Arterial blood pressure

The outwards (hydrostatic) pressure exerted by the blood on blood vessel walls.

The pressure exerted by the blood on the walls of the aorta and systemic arteries when the heart contracts.

Should not normally reach or exceed 140 mmHg under resting conditions

<p>The pressure exerted by the blood on the walls of the aorta and systemic arteries when the heart relaxes- during diastole.</p> Signup and view all the answers

<p>Should not normally reach or exceed 90 mm Hg under resting conditions</p> Signup and view all the answers

<p>Clinical presentation of blood pressure of 140/90 mmHg or higher and daytime average of 135/85 mmHg or higher.</p> Signup and view all the answers

<p>The difference between systolic and diastolic blood pressures</p> Signup and view all the answers

<p>Normally between 30 and 50 mm Hg</p> Signup and view all the answers

<p>Flow in the artery is blocked and no sound can be heard through the stethoscope.</p> Signup and view all the answers

<p>Flow is turbulent when blood pressure (blood pressure exceeds cuff pressure)- audible through the stethoscope.</p> Signup and view all the answers

<p>No sound is heard because of uninterrupted laminar flow</p> Signup and view all the answers

<p>There are 5 phases of the Korotkoff sounds which correspond to different phases of the cycle:-</p> <ol> <li> <ol> <li>First sound heard – peak systolic pressure</li> </ol> </li> <li>Intermittent sounds due to turbulent flow exceeding cuff pressure- becomes more intense and swishing</li> <li>Becomes more crisp and distinct.</li> <li>Last sound heard at minimum diastolic pressure (muted/muffled).</li> <li>No sound heard- this corresponds to the diastolic blood pressure, the pressure in the arteries when the heart is at rest between beats.</li> </ol> Signup and view all the answers

<p>The ventricular contraction and thus, the pressure gradient between the aorta and the right atrium drives the blood during the systemic circulation.</p> Signup and view all the answers

<p>Pressure gradient= Mean arterial pressure (MAP)- Central venous (right atrial) pressure (CVP)</p> Signup and view all the answers

<p>The average arterial blood pressure during a single cardiac cycle, which involves contraction and relaxation of the heart.</p> Signup and view all the answers

<p>Normal range is about 70 - 105 mmHg</p> Signup and view all the answers

<p>Inadequate perfusion of tissues (must be 60+ mmHg)</p> Signup and view all the answers

<p>Can damage blood vessels and create extra strain</p> Signup and view all the answers

<ol> <li>MAP = [(2x diastolic pressure) + systolic pressure]/3</li> <li>DBP + 1/3 pulse pressure</li> </ol> Signup and view all the answers

<p>The volume of blood pumped by each ventricle per minute</p> Signup and view all the answers

<p>The volume of blood pumped by each ventricle per heartbeat</p> Signup and view all the answers

<p>The sum of resistance of all vasculature in the systemic circulation. The arterioles are the main vessels providing resistance.</p> Signup and view all the answers

<ol> <li>MAP = [(2x diastolic pressure) + systolic pressure]/3</li> <li>MAP = DBP + 1/3 pulse pressure</li> <li>MAP = CO x SVR = HR x SV x SVR</li> </ol> Signup and view all the answers

<p>The baroreceptor reflex is a negative feedback mechanism to regulate blood pressure. It consists of three components:-</p> <ol> <li>Pressure sensor- baroreceptors</li> <li>Control centre- medulla</li> <li>Effectors- Heart (HR, SV) and blood vessels (SVR).</li> </ol> Signup and view all the answers

<p>Arch of aorta and the carotid sinus</p> Signup and view all the answers

<p>Baroreceptors cannot regulate blood pressure long-term because firing decreases if high blood pressure is sustained.</p> Signup and view all the answers

<ol> <li>Increased arterial pressure stretches the wall of the blood vessel, triggering the baroreceptors.</li> <li>These baroreceptors then feedback to the autonomic nervous system. 3)The ANS then acts to reduce the heart rate and cardiac contractility via the efferent parasympathetic fibres (vagus nerve), and decrease sympathetic constrictor tone (decreasing SVR), thus reducing blood pressure.</li> </ol> Signup and view all the answers

<ol> <li>Decreased arterial pressure is detected by baroreceptors, which then trigger a sympathetic response.</li> <li>This stimulates an increase in heart rate and cardiac contractility, and increased sympathetic constrictor tone (increasing SVR), leading to an increased blood pressure.</li> </ol> Signup and view all the answers

<p>The postural hypotension results from a failure of the baroreceptor responses to gravitational shifts in blood, when moving from horizonal to vertical position.</p> <ol> <li>Decreased baroreceptor firing then triggers a sympathetic response</li> <li>This stimulates an increase in heart rate and cardiac contractility, and increased sympathetic constrictor tone (increasing SVR), leading to an increased blood pressure.</li> </ol> Signup and view all the answers

<p>A positive result is indicated by a drop, within 3 minutes of standing from lying position:</p> <ol> <li>In systolic blood pressure of at least 20 mmHg (with or without symptoms).</li> <li>A drop in diastolic blood pressure of at least 10 mm Hg (with symptoms).</li> </ol> Signup and view all the answers