PHYSIO 1 Flashcards
Which of the following drugs increases the rate of gastric emptying in the vagotomised stomach?
Ondansetron Metoclopramide Cyclizine Erythromycin Chloramphenicol
Erythromycin
Chloramphenicol has no effect on gastric emptying. Ondansetron slows gastric emptying slightly. Metoclopramide increases the rate of gastric emptying but its effects are mediated via the vagus nerve. Erythromycin enhances gastric emptying by acting via the motilin receptor in the gut.
Which of the following is not secreted by the parietal cells?
Hydrochloric acid Mucus Magnesium Intrinsic factor Calcium
Mucus
Parietal cells: secrete HCl, Ca, Na, Mg and intrinsic factor
Chief cells: secrete pepsinogen
Surface mucosal cells: secrete mucus and bicarbonate
A 65 year old man is admitted for a below knee amputation. He is taking digoxin. Clinically the patient has an irregularly irregular pulse. What would you expect to see when you examine the jugular venous pressure?
Absent y waves Slow y descent Cannon waves Steep y descent Absent a waves
Absent a waves
This patient has atrial fibrillation and is most likely to have absent a waves.
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
Vitamin D
Vitamin D is needed to help mineralise bone. When this is deficient, mineralisation is inadequate and deformities may result.
Which of the following substances is released from the sympathetic nervous system to stimulate the adrenal medulla?
Nor adrenaline Acetyl choline Substance P Tyrosine Arginine
Acetyl choline
In the autonomic nervous system, noradrenaline is the commonly used neurotransmitter. However, in the adrenal medulla, Acetylcholine is released to stimulate adrenaline release.
von Willebrand factor is involved in the stabilization of which of the clotting factors listed below?
Factor VII Factor VIII Factor V Anti thrombin III Factor Xa
Factor VIII
vWF stabilizes factor VIII
Which part of the ECG represents atrial depolarization?
P wave Q wave T wave QRS complex P-R interval
P wave
The P wave represents atrial depolarization. Note that atrial repolarization is obscured within the QRS complex.
A 45 year old male has alcoholic cirrhosis and decompensated liver failure, which of the following clotting factors is least likely to be affected?
Factor V Factor VII Factor IX Factor VIII Factor XI
Factor VIII
Factor VIII is synthesised in the endothelial cells of the liver rather than the liver itself and therefore is less prone to the effects of hepatic dysfunction.
A patient has an arterial blood gas sample taken and the following result is obtained: pH 7.48 pO2 10.1 Bicarbonate 30 pCO2 4.5 Chloride 10meq What is the most likely cause?
Respiratory alkalosis Metabolic alkalosis Type 1 respiratory failure Metabolic acidosis with normal anion gap Metabolic acidosis with increased anion gap
Metabolic alkalosis
This would be a typical result of prolonged vomiting.
Which of the blood gas results listed below is most likely to fit with a patient who has acute respiratory acidosis?
pH 7.57, PaCO2 3.5, Pa O2 24.5 (FiO2 85%), Bicarbonate 23.5, Base excess +1.8 mmol pH 7.19, pCO2 10.2, pO2 16 (FiO2 85%), Bicarbonate 23.8, Base excess -2.2 mmol pH 7.14, PaCO2 7.4, PaO2 8.9 (FiO2 40%), Bicarbonate 14 mmol, Base excess -10.6 pH 7.36, PaCO2 7.3, PO2 8.9 (FiO2 40%), Bicarbonate 30.2, Base excess 5.3 pH 7.32, PCO2 3.8, PaO2 22.2 (FiO2 40%), Bicarbonate 19.1, Base excess -7.9
pH 7.19, pCO2 10.2, pO2 16 (FiO2 85%), Bicarbonate 23.8, Base excess -2.2 mmol
A 43 year old lady is recovering on the intensive care unit following a Whipples procedure. She has a central venous line in situ. Which of the following will lead to the y descent on the waveform trace ?
Ventricular contraction Emptying of the right atrium Emptying of the right ventricle Opening of the pulmonary valve Cardiac tamponade
Emptying of the right atrium
The y descent represents the emptying of the atrium and the filling of the right ventricle.
A 23 year old is stabbed in the groin and develops hypovolaemic shock. What is the most likely finding on analysis of his urine?
Decreased specific gravity Increased specific gravity Increased urinary glucose Increased urinary protein Increased red blood cells in the urine
Increased specific gravity
Hypovolaemic shock is likely to compromise renal blood flow especially if blood pressure falls below the range at which the kidney is able to autoregulate its blood flow. The result of this will be an increase of the specific gravity as water retention occurs in an attempt to maintain circulating volume
A healthy man has a blood pressure of 120/80 mmHg and an intra cranial pressure of 17 mmHg. What is the approximate cerebral perfusion pressure?
103 mmHg 63 mmHg 83 mmHg 91 mmHg 76 mmHg
76 mmHg
Cerebral perfusion pressure= Mean arterial pressure - intra cranial pressure
The mean arterial pressure can be calculated as:
MAP= Diastolic pressure+ 0.333(Systolic pressure- Diastolic pressure)
In this situation the MAP = 93.
The ICP is subtracted from this value; 93 - 17 = 76
The pressure within the pleural space is negative with respect to atmospheric pressure, except for which of the following?
At the end of inspiration When taking a deep breath If the patient is intubated with an endotracheal tube During a Valsalva manoeuvre At the end of expiration
During a Valsalva manoeuvre
During a Valsalva manoeuvre, the intra pleural pressure rises owing to extrinsic compression.
There is decreased secretion of which one of the following hormones in response to major surgery:
Insulin Cortisol Renin Anti diuretic hormone Prolactin
Insulin
Insulin is often released in decreased quantities following surgery
What is the main event involved in the neovascularization of the immature wound bed following surgery?
Endothelial cell proliferation Fibroblast proliferation Macrophage migration Neutrophil accumulation Granulocyte degradation
Endothelial cell proliferation
Angiogenesis is a key event in wound healing and occurs as a result of endothelial cell proliferation.
A 28 year old man undergoes an ileocaecal resection to treat terminal ileal Crohns disease. Post operatively he attends the clinic and complains of diarrhoea. His CRP is within normal limits and small bowel enteroclysis shows no focal changes. Which of the following interventions is most likely to be beneficial?
5 ASA drugs Azathioprine Pulsed methylprednisolone Infliximab Oral cholestyramine
Oral cholestyramine
Malabsorption of bile salts is a common cause of diarrhoea following ileal resection. A normal small bowel study and CRP effectively excludes active Crohns disease and therefore immunomodulator drugs are not appropriate.
The question is about high output diarrhoea following terminal ileal resection and the most likely cause is malabsorption of bile salts. The administration of cholestyramine (bile salt binding agent) will counter this and thats why its the correct answer.
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 that migrate to the nucleus to then affect gene transcription
Glucocorticoids exert their effects by binding intracellular receptors than are then transported to the nucleus where they affect gene transcription.
Which of the following statements related to the coagulation cascade is true?
The intrinsic pathway is the main pathway in coagulation Heparin inhibits the activation of Factor 8 The activation of factor 8 is the point when the intrinsic and the extrinsic pathways meet Tissue factor released by damaged tissue initiates the extrinsic pathway Thrombin converts plasminogen to plasmin
Tissue factor released by damaged tissue initiates the extrinsic pathway
The extrinsic pathway is the main path of coagulation. Heparin inhibits the activation of factors 2,9,10,11. The activation of factor 10 is when both pathways meet. Thrombin converts fibrinogen to fibrin. During fibrinolysis plasminogen is converted to plasmin to break down fibrin.
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 side effect of morphine treatment and stimulation of Mu receptors accounts for this process.
