Heart Flashcards
Heart Beats
75/minute
Average cardiac output
5.25 Liters/min
Dual pump for…
pulmonary and systemic
Components of Heart (4)
Atria Ventricles Pulmonary Circuit Systemic Circuit
Inferior or Diaphragmatic Surface Shape, Position, Component
- Concave
- Lower border of T8-T9
- Left Ventricle
Posterior Surface (base)
- Quadrilateral
- Opposite of T5-T8
- Left atrium
Anterior or Sternocostal Surface
- Flattened
- Posterior to sternum and costal cartilages 3-6
- Right atrium and right ventricle
Right Surface
- Convex
- Lateral to the right border of sternum
- Right atrium
Left Surface
- Convex
- 1/2 inch to left of manubriosternal junction to apex
- Left ventricle
Pericardium layers
Fibrous pericardium
Serous Pericardium
- Parietal layer
- Visceral layer
Pericardial Cavity contains…
Serous fluid
Pericardium Functions
Prevents undesired movement
Prevents overfilling of heart
Reduces friction
Pericarditis
Inflammation of pericardium
Heart Wall 3 layers
- Superficial–> Deep
- Epicardium (Same as visceral pericardium)
- Myocardium- Muscle infarctions occur here
- Endocardium- lines chambers, covers valves
Valves
- Structure
- Function
Structure-
Dense connective tissue
2 or 3 cusps
Function
Blood passes in one direction
Valve Closure
Left and right Atrioventricular valves close during systole
Pulmonary and aortic Semilular valves close during diastole
Sounds
Right atrioventricular valve
Inferior portion of sternum
Sounds
Left atrioventricular valve
Left fifth intercostal space
Sounds
Pulmonary Semilunar Valve
Second left intercostal space
Sounds
Aortic Semilunar Valve
Second right intercostal space
Lub sound
Closure of AV valves
Dub
Closure of semilunar valves
Fibrous Skeleton
Connective tissue located between the atria and ventricles
Seperates atria and ventricles physically and electrically
anchors heart valves
Cardiac muscle attachment
Conduction System
•Sinoatrial (SA) node
–Pacemaker
- Atrial muscle
- Atrioventricular (AV) node
- Atrioventricular bundle (Bundle of His)
- Left and right bundle branches
- Purkinje fibers
- Ventricular muscle
Cardiac Plexus
2 Innervations
Sympathetic innervation
Parasympathetic (vagal) innervation
Sympathetic Innervation
Increases heart rate
Increases force of contraction
Parasympathetic (vagal) Innervation
Decreases heart rate
Reduces force of contraction
Constricts the coronary arteries
Myocardial Infarction
Heart attack, blockage of coronary artery
