A&P Exam 1 Physiology

Question 1

Respiratory System

Answer 1

The structures involved in the exchange of gases between blood and the external environment. Includes:

• lungs
• passageways leading to lungs
• chest structures responsible for movement of air into and out of the lungs.

Question 2

Volume Flow Rate

Answer 2

The rate at which 1 cc of air moves past a point in 1 second. (cc/sec, LPS)

Question 3

Resistance

Answer 3

In aerodynamics, the opposition offered to the flow of air through a system. The ratio of pressure drop across the length of the system to the volume rate of air flow through it.

• R=P/V=cm H20/LPS

Question 4

What does a U-tube manometer measure?

Answer 4

Respiratory pressure in cm H20.

Question 5

Volume

Answer 5

The amount of air in a cavity, measured in cc, mL or L.

Question 6

Capacity

Answer 6

Functional combinations of volumes, measured in cc, mL, or L.

Question 7

Tidal Volume (TV)

Answer 7

Volume of air exchanged in one cycle (inhale & exhale) during quiet breathing.

• 0.5 - 0.75 L

Question 8

Inspiratory Reserve Volume (IRV)

Answer 8

Max. amount of air that can be inhaled after a tidal inspiration.

• 2.5 L

Question 9

Expiratory Reserve Volume (ERV)

Answer 9

AKA Resting Lung Volume. Max. amount of air that can be exhaled following passive tidal expiration.

• 1.0 L

Question 10

Residual Volume (RV)

Answer 10

The amount of air remaining in the lungs after maximum expiration, due to the lungs being stretched.

• 1.1 L

Question 11

“Dead air”

Answer 11

Residual Volume + air remaining in the airway passages.

Question 12

Vital Capacity (VC)

Answer 12

Maximum amount of air that can be inspired after maximum expiration. This is the capacity available for speech.

• VC = IRV + TV + ERV
• 4.0 L

Question 13

Functional Residual Capacity (FRC)

Answer 13

Volume of air remaining after passive exhalation

• FRC = ERV + RV
• 2.1 L

Question 14

Total Lung Capacity (TLC)

Answer 14

Volume of air in lungs and airway after max. inspiration. All of the volumes together.

• TLC = IRV + TV + ERV + RV
• 5.1 L

Question 15

Inspiratory Capacity (IC)

Answer 15

Maximum amount of air that can be inspired from RLV

• IC = TV + IRV
• 3.0 L

Question 16

Pressure

Answer 16

Force per unit of area (cm H2O)

Question 17

Atmospheric Pressure (P_atm)

Answer 17

The pressure on the surface of the earth. A constant that we call 0. We compare everything else to this.

Question 18

Intraoral pressure (P_m)

Answer 18

Pressure in the mouth.

Question 19

Subglottal pressure (P_s)

Answer 19

Pressure below the vocal folds.

Question 20

Alveolar pressure (P_al)

Answer 20

Pressure in the lungs.

Question 21

Intrapleural pressure (P_pl)

Answer 21

Pressure between parietal and visceral pleura. Always negative.

Question 22

Boyle’s Law

Answer 22

The pressure of a gas is inversely proportional to its volume, with temperature constant.

Question 23

Newton’s Law

Answer 23

An unbalanced force acting on any body (solid, liquid, gas) will cause acceleration.

• Air will flow from regions of high to low pressure
• The volume of air flow will be proportional to the difference between the two pressure regions

Question 24

Respiratory pressures at rest

Answer 24

Question 25

Respiratory pressures at inhalation

Answer 25

Question 26

Respiratory pressures at exhalation

Answer 26

Question 27

Alveolar pressure during tidal expiration

Answer 27

+2 cm H₂0

Question 28

Alveolar pressure during tidal inspiration

Answer 28

-2 cm H₂0

Question 29

Lung-Thorax Unit and Resting Lung Volume (RLV)

Answer 29

When lungs and thorax are connected, lungs are somewhat expanded relative to disconnected state, while thorax is somewhat compressed relative to disconnected state. This represents resting volume (RV).

Question 30

Volume, air flow, & pressure relationships during respiration:

Answer 30

Question 31

What happens with intraoral, subglottal and alveolar pressure during speech production?

Answer 31

* When vocal folds are open, P_s = P_m = P_al.  * When vocal folds are closed, the blockage causes an increase in P_s (lungs continue expiration) and a decrease in P_m (near P_atm) * If this increased pressure difference exceeds 3-5 cm H₂0, the vocal folds will be blown open.

Question 32

What percentage of our vital capacity do we use during different types of speech?

Answer 32

* Conversational speech: 35-60% VC * Loud speech: 80% VC * (TV: about 10% VC)

Question 33

Passive Forces: Gravity

Answer 33

Will result in potential energy (energy of position) being converted to kinetic energy (energy of motion). * Pulls ribs back to rest position after inhalation

Question 34

Passive Forces: Elasticity

Answer 34

Lungs are elastic, and expand when rib cage expands. They more they are stretched, the more recoil there is when the muscles that expand the rib cage relax.

Question 35

Relaxation pressure curve

Answer 35

Plots alveolar pressure generated by recoil forces vs. % vital capacity. * At higher VC, greater recoil forces are trying to return the stretched lungs to rest, generating positive pressure * At 38% VC (RLV), P_atm = P_alv produced by recoil forces, so no pressure is generated * At lower VC, the chest wall is attempting to return to rest, generating negative pressure.

Question 36

How does the relaxation pressure curve relate to sustained phonation?

Answer 36

P_alv required is constant. * A: recoil pressures are \> pressure needed, so muscles of inhalation "brake" the thorax to slow air flow * B: P_alv = pressure needed for utterance * C: recoil pressures are \< pressure needed, so muscles of exhalation work to squeeze out extra air and maintain pressure

Question 37

How does the addition of active muscular effort change the relaxation pressure curve?

Answer 37

* Pi = pressure from muscles of inspiration * Pr = pressure from relaxation of musclues of inspiration and expiration * Pe = pressure from muscles of expiration

Question 38

How does the pressure volume relationship change at different levels of speech (soft, normal, loud)?

Answer 38

* 1: for a soft utterance, more inspiratory muscle effort is required and less expiratory muscle effort is required relative to normal (2) * 3: for a loud utterance, less inspiratory muscle effort is required and more expiratory muscle effort is required relative to normal (2)

Question 39

Muscle activity during a sustained utterance

Answer 39

Negative muscular pressure is inspiratory muscle effort; positive muscular pressure is expiratory muscle effort.

Question 40

How does posture (upright vs. supine) affect speech?

Answer 40

* Sitting/standing upright: gravity acts in expiratory direction on rib cage, inspiratory direction on abdomen * Supine: gravity pulls abdomen toward spine and further distends the diaphragm into the thoracic cavity * Neither inspiration nore expiration is assisted * Use accessory muscles

Question 41

How does the timing of respiration differ between quiet breathing and speech breathing?

Answer 41

* Quiet: * 12+ times/minute * expirations slightly \> inspirations * Speech breathing: * frequency of breathing decreases * inspiration more abrupt * expiration lengthened

Question 42

How do passive and active forces work to help us during connected speech?

Answer 42

* Rapid changes in demand for muscle effort. * Pulsatile variations in muscle effort are overlaid on the usual background level of alveolar pressure for steady state utterances.

Question 43

How do changes in compliance affect the relaxation pressure curve?

Answer 43

* Excessive compliance: lungs stretch too far and don't recoil as efficiently. Have to force exhale to reach adequate pressure * Loss of compliance: lungs don't stretch far enough and elastic recoil is increased, which reduces vital capacity. Have to frequently pause during speech to inhale.