Physiology Book Notes

Question 1

in the airways, sympathetic adrenergic neurons activate ________ on bronchial smooth muscle, leading to their _______ and _______
activated by ______

Answer 1

B2 receptors
Relaxation and dilation
epinephrine

Question 2

in the airways, parasympathetic cholinergic neurons activate _______ receptors, leading to _______ and _______ of airways

Answer 2

muscarinic receptors

contraction and constriction

Question 3

pouchlike evaginations of the walls of the respiratory bronchioles, the alveolar ducts, and the alveolar sacs

Answer 3

alveoli

Question 4

Type __ pneumocytes synthesize pulmonary surfactant

Answer 4

type II pneumocytes

Question 5

changes in pulmonary arteriolar resistance are controlled mainly by

Answer 5

O2, a local factor

Question 6

inspiratory reserve volume

Answer 6

additional volume that can be inspired above tidal volume (~3000mL)

Question 7

expiratory reserve volume

Answer 7

additional volume that can be expired below tidal volume (~1200mL)

Question 8

residual volume

Answer 8

volume of gas remaining in the lungs after a maximal forced expiration (~1200mL)

Question 9

inspiratory capacity

Answer 9

composed of the tidal volume plus the inspiratory reserve volume

Question 10

physiologic dead space

Answer 10

total volume of the lungs that does not participate i ngas exchange
includes anatomic dead space

Question 11

minute ventilation

Answer 11

total rate of air movement into and out of the lungs

Question 12

alveolar ventilation

Answer 12

total rate of air movement into and out of the lungs but correcting for the physiologic dead space

Question 13

the higher the alveolar ventilation, the more ___ is pulled out of the blood and the lower the ____ and ____

Answer 13

CO2

PACO2 and PaCO2

Question 14

if CO2 production doubles, like during strenuous exercise, the ventilation must

Answer 14

also double, sto maintain a constant PACO2

Question 15

when alveolar ventilation is halved, the decrease in PAO2 will be slightly _____ than the increase in PACO2 due to the ______

Answer 15

slightly greater

respiratory exchange ratio of 0.8

Question 16

FEV1 refers to

Answer 16

the volume of air that can be forcibly expired in the first second

Question 17

obstructive lung diseases, like asthma, COPD affect the FEV1/FVC ratio by

Answer 17

lowering both FEV1 and FVC

FEV1 is decreased more - increased RESISTANCE to expiratory air flow

Question 18

restrictive lung diseases, like fibrosis, affect the FEV1/FVC ratio by

Answer 18

lowers but FEV1 and FVC
FVC decreased more
FEV1/FVC ratio will be increased

Question 19

hysteresis accounts for the difference in lung volume during inspiration and expiration: lung volume is ______ during expiration than during inspiration

Answer 19

lung volume is greater during expiratino than during inspiration because compliance is higher during expiration than during inspiration

Question 20

when the volume of the lungs is at FRC, the collapsing pressure of the ____ and the expanding pressure of the ____ equally oppose each other

Answer 20

collapsing pressure of lungs

expandnig pressure of chest wall

Question 21

at volumes less than FRC, the collapsing pressure becomes ____ ____ the expanding pressure

Answer 21

the collapsing pressure becomes less than the expanding pressure
tendency to expand increases
airway pressure is negative

Question 22

at volumes greater than the FRC, the collapsing pressure becomes _____ ____ the expanding pressure

Answer 22

the collapsing pressure becomes greater than the expanding pressure
lung and chest-wall system wants to collapse
airway pressure is positive

Question 23

emphysema is associated with what change in compliance and why

Answer 23

loss of elastic fibers in the lungs, increasing the compliance
decreases collapsing force of lungs, increasing FRC

Question 24

due to their higher FRC, patients with emphysema tend to

Answer 24

breathe at higher lung volumes and have barrel-shaped chests

Question 25

fibrosis is associated with what change in compliance and why

Answer 25

decreases compliance - due to being a restrictive disease
(stiffening of lung tissues)
tendency of lungs to collapse is greater than tendency of chest wall to expand
new lower FRC is established

Question 26

large alveoli have ____ collapsing pressure

small alveoli have ____ collapsing pressure

Answer 26

large have small collapsing while small have high collapsing pressure

Question 27

surfactant has what effect on lung compliance

Answer 27

increases lung compliance, reducing work of expanding the lungs during inspiration

Question 28

surfactant synthesis begins at week

Answer 28

24

Question 29

infants born before 24 weeks will never have

Answer 29

surfactant

Question 30

sites of highest airway resistance in the airways

Answer 30

medium-sized bronchi