export_resp 34

Question 1

what causes ventilation/perfusion (V/Q) inequality?

Answer 1

gravity

Question 2

V/Q is ___ in higher lung than in lover

Answer 2

lower

Question 3

PO2 is ___ in higher lung

Answer 3

higher

Question 4

why isn’t PCO2 affected by V/Q inequality?

Answer 4

CO2 has a greater solubility

Question 5

when do pulmonary capillaries reach pO2 of 100?

Answer 5

~25% of length

Question 6

which part of the lungs does most blood flow through?

Answer 6

bottom

Question 7

during exercise it takes ___ time to reach equilibrated PO2 (why?)

Answer 7

more, increased blood flow rate

Question 8

hyperventilation

Answer 8

dec PCO2, inc PO2

Question 9

normal P02 and PCO2

Answer 9

O2- 105mmHg

CO2- 40mmHg

Question 10

hyporventilation

Answer 10

dec PO2, inc PCO2

Question 11

CO2 ___ bronchiols

Answer 11

relaxes

Question 12

pulmonary edema and affects on O2/CO2

Answer 12

fluid in lungs, inc diffusion distance, PO2 dec, PCO2 same (when ventilate to compensate or in sever cases, inc CO2)

Question 13

pulmonary embolism

Answer 13

clots blocking arteries, dec flow to regions, dec PO2, more severe more inc PCO2

Question 14

emphysema

Answer 14

walls of alveoli and caps broken down, inc resistance, dec surface area, PO2 dec, PCO2 inc with severity

Question 15

pulmonary fibrosis

Answer 15

thickening of alveolar walls, inc diffusion distance, dec ventilation bc can’t expand lung, dec PO2, dec PCO2 with severity

Question 16

asthma

Answer 16

narrowed airways, high mucus production, dec ventilation, dec surface area, dec PO2, inc PCO2 with severity

Question 17

fick’s law

Answer 17

V= D*A*(P1-P2)/T
-A= surface area

-T= thickness

D= solubility coeff

Question 18

how is O2 carried in blood?

Answer 18

hemoglobin (4 binding sites/1)

Question 19

resting oxygen consumption

Answer 19

250 ml/min

we hold 1L

Question 20

hemoglobin structure

Answer 20

2 alpha
2 beta

1 heme in each

Question 21

what is PO2 measuring?

Answer 21

O2 disovled in plasma

Question 22

what happens to PO2 in blood?

Answer 22

when PO2 alveoli > PO2 blood, diffuses into plasma, binds to Hb, released when PO2 blood > PO2 tissues

Question 23

what % of O2 is released to tissues?

Answer 23

25

Question 24

what effects Hb saturation curve?

Answer 24

dec pH/inc H+ (right)
inc temp (right)

inc PCO2 (right)

inc 2,3DPG (right)

Question 25

what are DPGs?

Answer 25

- produced by RBCs during anaerobic glycolysis | - produced in response to hypoxia

Question 26

how does CO2 exist in blood?

Answer 26

1) dissolved in plasma (10%) 2) globin-bound (30%) 3) bicarbonate (HCO3-) (60%)

Question 27

CO2/HCO3 equation

Answer 27

CO2+H2O H2CO3 HCO3- + H+

Question 28

enzyme used in carbonic acid eq?

Answer 28

carbonic anhydrase

Question 29

pH is ___ in venous blood than arterial 

Answer 29

lower

Question 30

3 peripheral chemoreceptors

Answer 30

1) aortic 2) carotid 3) axons to medulla oblongata

Question 31

what stimulates chemoreceptors?

Answer 31

dec PO2, dec pH, inc PCO2

Question 32

central chemoreceptors

Answer 32

in brain, measure PCO2 change in inerstitial fluid, go to medulla oblongata

Question 33

how does brain pH change?

Answer 33

blood PCO2 > brain ECF PCO2, CO2 into brain and dec brain pH

Question 34

are central receptors sensitive to PO2 or H+?

Answer 34

NO

Question 35

when does ventilation change start (PO2)? what is responsible for this change?

Answer 35

60 mmHG | peripheral receptors

Question 36

what is responsible for ventilation change (PCO2 and H+)

Answer 36

central and peripheral chemoreceptors

Question 37

what drives ventilation inc during exercise?

Answer 37

pH (lactic acid)

Question 38

where do the peripheral chemoreceptors signal to?

Answer 38

medullary inspiratory center

Question 39

pH of blood is ___ in arterial blood vs venous

Answer 39

higher

Question 40

what is the CO2 buffer in cells?

Answer 40

proteins (globin)

Question 41

what is respiratory acidosis? alkalosis?

Answer 41

inc PCO2, inc H+, dec pH dec PCO2, dec H+, inc pH

Question 42

how does respiration compensate for metabolic acidosis? alkalosis?

Answer 42

hypoventilation (inc CO2, H+) | hyperventilation (dec CO2, H+)

Question 43

venous PO2 PCO2 pH

Answer 43

100mmHg 40mmHG 7.4

Question 44

arterial PO2 PCO2 pH

Answer 44

40mmHg 45mmHg 7.36

Question 45

Pre-Botzinger

Answer 45

pacemaker cells of respiratory center (in medulla oblongata)

Question 46

how does the respiratory center control inhale/exhale?

Answer 46

pre-botzinger --> VRG/DRG --> motor neurons -->diaphragm/intercostals   --> contractions

Question 47

pneumotaxic/apneustic center

Answer 47

in pons, send signals to pacemakers

Question 48

types of inputs to pre-botz?

Answer 48

sensory (PO2, pH, PCO2, stretch, irritants), pons, cortex (voluntary)

Question 49

action potentials cause?

Answer 49

inspiration

Question 50

what causes expiration?

Answer 50

stopping of APs (passive)

Question 51

what changes depth of breaths?

Answer 51

frequency of APs in burst

Question 52

how does gas exchange occur?

Answer 52

diffusion down the pressure gradient

Question 53

gas exchange direction at alveoli

Answer 53

- CO2 into alveoli | - O2 into blood

Question 54

gas exchange at cells

Answer 54

- CO2 into blood | - O2 into cells

Question 55

what does partial pressure measure?

Answer 55

gas concentration in blood

Question 56

what is the pressure of CO2 in the air?

Answer 56

neglegible

Question 57

what determines gas concentration?

Answer 57

solubility and partial pressure

Question 58

what is more soluble, O2 or CO2?

Answer 58

CO2 - 24x

Question 59

what do central chemoreceptors sense?

Answer 59

CO2 in brain