Circulatory System

• Circulatory System


  The heart, blood vessels, and blood together
• Circulatory System


  • Carries blood and dissolved substances around the body
  • Transports nutrients and oxygen to the body cells
  • Removes wastes and carbon dioxide from the cells
  • The heart pumps blood and substances around the body in tubes called blood vessels
• Heart


  • Cardiac muscle tissue causes the heart to contract
  • Pumps blood through the blood vessels
• Blood Vessels


  • Tubular structures carrying blood through the tissues and organs
  • There are 3 types: vein, artery, capillary
• Arteries


  Carry blood away from heart; has thick walls to withstand high pressure
• Veins


  • Carry blood toward heart; under low pressure
  • Valves help direct blood back to heart
• Capillaries


  • Surround each body cell
  • Allow oxygen and nutrients to enter cells
• Components of Blood


  • Red blood cells (45%)
  • White blood cells (<1%)
  • Platelets (<1%)
  • Plasma (approx. 55%)
• Red blood cells


  Transport oxygen to cells
• White blood cells


  Fight infections
• Platelets


  Cell fragments involved with blood clotting
• Plasma


  • Mostly water
  • Protein-rich liquid that carries blood cells
• Circulatory System


  1. Pulmonary Circuit (carries deoxygenated blood to lungs, returns oxygenated blood to heart)

  2. Systemic Circuit (carries oxygenated blood to body organs, returns deoxygenated blood to heart)
• Parts of the Heart

  • Superior vena cava
  • Aorta
  • Pulmonary artery
  • Left atrium
  • Pulmonary Vein
  • Mitral valve
  • Left ventricle
  • Aortic valve
  • Cardiac muscle
  • Right ventricle
  • Pulmonary valve
  • Inferior vena cava
  • Tricuspid valve
  • Right atrium
• How Heart Valves Work

  1. Constantly open and close to regulate blood flow

  2. Mitral and tricuspid valves control blood flow from atria to ventricles

  3. Aortic and pulmonary valves control blood flow out of ventricles

  4. Healthy valve minimizes obstruction and allows smooth, free flow in one direction

  5. Closes completely and quickly, not allowing backflow
• How Heart Pumps Blood

  1. Left and right atrium contract and relax

  2. Left and right ventricle contract and relax

  3. This sequence of contraction and relaxation is called a heartbeat
• Closed Circulatory System


  • Blood is enclosed within vessels at all times
  • Blood is pumped by a heart through these vessels
  • Blood does not normally fill body cavities
• Open Circulatory System


  • Blood is pumped into a hemocoel (primary body cavity) and diffuses back into the circulatory system between cells
  • Blood is pumped into body cavities and surrounds tissues
• Blood Pressure


  • The force of blood pushing against the arteries
  • Systolic pressure is highest when heart beats, pumping blood
  • Diastolic pressure is when heart is at rest, between beats
• Coronary Artery Disease


  • Coronary arteries become partially blocked with plaque
  • Symptoms include tiredness, dizziness, chest/arm pain or burning
  • Diagnosed with angiogram
  • Treated with lifestyle changes, medication, or surgery
• Heart Attack


  • Coronary arteries become completely blocked, preventing oxygen transport to heart
  • Heart tissue becomes damaged
  • Symptoms include chest pain, shortness of breath, nausea, anxiety, upper body pain, stomach pain, sweating, dizziness, unusual fatigue
  • Diagnosed with blood test or ECG
  • Treated with monitored cardiac rehab, lifestyle changes, medication, implanted devices, surgery
• Lifestyle Changes to Reduce Heart Disease Risk

  • Don't smoke
  • Maintain a healthy diet
  • Exercise, be physically active
  • Reduce stress
• Describe the function of the circulatory system
• Name and describe the functions of 3 different blood vessels
• Write down the various components of blood