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33 Cards in this Set
- Front
- Back
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What is the name of the cavity that surrounde the heart?
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Pericardial cavity
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What is the lining of the pericardial cavity called? What type of tissue is it made of?
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It is called the Pericardium and it is a serous membrane.
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what are the subdivisions of the pericardium? What is their funtion?
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Visceral pericardium or epicardium covers the outer surface of the heart.
Parietal pericardum lines the inner surface of the pericardial sac, which surrounds the heart. |
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What are the layers of the heart wall?
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Epicardium
Myocardium endocardium |
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Where is the epicardium and what tupe of tissue is the epicardium made of?
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This Serous membrane consists of exposed epitheliim and an underlyin layer of loose connective tissue.
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Where is the myocardium and what type of tisse is the myocardium made of?
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It is the muscular wall of the heart. It contains cardiac muscle tissue, blood vessels, and nerves
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Where is the endocardium and what type of tissue is the endocatrium made of?
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The hearts inner surface including the heart valves is a simple squamous epithelium that is continous with the endothelium.
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What is some distinguishing characteristics of heart tissue.
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The myo cardium formes lafers that wrap around th eheart atria.
cardiac muscle tissue uses mostly aerobic enerfy. cells contain intercalated discs. |
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what supplys blood to cardiac muscle?
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Coronary circulation
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What is the corinary system composed of?
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Left and right corinary arteries.
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What causes the corinary system to be so efficent supplying the mucsle with oxygen?
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The left and right coronary arteries are located at the base of the aorta. Their is allot of pressure going into these arteries allowing continuous flow of oxygen
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How is venous blood supplying the heart muscle collected again?
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the right and left coronary arteries form interconnections called anastomes, because of this conections alternate pathways exist for the blood supply to reach cardiac muscle. the great and middle cardiac veins carry blood away from the coronary capillaries and drain into the coronary sinus. the coronary sinus opens into the right atrium at the base of the inferior vena cava.
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What are the consequences of obstrustion of the coronary circulation.
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heart atack, when the corinary circulation becomes blocked cardiac muscle cells die from a lack of oxygen.
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Describe the contraction of a cardiac muscle cell?
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Step 1: Rapid depolarization
Step 2: The Plateau Teh calcium channels remain open for a relatively long time. Step 3:Repolorization. calcium channels begin to close and potassium ions rush out. the outcome is repolorization that restores the resting potential. |
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What does refactory mean?
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The period between the initation of an action potential and the restoration of the normal resting prtential. during this period the membrane wil not respond normally to stimulation.
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Describe the conduction system of the heart?
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Step 1: (SA node activity and atrial activation begin
Step 2: stimulus spreads across the atrial surface and reacheds the AV node Step 3: There is a 100-msec delay at the AV node. step 4: the impulse travels along the interventricular septum within the AV bundle and teh bundle branches to the Purkinje fibers |
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What is the function of pace maker cells.
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Not all nodal cells depolorize at te same rate., and teh normal rate of contraction is established by the pacemaker cells.
Step 5: the impulse is distributed by purkinje fibers and relayed throught the ventricular myocardium. Atrial contraction is completed, and ventricular contraction begins. |
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Where are pace maker cells located?
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sinoatrial node (SA node)
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Define Systole
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The rhythmic contraction of the heart, especially of the ventricles, by which blood is driven through the aorta and pulmonary artery after each dilation or diastole. Also called miocardia.
sys·tolic (s-stlk) adj. |
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define Diastole
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The normal rhythmically occurring relaxation and dilatation of the heart chambers, especially the ventricles, during which they fill with blood.
dia·stolic (d-stlk) adj. |
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Define fibrillation
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Uncoordinated contractions of individual muscle cells that impair or prevent normal contraction.
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Define cardiac arrest.
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A sudden cessation of cardiac function, resulting in loss of effective circulation.
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define tachycardia
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A rapid heart rate, especially one above 100 beats per minute in an adult. Also called tachyrhythmia.
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What does the P wave on a ECG graph correspond to?
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P, wave is caused by the depolarization of the atria, whose electrical changes in turn cause atrial contraction.
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What does the P wave correspond to in an ECG?
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A Small P wave accompanies the depolarization of te atria. teh atria begin contracting around 100 msec after the start of the P wave.
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What does the QRS complex correspond to in an ECG?
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A QRS compplex appears as teh ventricles depolarize. This portion of teh electrical signal is relatively strong because teh mass of the ventricular muscle is much larger than that of the atria. The ventricles begin contracting shortly after the peak of the R wave.
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What does the T wave corespond to in an ECG?
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a SMALLER t wave indicates ventriculat repolarization. Atrial repolarization s not apparent because it occures while the ventricles are sepolarizing, the electrical events there are masked by the QRS complex.
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Define bradycardia.
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A slow than normal heart beat
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Define angioplasty.
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Any endovascular procedure that reopens narrowed blood vessels and restores forward blood flow. Most often angioplasties are performed on coronary, carotid, or peripheral arteries occluded by atherosclerosis.
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Define ischemia.
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A temporary deficiency of blood flow to an organ or tissue. The deficiency may be caused by diminished blood flow either through a regional artery or throughout the circulation.
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Define stroke volume.
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The amount of blood pumped out of a ventricle each heart beat.
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Define cardiac output.
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The amount of blood pumped be each ventricle in 1 minute.
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how do you calculate cardiac output?
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Stroke volume X Heart rate = cardiac output.
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