The Cardiac Cycle (lesson 3) Flashcards
What is another name for a heartbeat?
What body system controls the beating of the heart?
A Cardiac cycle
The nervous system controls the beating of the heart which generates electrical impulses
How often does the heart beat per minute
How long does 1 heartbeat last for?
72 heart beats times per minute and one complete heartbeat last for 0.8 seconds
What are the two unique characteristics of the heart?
1) Beats automatically
2) Beats rhythmically in a continuous manner
While you are resting how much blood leaves each ventricle per heartbeat?
Approx. 70 ml of blood
What is systole and diastole? (on unit review)
Systole and Diastole
Systole:
~Contraction of the heart muscle
~Blood is being pumped out of the chambers
~High pressure
Diastole:
~Relaxation of the heart muscle
~Blood flowing into the chambers
~Low pressure
What produces the two heart sounds?
AV and SL valves
What is the 1st and 2nd heart sound called? (on unit review)
1st: “Lub”
2nd: “Dup”
What is the pacemaker?
The pacemaker (SA Node) controls the pace that the heart beats, through nerve signals
What is the SA node and AV node?
SA node (teacher): Located in the right atrium of the heart and sends signals to AV node
AV node (sub): Located in the lower back section of the septum and AV node can also generate a signal to bundle of his then purkinje fibres
What part of the brain controls heartbeat? (on unit review)
Medulla oblongata
What happens if the heart is beating too fast or too slow?
Too fast: Sensory cells in the aorta gets stretched, and these cells send signals to the medulla oblongata to slow down pacemaker
Too slow: Blood pressure in arteries drop and this signals the medulla oblongata to speed up heart rate
What chemical receptors in the blood vessels are sensitive too?
Sensitive to oxygen and carbon dioxide
What happens if there is too much carbon dioxide?
What happens if there isn’t enough oxygen?
Both increase of heart rate
What measures and records the electrical signals in heart?
An Electrocardiograph (ECG)
What is a P wave?
Atria fills ventricles with blood
