chapter 7

• Circulatory system


  Also called the cardiovascular system, consists of the heart, blood vessels, and blood
• Circulatory system


  • Transports oxygen, hormones and nutrients to all the cells in the body
  • Picks up waste products generated by metabolic processes and delivers them to other organs for disposal
• Heart


  Provides the "muscle" needed to pump blood throughout the body
• Circulatory system

  1. Pulmonary circuit

  2. Systemic circuit
• Pulmonary circulation

  Transports oxygen-poor blood from the right ventricle to the lungs where blood picks up a new oxygen supply
• Systemic circulation

  1. Returns oxygen rich blood and nutrients to the left atrium and is pumped out all over the body

  2. Picks up carbon dioxide and other waste products
• Circulatory system


  Works in conjunction with other body systems to keep it working properly
• Blood vessels


  Over 60,000 miles of blood vessels transport blood throughout the body
• Types of blood vessels

  • Arteries
  • Veins
  • Capillaries
• Arteries


  Blood vessels that carry blood away from the heart to other parts of the body, thicker than veins due to high blood pressure
• Veins

  Blood vessels that carry blood from the body back to the heart
• Capillaries


  Tiny tubes that carry blood from the arteries to the body's cells, and then back to the veins
• Capillaries


  • Walls are only one cell thick, allowing exchange of gases, nutrients, and wastes
  • Red blood cells must line up single-file to go through them
• Blood


  Forms about one-twelfth of the body weight of an adult, amounting to about 5 liters (11 pints) in volume
• Components of blood

  • 45-50% red blood cells
  • 50-55% plasma
• Plasma


  The liquid-only portion in which cellular components are distributed, containing 90% water with dissolved substances
• Red blood cells (erythrocytes)


  • Disk-shaped with depressions on both sides to maximize surface area for oxygen absorption
  • Lack a nucleus
  • Contain hemoglobin
  • Produced in red bone marrow
  • Live for 120 days
  • Destroyed in the liver and spleen
• White blood cells


  • Defend against disease by recognizing proteins that do not belong to the body
  • Able to ooze through capillary walls to patrol tissues and reach the lymph system
• Platelets


  • Cell fragments used in blood clotting
  • Derived from megakaryocytes
  • Have a short lifespan of about 10 days
• Blood types


  • A+, A-
  • B+, B-
  • AB+, AB-
  • O+, O-
• Rhesus (Rh) factor


  An inherited protein found on the surface of red blood cells, Rh positive or Rh negative
• Blood pressure


  Pressure exerted by blood against the walls of blood vessels, measured as systolic and diastolic pressure
• Heart's electrical system


  Starts with an electrical signal in the right atrium at the SA node, then spreads throughout the heart from top to bottom
• Electrocardiogram (ECG or EKG)


  A test that measures and records the electrical activity of the heart
• Angioplasty


  A procedure that opens blocked arteries and restores normal blood flow to the heart muscle, done by threading a catheter through a small puncture in a leg or arm artery to the heart
• Pacemaker


  A battery-operated device placed in the body to produce electrical pulses that cause the heart to beat at a normal rate