Term
| Describe the three components of the circulatory system |
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Definition
| The heart-a muscular pump that drives the flow of blood through blood vessels; 2. Blood vessels-conduits through which the blood flows and 3. Blood-a fluid that circulates around the body, carrying materials to and from the cells |
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Term
| What is the name of the upper 2 chambers of the heart |
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Definition
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Term
| what is the functions of the upper two chabers of the heart? |
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Definition
| Receive the blood that comes back to the heart from the vasculature |
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Term
| What is the name of the lower 2 chambers of the heart? |
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Definition
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Term
| what is the functions of the lower two chambers of the heart? |
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Definition
| Receive blood from atria and generate the force that pushes the blood away from the heart and through the blood vessels |
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Term
| From which "circulation" does the left side of the heart receive blood? |
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Definition
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Term
| From which circulation does the right side of the heart receive blood? |
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Definition
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Term
| What is the function of the valves in the heart? |
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Definition
| Valves of the heart ensure unidirectional flow; Valves passively open/close in response to pressure changes |
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Term
| Describe the physical properties of cardiac muscle. |
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Definition
| Aerobic muscle, No cell division after infancy-growth by hypertrophy, 99% contractile cells for pumping, 1% autorhythmic cells set pace |
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Term
| What type of cell junctions are found between cardiac tissue? |
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Definition
| Gap Junctions--allow passage of ions |
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Term
| Why is the myocardium considered to be a functional syncytium? |
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Definition
Cardiac muscle cells are mechanically, chemically, and electrically connected to one another, thus, the entire tissue resembles a single, enormous muscle cell. For this reason, cardiac
muscle has been called a functional syncytium. |
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Term
| What is the intrinsic source of excitation for cardiac tissue? |
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Definition
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Term
| What is the extrinsic source of excitation for cardiac tissue? |
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Definition
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Term
| Which ion is responsible for the depolarization of the pacemaker cells in the heart? |
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Definition
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Term
| Describe the intrinsic conduction pathway in the heart. |
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Definition
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Term
| Describe the events that are occurring in a heart during each wave of an EKG |
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Definition
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Term
| Describe an action potential in a contractile cardiac cell |
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Definition
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Term
| Why does the heart have a long refractory period? |
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Definition
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Term
| Describe the cardiac cycle. Begin with early ventricular diastole |
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Definition
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Term
| Define end diastolic volume |
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Definition
| Represents the maximum ventricular volume attained during the cardiac cycle, which is reached just before the start of ejection |
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Term
| Define end systolic volume |
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Definition
| Represents the minimum ventricular volume, which is attained just after ejection |
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Term
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Definition
| The difference between end-diastolic volume and end-systolic volume represents the volume of blood ejected from the heart during one beat, which is the stroke volume SV: SV=EDV-ESV |
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Term
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Definition
| The rate at which a ventricle pumps blood is called the cardiac output (CO), and it is usually expressed in liters per minute--Cardiac output=HRxSV |
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Term
| What are the three major factors that affect stroke volume? |
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Definition
Preload-amount ventricles are stretched by blood before contraction.
Contractility-^in cardiac cell contraction force
Afterload-back pressure exerted by blood in the large arteries leaving the heart that must be overcome to eject blood from ventricles |
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Term
| Of the three, which has the greatest influence? |
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Definition
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Term
| What happens to the heart under the influence of the sympathetic nervous system |
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Definition
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Term
| What happens to the heart under the influence of the parasympathetic nervous system |
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Definition
| The heart is inhibited by the parasympathetic--cardioinhibitory center |
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