Circulatory System

• Circulatory system


  Includes the heart, veins, capillaries, arteries, lymph vessels, and lymph glands
• Circulatory system


  • Responsible for: Distributing blood throughout the body
  • Removing wastes
  • Mounting immune responses to infection
  • Aiding in regulating body temperature
• Blood


  Provides organs, tissues and cells with oxygen, nutrients, gasses, hormones, and antibodies, and removes carbon dioxide and metabolic wastes
• Lymphatic system


  Responsible for draining fluid from the body and is an important defense mechanism against infection
• Heart


  A muscle divided into the left and right side, each made up of an atrium and a ventricle
• Heart


  1. Deoxygenated blood enters the right atrium

  2. Passes through the right A.V. valve and into the right ventricle

  3. Pumped through the pulmonary artery to the lungs

  4. Oxygenated blood returns from the lungs via the pulmonary vein and enters the left atrium

  5. Passes through the left A.V. valve and into the left ventricle

  6. Pumped out of the heart to the rest of the body via the aorta
• Heart anatomy


  • Walls
  • Chambers that are like rooms
  • Valves that open and close like doors to the rooms
  • Blood vessels like plumbing pipes
  • Electrical conduction system like electrical power
• Heart walls


  • Endocardium: Inner layer
  • Myocardium: Muscular middle layer
  • Epicardium: Protective outer layer
• Pericardium


  Protective sac that covers the entire heart, produces fluid to lubricate the heart
• Heart chambers


  • Right atrium
  • Right ventricle
  • Left atrium
  • Left ventricle
• Heart valves


  • Atrioventricular valves: Tricuspid valve, Mitral valve
  • Semilunar valves: Aortic valve, Pulmonary valve
• Types of blood vessels

  • Arteries
  • Arterioles
  • Veins
  • Venules
  • Capillaries
• Blood vessels


  • Arteries carry oxygen-rich blood from heart to body
  • Veins carry oxygen-poor blood back to heart
  • Capillaries are small blood vessels where body exchanges oxygen-rich and oxygen-poor blood
• Blood vessel structure


  1. Arteries divide into arterioles

  2. Veins divide into venules

  3. Capillaries are the smallest blood vessels
• Capillaries


  Involved in the transfer of oxygen, nutrients and gases to the cells of the body and the removal of carbon dioxide and metabolic waste
• Intercellular fluid is fluid between the capillaries and cells through with nutrients, gases and wastes diffuse
• Circulation systems


  • Pulmonary System
  • Systemic System
• Components of blood


  • Red blood cells (erythrocytes)
  • White blood cells (leukocytes)
  • Platelets (thrombocytes)
  • Plasma
• Red blood cells


  • Most numerous, contain hemoglobin which carries oxygen and aids in removal of carbon dioxide
• White blood cells


  • Responsible for the body's immune response, granulocytes and agranulocytes (lymphoid cells) aid in combating foreign bodies, bacteria, viruses and other infective agents
• Platelets (thrombocytes)


  Fragments of cytoplasm that play a role in clotting
• Plasma


  Yellowish extracellular fluid found in blood vessels, 90% water
• Lymphatic system


  Comprised of lymph vessels, lymph nodes, lymph organs and areas of lymph tissue within the intestinal wall
• Lymphatic system


  • Maintains internal fluid balance and is an important component of the body's immune system
• Lymphatic organs


  • Bone marrow
  • Thymus
  • Lymph nodes
  • Spleen
  • Mucosa-associated lymphoid tissue (MALT)
• Lymph


  Collection of extra fluid that drains from cells and tissues, contains proteins, minerals, fats, damaged cells, cancer cells and germs, transports infection-fighting white blood cells
• Lymphatic vessels


  Tubes that form a complex network, contain one-way valves to keep lymph moving the right way
• Collecting ducts


  Two main ducts in upper chest that empty lymph into subclavian veins
• Tonsils and adenoids


  • Trap pathogens from food and air, part of body's first line of defense
• Heart's conduction system


  • Sinoatrial (SA) node sends signals to make heart beat
  • Atrioventricular (AV) node carries signals from upper to lower chambers
  • Left and right bundle branches send impulses to ventricles
  • Bundle of His and Purkinje fibers make ventricles contract and pump blood
• Your heart is in the front of your chest, slightly behind and to the left of your sternum
• Your heart looks like an upside-down pyramid with rounded edges, with large blood vessels going into and out of it
• An adult's heart generally weighs about 10 ounces and is about the same size as their fist
• Common heart conditions and disorders


  • Arrhythmia
  • Cardiomyopathy
  • Congestive heart failure
  • Coronary artery disease
  • Diabetes
  • Heart attack (myocardial infarction)
  • Heart valve disease
  • High blood pressure
  • High cholesterol
  • Pericarditis