical Admissions Unit with abdominal pain. Blood tests taken on admission show the following:
Mg 0.40mmol/L (normal 0.7-1.0)
Which one of the following factors is most likely to be responsible for this result?
```
Excessive resus with IV saline
Digoxin therapy
Diarrhoea
Hypothermia
Rhabdomyolysis
```
Diarrhoea
104
Which of the following best accounts for the action of PTH in increasing serum calcium levels?
Activation of vit D to increase Ca absorption from the small intestine
Direct stimulation of osteoclasts to absorb bone with Ca release
Stimulation of phosphate absorption at the distal convoluted tubule of the kidney
Decreased porosity of vessels at Bowman's capsule to Ca
Vasospasm of the afferent renal arteriole thereby reducing GFR and Ca urinary loss
Activation of vit D to increase Ca absorption from the small intestine
PTH increases the activity of 1-α-hydroxylase enzyme, which converts 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol, the active form of vitamin D.
Osteoclasts do not have a PTH receptor and effects are mediated via osteoblasts.
105
A 43 year old lady is diagnosed with primary hyperparathyroidism. Her serum PTH levels are elevated. An endocrine surgeon performs a parathyroidectomy. How long will it take for the serum PTH levels to fall if the functioning adenoma has been successfully removed?
```
6 hours
24 hours
2 hours
1 hour
10 minutes
```
10 minutes
PTH has a very short half life usually <10 minutes. Therefore a demonstrable drop in serum PTH should be identified within 10 minutes of removing the adenoma. This is useful clinically since it is possible to check the serum PTH intraoperatively prior to skin closure and explore the other glands if levels fail to fall.
106
There is decreased secretion of which one of the following hormones in response to major surgery:
```
Insulin
Cortisol
Renin
ADH
Prolactin
```
Insulin
Endocrine parameters reduced in stress response:
Insulin
Testosterone
Oestrogen
107
Which of the following does not stimulate insulin release?
```
Gastrin
Atenolol
Protein
Secretin
Vagal cholinergic action
```
Atenolol
Beta blockers inhibit the release of insulin.
```
Stimulation of insulin release:
Glucose
Amino acid
Vagal cholinergic
Secretin/Gastrin/CCK
Fatty acids
Beta adrenergic drugs
```
108
Which of the following is the main site of dehydroepiandrosterone release?
```
Posterior pituitary
Zona reticularis
Zona glomerulosa
Zona fasciculata
Juxtaglomerular apparatus of the kidney
```
Zona reticularis
DHEA possesses some androgenic activity and is almost exclusively released from the adrenal gland.
109
Which of the following is not caused by cortisol in the stress response?
```
Anti-inflammatory effects
Hypoglycaemia
Skeletal muscle protein breakdown
Stimulation of lipolysis
Mineralocorticoid effects
```
Hypoglycaemia
An 'anti-insulin' effect occurs leading to hyperglycaemia.
110
Which of the following substances related to thyroid function has its effects mediated by a nuclear receptor?
```
Triiodothyronine
Thyroxine
Thyroglobulin
Thyroid stimulating hormone
Thyroxin binding globulin
```
T3 triiodothyronine
T3 binds to a receptor on chromatin to induce protein synthesis.
111
A 52 year old man develops septic shock following a Hartmans procedure for perforated diverticular disease. He is started on an adrenaline infusion. Which of the following is least likely to occur?
```
Peripheral vasoconstriction
Coronary artery vasospasm
Gluconeogenesis
Lipolysis
Tachycardia
```
Coronary artery vasospasm
Its cardiac effects are mediated via β1 receptors. The coronary arteries which have β2 receptors are unaffected.
Actions of adrenaline:
α adrenergic receptors =
Inhibits insulin secretion by the pancreas
Stimulates glycogenolysis in the liver and muscle
Stimulates glycolysis in muscle
β adrenergic receptors =
Stimulates glucagon secretion in the pancreas
Stimulates ACTH
Stimulates lipolysis by adipose tissue
112
A 48 year old man undergoes a right hemicolectomy for a large caecal polyp. In the immediate post operative period which of the physiological processes described below is least likely to occur?
```
Glycogenolysis
Increased production of acute phase proteins
Increased cortisol production
Bronchoconstriction
Release of NO by vessels
```
Bronchoconstriction
Response to surgery:
SNS = NA from sympathetic nerves, adrenaline from adrenal medulla; raised HR and cardiac contractility, bronchodilatation, increased glucagon and glycogenolysis, reduced insulin and GI motility
Acute phase response = TNF-α, IL-1, IL-2, IL-6, interferon and prostaglandins released, excess cytokines may cause SIRS, cytokine increase release of acute phase proteins
Endocrine = increased ACTH and cortisol, increased protein breakdown and blood glucose levels, aldosterone increases Na reabsorption, ADH increases water reabsorption and causes vasoconstriction
Vascular endothelium = NO causes vasodilatation, PAF enhances cytokine response, prostaglandins cause vasodilatation and induce platelet aggregation
