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47 Cards in this Set
- Front
- Back
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Mediastinum |
The median partition in the thorax, bound by connective tissue and pleura, dividing the region between the right and left pleural sacs Divided into sections: cranial, middle and caudal NOT symmetrical-deflected to the left in certain places due to larger right lung
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Apex |
lies to the left of the midline where the diaphragm and sternum meet |
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Dog Heart BW |
0.7% |
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Cat Heart BW |
0.33% |
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Auscultating the Pulmonic Valve |
Low left 3rd IC space (dogs) High left 4th IC space (cats) |
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Auscultating the Aortic Valve |
High left 4th IC space (cats/dogs) |
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Auscultating the Left Atrioventricular (Mitral) Valve |
Costochondral Junction 6th IC space (cats) Costochondral Junction 5th IC space (dogs) |
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Right Atrioventricular (Tricuspid) Valve |
Low right 3rd to 4th IC space (dogs) Low right 5th IC space (cats) |
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Pericardium |
Surrounds the heart and is divided into the outer most tough/protective fibrous and the serous epicardium that lays against heart and is divided into visceral and parietal layers |
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Myocardium |
the muscular layer between epi and endocardium (thin lining of inside of the heart) |
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The Right Atrium |
Receives DE-OXYGENATED BLOOD from systemic circulation via the vena cava and coronary circulation Holding the chamber for blood going to the lungs via the right ventricle Foramen Ovale closes at birth to form the Fossa Ovalis Venous flow from heart itself enters in coronary sinus |
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The Atrioventricular Valve |
"Tricuspid Valve" One way, opens as the ventricle relaxes (diastole) Closes when the ventricle contracts (systole) Uses papillary muscles, cordae tendinae, and has 2 valve leaflets (Ventral and Parietal) |
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The Right Ventricle |
Moves deoxygenated blood into the pulmonary system Thin walled compared to the left ventricle Inflow area below tricuspid Outflow tract (infundibulum) extending towards pulmonic valve |
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The Pulmonic Valve |
Semilunar Valve Prevents backflow from pulmonary artery to the right ventricle Annulus and 3 cusps close |
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Pulmonary Vessels |
Pulmonary Trunk collects blood from RV and delivers to the pulmonary arteries Right and left pulmonary artery Connected to the descending aorta via ligamentum arteriosum (remenant of ductus arteriosus) Pulmonary veins brings blood from the lungs to the left atrium |
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Left Atrium |
Receives OXYGENATED blood from the lungs Body and auricle Main pulmonary artery bifurcates just cranial to atrial body |
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Systemic Circulation |
80% of blood volume (everywhere)
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Pulmonary Circulation |
15% of blood volume (remaining 5% IN the heart) |
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Arteries |
Carry blood away from the heart Largest ones have a large proportion of elastic fibers Smaller ones have greater proportion of smooth muscle Arterioles regulate resistance to blood flow |
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Veins |
Carry blood towards the heart Low pressure system (controlled by the ANS) Predominantly composed of smooth muscle fibers Contain 65% of systemic blood volume Have valves to prevent backflow of blood (varicose veins) If presented with high pressure edema will form |
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Pulmonary Arteries and veins |
The Exception The only arteries that contain deoxygenated blood` |
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High Pressure System |
Contain 100% of systemic blood volume Bloodflow causes expanding and relaxing walls, felt as a pulse A- Tunica Interna (endothelium) B- Tunica Media C- Tunica Adventitia |
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Capillaries |
Low pressure system Contain 5% of systemic blood volume Single cell layer thick - only allow red blood cells to single file |
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Ventricular Contraction |
Maximum pressure (systole) |
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Ventricular relaxation |
Minimum pressure (diastole) |
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Tissue Perfusion |
Difference between systolic and diastolic pressure is felt as a pulse Force that is resisting blood flow is the systemic (peripheral) resistance Blood pressure must exceed this for blood flow to occur Control of blood pressure Many factors involved but main one is the ANS |
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Sympathetic Nervous System |
Vasoconstriction Increased Blood Pressure Blood directed to muscles "fight or flight response" |
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Parasympathetic Nervous System |
Vasodilation Lowers blood pressure blood is directed to the GI tract Post consumption response |
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Contractility |
Is the property that represents the strength of the myocardial contraction |
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Preload |
The amount of blood in the heart after the contraction of the atria (AKA diastolic volume) Increased preload causes increased force of contraction due to Starling's Law Valve disease affects preload (decrease) A weak myocardium will increase preload |
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Afterload |
The sum of the forces the myocardium has to overcome Sustained high afterload will cause myocardium to thicken |
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ESV |
End Systolic Volume- is the amount of blood left in the heart after ventricles contract |
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EDV |
End Diastolic Volume- is the amount of blood in the ventricles when they are full |
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SV |
Stroke Volume- is the amount of blood actually ejected from the heart |
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Cardiac Muscle |
Impulses travel from cell to cell Heart contracts as a unit Some cells can initiate impulses independently Long refractory period vs. skeletal muscle |
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Impulse Propagation |
Action Potentials are generated by automatic tissues Signals are propagated along specific pathways so that the timing of contraction is regulated |
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SA Node |
Sino Atrial is responsible for regular heart rate |
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AV Node |
Tricuspid Vavle; One way; Opens as the ventricle relaxes; Closes when the ventricle contracts; Papillary muscles and Chordae Tendinae hold the leaflets from prolapsing into the atrium 2 leaflet valves |
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Heart Rate |
Determined by autonomic nervous system |
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Heart Rate: Sympathetic |
HR increases |
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Heart Rate: Parasympathetic |
HR decreases |
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Heart Rate: Baroreceptors |
Change vascular tone and HR based on current BP |
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ECG: P Wave |
Represents atrial depolarization |
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ECG: PR interval |
Represents completion of atrial contraction and transmission of the electrical signal between the SA and AV node |
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ECG: QRS complex |
Represents ventricular depolarization (contraction) |
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ECG: ST segment |
Represents completion of the ventricular contraction |
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ECG: T wave |
Represents ventricular repolarization (relaxation) |
