respiratory - topic 3

Question 1

what is typical atmospheric pressure?

Answer 1

760 mmHg

Question 2

how do you calculate flow?

Answer 2

( Palv - Patm ) / R

Question 3

what is Ptp?

Answer 3

transpulmonary pressure = Palv - Patm

Question 4

what happens to the pressure relationships when you are mid inspiration?

Answer 4

inspiratory muscle force > elastic recoil force
P alv = -1 (lower than Patm)
Ptp = 5, Pip = -6

Question 5

what happens to the pressure relationships when you are mid expiration?

Answer 5

elastic recoil force > inspiratory muscle force
Palv = 1 (higher than Patm)
Ptp = 6, Pip = -5

Question 6

what happens to the pressure relationships after inspiration?

Answer 6

balance !
(Ptp = 7 and Pip = -7

Question 7

what happens to the pressure relationships after expiration?

Answer 7

balance !
Ptp = 4 and Pip = -4)

Question 8

what is a pneumothorax?

Answer 8

when the chest wall is pierced and Ptp becomes Patm, causes lung collapse and CW to spring out

Question 9

what is the word for lung collapse?

Answer 9

atelectasis

Question 10

how do you calculate minute ventilation?

Answer 10

Vt (tidal volume) x f (number of breaths per minute)

Question 11

how do you calculate alveolar ventilation?

Answer 11

Vt (tidal volume) - Vd (dead space) x f (number of breaths per minute)

Question 12

what are the two types of dead space?

Answer 12

anatomic dead space - volume in conducting airway (150ml)
physiological dead space - fucked up alveoli