week 6 heart Flashcards
The valves between the atrium and ventricles are called:
AV Valves
The valves between the ventricle and outgoing vessels are called:
Semilunar valves
The steps of blood flow :
deoxygenated blood comes from IVC and SVC-> blood enters right atrium-> blood then flows through the tricuspid valve->then to the right ventricle-> flows through the pulmonary artery-> then to the lungs where it becomes oxygenated->flows through the pulmonary veins->fills the left atrium-> then flows through the bicuspid valve-> into the left atrium->then goes through the aortic valve-> into the aorta and leaving to the rest of the body
The _______________ initiates & distributes the electrical impulses through the heart in an orderly fashion
conduction system
The ___________ starts the impulse & spreads it to both the Atria. This causes both atrias to Contract.
SA node
The ________________ Receive impulse from the AV node and gives it to the PJ
fibers.
Bundles of hiss
The _____________ receive impulse and spreads it among the Ventricles, this in turn causes Ventricles to Contract
Purkinje fibers
The _________ slows the impulse down (by holding on to it) thereby allowing Ventricles to fill with blood. The impulse then travels to the next segment.
AV node
Steps of SA node action potential (LONG):
- Pacemaker potential: begins at -60mv, opening of Na+ channels closing of K+ channels, membrane reaches threshold(-40mv) 2. Depolarization begins ( Ca+2 channels open causing an influx of calcium), when +5mv is reached Ca+2 channels close 3. Repolarization begins (Ca+2 channels close and K+ channels open causing K+ to efflux(exit) which bring membrane potential back to its most negative voltage (-60 mv RMP)
What are the three steps of SA node potential? (SHORT)
- Pacemaker potential 2. Depolarization 3. Repolarization
What are the steps to myocardial cell action potential? (SHORT)
Phase “0” Depolarization, Phase “1” early repolarization, Phase “2” plateau, Phase “3” repolarization, & Phase “4” resting membrane potential (-90mv)
What is resting membrane potential for SA node action potential ?
-60 mv
What is resting membrane potential for myocardial cell action potential ?
-90 mv
Phase “0” – Depolarization:
Opening of fast
Voltage Gated Sodium Channels →Sodium enters cell → membrane becomes positive
Phase “1” – Early Repolarization:
Opening of Voltage
Gated Potassium Channels → Potassium leaves cell → membrane becomes negative