The Respiratory System

Question 1

Conducting zone

Answer 1

• series of tubes through which gases travel,

- contain smooth muscle.

Question 2

Respiratory zone

Answer 2

• participates in gas exchange
• made up of only the alveoli and the respiratory bronchioles/ alveolar ducts.
• no smooth muscle present.

Question 3

Vibrissae

Answer 3

Nasal hairs

Question 4

Larynx

Answer 4

pathway for air

Question 5

Glottis

Answer 5

opening of larynx

Question 6

Epiglottis

Answer 6

covering flap to the opening

Question 7

Order of air travel

Answer 7

Nares → Nasal cavity → pharynx → Larynx → Trachea → Bronchi → Lungs

Question 8

Inhalation

Answer 8

• Based on “negative-pressure breathing”
  - Diaphragm flattening + external intercostal muscles expansion/flexion → expand thoracic cavity (intrathoracic volume)
  - Boyle’s law: increase in volume → decrease in pressure
  - Decrease in intrapleural pressure → lung expansion → lung pressure decrease → air comes into lungs due to higher atmospheric pressure outside

Question 9

Exhalation

Answer 9

• External Intercostal muscle + diaphragm relax → chest cavity volume ↓ → intrapleural pressure increase → lung air exhalation.
  - Internal intercostal muscle + abdominal muscles speed the process during exercise.
  - Lungs are indirectly connected to chest wall through pleurae.

Question 10

Spirometer

Answer 10

measures lung capacities and volumes but not residual volume.

Question 11

TLC (Total lung capacity)

Answer 11

maximum amount of air in lungs

Question 12

RV (Residual Volume)

Answer 12

Minimum amount left in lungs

Question 13

VC (Vital Capacity):

Answer 13

difference between RV and TLC OR addition of Tidal Volume +Expiratory reserve +Inspiratory Reserve

Question 14

TV (Tidal Volume)

Answer 14

amount passively inhaled or exhaled

Question 15

ERV (Expiratory reserve volume)

Answer 15

First deep breath out

Question 16

IRV (Inspiratory reserve volume)

Answer 16

First deep breath in

Question 17

Acidemia( ↑ blood [H+] )

Answer 17

• Decrease through speeding up respiration rate/ hyperventilation to remove extra CO2
  - A shift that generates more CO2 will increase respiration rate.

Question 18

Alkalemia ( ↓blood [H+])

Answer 18

• increase through slowing down respiration rate to keep more CO2

Question 19

• Control of pH

Answer 19

• Using bicarbonate buffer system to balance pH

- CO2 + H2O → H2CO3 → H + HCO3

Question 20

During exhalation the pressure in the lungs ______

Answer 20

increases and the intrapleural pressure decreases.

Question 21

purpose cilia in the respiratory track

Answer 21

Remove mucus.

Question 22

Regulation of breathing by ventilation center in the medulla oblongata.

Answer 22

• Nerves in this region contain chemoreceptors that respond to increased Carbon dioxide and decreased oxygen pressure
  - Hypercapnia and hypoxemia results in increased respiration rate

Question 23

Regulation of breathing by cerebrum

Answer 23

• We can willingly adjust rate

- may lead to hyper- or hypoventilation that will be overridden by medulla oblongata.

Question 24

if medulla neurons stop responding to increased carbon dioxide levels the what would stimulate the respiratory drive?

Answer 24

Decreased O2

Question 25

muscle actions during inhalation

Answer 25

External intercostal muscles flex and diaphragm contracts.