Heart

• Arterosclerosis


  Deposits form on an artery wall, reducing the cross sectional area and causing the vessel walls to become less elastic
• Atherosclerosis


  Deposits are cholesterol and trans fats
• Aneurysm


  Occurs when the vessel wall thins and bulges outwards, causing blood flow disruption when dissected
• Arterosclerosis


  • Deposits are minerals
  • Caused by genetic, diet, lifestyle factors
• Atherosclerosis


  • Caused by genetic, diet, lifestyle factors
• Aneurysm occurs when the vessel wall thins and bulges outwards
• Superior Vena Cava


  Returns blood from the body to the heart, low pressure, deoxygenated
• Inferior Vena Cava


  Returns blood from the lower body to the heart, low pressure, deoxygenated
• Right Atrium


  Collects blood from vena cava and pumps it to the right ventricle, thin walled, low pressure, deoxygenated
• Right AV Valve


  Allows one-way blood flow from atria to ventricle
• Right Ventricle


  Pumps blood to the lungs, thick walled, deoxygenated, high pressure, strong contractions
• Pulmonary Semilunar Valve


  Allows one-way blood flow from right ventricle to pulmonary trunk
• Pulmonary Artery


  Carries blood away from heart, to the lungs, high pressure, deoxygenated
• Pulmonary Vein


  Returns blood to the heart, from the lungs, low pressure, oxygenated
• Pathway

  Vena Cava → Right Atrium → Pulmonary Artery → Lungs → Right Ventricle → Pulmonary Veins → Left Ventricle → Aorta → Body
• Divisions of the Circulatory System

  • Pulmonary Circuit (Blood flow to and from the lungs)
  • Systemic Circuit (Blood flow to and from the body)
  • Coronary Circuit (Blood from the heart to the heart tissue)
• Sinoatrial Node


  Initiates contractions, impulses move from SA node to AV node, causing the atria to contract
• Atrioventricular Node


  Found between the right atria and ventricle, passes the impulse to Purkinje fibers
• Bundle of His


  Passes the impulse to Purkinje fibers, found at the top of the septum
• Purkinje Fibers


  Found in the walls of the ventricle, make the ventricle contract
• QRS Complex


  Ventricle is contracting
• Lubb


  The ventricles contract, the AV valves close
• Dubb


  The ventricles relax, the semilunar valves close
• Systole


  Ventricles contract
• Diastole


  Ventricles relax
• Heart Murmur


  Sounds don't come from the valves closing properly, causes backflow of blood
• Heart Defect


  A hole in the septum or elsewhere causes backflow of blood
• Artery


  Carries blood away from the heart, high blood pressure, thick layer of smooth muscle and elastic tissue
• Arterioles


  Branch off arteries, carry blood away from the heart, contain smooth muscle (less than artery), can vasoconstrict and vasodilate, controlled by autonomic nervous system
• Capillary


  Site of nutrient, gas, and waste exchange, thin walled, always near cells for diffusion, allow red blood cells to move in single file, have high cross-sectional area, low blood pressure
• Venules


  Bring blood back to the heart, low blood pressure, low amount of smooth muscle
• Veins


  Bring blood back to the heart, low blood pressure, low amount of smooth muscle, contain valves
• Cardiac Output


  The volume of blood that the heart pumps each minute, calculated as stroke volume x heart rate
• Blood Pressure


  The force of blood acting on artery walls, measured by a blood pressure cuff, systolic (120 mmHg) when ventricle contracts, diastolic (80 mmHg) when ventricle relaxes
• Factors that affect blood pressure are cardiac output, arterial resistance, and blood volume