Lec 24 Flashcards
air flow pathway
1- nasal cavity
2- pharynx
3- larynx
4- trachea
5- primary bronchi
6- many smaller bronchi
7- bronchioles
8- terminal bronchioles
9- alveoli
10- air Sachs
upper respiratory system is
nasal cavity to larynx
lower respiratory system
trachea to alveoli
function of respiratory system
1- gas exchange
2- homeostatic regulaton of Ph: CO2 effect
3- condiotioning inspired air: warming, add water vapour
4- protection
5- vocalization
External respiration
Exchange I: atmosphere to lung
Exchange II: lung t blood
Transport of gases in blood
Exchange III: blood to cells
Lung to blood tissue exchange and important factors
alveoli to exchange epithelium
– fix law
– very thin capillaries
inspiration
air moves into lungs
expiration
air move out of lungs
ventilation
moving respiratory medium over respiratory surface
Which lung is bigger
right lung is slightly bigger
Left pleural cavity function
stick lungs to rib cage
Muscle of inspiration in normal breathing
1- external intercostals
2- diaphragm
external intercostal movement in normal breathing
up and out
diaphragm movement in normal breathing
down
forceful inspiration, extra muscles
1- sternocleido-mastoids
2- Scalenes
forceful expiration, extra muscles
1- internal intercostals
2- abdominal muscles
Lung intrapleural fluid
parietal pleura vs visceral pleura
parietal pleura function
stick to thoracic cavity wall
visceral pleura function
surround elestic tissue of lung
Intrapleural fluid
1-watery
2- cannot separte parietal/visceral
when lungs collapsed
if air enter to intrapleural space
pleural membrane
1- visceral pleura
2- fluid intrapleural space
3- parietal pleura
pleural sac function
1- protect lung
2- lubricate membrane and slide against each other
3- stick lungs tightly to the thoracic wll
4- important for keeping the lungs inflated
Main role of the aairways
1- filter out foreign
2- warm air to body temperature
3- add water vapour = maximize exchange
cartilage ring tissue
connective tissue
can’t vasoconstrict/vasodilate
primary bronchus divide – more times to reach alveoli
22
bronchiole tissue
no connective tissue–are adjustable
bronchoconstriction
increase resistance
lower air flow
bronchodilation
decrease resistance
increase air flow
cystic fibrosis
lost watery layer
common cause of increased airway resistance
mucus build up
obstructive lung disease —- airway resistance
increase
cross-sectional area of trachea
2.5 cm^2
cross-scetionaal area of bronchioles
5*10^3 cm^2
most of resistance to flow is in
trachea
reistance is very low in
bronchioles
bronchodilation
decreased resistance to air flow
1- paracrine response to CO2
2- SNS response
Gs – AC – cAMP – PKA
bronchoconstriction
increased resistance to air flow
1- paracrine response to histamine released in an immune response
2- PNS response
Gq – PLC – IP3 – IP3R – Ca ion
alveolar and capillaries key important factors
1- high surface area
2- low distance
3- concentration gradient
Alveoli
1- bulk of lung tissue
2- each alveolus is made of one layer of epithelial cells
two type of alveolar epithelial cells
1- type I alveolar cells
2- type II alveolar cells
type I alveolar cell
-gas exchange
-95% of alveolar surface
type II alveolar cell
make and secrete surfactant
surfactant type
watery, lipidy
surfactant caused lung to
inflate
