resp 2

Question 1

what is the similar aspects of flow between the blood flow and respiratory air flow?

Answer 1

-mainly the pressure gradients created to cause flow
-both are fluids
-blood pressure and atmospheric pressure are reported in mm Hg

Question 2

what are fluids?

Answer 2

-a substance that continually deforms (flows) under an applied shear stress (gas, liquid)

Question 3

what is cm H2O and normal sea level atmospheric pressure?

Answer 3

cm H2O, where 1 mm Hg=1.36 cm H2O or kPa when 760mm Hg-101.325 kPa
-normal sea level atmospheric pressure is considered to be 760 mm Hg but is usually set to 0cm H2O or mm Hg by respiratory physiologists

Question 4

what is Daltons law?

Answer 4

the total pressure exerted by a mixture of gases is the sum of the pressure exerted by each gas
-also dependent on humidity (water vapour) of the air
-the pressure exerted by one has is known as its partial pressure (we are interested in PO2 and PCO2 specifically)

Question 5

what is the mixture of gases in atmospheric air?

Answer 5

Question 6

example of how to calculate partial pressure

Answer 6

Question 7

air moves by ____________

Answer 7

BULK FLOW: from a region of high pressure to low pressure described by

Question 8

what are the relevant pressures?

Answer 8

-alveolar pressure: Palv
-atmospheric pressure: Patm (set to 0)

Question 9

what does boyle’s law help explain?

Answer 9

-described pressure-volume relationships
-helps explain how a change in lung volume results in a change in lung pressure driving the bulk flow of air

Question 10

how does boyle’s law relate to the volume of the alveoli?

Answer 10

during inspiration we make the volume of out alveoli larger resulting in a drop in pressure below atmospheric pressure resulting in air flow from the atmosphere into our alveoli

Question 11

what is ventilation (breathing)?

Answer 11

-is the bulk flow exchange of air between the atmosphere and the alveoli
-a single respiratory cycle consists of a single inspiration followed by an inspiration
-lung volumes change during

Question 12

what is a spirometer?

Answer 12

Question 13

what is tidal volume (TV)?

Answer 13

-total ventilation during rest represents the product of tidal volume and frequency of breaths

Question 14

what is the total pulmonary ventilation?

Answer 14

TV x frequency of breaths

Question 15

what are the four primary volumes that do not overlap?

Answer 15

1. tidal volume
2. inspiratory reserve volume
3. expiratory reserve volume
4. residual volume

Question 16

what are the two important functions of lung volumes?

Answer 16

-prevents airway collapse, after a collapse it takes an unusually large pressure to re-inflate it
-it allows continuous exchange of gases

Question 17

what is inspiratory reserve volume (IRV)?

Answer 17

-the additional air that could still be inspired after quiet inspiration is IRV

Question 18

what is expiratory reserve volume (ERV)?

Answer 18

-at the end of quiet expiration, the volume of air that still remains within the lungs that can be expired is known as the ERV

Question 19

what is residual volume?

Answer 19

-even with maximal expiratory effort, air remains in the lungs
-cannot be measured with spirometer

Question 20

graph of a spirometer tracing showing lung volumes and capacities

Answer 20

Question 21

what are the four primary volumes for lung capacity?

Answer 21

1. total lung capacity
2. functional residual capacity
3. inspiratory capacity
4. vital capacity

Question 22

what is total lung capacity?

Answer 22

-the sum of all 4 volumes

Question 23

what is functional residual capacity?

Answer 23

-the capacity of air remaining in the lungs after quiet expiration
-sum of ERV and RV

Question 24

what is inspiratory capacity?

Answer 24

-the sum of IRV and TV
-representing the maximal amount of air that one can inspire after quiet expiration

Question 25

what is vital capacity?

Answer 25

-the sum of IRV, TV and ERV representing the maximal achievable air moved with a single breath

Question 26

what is a pulmonary function test?

Answer 26

-involves testing an individuals forced vital capacity (FVC) and comparing it to their forced expired volume in one second (FEV1)

Question 27

how is obstructive and restrictive shown using pulmonary function test?

Answer 27

-low initial FVC indicative of restrictive pulmonary disease (decrease in lung compliance)
-FEV1 is normally 80% of vital capacity
-below 80% indicative of obstructive pulmonary disease (increased resistance)

Question 28

when does inspiration occur?

Answer 28

when alveolar pressure decreases

Question 29

how do we change alveolar pressure?

Answer 29

-according to boyle’s law, an increase in volume will cause a decrease in pressure
-we use our inspiratory muscles (skeletal) to increase the volume of alveoli, resulting in a decrease in pressure
-60-75% of inspiratory volume change due to diaphragm

Question 30

what contributes to inspiration volume change?

Answer 30

-60-75% of inspiratory volume change due to diaphragm
-movements of the rib cage accounts for the rest (25-40%)

Question 31

how does the ribcage move for inspiration?

Answer 31

-external intercostals of upper ribs and scalenes attached to sternum cause “pump handle” motion
-external intercostals in lower ribs create “bucket handle” motion

Question 32

graph of intercostals

Answer 32

Question 33

when does expiration occurs?

Answer 33

-when alveolar pressure increases
-quiet expiration is passive (relaxation of the inspiratory muscles)