a&p final review

• compliance: the ability of the lungs to stretch out and fill with air
• respiration: exchange of gases
• external (alveolar) respiration is also known as pulmonary gas exchange
• internal respiration is also known as tissue gas exchange
• external respiration is the exchange of gases between the alveoli and the blood flowing through the capillaries
• internal respiration is the exchange of gases between blood vessels and tissues in the body
• each gas exerts its own partial pressure that allows it to diffuse
• henry's law states the degree to which a gas dissolves in fluid reflects how well that gas can diffuse
• if a gas dissolves in fluid easily, that means it can diffuse easily
• there are ventilatory centers in the pons and medulla of the brain
• the ventilatory centers in the brain maintain and control ventilation patterns and rhythm
• veins and lymphatic vessels both have valves to prevent backflow
• lymphatic vessels transport lymph
• lymph (aka lymphatic fluid) is made up of water + lipids + WBCs and lacks proteins
• lipids give lymph a slightly yellow color
• the 3 functions of lymph are:

  1. regulates ECF volume
  2. absorbs dietary fats
  3. plays an important role in immune functions
• the 2 major lymphatic vessels are the right lymphatic duct and the thoracic duct
• the right lymphatic duct is located on the right side, while the thoracic duct is located on the left side
• the right lymphatic duct is thinner than the thoracic duct
• the thoracic duct is thicker than the right lymphatic duct
• the right lymphatic duct drains excess fluids from the upper right side of the body (head, neck, chest, right limb)
• the thoracic duct drains excess fluid from the upper left side of the body (head, left limb) as well as the lower half of the body (torso, pelvis, both legs)
• the right lymphatic duct drains into the right subclavian vein
• the thoracic duct drains into the left subclavian vein
• the 2 primary lymphatic organs are red bone marrow and the thymus
• the primary lymphatic organs are the sites where lymphocytes become immunocompetent
• when lymphocytes become immunocompetent, that means they are functional and mature
• the thymus shrinks in size with age
• secondary lymphatic organs include tonsils, spleen, appendix, and lymph nodes
• after lymphocytes mature, they migrate to the secondary lymphatic organs and remain there until needed
• macrophages and dendritic cells are two types of phagocytes
• the 3 groups of cells present in the lymphatic system are:

  1. lymphocytes
  2. phagocytes (macrophages & dendritic cells)
  3. reticular cells
• reticular cells are found in the spleen and lymph nodes
• reticular cells produce reticular fibers that trap foreign substances
• the function of lymph nodes is to filter lymphatic fluid
• the 4 major groups of lymph nodes are:

  1. cervical
  2. axillary
  3. mesenteric
  4. inguinal
• cervical lymph nodes are found in the neck
• axillary lymph nodes are found in the armpits
• mesenteric lymph nodes are found in the abdominal region
• inguinal lymph nodes are found in the upper thighs next to genitalia