CARDIOVASCULAR 1

• The blood consists of the following formed elements:

  1. platelets
  2. white blood cells
  3. red blood cells
  4. plasma
• Blood is a fluid connective tissue that circulates through the arteries to reach the body’s tissues and returns to the heart through the veins.
• function of blood

  1. transport of dissolved gases, nutrients, metabolic waste products and hormones to and from tissues
  2. prevention of fluid loss via clotting mechanisms
  3. immune defense activities
  4. regulation of pH and electrolyte balance
  5. thermoregulation via blood vessel constriction and dilation
• When blood is “spun down” in a centrifuge, the RBCs precipitate

  to the bottom of the tube where they comprise about 45% of

  the blood volume. The next layer is a “buffy coat” that com-

  prises slightly less than 1% of the blood volume and includes

  the WBCs (leukocytes) and platelets. The remaining 55% of the

  blood volume is the plasma
• plasma includes

  1. Water
  2. Plasma proteins
  3. Other solutes (electrolytes, organic nutrients, organic wastes)
• The volume of the packed RBCs represents the hematocrit,

  which normally ranges from about 40% to 50% in males to 35%

  to 45% in females
• The WBCs include the following types of leukocytes


  1. neutrophils
  2. eosinophils
  3. lymphocytes
  4. basophils
  5. monocytes
• The “buffy coat” includes platelets and the

  WBCs.
• The most numerous of the granular WBCs (and

  all WBCs, granular and agranular), they possess a multilobed

  nucleus, function as phagocytes at sites of inflammation, live

  8 to 12 hours in the blood and about 1 to 2 days in the extra-

  vascular compartment

  Neutrophils
• are granular WBCs that respond to allergic

  reactions, participate in immune responses, phagocytose

  antigen-antibody complexes, live about 8 to 12 hours in the

  blood and for an unknown period of time in the connective

  tissues

  Eosinophils
• the most common type of agranular WBCs, they

  are one of three types (B cells that are derived from the bone

  marrow and produce circulating antibodies; T cells that are

  derived from the bone marrow but complete their differentiation

  in the thymus, they are either cytotoxic, helper, or suppressor

  cell-mediated immune cells; and natural killer (NK) cells that kill

  virus-infected cells)

  Lymphocytes
• Least numerous WBCs, they are granular, function

  in immune, allergic, and inflammatory reactions, release

  vasoactive substances that can lead to hypersensitivity or

  allergic reactions, live in the blood for about 8 hours and for an

  unknown period of time in connective tissues

  Basophils
• the largest of the WBCs, they are agranular, travel

  from the bone marrow into the connective tissue where they

  differentiate into macrophages, live as monocytes in the blood

  about 16 hours and for an unknown period of time in connec-

  tive tissues as macrophages

  monocytes
• blood cells

  1. red blood cells
  2. platelets
  3. neutrophil
  4. monocyte
  5. eosinophil
  6. lymphocyte
  7. basophil
• Red blood cells: do not possess a nucleus as mature

  cells (red)
• cardiovascular system consist of 


  1. heart
  2. pulmonary circulation
  3. systematic circulation
• pumps the blood throughout the circulation

  Heart
• closed loop circulation between the heart and lungs for gas exchange


  pulmonary circulation
• a closed loop circulation between the heart and all the tissues of the body


  systematic circulation
• circulatory system's vessels


  1. arteries
  2. veins
• any vessel that carries blood away from the heart

  Arteries
• any vessel that returns blood to the heart

  veins
• The venous side (left side) blue. Note that the vessels

  passing from the right ventricle (RV) to the lungs are

  the pulmonary arteries (even though the blood is less

  saturated with oxygen) and that the vessels from the

  lungs to the left atrium (LA) are called pulmonary

  veins (fully saturated with oxygen).
• The arterial side (right side) of the central schematic

  figure red
• The thoracic cavity is divided into a left and right pleural sac,

  which contains the lungs, and a “middle space” called the

  mediastinum
• mediastinum regions


  1. superior
  2. inferior
  3. anterior
  4. middle
  5. posterior
• lies deep to the manubrium of the sternum and

  contains the great vessels (superior vena cava and aorta)


  Superior
• lies deep to the body of the sternum and contains

  some fat and connective tissue

  Anterior
• lies deep to the anterior mediastinum and contains

  the heart encased in its pericardial sac

  middle
• lies deep to the heart and contains the descending

  thoracic aorta, thoracic lymphatic duct, and esophagus

  posterior
• The heart lies in the middle mediastinum and is encased within

  a tough fibrous sac called the pericardium
• 
  

  pericardium

  has a tough outer layer called the fibrous pericardium, which

  reflects onto the great vessels in the superior mediastinum.
• A parietal layer of the serous pericardium lines the inner aspect

  of the fibrous pericardium and then reflects onto the heart itself

  as the visceral serous pericardium (epicardium)
• Tough, outer layer that reflects onto great

  vessels

  fibrous pericardium
• Layer that lines inner aspect of fibrous

  pericardium (parietal layer); reflects onto

  heart as epicardium (visceral layer)


  serous pericardium
• Phrenic nerve (C3-5) for conveying pain;

  vasomotor innervation via sympathetics

  innervation
• Space posterior to aorta and pulmonary trunk;

  can clamp vessels with fingers in this sinus

  and above

  transverse sinus
• Pericardial space posterior to heart

  oblique sinus
• 
  

  The human heart has four chambers: two atria and two ventricles.
• Blood returning from the systemic circulation enters the

  right atrium and right ventricle and is pumped into the pulmonary

  circulation for gas exchange