Sinoatrial node

diseases of the cardiovascular system including angina pectoris, heart failure and myocardial infarction. The electrical conduction system of the heart can also change during ageing. For example, the number of pacemaker cells in the sinoatrial node decreases substantially with ageing, which in turn leads to bradycardia and ultimately a decline in cardiac output (Caroline 2014 seek…

throughout the heart tissue. Epinephrine 's binding to these receptors triggers a number of metabolic changes. High levels of epinephrine causes contraction of the smooth muscle that lines most arterioles. The way in which adrenaline acts on the sinoatrial node to accelerate the heart rate has hitherto been obscure. However, in various other parts of the heart adrenaline increases the slow inward (Ca2+/Na+)…

Tetrahydrozoline is an alpha agonist and acts by constriction of blood vessels. Jones DG et al, have clearly identified and reported that it resulted symptomatic sinoatrial node arrest because of ingestion by a 16 year boy of quantity less than 15 ml of 0.05% tetrahydrozoline [39]. Matthew E. Stillwell et al, have described that tetrahydrozoline can cause central nervous system (CNS) depression when it is consumed orally…

Mr. ABC came in to the emergency department (ED) with a chief complaint of left sided chest pain with giddiness and associated with diaphoresis the same morning. While in the ED, he developed a sudden episode of shortness of breath. Mr. ABC has nil past medical or surgical history and has an allergy to Enalapril. His parameters taken are as follows: • Blood pressure: 112 /60 mmHg • Pulse rate: 42 beats/min • Temperature: 35.9°C • Spo2: 97% on room air • Respiration rate: 17 breaths/min An…

Data regarding the cardiovascular system of older adults is slightly limited, due to the fact that older people are usually not included in clinical trials. However, enough research has been done to identify common physiological changes in the geriatric cardiovascular system, such as: increased heart weight; decreased number of myocardial cells with enlargement of remaining cells; increased left ventricle wall thickness; increased arterial stiffness; increased elastin levels; increased collagen…

Abstract Whens humans exercise, their oxygen supply needs to be increased in order to produce the energy needed to sustain this workload. Humans will use a variety of cardio-respiratory mechanisms in order to supply and meet the oxygen levels the body needs during exercise. In this study we wanted to see how different individuals respond to exercise, specifically how long they can work and how efficiently they work. We predicted that females who exercise will have a higher relative-VO2, higher…