Lecture 2

Question 1

properties of lung making it ideal for gas exchange

Answer 1

millions of alveoli
large surface area for increase gas exchange
extremely thin for fast diffusion

Question 2

Type 1 and 2 pneumocytes

Answer 2

type 1:
gas exchange
non-replicating
surceptable to toxin

type 2:
no gas exchange
replicates into types 1 and 2
produce surfactin 
2x more than type 1

Question 3

Spirometer tracing values

not known?

Answer 3

• inspiratory reserve (forced inspiratory volume)
• tidal volume (normal breathe)
• expiratory volume (forced expiratory volume)
• vital capacity (full breathe in and out)
• inspiratory capacity (insp + tidal)
• expiratory capacity (ex + tidal)

not known:
residual (air remaining in lung)
total lung capacity (vital capacity)

Question 4

Itpp on o2 delivery

Answer 4

alosteric effector

• lowers o2 affinity, more released to muscles
• increase P50

normalizes and even improves exercise deficiency (in ventilation or cardiovascular problems)

(oxygen dissociation curve)

Question 5

HbA2

Answer 5

2nd form of adult hemoglobin
2 alpha 2 delta
2-3% total adult hemoglobin

Question 6

Andrew-Minneapolis Hemoglobin mutation

Answer 6

Hb higher affinity for O2
less O2 released to tissue
- exercise deficiency

Question 7

Vital capacity

Answer 7

volume of full inspiration and expiration

- doesn’t include air that remains in lung (residual capacity

Question 8

control of ventilation

- must be 3 things

Answer 8

automatic (sleeping)
adaptable to needs (exercise/environment)
subject to voluntary control (voice, coughing)

Question 9

costal diaphragm

Answer 9

attached to ribs
contracts down to lower and expand ribs to decrease plural pressure
attached to crural diaphragm (spine) via central tendon

Question 10

pneumocyte

Answer 10

cells lining the alveoli
type 1 (gas exchange)
type 2 (secrete surfactin)

Question 11

surfactan

Answer 11

recreated by type 2 pneumocytes

decrease surface tension of alveoli preventing collapse

Question 12

Uniques features of diaphragm (5)

Answer 12

skeletal muscle
doesn't cross a joint
constantly active
fast atrophy (<12hrs)
no muscle spindles (proprioception)

2 parts - costal and crural

Question 13

Transdiaphragmatic Pressure

Answer 13

Pdi = Pab(+) - Pes(-)

Question 14

Duty Cycle

Answer 14

Ti / (Ti + Te)

• 30%–40%
• won’t change

Question 15

Switches breathing on

Answer 15

apneustic area

- in pons

Question 16

switches breathing off

Answer 16

pneumotoxic area

- in pons

Question 17

Respiration stimulated by

Answer 17

CO2

not o2

Question 18

Rhythmicity area

Answer 18

dorsal nucleus

• inspiration
• normal and heavy breathing

ventral nucleus

• expiration
• heavy breathing only

Question 19

Respiratory Alternans

Answer 19

alternating workload between different inspiratory muscles

• diaphragm main
• 12 respiratory muscles total

Question 20

transdiaphragmatic pressure proportional to..

Answer 20

tidal volume (Vt)

output / input) = (pdi / phr
- when low creates concern

Question 21

Holding breathe hurts - increase PaCO2

• breathe out releases pain, although CO2 hasn’t yet changed
• why?

Answer 21

pain to promote breathing

- limb muscle/ joint receptors sense movement of breathing, pain gone because breathing has been initiated