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| What four structures compose the conduction system? | SA node, AV node, AV bundle, and Purkinje Fibers |
| How are the structures of the conduction system different from regular cardiac tissue? | They are not contractile, they permit conduction of an action potential through the heart |
| What is the pacemaker? | SA node |
| What does it mean that the heart possesses an intrinsic rhythm? | It initiates impulses by itself, without any stimulation from nerves or hormones |
| Explain how an impulse travels through the heart. | SA node, atria contract, AV node, slows so heart can fully contract, AV bundle, Purkinje Fibers, ventricles contract |
| How fast does a normal heart beat with the SA node stimulating the heart? | 70 beats per minute |
| If the SA node can not initiate the heart beat, what takes over? | the AV node |
| What will the heart rate be if the beat is initiated from the AV node? | 40 to 60 beats per minute |
| This is a visible record of the heart's electrical activity. | Electrocardiogram (ECG or EKG) |
| Name the three wave of an electrocardiogram. | p, QRS,T |
| What happens during the P wave? | atria contract |
| What happens during the QRS wave? | atria relax and ventricles contract |
| What happens during the T wave? | ventricles relax |
| Another way to say relaxation when discussing chambers of the heart and and an ECG. | repolarize |
| Another way to say contraction. | Depolarization |
| Devices that electrically stimulate the heart at a steady rhythm are called _____. | pacemakers |
| When the heart is stimulated only when th heart rate drops below a set minimum | demand pacemaker |
| When the pacemaker stimulates the heart for every beat it is called ______. | continuously charging paremaker |
| Why are pacemakers inferior to the heart's own natural pacemaking? | Pacemakers can't speed up during exercise or slow down during sleep. |
| Ther nervous system that is inhibitory is called ______. | Parasympathetic |
| The nervous system that is stimulatory is called _______. | Sympathetic |
| This hormone speeds up the heart rate. | Norepinepherine |
| This hormone decreases heart rate. | acetylcholine (Ach) |
| Rescptors that are sensitive to changes in pressure are called _______. | Pressorflexors Baroreceptors |
| Where are the two baroreceptors located? | carotid and aortic |
| What affect will exercise have on the heart rate? | increase |
| What affect will anxiety have on the heart rate? | increase |
| What affect will grief have on the heart rate? | decrease |
| What affect will fever have on the heart rate? | increase |
| What affect will smoking have on the heart rate? | increase |
| What affect will cold have on the heart rate? | decrease |
| What affect will caffeine have on the heart rate? | increase |
| What affect will pain in the gallbladder or intestines have on the heart rate? | decrease, so much that the person may faint |
| Abnormal beating of the heart is called _____. | Arrythmia |
| Slowing fo the heart is called. | Bradycardia |
| What is considered to be too slow of a heart rate? | under 50 beats a minute, unless it is a trained athlete |
| A very rapid heart beat is called _______. | Tachycardia |
| What heart rate is considered Tachycardia? | over 100 beats per minute |
| Varying of the heart rate with breathing is called _______. | Sinus arrythmia |
| With sinus arrythmia, what happens with the heart rate when breathing in? | heart rate increases- it decreases with expiration |
| What are premature contractions? | Contractions that occur before the next expected contraction. |
| What causes premature contractions? | lack of sleep, too much caffeine, nicotine, alcholism, heart damage |
| This is a condition when cardiac muscle fibers are out of step with each other. | Fibrillation |
| Which type of fibrillation is life-threatening? | Ventricular Fibrillation |
| HOw is Ventricular Fibrillation treated? | Defibrillation |
| The first heart sound is called the ____ sound. | systolic |
| What causes the first heart sound? | The contraction of the ventricle and closing of the AV valve |
| What is a heart murmer? | Whent he heart valves do not close completely and blood can be heard going through the shut valve. |
| What happens during atrial systole? | Atria contract and force blood into the ventricles |
| This is the term used to describe a collection of mechanisms that influence the circulation of blood. | Hemodynamics |
| What are Newton's first and second laws of motion? | A fluid does not flow when the pressure is the same in all parts of the fluid. Fluid flows from high to low pressure. |
| Which has a higher blood pressure- the veins or the vena cava? | veins- it flows from the veins into the vena cava |
| The primary determinant of blood pressure is what? | blood volume |
| If blood volume increases, what happens to blood pressure? | It also increases |
| The most important things that control blood pressure, because they control blood volume, are: | cardiac output and peripheral resistance. |
| This is the primary indicator of whether the heart can meet the demands of physical activity. | cardiac output |
| The volume of blood pumped out of the ventricles by each beat is called the _______. | stroke volume |
| How do you find cardiac output? | stroke volume times heart rate |
| True or False, the greater the stroke volume, the greater the cardiac output. | True, but only if the heart rate stays the same |
| What affect does physical training have on stroke volume? | it increases it |
| How do you find the max heart rate? | 220- age |
| How do you find your target heart rate? | Max Heart Rate - Resting Heart Rate times .7 plus resting heart rate. |
| An increase in cardiac output will increase your potential for what? | aerobic metabolism |
| What does Startling's Law of the Heart say? | The longer the myocardial fiber is, the stronger the contraction. |
| What determines how stretched the cardiac fibers are? | The amount of blood returning to the left ventricle. |
| If too much blood stretches the heart beyond a critical point, what happens to the strength of the contraction? | it decreases |
| If peripheral resistance is increased, what happens to arterial blood pressure? | it also increases, the more resistance the more blood is left in the arteries, so more pressure. |
| What is peripheral resistance? | The force of friction between blood and the walls of the blood vessels. |
| What three things affect peripheral reistance? | viscosity, the length of the vessel, and the diameter of the vessel. |
| What determines blood viscosity? | The amount of red blood cells. |
| If a blood vessel contracts, what happens to peripheral resistance? | it increases |
| These mechanisms influence blood pressure by changing the diameter of the aterioles. | Vasomotor Control Mechanisms |
| Where are the vasomotor control mechanisms located? | carotid and aorta |
| If the cardiac pressorflexors detect high blood pressure, they decrease the heart rate. They also stimulate the vasomotor pressorflexors. What will the vasomotor pressorflexors do? | Inhibit the vasocontrictor and cause blood vessels to dialate. This decreases pressure. |
| What would the vasomotor pressorflexors do it a low arterial pressure had been detected? | They would stimulate the vasocontrictors and cause the blood vessels to constrict and increase arterial pressure. |
| Where are the chemoreceptors located? | carotid and aorta |
| What are chemoreceptors particulary sensitive to? | excess carbon dioxide called hypercapnia |
| A deficiency of oxygen is called _______. | Hypoxia |
| What two things promote venous return to the heart? | repiration and skeletal muscle contraction |
| These valves in veins close and prevent blood from falling back | SL valves |
| What two things determine minute volume of blood? | pressure gradient and peripheral resistance |
| Blood pressure is measured in terms of how many millimeters high the air pressure raises a column of _____. | mercury |
| What artery is used to take blood pressure? | brachial |
| The first heart sound is called the _____sound. | systolic |
| What does the systolic sound represent? | the force of the ventricles contracting |
| The lowest point at which sounds can be heard are called the _____ sounds. | diastolic |
| What does the diastolic pressure represent? | the force of blood when the ventricles relax. |
| What is normal blood pressure? | 120 over 80 |
| The difference between systolic and diastolic pressure is called the ____. | pulse pressure |
| Explain the difference between arterial and venous bleeding. | blood gushes fromarteries and seeps from veins |
| Why does blood not gush from veins? | The wall of a vein is elastic and continues to squeeze during the diastolic phase. |
| Does blood flow slower or faster in a vessel with a large cross-sectional size? | slower |
| Does blood flow faster in arteries or capillaries? | arteries |
| This si the alternate expansion and recoil of an artery. | pulse |
| Name two reasons why we can feel a pulse. | The heart releases blood in spurts which causes a change in pressure and arterial walls expand and recoil |
| What happens to a pulse wave as it gets farther from the heart? | it dissipates or decreases |
| Where can a pulse be felt? | Anywhere an artery lies near the surface and over a bone. |
| Name three common places for taking the pulse. | Radial artery, Brachial artery, and corotid artery |
| When trying to stop arterial bleeding, wher emust you apply pressure? | between the heart and the bleeding part. |
| Can a pulse be found in large veins. | Yes, but it is not used very often. |
| What happens to the blood pressure as a person ages? | it increases |
| What happens to the heart rate as a person ages? | it tends to decrease |
| The most common reason for a visit to the Dr. is _____. | Hypertension |
| What factors cause hypertension? | Genetics, oral contraceptives, hormone changes, obesity, caffeine, smoking, lack of exercise, calcium deficiencies, high alcohol intake, and type A personalities |
| What are symptoms of high blood pressure? | Often called the silent killer because generally there are no symptoms, but a person may experience headaches, dizziness, or fainting |
| When the body can't pump enough blood to sustain life it is called _______. | Heart Failure |
| Failure of athe circulatory system to deliver enough oxygen to the tissues is called _______. | Circulatory Shock |
| This type of shock results from any type of heart failure. | Cardiogenic shock |
| This type of shock results from the loss ob blood volume. | Hypovolemic Shock |
| Hypovolemic shock can also be caused by loss of interstitial fluid. What would cause loss of interstitial fluid? | Chronic diarrhea, vomiting, dehydration, severe or extensive burns. |
| Shock caused because nerves dialated blood vessels which reduced blood pressure and blood flow is called ________. | Neurogenic Shock |
| Shock when an allergic reaction dialates blood vessels. | Anaphylactic Shock |
| This type of shock results when toxins are released into the blood. | Septic Shock |
