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Apex beat. The apex beat (lat. ictus cordis ), also called the apical impulse, [1] is the pulse felt at the point of maximum impulse ( PMI ), which is the point on the precordium farthest outwards (laterally) and downwards (inferiorly) from the sternum at which the cardiac impulse can be felt. The cardiac impulse is the vibration resulting from ...
Overview. Your pulse is the vibration of blood as your heart pumps it through your arteries. You can feel your pulse by placing your fingers over a large artery that lies close to your skin. The ...
This will decrease the distance from wall of the chest to the apex of the heart. This will help to examine the point of maximal impulse. Also, this will help to hear extra heart sounds (S3 or S4). With the patient sitting upright. With the patient seated, leaning forward and holding breath after exhalation.
In neuroscience, threshold potentials are necessary to regulate and propagate signaling in both the central nervous system (CNS) and the peripheral nervous system (PNS). Most often, the threshold potential is a membrane potential value between –50 and –55 mV, [1] but can vary based upon several factors. A neuron 's resting membrane ...
As an action potential (nerve impulse) travels down an axon there is a change in electric polarity across the membrane of the axon. In response to a signal from another neuron, sodium- (Na +) and potassium- (K + )–gated ion channels open and close as the membrane reaches its threshold potential. Na + channels open at the beginning of the ...
All-or-none law. In physiology, the all-or-none law (sometimes the all-or-none principle or all-or-nothing law) is the principle that if a single nerve fibre is stimulated, it will always give a maximal response and produce an electrical impulse of a single amplitude. If the intensity or duration of the stimulus is increased, the height of the ...
The point spread function ( PSF) describes the response of a focused optical imaging system to a point source or point object. A more general term for the PSF is the system's impulse response; the PSF is the impulse response or impulse response function (IRF) of a focused optical imaging system. The PSF in many contexts can be thought of as the ...
The cardiovascular examination is a portion of the physical examination that involves evaluation of the cardiovascular system. The exact contents of the examination will vary depending on the presenting complaint but a complete examination will involve the heart (cardiac examination), lungs (pulmonary examination), belly (abdominal examination) and the blood vessels (peripheral vascular ...