midterm 2

Question 1

stretch Rc

Answer 1

slowly adapting lung stretch Rc

via vagus nerve can go back and inhibit inspiration

Question 2

irritant Rc

Answer 2

constrict airway, cough

epithelial layer

Question 3

J Rc

Answer 3

jextacapillary (lung tissue)

Question 4

C- fibres

Answer 4

slow firing pain Rc

bronchoconstriction, mucous secretion and rapid shallow breathing (keep foreign out)

Question 5

upper airway Rc

Answer 5

cause sneeze/ cough

Question 6

joint and muscle Rc

Answer 6

increase ventilation

Question 7

arterial BaroRc

Answer 7

decrease MAP sensed and increase ventilation and HR

Question 8

pain and temp Rc

Answer 8

increase ventilation to react to pain

Question 9

Bitter Rc

Answer 9

constriction of airway

related to asthma

Question 10

ficks law

Answer 10

Vgas proportional to A/T x D x delta P

Question 11

clinical implications of Ficks Law

Answer 11

1. surface area: emphysema, mucous, cancer, aging, atelectasis (lung collapse)
2. P gradient: altitude, increase Vd (deadspace) from cancer, and decrease VA (alveolar ventilation) from drugs
3. thickness of alveolar membrane: increase fluid or mucous (pneumonia/inflammation), IPF and COPD

Question 12

perfusion limited

Answer 12

when P1 = P2

Question 13

diffusion limited

Answer 13

when P1 does not = P2 bad cause don’t become fully saturated (pick up enough O2)

Question 14

recruitment

Answer 14

open all capillaries that were collapsed (with increase arterial pressure or venous pressure get distension)

Question 15

distension

Answer 15

open wider the ones that were open already

Question 16

circulatory function of lung

Answer 16

1. gas exchange
2. clear bl clots
3. immune
4. stem cells
5. metabolism of vast active subs. (Inactivation–> NE/epi, brady kinin, serotonin, PGs. Activation–> AI –> AII 50x as a VC)

Question 17

respiratory failure

Answer 17

inability to sustain expected level of Pr (force) production (apnea)

Question 18

ventilatory failure

Answer 18

alveolar ventilation insufficient to eliminate CO2 therefore hypercapnia (pCO2> 50)

Question 19

central failure

Answer 19

decrease central neural output (despite adequate or increased stimulation)

Question 20

neuromuscular transmission failure

Answer 20

impaired transmission of AP across NMJ

Question 21

peripheral muscle failure

Answer 21

impaired output

Question 22

fatigue

Answer 22

loss in capacity for developing force and/ or velocity muscle, resulting from muscle activity under load and reversible by rest (RECOVERY)

1. weakness is not reversible by rest
2. attributed to muscle not nervous system

Question 23

pathway for failure

Answer 23

brain–> spinal cord –> peripheral nerve

• -> NMJ
• -> muscle cell membrane–> transverse tubules–> Ca2+ release –> cross bridge formation