Cardio

• Functions of the heart

  • Managing blood supply
  • Producing blood pressure
  • Securing one-way blood flow
  • Transmitting blood
• Variations in the rate and force of heart contraction

  Match blood flow to the changing metabolic needs of the tissues during rest, exercise, and changes in body position
• Cardiovascular system


  A muscular pump equipped with one-way valves and a system of large and small plumbing tubes within which the blood travels
• Heart


  • Approximately the size of a person's fist
  • Hollow, cone-shaped
  • Weighs less than a pound
  • Enclosed in the mediastinum, flanked by the lungs
  • Apex points to the left hip, rests on the diaphragm
  • Base points to the right shoulder, lies beneath the second rib
• Pericardium


  Double-walled sac that encloses the heart
• Fibrous pericardium


  Outermost layer of the pericardium, helps protect the heart and anchors it to surrounding structures
• Serous pericardium


  Two-layer lining deep to the fibrous pericardium
• Layers of the heart

  • Epicardium
  • Myocardium
  • Endocardium
• Epicardium


  Visceral and outermost layer of the heart wall
• Myocardium


  Thick bundles of cardiac muscle that contract
• Endocardium


  Innermost layer of the heart, a thin, glistening sheet of endothelium that lines the heart chambers
• Pericarditis


  Causes the pericardial layers to rub, bind, and stick to each other, forming painful adhesions that interfere with heart movements
• Pericardial effusion


  Fluid build-up in the space between the pericardium, can cause cardiac tamponade
• Types of pericarditis


  • Viral
  • Bacterial
  • Fungal
  • Parasitic
• Autoimmune diseases and other conditions can also cause pericarditis
• Heart chambers


  • Two atria (receiving chambers)
  • Two ventricles (discharging chambers)
• Septum


  Divides the heart longitudinally, can be the interventricular septum or the interatrial septum
• Functions of the heart

  • Managing blood supply
  • Producing blood pressure
  • Securing one-way blood flow
  • Transmitting blood
• The cardiovascular system can be compared to a muscular pump equipped with one-way valves and a system of large and small plumbing tubes within which the blood travels
• Heart


  • Approximately the size of a person's fist, the hollow, cone-shaped heart weighs less than a pound
  • Snugly enclosed within the inferior mediastinum, the medial cavity of the thorax, the heart is flanked on each side by the lungs
  • Its more pointed apex is directed toward the left hip and rests on the diaphragm, approximately at the level of the fifth intercostal space
  • Its broad posterior superior aspect, or base, from which the great vessels of the body emerge, points toward the right shoulder and lies beneath the second rib

  
• Pericardium


  • The heart is enclosed in a double-walled sac called the pericardium and is the outermost layer of the heart
  • The loosely fitting superficial part of this sac is referred to as the fibrous pericardium, which helps protect the heart and anchors it to surrounding structures such as the diaphragm and sternum
  • Deep to the fibrous pericardium is the slippery, two-layer serous pericardium, where its parietal layer lines the interior of the fibrous pericardium

  
• Layers of the heart

  • Epicardium
  • Myocardium
  • Endocardium

  
• Epicardium


  The epicardium or the visceral and outermost layer is actually a part of the heart wall

  
• Myocardium


  The myocardium consists of thick bundles of cardiac muscle twisted and whirled into ring-like arrangements and it is the layer that actually contracts

  
• Endocardium


  The endocardium is the innermost layer of the heart and is a thin, glistening sheet of endothelium that lines the heart chambers

  
• Pericarditis


  1. Inflammation of the pericardium often results in a decrease in the already small amount of serous fluid

  2. This causes the pericardial layers to rub, bind, and stick to each other, forming painful adhesions that interfere with heart movements

  
• Pericarditis can cause chest pain that is sharp and stabbing (caused by the heart rubbing against the pericardium), may get worse when you cough, swallow, take deep breaths or lie flat, and feels better when you sit up and lean forward
• Pericardial effusion


  1. When there is a fluid build-up in the space between the pericardium, it can cause a condition called pericardial effusion

  2. If the fluid builds up quickly, it can cause cardiac tamponade, a sudden build-up of fluid in between the layers of the pericardium that keeps your heart from working like it should and can cause your blood pressure to drop

  
• Causes of pericarditis


  • Viral
  • Bacterial
  • Fungal
  • Parasitic
• Some autoimmune diseases, such as lupus, rheumatoid arthritis and scleroderma can cause pericarditis. Other causes of pericarditis include injury to the chest, such as after a car accident, other health problems such as kidney failure, tumors, genetic diseases such as Familial Mediterranean Fever, or rarely, medications that suppress the immune system

  
• Chambers of the heart

  • Two atria (receiving chambers)
  • Two ventricles (discharging chambers)
• Septum


  The septum that divides the heart longitudinally is referred to as either the interventricular septum or the interatrial septum, depending on which chamber it separates
• Great blood vessels


  • Superior and inferior vena cava
  • Pulmonary arteries
  • Pulmonary veins
  • Aorta

  
• Atrioventricular valves


  Located between the atrial and ventricular chambers on each side, and they prevent backflow into the atria when the ventricles contract
• Bicuspid valve


  The left AV valve, consisting of two flaps, or cusps, of endocardium
• Tricuspid valve


  The right AV valve, having three flaps
• Semilunar valves


  Guard the bases of the two large arteries leaving the ventricular chambers, known as the pulmonary and aortic semilunar valves
• Heart valves are simple devices, and the heart—like any mechanical pump—can function with "leaky" valves as long as the damage is not too great. However, severely deformed valves can seriously hamper cardiac function

  
• Valvular incompetence


  An incompetent valve forces the heart to pump and repump the same blood because the valve does not close properly, so blood backflows
• Valvular stenosis


  The valve cusps become stiff, often because of repeated bacterial infection of the endocardium (endocarditis), forcing the heart to contract more vigorously than normal to create enough pressure to drive blood through the narrowed valve