Circulatory System

• circulatory system - responsible for transporting throughout the body oxygenated blood from the heart and lungs via the arteries.
• Circulatory system is made of two components: the cardiovascular and lymphatic system
• cardiovascular system is composed of the heart, blood vessels, and blood which helps circulation
• lymphatic system - made up of lymph, lymph nodes, and vessels
• heart is hollow muscular organ that has four chambers (left atrium, right atrium, left ventricle,and right ventricle) and surrounded by thin fluid sac (pericardium)
• Layers of the Heart

  1. Epicardium - thin, watery membrane on the outer layer of the heart. Function: covers the heart and is attached to the pericardium
  2. Myocardium - thick layer of cardiac muscles in the middle layer of the heart. Function: pumps blood into the arteries by contracting
  3. Endocardium - thin layer of epithelial cells in the inner layer of the heart. Function: lines the valves and interior chambers
• Chambers of the Heart.

  Right Atrium - upper right chamber.

  Function: receives deoxygenated blood from the body.

  2. Right Ventricle- lower right chamber.

  Function: receives the blood from the right atrium and pumps it into the pulmonary artery

  3. Left Atrium- upper left chamber. Function: receives oxygenated blood from the lungs and pumps

  init into the left ventricle

  4. Left Ventricle - lower left chamber

  Function: receives blood from the left atrium and pumps it into the aorta
• Valves of the Heart

  • Right AV valve - tricuspid valve located between the right atrium and the right ventricle

  Function: closes as the right ventricle contracts preventing blood from flowing back ot the right atrium

  • Left AV valve - bicuspid or mitral valve located between the left atrium and the left ventricle

  Function: closes as the left ventricle contracts preventing blood from flowing back to the left atrium
• Valves of the Heart

  • Right semilunar valve - pulmonary or pulmonic valve located at the entrance of the pulmonary artery

  Function: closes when the right ventricle relaxes preventing blood from flowing back tothe right ventricle

  • Left semilunar valve - aortic valve located at the entrance of the aorta

  Function: closes when the left ventricle relaxes preventing blood from flowing back to the left ventricle
• Septa

  1. Interatrial septum - partition that separates the right from the left atria.
  2. Interventicular septum - separates the right and the left ventricles
• Coronary Circulation - supply through the left andright coronary arteries, and the coronary veins return the oxygen-depleted blood from the heart muscle back to the heart.
• Notes: Poor circulation could lead to ischemia which si caused by inadequate supply of oxygen and myocardial infarction or heart atack due to complete obstruction of the coronary artery.
• Function of Human Heart

  1. Cardiac Cycle- Systole (contraction) and diastole (relaxation) which lasts about 0.8 seconds
• Function of the Human Heart

  1. Electrical Conduction System - Sends electric impulses throughout the myocardium
• Function of the Human Heart

  Electrocardiogram (ECG) - Provides the graphical representation of the cardiac cycle's activity
• Function of the Human Heart

  Origin of Heart Sounds - "Lubb" whichsi the first sound as the ventricles contract or the AV valves close and "dupp" or the second sound which is heard when the semilunar valves close and the ventricles relax.
• Function of Human Heart

  Heart Rate and Cardiac Output - average heart rate is 72 beats per minute (bpm) and the cardiac output refers to the volume of blood pumped per minute
• Function of Human Heart

  Pulse - rhythmic throbbing resulting from the alternating expansion and contraction of the artery
• Function of Human Heart

  Blood Pressure - force exerted by the blood on thewalls of the vessel measured by the sphygmomanometer; the difference between the systolic (pressure during contraction) and diastolic (pressure during relaxation)
• Disorders and Diagnostic of Heart

  1. Angina pectoris - chest pain resulting from reduced blood flow to the heart
  2. Aortic stenosis - a murmuring sound produced when the aortic leaflets fail ot fuly open during systole
• Disorders and Diagnostic of Heart

  3. Bacterial endocarditis - an infection that happens when a bacteria enters and resides in the heart lining or blood vessel

  4. Congestive heart failure - achronic progressive condition that affects the pumping power of the heart muscles
• Disorders and Diagnostic of Heart

  1. Myocardial infarction - known sa heart attack, it si caused by a decrease or full stoppage of blood flow that damages the heart muscle
  2. Pericarditis - inflammation of the pericardial sac that may be due to viral infection
• List of Diagnostic Test for Heart

  Arterial blood gases (ABG)

  • Aspartate aminotransferase (AST) or serum glutamic-oxaloacetic

  transaminase (SGOT)

  • Cholesterol

  • Creatine kinase (CK)

  • Creatine kinase (CK)-MB

  • Digoxin

  • Electrocardiogram (ECG or EKG)

  • Lactate dehydrogenase (LDH) isoenzymes

  • Microbial cultures

  • Myoglobin

  • Potassium (K)

  • Triglycerides

  • Troponin T(ThT)