Physiology Flashcards
Which nerve descends across the lateral borders of both sides of the pericardium?
Phrenic nerve
Which sinus do surgeons use to correctly identify and isolate the great vessels for cardiopulmonary bypass?
The transverse pericardial sinus
The first heart sound (lub) indicates which 2 valves closing?
Mitral and Tricuspid
The second heart sound (dub) indicates which 2 valves closing?
Aortic and Pulmonary
What does the P wave in the ECG signify?
Atrial Depolarisation
At what stage in the ECG do the atria contract?
Between the P wave and the QRS complex
Ventricular contraction occurs where on the ECG?
Immediately after the QRS complex (signals ventricular depolarisation) (becoming more +ve)
What does the T wave on an ECG signify?
Ventricular repolarisaton
S1 signifies the beginning of what?
Systole
S2 signifies what?
The end of systole and beginning of diastole
What is shock?
An abnormality of the circulatory system resulting in inadequate tissue perfusion and oxygenation
What is stroke volume?
The volume of blood pumped by each ventricle of the heart every heart beat
What is cardiac output?
The volume of blood pumped by each ventricle of the heart each minute
How can we calculate cardiac output?
Stroke Volume x Heart rate
How can we calculate the Mean Arterial Pressure?
Cardiac output x Total Vascular Resistance