Cardiac Anatomy & Electrical Function Flashcards
(25 cards)
What are the four chambers of the human heart?
Right atrium, right ventricle, left atrium, left ventricle.
Which vessels carry blood into the right atrium?
Superior vena cava and inferior vena cava.
Which vessel carries blood from the left ventricle to the body?
Aorta.
What valves separate the atria and ventricles?
Tricuspid and mitral (bicuspid) valves.
What valves separate the ventricles from the arteries?
Pulmonary valve and aortic valve.
Which side of the heart handles oxygenated blood?
Left side.
Which side of the heart handles deoxygenated blood?
Right side.
What is the function of heart valves?
Prevent backflow of blood.
Where is the sinoatrial (SA) node located?
Right atrium near the superior vena cava.
What is the role of the SA node?
Initiates electrical impulses for heartbeats.
What does the P wave on an ECG represent?
Atrial depolarization.
What does the QRS complex represent?
Ventricular depolarization.
What does the T wave represent?
Ventricular repolarization.
What is the atrioventricular (AV) node?
Located at the junction between atria and ventricles.
What is the role of the AV node?
Delays impulse to allow ventricular filling.
What are Purkinje fibers?
Specialized fibers that conduct impulses to ventricular muscle.
What is the order of electrical conduction through the heart?
SA node → AV node → Bundle of His → Bundle branches → Purkinje fibers.
What is an action potential in cardiac muscle?
A rapid change in membrane voltage in response to stimulus.
What are the five phases (0–4) of a cardiac action potential in ventricular cells?
0: Na+ influx; 1: K+ efflux; 2: Ca2+ influx; 3: K+ efflux; 4: resting.
What ion primarily moves during phase 0 of a cardiac action potential?
Sodium (Na+).
Which ion is responsible for the plateau phase (phase 2) in ventricular action potentials?
Calcium (Ca2+) influx.
What is the difference between pacemaker and ventricular action potentials?
Pacemaker cells have spontaneous depolarization; ventricular cells require stimulation.
Which cells have unstable resting membrane potentials?
Pacemaker cells (e.g., SA node).
What causes depolarization in pacemaker cells?
Opening of funny (If) sodium channels.
