circulatory and respiratory system

• Circulatory System Function


  Transports oxygen and nutrients, removes waste products, and regulates body temperature and pH levels
• Respiratory System Function 1

  Exchanges oxygen and carbon dioxide between lungs and bloodstream
• Respiratory System Function 2

  Provides oxygen to body cells for energy production
• Circulatory System Component


  Pumps blood throughout the body, regulates blood flow and pressure
• Circulatory System Function 2

  Transports blood through arteries, veins, and capillaries
• Circulatory System Component 2

  Carries oxygen, nutrients, and waste products between organs and tissues
• Respiratory System Component


  Expands and contracts for air exchange in and out of the lungs
• Respiratory System Component 2

  Filters and humidifies air for inhalation
• Arterial Characteristics


  Carry oxygen-rich blood from the heart to the body tissues; Higher blood pressure; Thicker walls; Mainly from heart to periphery
• Veinous Characteristics


  Carry deoxygenated blood from body tissues to the heart; Lower blood pressure; Thinner walls; Return blood from periphery to heart
• Heart Chambers


  Right Atrium: receives deoxygenated blood from body's veins, Right Ventricle: pumps deoxygenated blood to lungs, Left Atrium: receives oxygen-rich blood from lungs, Left Ventricle: pumps oxygen-rich blood to body
• Septom's Role


  Divides heart into chambers: (1) Atrioventricular Septum (separates atria and ventricles) and (2) Interventricular Septum (separates right and left ventricles), helps maintain blood pressure and flow, prevents blood mixing between chambers
• Hemoglobin (Hb)


  A protein-heme protein in red blood cells, Function 1: Oxygen transport from lungs to tissues, Function 2: Carbon dioxide removal from tissues to lungs, Function 3: pH regulation (buffering), Made up of globin and heme, Binds easily to oxygen, Carries carboxyhemoglobin (COHb) and absorbs carbon dioxide
• Arteries


  Blood vessels that transport oxygenated blood from the heart to the rest of the body, Features: Thick walls (intima, media, and adventitia), Higher blood pressure due to heart pumping, Elastic, allowing for stretching and compression
• Arterial Branches


  Small arteries branching off from larger arteries, carry oxygenated blood to smaller organs and tissues
• Arterioles


  Small arteries leading to capillaries, regulate blood flow by constricting or dilating
• Left Atrium (LA)


  Receives oxygenated blood from the lungs and pumps it to the left ventricle
• Aortic Valve


  Prevents backflow of blood from the aorta to the left ventricle
• Paths of pulmonary and systemic circulation

  1. Blood coming from the head and lower body via the inferior vena cava

  2. Blood enters the right atrium

  3. Blood flows to the right ventricle

  4. Blood flows to the pulmonary arteries

  5. Blood flows to the capillary bed of the lungs where gas exchange occurs

  6. Blood flows to the pulmonary veins

  7. Blood flows to the left atrium

  8. Blood flows to the left ventricle

  9. Blood flows to the aorta and its branches (systemic arteries)

  10. Blood flows to the capillary bed of all body tissues where gas exchange occurs

  11. Blood flows to the systemic veins

  12. Blood flows back to the inferior vena cava
• Pulmonary circuit


  • Pulmonary arteries
  • Pulmonary veins
  • Capillary bed of lungs where gas exchange occurs
• Systemic circuit


  • Aorta and branches (systemic arteries)
  • Capillary bed of all body tissues where gas exchange occurs
  • Systemic veins
  • Vena cavae
• Valves


  Flaps of muscles that prevent blood from back flowing
• Sets of valves


  • Atrioventricular valves
  • Pulmonary valves
• Semilunar valves


  Located at the bases of the large vessels leaving the ventricles
• Right atrioventricular valve


  Tricuspid valve
• Left atrioventricular valve


  Bicuspid or mitral valve
• Valve between right ventricle and pulmonary artery

  Pulmonary semilunar valve
• Valve between left ventricle and aorta

  Aortic semilunar valve
• When ventricles contract


  Atrioventricular valves close to prevent blood from back flowing into the atria
• When ventricles relax


  Semilunar valves close to prevent blood from flowing back into the ventricles
• Vena cava


  Largest vein connected to the heart, conveys oxygen-poor blood from all parts of the body back to the right atrium
• Aorta


  Largest artery, conveys oxygen-rich blood pumped by the left ventricle to all parts of the body
• Pulmonary artery


  Conveys blood pumped by the right ventricle to the lungs for oxygenation
• Pulmonary veins


  Convey oxygen-rich blood back to the left atrium of the heart
• Coronary arteries and veins

  Supply blood to sustain the heart muscle
• Types of blood vessels

  • Arteries
  • Veins
  • Capillaries
• Arteries


  • Convey oxygen-rich blood away from the heart
  • Except pulmonary arteries which transport blood with low oxygen content from right ventricle to lungs
• Arteries


  • Elastic blood vessels
  • Blood passes through in a pulsating manner due to high pressure from heart pumping
• Arterial walls


  • Tunica externa (connective tissue with elastic and collagen fibers)
  • Tunica media (smooth muscle layers)
  • Tunica intima (connective tissue and epithelium)
• Veins


  • Thinner tunica media
  • Wider lumen
  • Equipped with valves to prevent back flow of blood
  • Easily collapse when cut