2.6 The Heart Flashcards
Label in your head, the aorta, pulmonary artery, pulmonary vein, AV valve, SL valve, atrium, ventricles, vena cava and thick muscular wall?
Good, yes sir
Where are the AV valves?
Between the atrium and ventricles
Where are the SL valves?
The Aorta and pulmonary artery
Why does SL and AV valves close?
Blood comes from vena cava, through ventricles, go through the SL valve and the AV valve closes to stop vena cava from filling ventricles with blood
What’s cardiac output?
Volume of blood pumped between each ventricle per minute
What formula might calculate Heart rate or stroke volume and the units?
Co
Hr I SV
Co- L
Sv- ml -> L
HR- bpm
What’s systole and diastole?
Systole is the contraction (squeeze in) of the cardiac muscles
Diastole is the relaxation (rest) of the cardiac muscles
How long does one complete heart beat take?
0.8 seconds
What’s the cardiac cycle main phases?
Atrial systole (blood goes through SL valves (already been through AV valves) Ventricular systole (goes out from heart) Diastole (blood comes back to heart)
What measures blood and the unit?
A sphygmomanometer and unit is mmHg
How does blood pressure machine work?
Inflated a ring which then listens to your systolic pressure (pulse is detected), if not read it’s because there is blood travelling in artery at diastolic pressure
What’s an average blood pressure and a high blood pressure?
Average- 120/80mmHg
High- 140/90mmHg
What valve is open and closed during ventricular systole?
Ventricular systole, the AV valve closed and SL valve opens
What valve is open and closed during diastole?
During diastole, the AV valve is open and the SL valve is closed
How does the heart contract and when does it know to contract?
The electrical nerve fibres tell the heart muscles to contract. AV node picks up signal from SA node and sends electrical signal down ventricle walls
For the heart to contract, what’s the 3 main electrical Berger fibres?
Sino-Atrial node (SAN)
Atrio-ventricular nose (AVN)
Fibres in ventricle walls
Where is are SAN/ pacemakers?
On the wall of the atrium, Sat near the vena cava and is coordinated with the heart beat
How is the heart rated regulated?
By the medulla in the brain which sends electrical impulses to the SAN (remember the SA sends it to the VN which then goes to ventricle walls)
How does ECG work?
The heart generates currents which can be picked up by an ECG machine
What causes the lub dub sounds?
The closing of the AV and SL cables
How do you calculate cardiac cycle?
60/HR
What stage does the SL valves open?
ventricular systole
Label where the SA and AV nodes are
Yes babes
When going from artery to capillary, how might blood flow decrease?
Vasoconstriction
