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20 Cards in this Set
- Front
- Back
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The circulatory system is composed of ______
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blood, vessels and the heart
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What is the circulatory cycle?
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Beginning at the heart, blood passes through a loop of arteries, arterioles, capillaries, venules, veins and back to the heart
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What are the arteries and what do they do?
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They are thick, muscular vessels that carry blood away from the heart. As the heart pumps blood into the arteries they expand such that one is able to feel a pulse
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. Smooth muscles in the arterial walls regulate _____ and ______ while precapillary sphincters regulate blood flow to the capillaries.
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vasodilation, vasoconstriction
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What are capillaries and what do they do?
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Capillaries are one cell thick and form branching networks that allow for the exchange of materials between the blood and tissues.
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What are veins and what do they do?
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Veins carry blood back to the heart and also serve as a reservoir for blood volume.
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How is blood moved against gravity?
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Blood is moved against gravity toward the heart by the contracting skeletal muscles and by pressure differences caused by the movement of the thoracic cavity during breathing. Blood is prevented from flowing backwards by valves found in the veins.
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What is blood pressure and how is it measured? What is systolic and diastolic pressure?
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Blood pressure is its highest (systolic) when the ventricles contract sending blood into the arteries and at its lowest (diastolic) when the heart relaxes between beats. A sphygmomanometer measures blood pressure
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What is atherosclerosis?
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Atheroscloerosis, a narrowing of the arteries due to fatty deposits and thickening of the wall, can lead to heart attack or stroke.
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What is the lymphatic system?
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The lymphatic system functions to return interstitial fluid to the blood stream, to transport products of fat digestion and to defend the body against disease-causing organisms and abnormal cells
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What are lymph nodes?
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Lymph nodes filter lymph and contain cells that actively defend against disease-causing organisms.
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Where is the heart contained?
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the pericardium
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How many parts of the heart are there? How many chambers?
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2, separated by the septum. 4 chambers - smaller thin walled = atrium, larger more muscular = ventricle
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What are the valves separating the atrium/ventricle? the ventricle/exit vessels?
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AV valves, semilunar valves
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What do the right and left side of the heart contain?
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The right side of the heart contains blood rich in carbon dioxide that flows in from the tissues and out to the lungs. The left side of the heart contains blood rich in oxygen returning from the lungs and flowing out to the tissues
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What is the trip to and from the lungs called? The trip to and from the tissues?
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pulmonary circuit, systemic circuit
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What are the 3 steps of the cardiac cycle?
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The cardiac cycle consists of the contracting of the atria followed by contracting of the ventricles followed by a rest when neither chamber is contracting.
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What sets the tempo of the heart? (pacemaker)
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SA node
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What reaction does the SA node cause?
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It causes contraction of the atria and sends a signal to the atrioventricular (AV) node (note pause for efficiency of contraction) which relays information to the atrioventricular bundle and out through the Purkinje fibers causing the ventricles to contract.
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What is an electrocardiogram?
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An electrocardiogram (ECG/EKG), a powerful diagnostic tool, is a recording of the electrical events associated with the heartbeat.
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