Cardiovascular System (Finals)

• Cardiovascular System

  • part of the circulatory system that circulates blood
  • consists of the heart, blood, and blood vessels
  • Function: transport of inhaled oxygen from the lungs to body's tissues, and removal of carbon dioxide in the opposite direction to be exhaled
• Circulatory System

  • includes the lymphatic system, which circulates lymph
• Describes Blood Circulation

  • Cardiovascular System
  • Lymphatic System
• Heart

  • a pump that moves blood through the vessels
  • organ made up of several tough layers of muscle
• Chambers of the Heart

  • Right atrium
  • Left atrium
  • Right ventricle
  • Left ventricle
• Valves (One-way blood flow)

  • Aortic
  • Pulmonary
  • Tricuspid
  • Mitral
• Pericardium

  • double-walled protective sac that encloses the heart
  • thin layer that cover the exterior
• Pericardial cavity

  • fluid which serves as a lubricant and allows heart to contract and relax with minimum friction
• Layers of Heart Wall

  • Epicardium - outer layer, lines the pericardial cavity
  • Endocardium - inner layer, lines heart chambers and valves and is continuous with the endothelium of blood vessels
  • Myocardium - thick middle layer, muscle tissue responsible for beating of the heart
• Action potentials

  • electrical impulses of the contraction of the heart muscle
• Pacemaker cells

  • group of small cells where impulses start
  • constitute the cardiac conduction system
• Sinoatrial (SA) node

  • primary pacemaker; initiates all heartbeats and controls heart rate
• Blood

  • transport of gases
  • supplies body's tissues with nutrients
  • removes metabolic wastes
  • carries hormones from endocrine glands to target organs
  • plays an important role in body's immune defense
• Two Components of Blood

  • Plasma; clear extracellular fluid
  • Formed elements; red blood cells, white blood cells, and platelets
• Red blood cells (RBC)

  • transport oxygen and carbon dioxide
• White blood cells (WBC)

  • participate in various defense mechanisms against invading organismms
• Platelets

  • responsible for blood clotting, minimizing blood loss during an injury
• Blood Flow

  1. Aorta
  2. Arteries
  3. Arterioles
  4. Capillaries
  5. Venules
  6. Veins
  7. Vena cava
• Capillaries

  • where exchange of substances takes place
  • 60,000 miles
• Walls of Arteries and Veins

  1. Tunica externa - outer layer of loose connective tissue serves to anchor the vessels to the surroundings
  2. Tunica media - middle layer of mostly smooth muscles allows vessels to constrict or dilate
  3. Tunica intima - inner layer consisted of thin squamous endothelium, separated from outer layers by a basement membrane
• Atrium

  • upper chambers that receive blood
• Ventricles

  • lower chambers that pump blood out
• Heart beats

  • Day: 100,000 (One hundred thousand) times
  • Year: 40,000,000 (Forty million) times
  • Lifespan: 3,000,000,000 (Three billion) times