bio review pt 1

• Primary Functions of the circulatory system

  • Transports: Delivers 02 & nutrients to cells, removes waste and CO₂ from cells, hormones & Chemical messengers
  • Heat: circulates heat through the body
  • Immunity: Defends against disease (WBCs)
• Chambers of the heart

  • Atria (upper chambers) - receiving chambers as blood returns to the heart
  • Ventricles (Lower Chambers) - pumping chambers (to lungs or body), receive blood from atria, thick w/muscle (left is more muscular)
• Heart valves


  • Atrioventricular Valves - b/w atria and ventricles
  • Semilunar valves - tricuspid (right), bicuspid (left) - blw ventricles and arteries, pulmonary valve (right), aortic valve (left)
• Pulmonary Circuit


  Low pressure, blood flow to and from the lungs
• Systemic Circuit


  High pressure, blood flow to the body
• Blood flow summary


  inferior & superior vena cava → venules/veins → capillaries → arteries /arterioles → right atrium → tricuspid valve → right ventricle → pulmonary artery → Lungs → pulmonary vein → left atrium → bicuspid valve → left ventricle → aorta → body
• Lub


  AV valves closing during contraction (systole)
• Dub


  SL valves closing during relaxation (diastole)
• Heart rate


  Beats/min, influenced by hormones, nerves and metabolic factors
• Changes in heart rate

  • Exercise: muscles demand food/nutrients & 02 and generate waste (CO2) which must be removed (also ↑ breathing)
  • Stress or excitement: "Fight or flight"
  • Chemicals: nicotine, caffeine
• Arteries


  • Carry blood AWAY from the heart, carry oxygenated blood in systemic circuit, carry deoxygenated blood in pulmonary circuit
• Arterioles


  • Arteries branch into arterioles
• Capillaries


  • One cell thick to allow easy exchange of materials, 02 & nutrients INTO cells/muscles, CO₂ & wastes Out of cells/muscles to be taken to Lungs and expelled
• Venules


  • Capillaries merge into venules
• Veins


  • Venules branch into veins, RETURN blood to the heart, have valves, 1 way flow, can cause buildup/pool of blood (varicose veins)
• Systole


  Contracting phase (atria contract together, ventricles contract together)
• Diastole


  Relaxation phase (filling phase)
• Average Blood pressure


  Systolic 120 mmHg, Diastolic 80 mmHg
• Factors that increase blood pressure

  • Smoking / vaping/drinking
  • Poor diet
  • NO exercise
  • High stress level / bad sleeping
• HDL


  Good cholesterol, removes cholesterol from artery walls and take to the liver to be removed
• LDL


  Bad cholesterol, Deposit on artery wall
• Atherosclerosis


  • Disease caused by a build up of plaque that blocks and artery, can cause hypertension
• Heart attack


  • Blockage from clot in coronary artery
• Stroke


  • Blockage of artery in brain
• Aneurysm


  • Weakening of an artery wall (often aorta)
• Septal Defect


  • Hole in heart blw right & left atria, mix oxygenated & deoxygenated blood, strains lungs over time
• Valvular Heart Disease


  • Mechanical Valve - made of metal, Last Longer, need to be on blood thinners to not clots
  • Bioprosthetic Valve - made from animal or human tissue, no blood thinners required, doesn't Last as long
• 5 Main Roles of Blood

  • Carry food Inutrients & 02 to cells
  • Remove wastes & CO2 from cells and Carry to disposal organs
  • Maintain body temp
  • Carry disease and infection fighting cells
  • Close wounds to minimize blood Loss