eMRCS Physiology Flashcards
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
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.
Which of the following is not directly affected by warfarin?
Protein C Factor II Factor VII Factor VIII Factor IX
Factor VIII
Warfarin affects synthesis of factors II, VII, IX, X and protein C.
Which of the following is responsible for the release and synthesis of calcitonin?
Parathyroid glands Anterior pituitary Thyroid gland Posterior pituitary Adrenal glands
Thyroid
Calcitonin has the opposite effect of PTH and is released from the thyroid gland.
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
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.
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
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.
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
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.
Cortisol is predominantly produced by which of the following?
Zona fasciculata of adrenal Zona glomerulosa Zona reticularis Adrenal medulla Posterior lobe of pituitary
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
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
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.
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
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.
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
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.
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
Metabolic alkalosis
These ABG results are classically seen in situations where there is metabolic alkalosis such as may occur following prolonged vomiting.
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
Respiratory alkalosis
The hyperventilation results in decreased carbon dioxide levels, causing a respiratory alkalosis (non-compensated).
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
Vesicovaginal fistula
Vesicovaginal fistulae should be suspected in patients with CONTINUOUS DRIBBLING incontinence after prolonged labour and from an area with limited obstetric services.
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
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.
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.
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
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.
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
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.
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
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.
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
pH 2
The intragastric pH is usually 2. Administration of PPIs can result in almost complete abolition of acidity.
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
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.
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
pH 7.25, pO2 8.9, pCO2 3.2, bicarb 10
This is usually associated with acidosis, hyperventilation and reduction in bicarbonate.
Which one of the following would cause a rise in the carbon monoxide transfer factor (TLCO)?
Emphysema PE Pulmonary haemorrhage Pneumonia Pulmonary fibrosis
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.
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
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.
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
Urodynamic studies
Urodynamic studies are indicated when there is diagnostic uncertainty or plans for surgery.
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
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).
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.
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.
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.
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
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.
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.
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.
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.
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.
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
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.
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.
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
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
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.
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.
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.
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%).
