PHYSIO 4 Flashcards
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
The choroid plexus is only present in the lateral ventricles
The choroid plexus lies in all ventricles.
Which substance can be used to achieve the most accurate measurement of the glomerular filtration rate?
Glucose Protein Inulin Creatinine Para-amino hippuric acid
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.
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 - 45mm Hg 45 - 55mm Hg <15mm Hg 25 - 35mm Hg 25 - 30 mm Hg
<15mm Hg
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.
A 55-year-old man with a history of type 2 diabetes mellitus, bipolar disorder and chronic obstructive pulmonary disease has bloods taken during a pre operative assessment of an inguinal hernia repair:
Na+ 125 mmol/l K+ 3.8 mmol/l Bicarbonate 24 mmol/l Urea 3.7 mmol/l Creatinine 92 µmol/l
Due to his smoking history a chest x-ray is ordered which is reported as normal. The Consultant asks you what is the most likely cause for the hyponatraemia?
Metformin Lithium Carbamazepine Sodium valproate Pioglitazone
Carbamazepine
Lithium can cause diabetes insipidus but this is generally associated with a high sodium.
A 24 year old man is involved in a road traffic accident. His right leg is trapped for 6 hours whilst he is moved. On examination his foot is insensate and a dorsalis pedis pulse is only weakly felt. Which of the biochemical abnormalities listed below is most likely to be present?
Alkalosis Hypercalcaemia Hypocalcaemia Hyperkalaemia Hyponatraemia
Hyperkalaemia
In this scenario the patient will have a compartment syndrome, delayed diagnosis and muscle death. The effect of muscle death will result in the release of potassium
A 39 year old lady has recurrent attacks of biliary colic. What is the approximate volume of bile to enter the duodenum per 24 hours?
500 mL 50 mL 100 mL 2000 mL 150 mL
500 mL
Between 500 mL and 1.5 L of bile enters the small bowel daily.
At which of the following sites is the most water absorbed?
Right colon Left colon Stomach Jejunum Duodenum
Jejunum
Water absorption in the gastrointestinal tract predominantly occurs in the small bowel (jejunum and ileum). The colon is an important site of water absorption, however, its overall contribution is relatively small
Which of the following is not a characteristic of the proximal convoluted tubule in the kidney?
Up to 95% of filtered amino acids will be reabsorbed at this site It is a risk of damage in a patient with compartment syndrome due to a tibial fracture It is responsible for absorbing more than 50% of filtered water Its secretory function is most effective at low systolic blood pressures (typically less than 100mmHg) Glucose is reabsorbed by a process of facilitated diffusion
Its secretory function is most effective at low systolic blood pressures (typically less than 100mmHg)
The proximal convoluted tubule may undergo necrosis in situations such as compartment syndrome. It is responsible for reabsorbing up to two thirds of filtered water. Low systolic blood pressures (below the renal autoregulatory range) are a risk factor for acute tubular necrosis. Within the autoregulatory range the absolute value of systolic BP has little effect.
An arterial blood gas sample is taken and the following results obtained;
PaO2 8kPa
PaCO2 4kPa
pH 7.4
With which of the following are these values most consistent?
Compensated metabolic alkalosis Pulmonary atelectasis Alveolar hypoventilation Residing at 4500M for 48 hours LAD occlusion
Residing at 4500M for 48 hours
The patient has low oxygen tension and low carbon dioxide. The pH is normal so there is compensation for a long standing condition in which oxygenation is reduced. There is neither alkalosis, nor hypoventilation as the carbon dioxide is low. At very high altitude, the low oxygen tension can exceed the anaerobic threshold and carbon dioxide levels increase.
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.
Which one of the following would cause a rise in the carbon monoxide transfer factor (TLCO)?
Emphysema Pulmonary embolism Pulmonary haemorrhage Pneumonia Pulmonary fibrosis
Pulmonary haemorrhage
Where alveolar haemorrhage occurs the TLCO tends to increase due to the enhanced uptake of carbon monoxide by intra-alveolar haemoglobin.
Which of the following is least likely to be associated with hypercalcaemia?
Thiazides Antacids Coeliac disease Sarcoidosis Zolinger-Ellison syndrome
Coeliac disease
Patients with coeliac disease tend to develop hypocalcaemia due to malabsorption of calcium by the bowel.
Release of somatostatin from the pancreas will result in which of the following?
Decrease in pancreatic exocrine secretions Contraction of the gallbladder Increase in the 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.
A 34 year old lady develops septic shock and features of the systemic inflammatory response syndrome as a complication of cholangitis. Which of the following is not a typical feature of this condition?
Body temperature less than 36oC or greater than 38oC Respiratory rate >20 Lactate <4 mmol/L High levels of tumour necrosis factor α WCC >12,000 mm3
Lactate <4 mmol/L
Septic shock will typically result in end organ hypoperfusion and as a result lactate levels will often be high. In the surviving sepsis campaign it is suggested that elevated lactate levels are an independent indicator for vasopressor support in patient with sepsis
Which of the following stimulates gastric acid secretion?
Cholecystokinin Gastric inhibitory peptide Secretin Histamine Somatostatin
Histamine
Which of the following statements relating to gastric acid secretions are untrue?
In parietal cells carbonic anhydrase generates hydrogen ions which are then actively secreted The cephalic phase is abolished following truncal vagotomy The intestinal phase accounts for 60% of gastric acid produced Histamine acts in a paracrine manner on H2 receptors H2 receptor antagonists will not completely abolish gastric acid production
The intestinal phase accounts for 60% of gastric acid produced
The intestinal phase of gastric acid secretion accounts for only 10% of gastric acid produced.
