physiology: Organisation of the respiratory system Flashcards
General function of respiration
to obtain the 02 thats used for body cells
to get rid of the C02 the cells produce
contains two separate processes
internal respiration - ( oxidation phosphorylation )
external -exchange of 02 and C02 between atmosphere and body tissues
internal respiration
what is it
refers to
cellular respiration
metabolic process in mitochond. , uses 02 and produces C02 while deriving energy from other nutrient molecules
steps of external respiration
pt1
1-ventilation/gas exchange betw atmosphere and alveoli in lungs
2-exchange of 02 and c02 in alveoli in lungs to blood in pulmonary capillaries
steps of external respiration
pt2
3- transport of 02 and c02 by blood between lungs and tissues
4-exchange of 02 and c02 between blood in systemic capillaries and tissue cells
secondary functions
eliminates heat and water
short term regulates pH
assists venous return
helps defends against pathogen in airways
Respiratory airways
upper airways
nasal cavity
oral cavity
pharynx
Airways from pharynx to lungs
larynx
conducting zone
Respiratory zone
Structures of the Conducting Zone
trachea
pri , sec , tri bronchus
bronchioles
terminal bronchioles
trachea:
diameter
length
shape
- 2.5. cm
- 10cm
- c shape cartilage bands for structural rigidity
primary bronchi
divided into
contains
R&L
rings of cartilage
secondary bronchi
right
left
3 ( to the 3 lobes of the right lung)
2
Tertiary Bronchi
20-23 orders of branching
up to 8 mil tubules
Bronchioles
diameter
contains
less than 1 mm
no cart , instead has walls of elastic fibres and smooth muscle to prevent collapsing
Functions of the Conducting Zone
- air passageway
- increase air temp to body temp
- humidify air
Epithelium of the Conducting Zone
goblet cells -secrets mucus and traps foreign particles
ciliated cells -propel the mucus up to the glottis to be swallowed or expelled
process : mucus escalator
Structures of the Respiratory Zone
respiratory bronchioles
alveolar ducts and sacs
alveoli
Function of the Respiratory Zone
exchange of gases between air and blood through diffusion
Epithelium of the Respiratory Zone
respiratory membrane
epithelial cells of alveoli and ‘ ‘’ of capillaries
Alveoli
what
number of
site of gas exchange
300-500 mil : facilitate gas exchange
alveoli also contains
rich blood supply - capillaries form sheet of alveoli
PORES OF KOHN -allows airflow between adjacent alveoli aka Collateral ventilation
3 cells types of alveoli
type I alveolar cells
‘’ II
alveolar macrophages
type I alveolar cells functions
make up alveolar wall , single layer epithelial cells
type II alveolar cells
secrete surfactant
reduces surface tension in alveolar walls
helps prevent alveolar collapse
