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66 Cards in this Set
- Front
- Back
Cardiac Cycle |
Refers to the events that occur during a complete heartbeat |
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Systole |
Contraction of the heart muscle |
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Diastole |
Relaxation of the heart muscle |
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Events of the cardiac cycle |
1. Blood returns to the heart and flows into the atria 2. Atrial systole 3. Ventricular systole 4. Ventricular diastole |
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What happens during atrial systole? |
The pressure within the atria increases, forcing the remaining 30% of blood that did not flow directly into the ventricles through the AV valves |
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What happens during ventricular systole? |
1. Atrial diastole 2. Pressure within the ventricles and the atria increases 3. Semilunar valves open and blood goes into either the ascending aorta or pulmonary trunk |
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Why does the pressure in the atria increase during ventricular systole? |
Blood is forced against the AV valves, which push into the atria slightly |
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What prevents the cuspid valves from opening into the atria? |
The contractions of the papillary muscles put tension on the chordae tendonae |
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What occurs during ventricular diastole? |
The pressure in the ventricles lowers, allowing the AV valves to open The semilunar valves close to prevent blood from flowing back into the ventricles from the higher pressure aorta and pulmonary trunk.
Blood begins to flow into the ventricles from the atria |
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What term is used to describe heart sounds? |
Lub-Dub |
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Lub |
Refers to the closure of the AV valves |
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Dub |
Refers to the closure of the semilunar valves |
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What are the specialized areas that are specially adapted to initiate and conduct impulses? |
1. Sinoatrial Node 2. Atrioventricular node 3. Bundle of His 4. Purkinje fibers |
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What is the name of the machine that records the electrical impulses of the heart? |
Electrocardiograph |
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In response to electric impulses, the electrocardiograph produces a series of ____ that are recorded onto a ______ |
Deflection waves Electrocardiogram |
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Types of deflection waves |
P wave QRS complex T wave |
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P wave |
Records electrical activity associated with atrial depolarization |
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QRS complex |
Ventricular depolarization (main deflection) Atrial repolarization |
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T wave |
Ventricular repolarization |
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What controls the heart rate? |
Autonomic nervous system |
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Divisions of your autonomic nervous system |
Sympathetic Parasympathetic |
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What carries sympathetic impulses? |
Accelerator nerves |
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What carries parasympathetic impulses? |
Vagus nerve |
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Cardiac muscle depolarization leads to ____ |
Systole |
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Cardiac repolarization leads to ______ |
Diastole |
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Deoxygenated blood |
High CO2, low O2 Pumped by the right side of the heart |
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Oxygenated blood |
High O2, Low CO2 pumped by the left side |
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Septum |
A partition separating the atria or the ventricles Prevents the mixing of oxygenated and deoxygenated blood |
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Name of septum separating the atria? |
Interatrial septum |
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Name of the septum separating the ventricles? |
Interventricular septum |
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Valves |
Prevent the backflow of blood |
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How many valves are in the heart? |
4 |
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Heart sounds |
Produced by the closure of valves |
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Potential cause of a murmur |
Sometimes caused by a leaking valve |
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What are the exchange vessels? |
Capillaries |
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What are the first arterial branches that come off of the ascending aorta? |
Branches to the coronary arteries |
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What is the first structure the heart sends oxygenated blood? |
The heart |
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Where do the coronary arteries deliver blood? |
Myocardium |
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Characteristics of cardiac muscle |
Single, rounded nucleus in striated cells Intercolated discs Many mitochondria High concentration of myoglobin Totally dependent on aerobic metabolism |
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Intercolated discs |
Thickenings of the cell membrane Strengthen the muscle tissue Aid in nerve impulse conduction over the muscle tissue |
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What are mitochondria used for? |
ATP production |
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Myoglobin |
Compound that stores O2 |
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CAD |
Coronary artery disease |
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Artherosclerosis |
Plaque build up in the coronary arteries |
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Plaque |
Fatty deposits that calcify |
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Calcification |
Hardening |
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Angina pectoris |
Chest pain caused by insufficient O2 to the heart muscle |
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Arterial sclerosis |
A loss of elasticity (or hardening) of the coronary arteries |
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Myocardial Infarction |
Aka heart attack Most commonly caused by a blood clot |
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Heart reflexes that affect cardio output |
Atrial (bainbridge) reflex Starling principle |
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Atrial Reflex |
- Aka Bainbridge reflex - Occurs when an increase in blood volume is detected within the atria, causing the walls to stretch - increases sympathetic activity, which increases heart rate |
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Starling Principle |
- Occurs when an increase in blood volume is detected within the ventricles, which causes the walls to stretch - increases the force of contraction of ventricular myocardium |
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Heart rate |
Number of beats per minute |
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Average heart rate |
80bpm |
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Stroke volume |
Amount of blood pumped by the ventricle in a single contraction |
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Average stroke volume |
80ml/beat |
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Cardiac Output (CO) |
Amount of blood pumped by the ventricle in one minute Calculated CO ( L/min) = HR x SV |
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Effect of beta stimulation? |
Excitatory Increase in HR, SV, and CO |
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Where is the cardiac center located? |
The brainstem, specifically in the medulla |
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Parts of the cardiac center |
Cardioacceleratory center Cardioinhibitory center |
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Cardioacceleratory center |
Increases heart activity |
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Cardioinhibitory center |
Slows heart activity |
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What gland secretes which hormones involved in the sympathetic activity of the heart? |
Adrenal gland Norepinephrine (this is the relevant hormone) and Epinephrine |
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Acetylcholine |
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Post Ganglionic Neuron |
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Preganglionic neuron |