CIRCULATORY SYSTEM

• Circulatory System


  Responsible for transporting oxygenated blood from the heart and lungs via the arteries, and transporting deoxygenated blood back to the heart via the veins
• Functions of the Circulatory System

  • Delivers oxygen and nutrients to all cells
  • Transports carbon dioxide and other wastes away from the cells
  • Helps in the coagulation process
  • Regulates body temperature
  • Assists in fighting diseases
• Two Main Components of the Circulatory System

  • Cardiovascular System (heart, blood vessels, blood)
  • Lymphatic System (lymph, lymph nodes, vessels)

  
• Heart


  Hollow muscular organ with four chambers, surrounded by a thin, fluid-filled sac called pericardium
• Heart


  • Size: same size of a person's clenched fist
  • Layers: Epicardium (thin, watery membrane), Myocardium (thick layer of cardiac muscle), Endocardium (thin layer of epithelial cells)

  
• Chambers of the Heart

  • Right Atrium (receives deoxygenated blood from the body)
  • Right Ventricle (receives blood from the right atrium and pumps it into the pulmonary artery)
  • Left Atrium (receives oxygenated blood from the lungs and pumps it into the left ventricle)
  • Left Ventricle (receives blood from the left atrium and pumps it into the aorta)

  
• Valves of the Heart

  • Right AV (atrioventricular) valve: tricuspid valve (closes as the RV contracts preventing blood from flowing back to the RA)
  • Left AV (atrioventricular) valve: bicuspid or mitral valve (closes as the LV contracts preventing blood from flowing back to the LA)
• Septa


  • Interatrial Septum (partition that separates the RA from the LA)
  • Interventricular Septum (separates the RV from the LV)
• Coronary Circulation


  Receives blood supply through the left and right coronary arteries, and coronary veins return the oxygen depleted blood from the heart muscle back to the heart
• Blood Flow through the Heart in 2 MINUTES
• Functions of the Heart

  • Cardiac Cycle (systole and diastole)
  • Electrical Conduction System (sends electric impulses throughout the myocardium)
  • ECG/electrocardiogram (graphical representation of the cardiac cycle's activity)
  • Origin of the Heart Sounds ("Lubb" first sound, "Dupp" second sound)
  • Heart Rate and Cardiac Output (average heart rate is 72 bpm)
  • Pulse (rhythmic throbbing resulting from the alternating expansion and contraction of the artery)
  • Blood Pressure (force exerted by the blood on the walls of the vessel)

  
• Disorders of the Heart

  • Angina pectoris (chest pain from reduced blood flow)
  • Aortic stenosis (murmuring sound when aortic leaflets don't fully open)
  • Bacterial endocarditis (infection in heart lining or blood vessel)
  • Congestive heart failure (chronic progressive condition affecting pumping power)
  • Myocardial infarction (heart attack from decreased/stopped blood flow)
  • Pericarditis (inflammation of the pericardial sac)
• Diagnostic Tests for Heart Disorders

  • Arterial Blood Gas (ABG)
  • Aspartate aminotransferase (AST) or Serum Glutamic-Oxaloacetic Transaminase (SGOT)
  • Cholesterol
  • Creatine Kinase (CK)
  • Creatine Kinase-MB (CK-MB)
  • Digoxin
  • ECG
  • Lactate dehydrogenase (LDH) isoenzyme
  • Microbial Cultures
  • Myoglobin
  • Potassium
  • Triglycerides
  • Troponin T (TnT)
• Vascular System


  The loop which consists of a system of blood vessels through which blood is circulated to the rest of the body
• Two Divisions of the Vascular System

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

  • Arteries
  • Arterioles
  • Veins
  • Venules
  • Capillaries
• Blood Vessel Structure


  • Layers: Tunica adventitia (outer connective tissue), Tunica media (middle muscle and elastic fiber), Tunica intima (inner, endothelial cells)
  • Lumen
  • Valves

  
• Oxygenated blood then returns to the left side of the heart through pulmonary veins.
• The heart is divided into four chambers, two atria (right and left) and two ventricles (right and left).
• Red Blood Cells (RBC): Carry oxygen from the lungs to all parts of the body.
• Oxygenated blood from the lungs enters the left atrium via the pulmonary veins.
• Deoxygenated blood from the left ventricle exits the heart via the aorta.
• Blood flows from the right side to the lungs where it picks up oxygen.
• Atrioventricular valve separates the right atrium from the right ventricle and prevents backflow of blood during contraction.
• Semilunar valve separates the right ventricle from the pulmonary artery and prevents backflow of blood during relaxation.
• The heart has three layers: epicardium, myocardium, and endocardium.
• Deoxygenated blood from the right ventricle enters the lungs via the pulmonary artery.
• Systolic pressure (top number) represents the maximum pressure when the heart contracts and pumps blood out into the arteries.
• White Blood Cells (WBC): Defend against infection by destroying bacteria, viruses, fungi, parasites, and other foreign substances.
• White Blood Cells (WBC): Defend against infection by attacking foreign substances such as bacteria and viruses.
• Red Blood Cells (Erythrocytes): Small biconcave disks with no nucleus or organelles, primarily contain hemoglobin which carries oxygen from lungs to tissues.
• Platelets: Help form clots that stop bleeding when an artery or vein is damaged.
• Platelets: Help stop bleeding when an artery or vein is damaged.
• White Blood Cells (WBC): Defend against infection by attacking foreign substances such as bacteria or viruses.
• Responsible for transporting oxygenated blood from the heart and lungs via arteries, returning deoxygenated blood through veins.
• Responsible for transporting oxygenated blood from the heart and lungs via arteries, returning deoxygenated blood through veins. Circulatory System