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Flashcards in PHYSIO 2 Deck (50)
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1
Q

What is the approximate volume of pancreatic secretions in a 24 hour period?

	100ml
	200ml
	500ml
	1500ml
	3000ml
A

1500ml

Typically the pancreas secretes between 1000 and 1500ml per day

2
Q

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 intravenous calcium gluconate
	Administration of intravenous lorazepam
	Removal of the skin closure on the ward
	Direct laryngoscopy
	Administration of calcichew D3 orally
A

Administration of intravenous 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 intravenous 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).

3
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.

4
Q

A 23 year old man presents with blunt abdominal trauma and a splenic bleed is suspected. He is commenced on an infusion of tranexamic acid. Which of the following best describes its mechanism of action?

	Inhibition of plasmin
	Inhibition of thrombin
	Inhibition of factor II
	Inhibition of factor Xa
	Activation of factor VIII
A

Inhibition of plasmin

Tranexamic acid inhibits plasmin and this prevents fibrin degradation.

5
Q

A 34 year old male donates a unit of blood. It is stored at 4 oC. After 72 hours which of the following clotting factors will be most affected?

	Factor V
	Factor II
	Factor VII
	Factor IX
	Factor XI
A

Factor V

Factors V and VIII are sensitive to temperature which is the reason why FFP is frozen soon after collection.

6
Q

Cortisol is predominantly produced by which of the following?

	Zona fasciculata of the adrenal
	Zona glomerulosa of the adrenal
	Zona reticularis of the adrenal
	Adrenal medulla
	Posterior lobe of the pituitary
A

Zona fasciculata of the adrenal

Cortisol is produced by the zona fasciculata of the adrenal gland.

7
Q

Which of these fluids is not an intravenous colloid?

	Gelofusine
	Dextran 40
	Human albumin solution
	Hydroxyethyl starch
	Bicarbonate 8.4%
A

Bicarbonate 8.4%

Bicarbonate is a crystalloid.

8
Q

A 25 year old man undergoes an appendicetomy for appendicitis. The appendix is submitted for histopathological evaluation. Which of the following is most likely to be identified microscopically?

	Macrophages
	Neutrophils
	Fibroblasts
	Lymphocytes
	Stem cells
A

Neutrophils

Neutrophil polymorphs are the cell type most commonly encountered in acute inflammation.

9
Q

A 53 year old man is on the intensive care unit following an emergency abdominal aortic aneurysm repair. He develops abdominal pain and diarrhoea and is profoundly unwell. His abdomen has no features of peritonism. Which of the following arterial blood gas pictures is most likely to be present?

pH 7.45, pO2 10.1, pCO2 3.2, Base excess 0, Lactate 0
pH 7.35, pO2 8.0, pCO2 5.2, Base excess 2, Lactate 1
pH 7.20, pO2 9.0, pCO2 3.5, Base excess -10, Lactate 8
pH 7.29, pO2 8.9, pCO2 5.9, Base excess -4, Lactate 3
pH 7.30, pO2 9.2 pCO2 4.8, Base excess -2, lactate 1
A

pH 7.20, pO2 9.0, pCO2 3.5, Base excess -10, Lactate 8

This man is likely to have a metabolic acidosis secondary to a mesenteric infarct.

10
Q

The Cori cycle is important in lactate metabolism in the septic surgical patient. It is used to describe a pathway in which glucose is metabolised anaerobically to lactate in one tissue and the lactate is converted back to glucose in another. Which one of the following relies on this cycle to meet all of its energy needs?

	Hepatocyte
	Leucocyte
	Erythrocyte
	Pneumocyte
	Goblet cells
A

Erythrocyte

Erythrocytes lack a mitochondria and therefore they generate energy via glycolytic pathways only. All the other cell types have mitochondria and will therefore use the Krebs cycle unless true anaerobic conditions prevail.

11
Q

A 48 year old women 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
A

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.

12
Q

A patient is seen in clinic complaining of abdominal pain. Routine bloods show:

Na+	142 mmol/l
K+	4.0 mmol/l
Chloride	104 mmol/l
Bicarbonate	19 mmol/l
Urea	7.0 mmol/l
Creatinine	112 µmol/l

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 (sodium + potassium) - (bicarbonate + chloride)

= (142 + 4.0) - (104 + 19) = 23 mmol/L

13
Q

A 73 year old man has an arterial line in situ. On studying the trace the incisura can be seen. What is the physiological event which accounts for this process?

	Atrial repolarisation
	Mitral valve closure
	Ventricular repolarisation
	Elastic recoil of the aorta
	Tricuspid valve closure
A

Elastic recoil of the aorta

It is the temporary rise in aortic pressure occurring as a result of elastic recoil. its the same thing as the dicrotic notch

14
Q

A surgeon is considering using lignocaine as local anasthesia for a minor procedure. Which of the following best accounts for its actions?

Blockade of neuronal acetylcholine receptors
Blockade of neuronal nicotinic receptors
Blockade of neuronal sodium channels
Blockade of neuronal potassium channels
Blockade of neuronal calcium channels
A

Blockade of neuronal sodium channels

Lignocaine blocks sodium channels. They will typically be activated first, hence the pain some patients experience on administration.

15
Q

Which of the substances below is derived primarily from the zona reticularis of the adrenal gland?

	Mineralocorticoid hormones
	Glucocorticoid hormones
	Sex hormones
	FSH
	Vasopressin
A

Sex hormones

16
Q

A 28 year old man undergoes a completion right hemicolectomy for treatment of a 5cm appendiceal carcinoid. As part of his follow up he is due to undergo 24 hour urine collection for 5-HIAA. Which of the following causes an elevated 5-HIAA in a 24-hour urine collection?

	Naproxen
	Oranges
	Flucloxacillin
	Amiodarone
	Beef
A

Naproxen

It is important to be aware of what can falsely elevate 5-HIAA to avoid diagnosing carcinoid syndrome incorrectly. These include:

Food: spinach, cheese, wine, caffeine, tomatoes
Drugs: Naproxen, Monoamine oxidase inhibitors
Recent surgery

17
Q

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 blood pressure
	Mean arterial pressure
	Intra cranial pressure
	Hypoxaemia
	Acidosis
A

Intra cranial pressure

Hypoxaemia and acidosis may both affect cerebral blood flow. However, in the traumatic situation increases in intracranial pressure are far more likely to occur especially when GCS is low. This will adversely affect cerebral blood flow.

18
Q

A 43 year old man has recurrent episodes of dyspepsia and treatment is commenced with oral antacids. Which of the hormones listed below is released in response to increased serum gastrin levels and decreases intra gastric pH?

	Cholecystokinin
	Histamine
	Somatostatin
	Insulin
	Vasoactive intestinal peptide
A

Histamine

Histamine is released from enterochromaffin cells in the stomach mucosa which stimulates acid secretion. It is usually released in response to increased serum gastrin levels. Histamine blockers (e.g. cimetidine) were extremely popular treatments until the advent of proton pump inhibitors.

19
Q

Which main group of receptors does dobutamine bind to?

	α-1
	α-2
	ß-1
	ß-2
	D-1
A

ß-1

Dobutamine is a sympathomimetic with both alpha- and beta-agonist properties; it displays a considerable selectivity for beta1-cardiac receptors

20
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 gland

Calcitonin has the opposite effect of PTH and is released from the thyroid gland.

21
Q

What is the half life of insulin in the circulation of a normal healthy adult?

	Less than 30 minutes
	Between 1 and 2 hours
	Between 2 and 3 hours
	Between 4 and 5 hours
	Over 6 hours
A

Less than 30 minutes

Insulin is degraded by enzymes in the circulation. It typically has a half life of less than 30 minutes. Abnormalities of the clearance of insulin may occur in type 2 diabetes.

22
Q

Which of the following statements about blood clotting is untrue?

Platelet adhesion to disrupted endothelium is dependent upon von Willebrand factor
Protein C is a vitamin K dependent substance
The bleeding time provides an assessment of platelet function
The prothrombin time tests the extrinsic system
Administration of aprotinin during liver transplantation surgery prolongs survival
A

Administration of aprotinin during liver transplantation surgery prolongs survival

Although aprotinin reduces fibrinolysis and thus bleeding, it is associated with increased risk of death and was withdrawn in 2007. Protein C is dependent upon vitamin K and this may paradoxically increase the risk of thrombosis during the early phases of warfarin treatment.

23
Q

Which of the following cell types is least likely to be found in a wound 1 week following injury?

	Macrophages
	Fibroblasts
	Myofibroblasts
	Endothelial cells
	Neutrophils
A

Myofibroblasts

Myofibroblasts are differentiated fibroblasts, in which the cytoskeleton contains actin filaments. These cell types facilitate wound contracture and are the hallmark of a mature wound. They are almost never found in wounds less than 1 month old.

24
Q

The blood - brain barrier is not highly permeable to which of the following?

	Carbon dioxide
	Barbituates
	Glucose
	Oxygen
	Hydrogen ions
A

Hydrogen ions

The blood brain barrier is relatively impermeable to highly dissociated compounds.

25
Q

A 43 year old presents to the urology clinic complaining of impotence. Which of the following will occur in response to increased penile parasympathetic stimulation?

Detumescence
Ejaculation
Erection
Vasospasm of the penile branches of the pudendal artery
Contraction of the smooth muscle in the epididymis and vas deferens
A

Erection

Parasympathetic stimulation causes erection. Sympathetic stimulation will produce ejaculation, detumescence and vasospasm of the pudendal artery. It will also cause contraction of the smooth muscle in the epididymis and vas to convey the ejaculate.

26
Q

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
A

Triiodothyronine

T3 binds to a receptor on chromatin to induce protein synthesis.

27
Q

Which of the following best accounts for the action of PTH in increasing serum calcium levels?

Activation of vitamin D to increase absorption of calcium from the small intestine.
Direct stimulation of osteoclasts to absorb bone with release of calcium.
Stimulation of phosphate absorption at the distal convoluted tubule of the kidney.
Decreased porosity of the vessels at Bowmans capsule to calcium.
Vasospasm of the afferent renal arteriole thereby reducing GFR and calcium urinary loss.
A

Activation of vitamin D to increase absorption of calcium 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.

28
Q

Which of the following drugs is least likely to cause syndrome of inappropriate anti diuretic hormone release?

	Haloperidol
	Carbamazepine
	Amitriptylline
	Cyclophosphamide
	Methotrexate
A

Methotrexate

Drugs causing SIADH: ABCD

A nalgesics: opioids, NSAIDs
B arbiturates
C yclophosphamide/ Chlorpromazine/ Carbamazepine
D iuretic (thiazides)

29
Q

Which of the following changes are not typically seen in established dehydration?

	Rising haematocrit
	Urinary sodium <20mmol/ litre
	Metabolic acidosis
	Decreased serum urea to creatinine ratio
	Hypernatraemia
A

Decreased serum urea to creatinine ratio

Diagnosing dehydration can be complicated, laboratory features include:
Hypernatraemia
Rising haematocrit
Metabolic acidosis
Rising lactate
Increased serum urea to creatinine ratio
Urinary sodium <20 mmol/litre
Urine osmolality approaching 1200mosmol/kg
30
Q
A 67 year old male is admitted to the surgical unit with acute abdominal pain. He is found to have a right sided pneumonia. The nursing staff put him onto 15L O2 via a non rebreathe mask. After 30 minutes the patient is found moribund, sweaty and agitated by the nursing staff. An arterial blood gas reveals:
pH	7.15
pCO2	10.2
pO2	8
Bicarbonate	32
Base excess	- 5.2

What is the most likely cause for this patients deterioration?

Acute respiratory alkalosis secondary to hyperventilation
Over administration of oxygen in a COPD patient
Metabolic acidosis secondary to severe pancreatitis
Metabolic alkalosis secondary to hypokalaemia
Acute respiratory acidosis secondary to pneumonia
A

Over administration of oxygen in a COPD patient

This patient has an acute respiratory acidosis, however this is on a background of chronic respiratory acidosis (due to COPD) with a compensatory metabolic alkalosis (the elevated bicarbonate is the main clue to the chronic nature of the respiratory acidosis). This blood gas picture is typical in a COPD patient who has received too much oxygen; these patients lose their hypoxic drive for respiration, therefore retain CO2 and subsequently hypoventilate leading to respiratory arrest. If the bicarbonate was normal, then the answer would be acute respiratory acidosis secondary to pneumonia.

31
Q

Which of the following statements relating to the pharmacology of warfarin is untrue?

Interferes with clotting factors 2,7,9 and 10
It may not be clinically effective for up to 72 hours
The half life of warfarin is 40 hours
Warfarin has a large volume of distribution
It is metabolized in the liver
A

Warfarin has a large volume of distribution

Warfarin interferes with fibrin formation by affecting carboxylation of glutamic acid residues in factors 2,7,9 and 10. Factor 2 has the longest half life of approximately 60 hours, therefore it can take up to 3 days for warfarin to be fully effective. Warfarin has a small volume of distribution as it is protein bound.

32
Q

Which of the following does not cause an increased anion gap acidosis?

	Uraemia
	Paraldehyde
	Diabetic ketoacidosis
	Ethylene glycol
	Acetazolamide
A

Acetazolamide

Causes of increased anion acidosis: MUDPILES

M - Methanol
U - Uraemia
D - DKA/AKA
P - Paraldehyde/phenformin
I - Iron/INH
L - Lactic acidosis
E - Ethylene glycol
S - Salicylates
33
Q

Which one of the following is least associated with thrombocytopenia?

	Heparin therapy
	Rheumatoid arthritis
	Infectious mononucleosis
	Liver disease
	Pregnancy
A

Rheumatoid arthritis

Rheumatoid arthritis, unlike systemic lupus erythematous, is generally associated with a thrombocytosis. In some cases of Felty’s syndrome thrombocytopaenia may be seen secondary to hypersplenism. This however represents a small percentage of patients with rheumatoid arthritis.

34
Q

Which of the following will increase the volume of pancreatic exocrine secretions?

	Octreotide
	Cholecystokinin
	Aldosterone
	Adrenaline
	None of the above
A

Cholecystokinin

Cholecystokinin will often increase the volume of pancreatic secretions

35
Q

Where is the majority of iron found in the body?

	Bone
	Haemoglobin
	Ferritin and haemosiderin
	Myoglobin
	Plasma iron
A

Haemoglobin

Approximately 70% of body iron is found bound to haemoglobin.

36
Q

A 44 year old man receives a large volume transfusion of whole blood. The whole blood is two weeks old. Which of the following best describes its handling of oxygen?

It will have a low affinity for oxygen
Its affinity for oxygen is unchanged
It will more readily release oxygen in metabolically active tissues than fresh blood
The release of oxygen in metabolically active tissues will be the same as fresh blood
It will have an increased affinity for oxygen
A

It will have a low affinity for oxygen

Stored blood has less 2,3 DPG and therefore has a higher affinity for oxygen, this reduces its ability to release it at metabolising tissues.

37
Q

A 43 year old lady undergoes a day case laparoscopic cholecystectomy. The operation is more difficult than anticipated and a drain is placed to the operative site. Whilst in recovery, the patient loses 1800ml of frank blood into the drain. Which of the following will not occur?

Release of aldosterone via the Bainbridge reflex
Reduced urinary sodium excretion
Increase in sympathetic discharge to ventricular muscle
Fall in parasympathetic discharge to the sino atrial node
Decreased stimulation from atrial pressure receptors
A

Release of aldosterone via the Bainbridge reflex

The Bainbridge reflex is the increase in heart rate mediated via atrial stretch receptors that occurs following a rapid infusion of blood. Note the question asks which will not occur and that is why it is A and not the other options.

38
Q

Approximately what proportion of salivary secretions is provided by the submandibular glands?

	10%
	70%
	40%
	90%
	20%
A

70%

Although they are small, the submandibular glands provide the bulk of salivary secretions and contribute 70%, the sublingual glands provide 5% and the remainder from the parotid

39
Q

Which is the least likely to cause hyperuricaemia?

	Severe psoriasis
	Lesch-Nyhan syndrome
	Amiodarone
	Diabetic ketoacidosis
	Alcohol
A

Amiodarone

Decreased tubular secretion of urate occurs in patients with acidosis (eg, diabetic ketoacidosis, ethanol or salicylate intoxication, starvation ketosis). The organic acids that accumulate in these conditions compete with urate for tubular secretion.

40
Q

Which of the following statements relating to low molecular weight heparins is false?

They act via inhibition of Factor Xa
Large doses may be used prior to commencing cardiopulmonary bypass
They have a highly predictable pharmacokinetic profile
They are derivatives of unfractionated heparin
They have a molecular mass in the range of 3000-10000Da
A

Large doses may be used prior to commencing cardiopulmonary bypass

As they are not easily reversed they are unsuitable for this purpose.

41
Q

A 43 year old lady presents with urinary incontinence. At which of the following locations is Onufs nucleus likely to be found?

	Medulla oblongata
	Anterior horn of L5 nerve roots
	Micturition centre in the Pons
	Anterior horn of S2 nerve roots
	None of the above
A

Anterior horn of S2 nerve roots

Onufs nucleus is located in the anterior horn of S2 and is the origin of neurones to the external urethral sphincter.

42
Q

Which of the following is associated with reduced lung compliance?

	Older age
	Emphysematous type COPD
	Decline in pulmonary blood flow
	Adopting a vertical posture
	Adjusting a ventilator to maintain high lung volumes
A

Adjusting a ventilator to maintain high lung volumes

Lung compliance is a measure of the ease of expansion of the lungs and thorax, determined by pulmonary volume and elasticity. A high degree of compliance indicates a loss of elastic recoil of the lungs, as in old age or emphysema. This increased lung compliance is due to loss of supportive tissue around the airways. While a normal lung has a high passive elastic recoil, the sick lung has a decreased elasticity (i.e. decreased transpulmonary pressure) which leads to increased lung compliance.

Decreased compliance means that a greater change in pressure is needed for a given change in volume, as in atelectasis, pulmonary fibrosis, pneumonia, or lack of surfactant.

43
Q

Which of the following statements relating to alveolar ventilation is untrue?

Anatomical dead space is measured by helium dilution
Physiological dead space is increased in PE
Alveolar ventilation is defined as the volume of fresh air entering the alveoli per minute
Anatomical dead space is increased by adrenaline
Type 2 pneumocytes in the alveoli secrete surfactant
A

Anatomical dead space is measured by helium dilution

Anatomical dead space is measured by Fowlers method.

44
Q

Which opioid receptor does morphine attach to?

	mu
	alpha
	sigma
	beta
	kappa
A

mu

Pethidine and other conventional opioids attach to this receptor.

45
Q

Which of the following inhibits the secretion of insulin?

	Adrenaline
	Lipids
	Gastrin
	Arginine
	Vagal cholinergic activity
A

Adrenaline

Inhibition of insulin release:

Alpha adrenergic drugs
Beta blockers
Sympathetic nerves

46
Q

What is measured to obtain renal plasma flow?

	Creatinine
	Para-amino hippuric acid (PAH)
	Inulin
	Glucose
	Protein
A

Para-amino hippuric acid (PAH)

Renal plasma flow = (amount of PAH in urine per unit time) / (difference in PAH concentration in the renal artery or vein)

Normal value = 660ml/min

47
Q

Which of the following surgical procedures will have the greatest long term impact on a patients calcium metabolism?

	Distal gastrectomy
	Cholecystectomy
	Extensive small bowel resection
	Sub total colectomy
	Gastric banding for obesity
A

Extensive small bowel resection

Calcium is mainly absorbed from the small bowel and this will have a direct long term impact on calcium metabolism and increase the risk of osteoporosis. Gastric banding and distal gastrectomy may affect a patients dietary choices but any potential deleterious nutritional intake may be counteracted by administration of calcium supplements orally. Only 10% of calcium is absorbed from the colon so that a sub total colectomy will only have a negligible effect.

48
Q

A 52-year-old woman with a history of gastrectomy reports lethargy and a sore tongue. Blood tests are reported as follows:

Hb 10.7 g/dl
MCV 121 fl
Plt 177 * 10^9/l
WBC 5.4 * 10^9/l

What is the most likely cause?

	Vitamin B12 deficiency
	Vitamin C deficiency
	Iron deficiency anaemia
	Anaemia of chronic disease
	Vitamin E deficiency
A

Vitamin B12 deficiency

A history of gastrectomy and a macrocytic anaemia should indicate a diagnosis of B12 deficiency.

49
Q

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
A

10 minutes

PTH has a very short half life usually less than 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.

50
Q

Which of the following statements relating to abnormal coagulation is false?

Warfarin affects the synthesis of factor 2,7,9,10
The prothrombin time is prolonged in Haemophilia A
Cholestatic jaundice can cause vitamin K deficiency
Disseminated intravascular coagulation is associated with thrombocytopenia
Massive transfusion is associated with reduced levels of factor 5 and 8
A

The prothrombin time is prolonged in Haemophilia A

In haemophilia A the APTT is prolonged and there is reduced levels of factor 8:C. The bleeding time and PT are normal. Cholestatic jaundice prevents the absorption of the fat soluble vitamin K. Massive transfusion (>10u blood or equivalent to the blood volume of a person) puts the patient at risk of thrombocytopaenia, factor 5 and 8 deficiency.