Ventilation

Question 1

airflow is governed by

Answer 1

the same principles of flow, pressure, and resistance that govern blood flow

Question 2

atmospheric pressure drives

Answer 2

respiration

Question 3

intrapulmonary pressure is

Answer 3

the pressure within the alveoli, also reffered to as alveolar pressure

Question 4

direction that air flows depends on

Answer 4

the gradient between atmospheric pressure and intrapulmonary pressure

Question 5

Boyle’s Law

Answer 5

states that the pressure of a gas in a closed container is inversely proportional to the volume of its container, at a constant temperature

Question 6

Charles’ Law

Answer 6

states that the volume of a gas in a closed container is directly proportional to its absolute temperature, at a constant pressure
ex. basketball in cold

Question 7

Dalton’s Law

Answer 7

states that each gas in a mixture exerts a partial pressure (p) independent of the partial pressures of the other gases in the mixture

Question 8

Henry’s Law

Answer 8

states that the amount of gas that dissolves in a liquid is directly proportional to its solubility in that liquid and its partial pressure

Question 9

for air flow into lungs,

Answer 9

intrapulmonary pressure must be lower than atmospheric air pressure and this is accomplished by increasing the volume of the lungs
-Boyles law is important here.

Question 10

when diaphragm and external intercostal muscles contract,

Answer 10

volume of the thoracic cavity increases

Question 11

contraction of the diaphragm

Answer 11

increases the volume of the thoracic cavity from top to bottom

Question 12

contraction of the external intercostal muscles

Answer 12

pulls the ribs upward and outward to increase volume of thoracic cavity from front to back

Question 13

because the visceral and parietal pleurae adhere strongly to one another,

Answer 13

lung volume will expand as the volume of the thoracic cavity expands

Question 14

increasing the volume of the lungs causes

Answer 14

a drop in intrapulmonary pressure

• so atmospheric air pressure is now greater than intrapulmonary pressure, so air rushes into lungs along pressure gradient
• Boyles law

Question 15

normal inspiration is

Answer 15

an active process

Question 16

normal inspiration can be increased by

Answer 16

contracting additional chest muscles, which further enlarges volume of thoracic cavity and decreases intrapulmonary pressure

Question 17

inspiration

Answer 17

air flow into lungs

Question 18

expiration

Answer 18

air flow out of lungs

Question 19

for air flow out of lungs,

Answer 19

intrapulmonary pressure must be higher than atmospheric air pressure and this is accomplished by decreasing the volume of the lungs

Question 20

when diaphragm and external intercostal muscles relax,

Answer 20

volume of the thoracic cavity decreases

-volume of the thoracic cavity returns to normal, which forces lungs to become smaller

Question 21

decreasing the volume of the lungs cause

Answer 21

a rise in intrapulmonary pressure (boyles law)
-intrapulmonary pressure is now greater than atmospheric air pressure, so air rushes out of lungs along pressure gradient

Question 22

normal expiration during quiet breathing is

Answer 22

a passive process that can be made active by contracting abdominal and internal muscles to compress the thoracic cavity

Question 23

resistance affects

Answer 23

airflow

Question 24

pulmonary compliance

Answer 24

the ease with which the lungs expand relative to a change in the pressure gradient between the atmosphere and the lungs

Question 25

high compliance means that

Answer 25

the lungs will expand easily, low compliance means lungs will resist expansion

Question 26

degenerative lung diseases

Answer 26

decrease compliance (tuberculosis)

Question 27

____________ controls resistance

Answer 27

diameter of the bronchioles

Question 28

bronchoconstriction can be triggered by

Answer 28

airborne irratants, cold air, parasympathetic innervation, or histamines

Question 29

bronchodilation can be triggered by

Answer 29

sympathetic innervationor epinephrine

Question 30

________ must be overcome for lungs to expand during each inspiration

Answer 30

alveolar surface tension

Question 31

surfactant

Answer 31

a mixture of phopholipids and lipoproteins that lowers surface tension to reduce tendency of alveoli to collapse and adhere to each other during expiration

Question 32

surfactant deficiency in premature babies leads to

Answer 32

respiratory distress syndrome, causes alveoli to collapse at end of each expiration

Question 33

some air always remains in non-respiratory airways as

Answer 33

anatomic dead space volume

Question 34

a normal, healthy adult averages ________ per minute

Answer 34

12 quiet breathing cycles

Question 35

a spirometer measures

Answer 35

volume of air exchanged during a breathing cycle

Question 36

spirometry is used to

Answer 36

measure pulmonary function

Question 37

restricitve lung disorders

Answer 37

reduce pulmonary compliance; limits inflation of lungs, which causes reduction in vital capacity

Question 38

obstructive lung disorders

Answer 38

interfere with airflow, which makes it harder to exhale

Question 39

tital volume

Answer 39

the volume of air exchanged during one breathing cycle | -about 500 mL

Question 40

inspiratory reserve volume

Answer 40

the volume of air that can be inhaled in excess of tidal volume with maximal effort

Question 41

expiratory reserve volume

Answer 41

the volume of air that can be exhaled in excess of tidal volume with maximal effort

Question 42

residual volume

Answer 42

the volume of air that remains in lungs after maximum exhalation and it keeps the alveoli open

Question 43

vital capacity

Answer 43

the maximum volume of air that can be moved into and out of the lungs during one forced breathing cycle

Question 44

inspiratory capacity

Answer 44

the maximum volume of air tha can be inhaled after a normal expiration

Question 45

functional residual capacity

Answer 45

the resting lung volume

Question 46

total lung capacity

Answer 46

the sume of all pulmonary volumes

Question 47

the basic rhythm of breathing is controlled by

Answer 47

neurons in the medulla oblongata and pons

Question 48

inspiratory and expiratory neurons

Answer 48

travel down the spinal cord to the phrenic nerve and intercostal nerves to innervate diaphragm and intercostal muscles

Question 49

the medullary rhythmicity area has

Answer 49

ventral (VRG) and dorsal (DRG) respiratory groups

Question 50

inspiratory neurons from the ventral respiratory group

Answer 50

send impulses to stimulate muscles needed for inspiration

Question 51

after about 2 seconds the impulses from the inspiratory neurons

Answer 51

cease and inspiratory muscles relax, which allows passive expiration for about 3 seconds

Question 52

expiratory neurons from the ventral respiratory group

Answer 52

fire and output stops

Question 53

dorsal respiratory group

Answer 53

integrates input from stretch receptors and chemoreceptors

Question 54

the pons contains a pontine respiratory group to

Answer 54

modify the rate and depth of breathing that is established by the ventral respiratory group

Question 55

respiratory centers in the brainstem

Answer 55

receive input from a variety of sources

Question 56

input from the limbic system and hypothalamus

Answer 56

allows pain/emotion to affect respiration

Question 57

input from chemoreceptors

Answer 57

adjust breathing to maintain homeostasis

Question 58

stretch receptors in the bronchial tree and visceral peura

Answer 58

monitor lung inflation

Question 59

Hering-Breuer reflex is

Answer 59

a protective mechanism that inhibits inspiratory neurons to prevent overinflation of lungs

Question 60

voluntary control over ventilation originates in

Answer 60

the frontal lobe of the cerebral cortex

Question 61

Ondine's curse

Answer 61

can be caused from brainstem damage from poliomyelitis or from an accident automatic respiratory functions are disabled and individual must constantly remember to take each breath. he/she cannot go to sleep without ventilator