circulatory system

• Circulatory system


  The role of the heart, blood and blood vessels

  
• 3 Main Functions of the circulatory system

  • Homeostasis
  • Transportation
  • Protection
• Homeostasis


  Balances fluid, electrolytes, and pH levels, and aids in temperature regulation
• Transportation


  Transports nutrients, hormones, and oxygen and removes wastes throughout the body
• Protection


  Prevents fluid loss and circulates chemicals to eliminate pathogens from the body
• Heart


  The pump that pushes blood through your body
• Blood vessels


  The highways that carry blood throughout your body

  
• Major components of the circulatory system

  • Heart
  • Blood vessels
  • Blood

  
• Blood


  Carrier of oxygen, nutrients, and wastes like a delivery system
• Heart


  • It is about the size and shape of a closed fist
  • It lies behind and slightly to the left of the sternum and positioned between the lungs, within a space, called mediastinum
• Layers of the heart wall

  • Epicardium
  • Myocardium
  • Endocardium
• Upper chambers of the heart

  • Right atrium
  • Left atrium
• Lower chambers of the heart

  • Right ventricle
  • Left ventricle
• Heart vessels

  • 2 Arteries (Aorta, Pulmonary artery)
  • 2 Veins (Vena cava, Pulmonary veins)
• Heart valves


  • 2 Atrioventricular valves (Bicuspid valve, Tricuspid valve)
  • 2 Semilunar valves (Aortic valve, Pulmonary valve)
• Blood flow through the heart

  1. Blood enters right atrium

  2. Blood flows to right ventricle

  3. Blood flows to lungs

  4. Oxygen-rich blood enters left atrium

  5. Blood flows to left ventricle

  6. Blood pumped to body

  
• Major cardiovascular vital signs

  • Pulse rate
  • Respiratory rate
  • Heart rate
  • Blood pressure
• Pulse rate


  The expansion and contraction of an artery due to the ejection of blood from the heart
• Respiratory rate


  Number of breaths taken per minute
• Heart rate


  • Number of times your heart beats per minute
  • 1 complete heartbeat takes 0.8 seconds
  • Average heartbeat of 60 - 100 beats per minute
• Blood pressure


  • The force exerted by circulating blood against the walls of blood vessels
  • Systolic pressure - Measured during heart contraction
  • Diastolic pressure - Measured during heart relaxation
• Functions of blood


  • Carries transporters in supplying nutrients and hormones
  • Regulates body temperature
  • Carries cells that fight off infection
  • Brings waste products to the kidney and liver to be excreted
• Hematology


  The study of blood
• Whole blood


  • A mixture of about 55% plasma and 45% blood cells (about 40-44% is RBC and the rest is WBC and Platelets)
  • About 7 to 8 percent of your total body weight is blood
• Red blood cells (RBC)

  • Their main function is to carry oxygen from the lungs and deliver it throughout the body
  • They can carry oxygen due to a protein called "hemoglobin"
• Hemoglobin


  Made up of two main parts: the "heme" group (contains Iron(Fe) which gives the red color) and the "globin" group (the protein that helps RBC carry and hold oxygen)
• Anemia


  Blood contains less RBC throughout the body, could be due to trauma, surgery, blood loss or blood disorders
• Erythropoietin


  A glycoprotein hormone naturally produced by the peritibular cells of the kidney that stimulates the red blood cell production
• Polycythaemia


  Increase in RBC concentration and hemoglobin, the protein in red blood cells that carries oxygen to the body's tissues
• White blood cells


  • Originate from cells that morph into other cells in the body (stem cell) within the bone marrow
  • Most are individualized to our specific bodies, which is why they are removed from transfusable blood (leuko-reduction)

  
• Types of white blood cells

  • Agranulocytes
  • Granulocytes

  
• Agranulocytes

  Have a larger nucleus due to the lack of noticeable cytoplasmic granules
• Granulocytes


  Contain granules or sacs in their cytoplasm
• Platelets


  • Tiny fragments that rush to an injury in the blood vessel and form a plug to fix the damage (clot or thrombus)
  • Referring to them as cells is a misnomer as they are circulating fragments of cells

  
• Thrombocythemia


  Excessive clotting because of too many platelets

  
• Thrombocytopenia


  Bruising and abnormal bleeding become more likely because there are too few platelets in the blood

  
• Plasma


  The extracellular matrix that is fluid and suspends the formed blood elements, composed primarily of water with dissolved or suspended substances, mostly proteins
• Types of circulation


  • Pulmonary circulation
  • Systemic circulation
  • Coronary circulation
• Pulmonary circulation


  Transports oxygen-poor blood from the right ventricle to the lungs, where blood picks up oxygen, then returns the oxygen-rich blood to the left atrium
• Systemic circulation


  Provides the functional blood supply to all body tissue, carrying oxygen and nutrients to the cells and picking up carbon dioxide and waste products