Respiratory Phys II Flashcards
What is the function of type I alvelolar cells (what % of all)
95% of the alveolar surface
-The exchange of o2 and co2 occurs thru its cell membranes
What is the function of type II alvelor cells (what % of all)
5%
-can synthesize, store and release surfactant
What is the function of alveolar macrophage (dust cell)
utalizes phagocytosis to capture any foriegn particles and infectious microorganisms in the airway
What is the layers of the respiratory tract from surface to in (6)
- Fluid containing surfacant
- Alvelolar epithelium
- Epithelial basement layer
- Interstitial space
- capillary basement membrane
- Capillary endothelial membrane
What are the 4 factors that infulence gas exchange across the membrane
- surface area (affected by emphysema)
- Thickness of respiratory membrane
- Partial pressure of o2, co2
- relation bw ventilation + perfusion
What are the 2 ways o2 is transported (+%s)
Chemical form- binding to hemoglobin 98.5%
Physical for- dissolved in plasma (1.5%)
What factors decrease affinity of Hb to O2 at tissues (promoting release; 4)
- blood pco2
- blood acidity
- blood temp
- conc of 2,3 DPG in RBC
What is Bohrs effect
effect of pco2 and H+ on Hb dissociation curve.
What does a shift to the left of the dissasosian curve mean
increased affinity of Hb to O2 leading to increase % Hb saturation ad Hb retains O2
What does a shift to the right of the disasosian curve mean
decreased affinity of hb to O2 leading to increased o2 release
(decreased PH, Increased DPG, Temp)
During exercise what happens to the curve
Curve shifts to right
increased temp PCo2 and H+ occurs at tissues the Hb affinity for o2 is decreased enhancing release
How is CO2 transported in the blood (2)
- physically disolved
2. Chemically combined (in Hb/plasma or bicarbonate)
What does crbon monoxide poisoning contribute to
affinity bw Hb and CO is 230x stronger
-Prevents the Hb from binding to O2 shifting curve to left and preventing O2 releae
tidal volume
vol of air inspired + expired during normal breathing
Insiratory reserve volum and expiratory reserve volum
inspiratory- amount of air insired forcefully after normal inhale
Expir- amount of air forcefully expired after expiration of normal
Residual volume
- min volume of air in lungs after a max expiration
Inspiratory capacity
max volume inhaled (TV +Inpiratory reserve)
Functional residual capacity
volume of air left after normal expiration
Vital capacity
max volume of air that can be expired following max inspiration (Inspiratory capacity + expiratory reserve capacitY)
What is minute resoiratory volume vs alveolar ventilation per min
minute- amount of air moved into respiratory passages each min
Alveolar ventilation- Total vol of air entering alveoli and gas exchange areas each min
What is breathing rythm generated by
Pre Botzinger complex (in medulla)
What is the hering breur reflex
activated during inspiration when there is too much stretch of the lungs
-inhibtits inspiration
How does the cough relex work
iratating substance sensed in bronchi + trachia, signal pass along vagus nerve to medulla
How does the sneeze reflex work
iratating substance sensed, signal conducted along trigeminal n to the medulla
What 3 things can influece level of pulmonary ventilation
- rise in pCO2
- rise in H+
- Drop in PO2
What are the 2 respiratory chemoreceptors and where are they found
peripheral- Carotid and aortic bodies
Central- Medulla oblongata
How are central chemoreceptors stimed
Stimed only by rise in blood CO2 (only thing that can cross bbb)
-causes H+ increase in CSF which stims central chemo
How are peripheral chemorectors stimed
stimed by increased in pCO2, H+ and by decrease in PO2
