Respiratory Phys II

Question 1

What is the function of type I alvelolar cells (what % of all)

Answer 1

95% of the alveolar surface

-The exchange of o2 and co2 occurs thru its cell membranes

Question 2

What is the function of type II alvelor cells (what % of all)

Answer 2

5%

-can synthesize, store and release surfactant

Question 3

What is the function of alveolar macrophage (dust cell)

Answer 3

utalizes phagocytosis to capture any foriegn particles and infectious microorganisms in the airway

Question 4

What is the layers of the respiratory tract from surface to in (6)

Answer 4

1. Fluid containing surfacant
2. Alvelolar epithelium
3. Epithelial basement layer
4. Interstitial space
5. capillary basement membrane
6. Capillary endothelial membrane

Question 5

What are the 4 factors that infulence gas exchange across the membrane

Answer 5

1. surface area (affected by emphysema)
2. Thickness of respiratory membrane
3. Partial pressure of o2, co2
4. relation bw ventilation + perfusion

Question 6

What are the 2 ways o2 is transported (+%s)

Answer 6

Chemical form- binding to hemoglobin 98.5%

Physical for- dissolved in plasma (1.5%)

Question 7

What factors decrease affinity of Hb to O2 at tissues (promoting release; 4)

Answer 7

1. blood pco2
2. blood acidity
3. blood temp
4. conc of 2,3 DPG in RBC

Question 8

What is Bohrs effect

Answer 8

effect of pco2 and H+ on Hb dissociation curve.

Question 9

What does a shift to the left of the dissasosian curve mean

Answer 9

increased affinity of Hb to O2 leading to increase % Hb saturation ad Hb retains O2

Question 10

What does a shift to the right of the disasosian curve mean

Answer 10

decreased affinity of hb to O2 leading to increased o2 release

(decreased PH, Increased DPG, Temp)

Question 11

During exercise what happens to the curve

Answer 11

Curve shifts to right

increased temp PCo2 and H+ occurs at tissues the Hb affinity for o2 is decreased enhancing release

Question 12

How is CO2 transported in the blood (2)

Answer 12

1. physically disolved

2. Chemically combined (in Hb/plasma or bicarbonate)

Question 13

What does crbon monoxide poisoning contribute to

Answer 13

affinity bw Hb and CO is 230x stronger

-Prevents the Hb from binding to O2 shifting curve to left and preventing O2 releae

Question 14

tidal volume

Answer 14

vol of air inspired + expired during normal breathing

Question 15

Insiratory reserve volum and expiratory reserve volum

Answer 15

inspiratory- amount of air insired forcefully after normal inhale

Expir- amount of air forcefully expired after expiration of normal

Question 16

Residual volume

Answer 16

• min volume of air in lungs after a max expiration

Question 17

Inspiratory capacity

Answer 17

max volume inhaled (TV +Inpiratory reserve)

Question 18

Functional residual capacity

Answer 18

volume of air left after normal expiration

Question 19

Vital capacity

Answer 19

max volume of air that can be expired following max inspiration (Inspiratory capacity + expiratory reserve capacitY)

Question 20

What is minute resoiratory volume vs alveolar ventilation per min

Answer 20

minute- amount of air moved into respiratory passages each min

Alveolar ventilation- Total vol of air entering alveoli and gas exchange areas each min

Question 21

What is breathing rythm generated by

Answer 21

Pre Botzinger complex (in medulla)

Question 22

What is the hering breur reflex

Answer 22

activated during inspiration when there is too much stretch of the lungs

-inhibtits inspiration

Question 23

How does the cough relex work

Answer 23

iratating substance sensed in bronchi + trachia, signal pass along vagus nerve to medulla

Question 24

How does the sneeze reflex work

Answer 24

iratating substance sensed, signal conducted along trigeminal n to the medulla

Question 25

What 3 things can influece level of pulmonary ventilation

Answer 25

• rise in pCO2
• rise in H+
• Drop in PO2

Question 26

What are the 2 respiratory chemoreceptors and where are they found

Answer 26

peripheral- Carotid and aortic bodies

Central- Medulla oblongata

Question 27

How are central chemoreceptors stimed

Answer 27

Stimed only by rise in blood CO2 (only thing that can cross bbb)
-causes H+ increase in CSF which stims central chemo

Question 28

How are peripheral chemorectors stimed

Answer 28

stimed by increased in pCO2, H+ and by decrease in PO2