Exam Tips
Lung Volumes and Capacities
Lung volumes, which are also known as respiratory volumes, refer to the various volumes of gas in the lungs at any given time during the respiratory cycle. Lung capacities are derived from a summation of different lung volumes. It is important to have an understanding...
The Renin-Angiotensin-Aldosterone System
The renin-angiotensin-aldosterone system (RAAS) is a hormonal system that is responsible for the regulation of arterial blood pressure and of the concentration of sodium in the plasma. Renin and angiotensinogen The first stage of the RAAS is the release of the...
Addison’s Disease
Addison’s disease (primary adrenal insufficiency) is caused by the underproduction of the steroid hormones by the adrenal glands. Glucocorticoid, mineralocorticoid and sex steroid production are all affected. It is more common in women than in men and most commonly...
Hyperaldosteronism
Hyperaldosteronism occurs when there are excessive circulating levels of aldosterone. Hyperaldosteronism can be subdivided into two main types: Primary hyperaldosteronism (~95% of cases) Secondary hyperaldosteronism (~5% of cases) Primary hyperaldosteronism is...
Test Your ECG Knowledge – Waves, Segments and Intervals
Test your knowledge of the ECG waves, segments and intervals with these questions. 1. Which single statement regarding the p wave on the ECG is true? A. It is normally between 120 and 150 ms in duration B. It is positive in lead AVR C. It represents atrial...
Test Your ECG Knowledge – Rate, Rhythm & Axis
Test your knowledge of the ECG rate, rhythm and axis with these questions.1. Which of the following is the usual paper speed of an ECG? A. 10 mm/secB. 25 mm/secC. 50 mm/secD. 75 mm/secE. 100 mm/secAnswer: B. 25 mm/sec The usual paper speed of an ECG is 25...
Test Your ECG Knowledge – Anatomy & Physiology
Test your knowledge of the anatomy and physiology of the ECG with these questions.1. Which of the following is the correct location of the sino-atrial (SA) node? A. Right atriumB. Left atriumC. Right ventricleD. Inter-atrial septumE. Inter-ventricular septumAnswer: A....
How To Read a Paediatric ECG
The basic methodology used to read a paediatric ECG is the same as that used in an adult ECG, but the anatomical and physiological differences between children and adults mean that some features of the ECG that will be different. Furthermore, the progressive changes...
Cushing’s Syndrome
Cushing’s syndrome is a collection of symptoms and signs caused by prolonged exposure to elevated levels of either endogenous or exogenous glucocorticoids. The incidence of Cushing’s syndrome is approximately 10-15 per million, and the incidence is higher in people...
Phaeochromocytoma
A phaeochromocytoma is a rare functional tumour that arises from chromaffin cells in the adrenal medulla. Extra-adrenal paragangliomas (extra-adrenal pheochromocytomas) are closely related, though less common, tumours that originate in the ganglia of the sympathetic...
