Respiratory System II Flashcards
lung medial surface
-region where pulmonary vessels and bronchi pass into lung tissue
lung costal surface
-in contact with ribs; anterior surface
lung apex surface**
-extends above clavicle; superior
lung base surface
- inferior; concave
- fits over convex dome of diaphragm
pleura of lungs
- double-walled sac
- encloses and protects lungs
- composed of serous membrane
visceral pleural
-adheres directly to the surface of lung
parietal pleura
-lines the walls of thoracic cavity
pleural cavity
-space btwn visceral and parietal pleural membranes which contains pleural fluid for lubrication
midclavicular line at lung and pleura level
- lung level: rib 6
- pleura level: rib 8
midaxillary line at lung and pleura level
- lung level: rib 8
- pleura level: rib 10
midscapular line at lung and pleura level
- lung level: rib 10
- pleura level: rib 12
right lung components
-3 lobes (superior, middle, inferior)
left lung components
-2 lobes (superior and inferior)
what are bronchopulmonary segments supplied by?
- tertiary bronchus
- pulmonary arteriole
- pulmonary venule
alveoli composition
- simple squamous cells of alveolar wall
- surrounded by a capillary network and venules
the respiratory membrane where air exchange occurs is composed of what?
- type I cells: simple squamous cells of alveoli
- simple squamous cell of capillary
alveolar membrane components
- macrophages
- type II cells
macrophages
-responsible for the removal of dust and other debris
type II cells**
-specialized cells that secrete surfactant
surfactant
- lowers the surface tension in alveoli
- helps them recoil (return to original size)
what are the muscles of respiration?
- diaphragm
- intercostal muscles
diaphragm**
- thin, dome shaped sheet of skeletal muscle
- separates thoracic and abdominal cavities
- supplied by phrenic nerve which originates from C3, C4,C5 (C3, 4, 5 keep you alive)
intercostal muscles
- located btwn ribs in intercostal spaces
- internal and external layers of skeletal muscles help alter size of thoracic cavity
where does air flow from?
- region of higher pressure to lower pressure
- it’ll flow until pressure in lungs equals atmospheric pressure
how is air flow accomplished?
- inspiration(movement of air into lungs)
- expiration (movement of air out of lungs)
inspiration
- contraction of diaphragm flattens/lowers dome
- contraction of external intercostals elevation of ribs (ribs move up & out)
expiration components
- passive elastic recoil (muscles relax)
- forced expiration
passive elastic recoil
- relaxation of skeletal muscle of diaphragm (it rises)
- relaxation of internal intercostals (moves down and inward)
- results in dec vertical dimension of thoracic cavity (in pressure and air moves out)
forced expiration
- abdominal muscles contract
- pushes organs and diaphragm upward further
- dec. size of thoracic cavity to fore more air out
what controls breathing?
- nervous system
- peripheral chemoreceptors
nervous system controlling breathing function
- respiratory centers in brainstem (pons and medulla)
- hypothalamus sends input to ^
- CNS & PNS motor neurons control contraction of diaphragm & intercostal muscles
- baroreceptors of lung respond to pressure charges, stretch
peripheral chemoreceptors
- carotid body (near bifurcation of common carotid)
- aortic bodies (aortic arch)
- -> response to changes in pH (due to CO2 levels)
- ->CN IX and X transmit message to brainstem
