UNit 2 Flashcards
Fxn of resp
Pulm ventilation
Transport in o2
Transport out of co2
Regulation of ventilation
Pulmonary ventilation
1) Down and up mvt of diaphragm Inspiration muscles: Ext intercostals scale SCM Scalenes Seratus ant
Expiration: Int intercostals
and Abd recti
What factors determin po2 and pco2 in alveoli
Rate of alv ventilation
Rate transfer of o2 and co2 thru resp membrane
Respiratory zones
zone 1 - no blood flow in all cardiac cycles
zone 2- intermitent blood flow syst p > alv p
diastole p < alv p
zone 3 - cont flow thru all cardiac cycles alv capil > alv air p
Pulmonary circulation
high p low flow - supply trachea and lungs
low p high flow - supply venous blood from body to alv capil
Factors affecting gas diffusion
Solubility of gas Cross sectional area of fluid distance thru diffusing parts M.W of gas Temp of fluid
Difference between alveolar and atm air
1) alveolar air is only partially replaced
2) o2 is constantly absorbed from alv air
3) Co2 is constantly diffusing from pulm blood capil to alv
4) Dry air is hummidified reaching the alveoli
Respiratory membrane
1-fluid lining 2-alv epithel 3-epithel basement membrane 4- thin interstitial space 5-capil basement membrane 6-capil endothel membrane
Factors affecting rate of gas diffusion
1-thickness membrane
2-surface area of memb
3-diffusion coef of gas
4-partial P diff
Respiratory unit
made of resp bronchiol, alv ducts atria and alveoli
Respiratory control
1-dorsal group - NTS inspiration of ramp control
2-ventral group - expiration
3-pneumotaxic center - sup pons - depth of respiration
Hering bruer reflex
Prevents excess lung inflation, detect thru stretch-R in bronchioles and bronchi - transmit thru vagus and dorsal resp group stopping insp ramp
Aortic bodies
arch of aorta - send fibers thru vagus , measure drop in o2
Carotid bodies
c.c artery- send fibers thru hering nerves to glosso nerve - measure drop in o2
What happens when evaporated air enter lungs?
Surface area water evaporates to hummidify it, to prevent alveolar damage
