Bio

• Cardiovascular System


  System of organs that transport blood throughout the body
• Main parts of the cardiovascular system

  • Heart
  • Blood vessels (arteries, capillaries, veins)
• The heart is an organ that is part of the cardiovascular system
• Heart


  • Located in the center of the chest cavity
  • Has a left and right side
  • Has an upper chamber (atrium) and a lower chamber (ventricle)
  • Has valves that control the flow of blood
• Flow of blood through the heart


  1. Blood enters the right atrium

  2. Blood flows from right atrium to right ventricle

  3. Blood flows from right ventricle to lungs

  4. Blood flows from lungs to left atrium

  5. Blood flows from left atrium to left ventricle

  6. Blood flows from left ventricle to body
• The "lub-dub" sound of the beating heart is caused by the valves closing
• The cardiovascular system helps maintain homeostasis by carrying nutrients to cells and removing wastes
• The cardiovascular system helps in regulation by carrying chemical signals (hormones) throughout the body
• Blood vessels


  Hollow tubes that carry blood throughout the body
• Types of blood vessels

  • Arteries
  • Capillaries
  • Veins
• Arteries


  • Carry blood away from the heart
  • Have thick walls with a layer of smooth muscle
  • Each heartbeat pumps blood into them at high pressure
• Capillaries


  • Allow exchange of nutrients, oxygen, carbon dioxide and other substances between blood and body cells
  • Walls are only one cell thick
  • Blood cells must pass through them in single file
• Veins


  • Carry blood back to the heart
  • Have valves to prevent backflow of blood
  • Skeletal muscle contractions help push blood towards the heart
• Pulmonary circulation


  1. Blood pumped from heart to lungs

  2. Carbon dioxide leaves blood, oxygen enters blood

  3. Oxygen-rich blood flows back to heart
• Systemic circulation


  1. Oxygen-rich blood pumped from heart to rest of body

  2. Oxygen and nutrients delivered to body cells

  3. Carbon dioxide and waste products carried back to heart
• Cardiovascular problems can harm the whole body
• Cardiovascular problems can be caused by smoking, high cholesterol, stress, physical inactivity, or heredity
• Eating a healthy diet and getting plenty of exercise can reduce the risk of cardiovascular problems
• Atherosclerosis


  Buildup of cholesterol inside blood vessels, causing them to become narrower and less elastic
• Atherosclerosis is a major cause of heart diseases, the leading cause of death in the United States
• Hypertension


  Abnormally high blood pressure
• Hypertension increases the risk of heart attack, heart failure, kidney disease, and stroke
• Heart attack


  Death of heart muscle cells and damage to part of the heart muscle
• Heart failure


  Heart cannot pump enough blood to meet the body's needs, leading to damage to organs like the brain, lungs, and kidneys
• Components of blood


  • Plasma
  • Red blood cells
  • Platelets
  • White blood cells
• Plasma


  The fluid part of blood, containing water, minerals, nutrients, sugars, proteins, and other substances
• Red blood cells


  • Most numerous blood cells
  • Contain hemoglobin to transport oxygen
  • Give blood its red color
• Platelets


  • Help form blood clots to reduce blood loss from damaged blood vessels
• White blood cells


  • Help destroy pathogens and clean up dead or damaged body cells
  • Some release antibodies to identify and destroy pathogens
• Blood helps regulate body temperature by transferring heat from the core to the skin
• Blood pressure


  The force exerted by blood on the inside walls of arteries
• Systolic pressure


  The pressure inside large arteries when the ventricles contract
• Diastolic pressure


  The pressure inside arteries when the ventricles relax
• A healthy blood pressure for adults is 120/80 mm Hg or below
• High blood pressure can cause heart or kidney damage
• Blood pressure


  The pressure on the artery walls that can push a narrow column of mercury to a height of 110 mm
• Systolic pressure


  The pressure inside large arteries when the ventricles contract, causing the arteries to bulge and produce a pulse
• For adults, a blood pressure of 120/80 mm Hg or below is considered healthy
• Blood types


  A, B, AB, or O
• Antigens


  The type of chemicals on the surface of red blood cells