Cardiovascular system Flashcards
The nodal system in the heart….
- Generates its own electricity
SA node (sinoatrial node)
- Special type of nervous tissue
- Pace maker
- Generates impulses
Atrioventricular Node
- AV bundle connects the atria to the ventricles.
Sequence of electrical excitation in the heart
- Sinoatrial node generates the impulses
- The impulses pause (0.1s) at the Atrioventricular node
- The atrioventricular bundle connects the atria to the ventricles
- The bundle branches conduct impulses throught the interventricular septum
- The subendocardial conducting networkdepolarizes the contractile cells of both ventricles
SA node
- Sinoatrial node
AV node
Atrioventricular node
The nodal system in the heart generates its own ________.
electricity
The SA node is the _________ of the heart.
Pacemaker
The AV node is connected to the __________.
- Bundle branches
- Bundle brances contain conducter cells that carry out electrical signal through out the heart
- bundle branches are located in the interventricular septum
Arrhythmias
- Heart rythm abnormalities
- means without rythm
Cardiac Output
The volume of blood pumped per minute by each ventricle of the heart. Cardiac output is equal to the stroke volume (the amount of blood pumped from a ventricle in a single heartbeat) times the heart rate.
Stroke volume
Stroke volume (SV) is the amount of blood pumped out of the heart (left ventricle - to the body) during each contraction measured in mL/beat (millilitres per beat).
- Volume of blood pumped out by one ventricle with each beat
What is the equation for cardiac output?
CO= Heart Rate x Stroke Volume
What is Heart rate?
the # of beats per minute
What is normal cardiac output?
5.25 L/min