Respiration

Question 1

What is respiration mechanics? (2)

Answer 1

1) Study of mechanical properties of lung and chest wall

2) Process by which air enters and leaves the lungs

Question 2

What are the basics of breathing? (2)

Answer 2

1) Lungs

Question 3

What other systems interact with the respiratory system? (2)

Answer 3

1) Cardiovascular (pulmonary and peripheral)

2) Muscle system

Question 4

Why is respiratory mechanics important? (3)

Answer 4

1) To understand how lungs work normally and in a diseased state
2) Almost all lung disease affect mechanical properties of lung
3) Death from lung disease usually due to inability to overcome changes in lung and/or chest mechanics

Question 5

Breathing maintains…

Answer 5

blood gas homeostasis (02, CO2, pH)

Question 6

At rest, what is the partial pressure of oxygen and carbon dioxide

Answer 6

P02 =  100+/-2 mmHg
PC02 = 40+/-2 mmHG

Question 7

At rest the exchange values of oxygen and carbon dioxide are

Answer 7

~ 250ml 02/min

~ 200ml 02/min

Question 8

When walking 3mph the exchange values of oxygen and carbon dioxide are

Answer 8

~ 800ml 02/min

~ 750ml C02/min

Question 9

During severe exercise the exchange values of oxygen and carbon dioxide are

Answer 9

~ 5000ml 02/min

~ 6000ml C02/min

Question 10

What is the role of the nasal cavities and paranasal sinuses?

Answer 10

Filter, warm, humidify air, detect smells.

Question 11

What is the role of the pharynx?

Answer 11

Conducts air to the larynx

Question 12

What is the role of the larynx?

Answer 12

Protects opening to trachea and contains vocal cords

Question 13

What is the role of the trachea?

Answer 13

Filters air, traps particles in mucus; cartilages keep airways open

Question 14

What is the role of the bronchi?

Answer 14

Filters air, traps particles in mucus; cartilages keep airways open

Question 15

What is the role of the lungs?

Answer 15

Responsible for air movement through volume changes during movement of ribs and diaphragm; including airways and alveoli

Question 16

What is the role of the alveoli?

Answer 16

Act as a site of gas exchange between air and blood

Question 17

What are the major functions of the upper airways? (3)

Answer 17

1) humidify (saturate with water)
2) Warm (to body temperature)
3) Filter

Question 18

What type of epithelial cells line the upper airways to the bronchioles?

Answer 18

pseudo-stratified ciliated, columnar epithelium

Question 19

What is the function of pseudo-stratified ciliated, columnar epithelium

Answer 19

To filter air/ trap dirt using mucus from goblet cells

Question 20

What is the rate of ventilation at rest?

Answer 20

6L/min, ~12 breaths of 500ml

Question 21

What is the max. ventilation?

Answer 21

160L/min, ~40 breaths of 4L

Question 22

What is the rate of cardiac output at rest?

Answer 22

5L/min, 70bpm, 70ml/beat

Question 23

What is max. cardiac output

Answer 23

25L/min, 200bpm, 125ml/beat

Question 24

What are the steps in Quiet breathing?

Answer 24

Inspiration: Active

• diaphragm contracts (1cm)
• external intercostal muscles pull ribs outwards and upwards
• intra-pulmonary volume increases –> pressure decreases (-1)
• therefore pressure inside, lower then outside
• air moves down pressure gradient = breathe in

Expiration: Passive (elastic recoil)

• diaphragm relaxes
• intra-pulmonary volume decreases –> pressure increases
• therefore pressure inside is higher (+1) then outside
• air moves down pressure gradient = breath out

Question 25

What are the steps in strenuous breathing?

Answer 25

Inspiration: Active - diaphragm has greater contraction (10cm) - external intercostal muscles have greater contraction - accessory muscles are active: - sternocleidomastoid - alae nasi - genioglossus ``` Expiration: Active abdominal muscles: - rectus abdominus - internal oblique - external oblique - transverse abdominus Internal intercostal muscles oppose external intercostals by pushing ribs down and inwards. ```

Question 26

What are the muscles of inspiration?

Answer 26

- Diaphragm - External intercostals - Parasternal intercartilaginous muscles - Scalenus (posterior, middle, anterior) - Sternocleidomastoid

Question 27

What are the muscles of expiration?

Answer 27

- Rectus abdominis - External oblique - Internal oblique - Transverse abdominis - Abdominal muscles

Question 28

What type of muscle is the diaphragm?

Answer 28

skeletal muscle

Question 29

What is intrapleural pressure (mmHg)?

Answer 29

Pressure change between lung and chest wall. Pressure always negative

Question 30

What is tidal volume (ml)?

Answer 30

Volume of air going into lung during each breathe