PRIN 2 - Circulatory System

• Blood flows from the right atrium into the right ventricle through the tricuspid valve.
• Circulatory System


  Delivers oxygen & nutrients, removes waste products, helps in coagulation, regulates body temperature, important in body defenses (WBCs)
• Two main components of the Circulatory System

  • Cardiovascular System
  • Lymphatic System
• Cardiovascular System


  • Heart
  • Blood vessels
  • Blood
• Heart


  Hollow muscular organ with four chambers, surrounded by a thin, fluid-filled sac called pericardium
• Pericardium / Pericardial Sac

  Sac that anchors and protects the heart, keeps the heart contained in the chest cavity, prevents the heart from overexpanding, limits heart motion
• Layers of the pericardium

  • Fibrous pericardium
  • Serous pericardium
• Parietal pericardium


  Portion of the serous pericardium lining the fibrous pericardium
• Visceral pericardium / Epicardium

  Portion covering the heart surface
• Layers of the heart wall

  • Epicardium (Outer)
  • Myocardium (Middle)
  • Endocardium (Inner)
• Chambers of the heart

  • Right Atrium (Upper right)
  • Right Ventricle (Lower right)
  • Left Atrium (Upper left)
  • Left Ventricle (Lower left)
• Valves of the heart

  • Right AV valve (Tricuspid valve)
  • Left AV valve (Bicuspid or Mitral valve)
  • Right semilunar valve (Pulmonary valve)
  • Left semilunar valve (Aortic valve)
• Septa of the heart

  • Interatrial septum
  • Interventricular septum
• Functions of the human heart

  • Cardiac Cycle
  • Electrical Conduction System
  • ECG
  • Heart sounds
  • Heart Rate and Cardiac Output
  • Pulse
  • Blood Pressure
• Angina Pectoris


  Sharp chest pain caused by decreased blood flow to the heart usually due to an obstruction in the coronary arteries
• Aortic Stenosis


  A murmuring sound produced when the aortic leaflets fail to fully open during systole
• Bacterial Endocarditis


  Inflammation of the inner lining of the heart caused by a bacterial infection (Staphylococcus epidermidis)
• Congestive Heart Failure


  Impairs the ability of the heart to pump blood efficiently, causing fluid accumulation in the lungs and tissues
• Myocardial Infarction


  Death (necrosis) of the heart muscle caused by lack of oxygen to the myocardium because of an occluded artery, commonly known as a heart attack
• Pericarditis


  Inflammation of the pericardium of the heart caused by bacteria, viruses, trauma or malignancy
• Rheumatic Heart Fever


  Autoimmune disorder affecting heart tissue following a streptococcal infection
• Diagnostic Tests for Heart Disorders

  • Arterial blood gases
  • AST/SGOT
  • Cholesterol
  • CK/CK-MB
  • Digoxin
  • ECG
  • LDH
  • Microbial cultures
  • Myoglobin
  • Potassium
  • TAG
  • Troponin
• Ways to lower the odds of getting heart disease

  • Quit smoking
  • Improve cholesterol levels
  • Control high blood pressure
  • Get active
  • Follow a heart-healthy diet
  • Get to a healthy weight
  • Control diabetes
  • Manage stress and anger
• Blood Vessels


  • Pulmonary circulation
  • Systemic circulation
• Structures of the Vascular System

  • Arteries
  • Arterioles
  • Veins
  • Venules
  • Capillaries
• Layers of Blood Vessels

  • Tunica externa/adventitia (Outer layer, connective tissue)
  • Tunica media (Middle layer, smooth muscle + elastic tissue)
  • Tunica intima (Innermost layer, epithelial cells)
• Lumen


  Space within the blood vessel
• Structures of the Vascular System

  • Arteries - carry oxygen-rich blood
  • Arterioles - small diameter blood vessels that branch out from the arteries and transport blood from small arteries to capillaries
  • Veins - carry deoxygenated blood
  • Venules - have a diameter slightly larger than that of capillaries, very small veins that collect blood from the capillaries
  • Capillaries - fine hair-like blood vessels that connect arterioles and veins
• Circulation of Blood


  1. Vena Cava

  2. Aorta

  3. Arteries

  4. Arterioles

  5. Capillaries

  6. Venules

  7. Veins
• Blood vessel structure


  • Tunica externa / adventitia - Outer layer (connective tissue)
  • Tunica media - Middle layer (smooth muscle + elastic tissue)
  • Tunica Intima - Innermost histologic layer (epithelial cells)
• Lumen


  Space inside the blood vessel where the blood flows
• Valves


  Thin leaflets that prevent backflow of blood
• Arteries carry blood away from the heart and veins carry blood toward the heart. The capillaries are exchange vessels located between the arterial and venous systems.
• ANEURYSM - Bulge formed by a weakness in the wall of a blood vessel; usually an artery that can burst and cause severe hemorrhage.
• ARTERIOSCLEROSIS - Hardening of the artery walls
• ATHEROSCLEROSIS - Form of arteriosclerosis characterized by accumulation of lipids and other materials in the lumen of the vessel to narrow and stimulate clot formation.
• EMBOLISM - Moving clot that can obstruct a blood vessel
• EMBOLUS - Obstruction that is carried and lodged in a vessel
• HEMORRHOIDS - Swollen veins in the anus area
• PHLEBITIS - Inflammation of the vein wall