Heart Flashcards
Heart Characteristics and Function
- Beats 75/ minute, 108,000/day
- Avg cardiac output 5.25L/min
- Functions as dual pump for pulmonary and systemic circuits
Pulmonary and systemic circuits
Carry blood where
Pumps
- Pulmonary
- Carries blood to and from lungs
- Right ventricle pump
- Systemic
- Carries blood to and from body tissues
- Left ventricle is pump
Heart Orientation
Base and apex
Lies on diaphragm, posterior to sternum, in mediastinum
Base: Posterior and superior surface of heart
Apex: Anterior and inferior, points to left hip, level of 5th left intercostal space
Inferior or Diaphragmatic surface
Concave
Lower border of T8 or T9
Mostly Left ventricle
Posterior Surface or base
Quadrilateral
Opposite T5-T8
Left atrium
Anterior or sternocostal surface
Flattened
Posterior to sternum and costal cartilages 3-6
Right atrium and right ventricle
Right surface
Conves
Lateral to right border of sternum
Right atrium
Left Surface
Convex
1/2 inch to left of manubriosternal junction to apex
Left ventricle
Mediastinum
Structure, contents
- Thick flexible soft tissue
- Seperates 2 pleural cavities
- Contents
- heart, esophagus, trachea, nerves, blood vessels
Mediastinum location and sections
- In thoracic cavity
- Superior mediastinum
- Inferior mediastinum
- Anterior
- Middle
- Pericardium and heart
- Posterior
Pericardium layers
- Fibrous pericardium
- Serous pericardium
- Parietal and visceral layer
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- Parietal and visceral layer
Pericardium Functions
Prevents undesired movement
Prevents overfilling of heart
reduces friction
Pericarditis: Inflammation of pericardium
Heart Wall layers
- Epicardium ( aka visceral layer of serous pericardium)
- Myocardium
- Cardiac muscle
- myocardial infarctions occur here due to lack of oxygen
- Epicardium
- lines chambers
- covers valves
- Recieving chamber of oxygen poor blood from systemic
- Superior Vena Cava
- Inferior Vena Cava
- Coronary sinus
- Interatrial septum
- Pectinate Muscles
- Fossa ovalis (foramen ovalen in fetal)
- Sinoatrial node
- Atrioventricular node
- Right atrioventricular valve Tricuspid valve
- Sinus venarum
- Pump of pulmonary circuit ejects blood into pulmonary trunk
- Interventricular septum
- Trabeculae carneae cross bars of flesh
- Papillary muscles, anchor chordae tendinaea
- Chordae tendinaea, prevent valves from everting
- Moderator band (septomarginal trabeculae support)
- Conus arteriosis (infundibulum)
- Pulmonary semilunar valve
Left Atrium
Posterior surface
Receives oxygen rich blood from lungs through pulmonary veins
Left atrioventricular valve Bicuspid valve, Mitral valve
Left Ventricle
Pump of the systemic circuit, ejects oxygen blood into aorta
Aortic Semilunar valve
Aortic vestibule
Forms apex and inferior surface
Most muscular chamber, 3 times thicker than RV
Valves Structures
Dense connective tissue
2 or 3 cusps
Valve function
One way passage of blood
prevent backflow
Valve closure
Atrioventricular valves close during systole
Semilunar valves close during diastole
Atrioventricular and semilunar Valve positions to hear
- Right Atrioventricular Valve
- Inferior portion of strnum body
- Left Atrioventricular Valve
- Left 5th intercostal space
- Pulmonary Semilunar valve
- 2nd left intercostal space
- Aortic Semilunar Valve
- 2nd right intercostal space
Heart sounds
Lub- AV valves close
Dub- Semilunar close
Fibrous Skeleton
Structure
Function
- CT between atria and ventricles
- Seperates both physical and electrical
- Anchors heart valves
- Framework for muscle attachment
Oxygen poor blood
Oxygen risch blood
- Oxygen poor blood
- Coronary sinus
- Superior vena cava
- Inferior vena cava
- Right atrium
- Right ventricle
- Pulmonary trunk
- Pulmonary arteries
- Pulmonary veins (Oxygen Rich)
- Left atrium
- Left ventricle
- Aorta, aortic arch
- coronary arteries
