…retina via the optic nerve (CN II) to the midbrain, where interneurons in the pretectal area activate the Edinger–Westphal nuclei. Parasympathetic fibers (carried by…

…for a surgical airway or awake fibreoptic intubation. A difficult airway is anticipated in a stable patient — awake fibreoptic intubation or anaesthetic back up is…

…has an electrical conduction system composed of specialized myocardial cells (henceforth referred to as conduction cells). These cells form bundles of fibers that act as…

…myocardial fibers The left ventricular wall can be subdivided into several layers. These layers are similar to those seen in arteries throughout the circulatory system…

…combinations of foods habitually consumed rather than isolated nutrients considered independently. For cardiometabolic health, the most favourable patterns generally contain more minimally processed, fibre rich…

…60° in relation to the fibers of the mid wall. Contraction in this layer results in a twisting (rotating) motion of the entire left ventricle…

…Hz, sensitivity about 75 %; single fibre EMG about 95 %). Contraindications Known hypersensitivity to edrophonium. Mechanical obstruction of the bowel or the urinary tract. Marked bradycardia…

…potential occurs. If any component of the ventricular conduction system has not fully repolarized by the time the next impulse reaches the ventricles, the impulse…

…Thus, withdrawal of parasympathetic activity results in increased heart rate and increased impulse transmission across the AV node. Sympathetic fibers innervate the entire heart, particularly…

…fascicle. Approximately 5–10% of all individuals have a third fascicle – the median or centroseptal fascicle – which gives off Purkinje fibers to the interventricular septum…

…impulses will spread through the right ventricle partly or entirely outside of the conduction system which will be slow and therefore cause a wide QRS…

…the sinus node–and an electrical conduction system composed of specialized myocardial cells. Conduction cells form bundles of fibers that spread the action potential rapidly…

…Bundle of His, bundle branches (left and right bundle branch), and Purkinje fibers. The conduction system allows for rapid spread of the depolarization to the…

…and fascicles, Purkinje fibers extend into the myocardium. Conduction through the Purkinje system is very rapid, due to the high density of gap junctions. This…

…myocardial elasticity. The greater the compliance, the more rapid and pronounced the relaxation (i.e the stretching of myocardial fibers). The opposite is also true;…

…which supplies the inferior wall of the left ventricle, determines the coronary artery dominance. A right dominant system implies that the PDA is supplied by…

…but the cannula kinks when the arm is flexed. The dorsum of the hand is suitable for finer cannulae. Avoid the lower limb in adults…

…is because the Purkinje fibers run through the endocardium, where they deliver the action potential to contractile cells. The subsequent spread of the action potential…

…the development of myocardial fibrosis. Contractile dysfunction further aggravates the regurgitation (the regurgitation volume increases). Mechanically, wall stress (the load on individual muscle fibers) increases…

…fibers are still refractory. If an atrial impulse reaches the atrioventricular node when there are two pathways, one being refractory and the other capable of…

…of His), the longer the PR interval (because more fibers will be refractory). If the premature atrial impulse reaches the atrioventricular node (or bundle of…

…All these fibers possess automaticity with an intrinsic rate of depolarization of around 20–40 beats/min. If the impulses are discharged from fibers proximal…

…poorest prerequisites in case of ischemia. The infarction process starts in the subendocardium from where it spreads to the epicardium. Purkinje fibers often manage to…

…ineffective. The likelihood of successful defibrillation is high in coarse VF (the early phase), but diminishes rapidly as the waveform becomes finer (Figures 2, 3…

…sound waves reflected from myocardium have high amplitude. This is due to the high density of myocardium. It follows that myocardium generates reflections with high…

…seconds). The QRS complex is wide simply because the ectopic impulses that cause these rhythms spread partially or entirely outside of the ventricular conduction system…