Ch 20: Continued Flashcards
What happens when there is an increase pressure in the atrium
The atrium is open which allows ventricles to relax for blood flow 
-ventricular diastole
What happens when there’s an increase in pressure of the ventricle
The AV valve closes and the aortic semi lunar valve opens
-Ventricular systole
Diostole
Relaxation
Systole
Contraction
Blood pressure
systolic/diastolic
Blood pressure units
MmHg
What happens when any valve closes?
It produces a sound in the heart
-Lub- dub
S1
AV valves are closed
S2
Aortic semi lunar valves are closed
Definition of isovolumetric
Same volume
-All four valves are closed
When does isovolumic occur?
Occur shortly before valves are open in right before contraction
S3
Passive filing a ventricle
S4
Pathologically
EDV
Volume is measured at the end of diastole
ESV
Volume is measured at the end of the systole
Actively filing a ventricle
Atrium contracts, ventricles are relaxed, and AV is open
Blood flow through the heart
- Blood comes from Superior and inferior Venna cava to right atrium from tricuspid valve.
- Blood flows from right ventricle through pulmonary semilunar valve.
3 blood flows to the pulmonary trunk. - From the pulmonary trunk, it goes to the pulmonary arteries. (Lungs)
- Blood from the lungs goes to pulmonary veins.
- From the vans flows to the left atrium through the bicuspid valve.
- From the valve, it flows to the left ventricle through the aortic semilunar valve to the aorta.
- From the aorta, it goes to coronary and systemic circuits to the coronary sinus and cardiac veins. Then back to right atrium.
Arteries in the right side of the coronary artery
- Right marginal artery.
- Posterior interventricular artery.
Arteries on the left coronary artery
- Anterior interventricular artery.
- Circumflex artery.
- Left marginal artery.
Two arteries that causes heart attacks
- MI - left marginal artery.
- Posterior interventricular artery.
Conducting cells
Electrical system of the heart
Contractile cells
Contracting property of the heart
Action potential in cardiac muscle
Action potential is slow because of gap junctions
1. Increase in Na+ channels, K+ channels are closed.
2. Early repolarization phase
3. Voltage Ca2+ channels are open with influx of Ca2+
-K+ channels are open to counter influx of Ca2+
4. Na+ is open, K+ is closed, Ca2+ begins to open
Electrical pathway of heart
- Sino atrial node.
- Atrioventricular node.
- Atrioventricular bundle.
- Left and right bundle branches.
- Purkinje fibers.
Sino atrial node
-Hearts natural pacemaker
-If SA node isn’t working, it’s replaced with artificial pacemaker
P-wave
Atrial depolarization
QRS complex
Ventricular depolarization
-Systolic
T-wave
Ventricular repolarization
PR interval
Atria contracts and begins to relax, ventricles begin to contract
QT interval
Ventricles contract and begin to relax
