Respiratory system

Question 1

Anatomy of right lung

Answer 1

Wider and shorter than left
3 lobes - superior, middle, inferior
2 fissures - oblique, horizontal

Question 2

Anatomy of left lung

Answer 2

Narrower and longer than right
2 lobes - superior and inferior
1 fissure - oblique

Question 3

Pleural cavity

Answer 3

Visceral pleura - covers lung
Parietal pleura - lines chest wall
Hilum
> reduces friction
creates a pressure gradient to assist ventilation
isolates lungs

Question 4

Upper respiratory tract

Answer 4

Nose, nasal cavity, paranasal sinuses, pharynx, larynx

Question 5

Lower respiratory tract

Answer 5

Trachea, bronchi, bronchioles, alveoli

Question 6

Conducting zone

Answer 6

nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles

• filters, warns and moistens air
• transmits air to and from lungs

Question 7

Respiratory zone

Answer 7

respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
- site of gas exchange

Question 8

Nasal cavity

Answer 8

Warms, cleanses and humidifies air
Detects odours
Resonating chamber that modifies voice
Conchae
Meati
Paranasal air sinuses

Question 9

Pharynx

Answer 9

Extends from nose to larynx
Passageway for airway and food
Warms and humidifies air
Resonating chamber for speech sounds

Question 10

Larynx

Answer 10

9 pieces of cartilage
Maintains an open airway
Switching mechanism:
- swallowing - larynx in pulled upwards, epiglottis moves down to cover laryngeal inlet 
- cough reflex
Changes tension in vocal chords

Question 11

Trachea (+oesophagus)

Answer 11

Cartilage rings
Smooth muscle
Respiratory mucosa

Question 12

Muco-ciliary escalator

Answer 12

Cilia in upper respiratory tract move mucus down towards pharynx
Cilia in lower respiratory tract move mucus up towards pharynx

Question 13

Bronchial tree

Answer 13

Trachea - primary bronchi - secondary bronchi - tertiary bronchi - bronchioles - terminal bronchioles

Question 14

Difference between bronchus and bronchioles

Answer 14

Bronchus have cartilage in their walls

Question 15

Alveoli

Answer 15

Type I alveolar cell = squamous epithelium
Type II alveolar cells = septal cells
- gaseous exchange

Question 16

Blood supply to lungs

Answer 16

Pulmonary arteries carry blood to be oxygenated
Pulmonary veins carry oxygenated blood from lungs to the heart
Bronchial arteries supply lung tissue with blood, arise from the aorta and branch with bronchi (don’t supply alveoli)

Question 17

Intrapulmonary pressure: inspiration

Answer 17

1. Diaphragm and external intercostal muscles contract
2. rib cage moves up and outwards
3. thoracic cavity volume increases
4. intrapulmonary volume increases
5. intrapulmonary pressure decreases
6. air enters lungs down pressure gradient until intrapulmonary pressure = atmospheric pressure

Question 18

Intrapulmonary pressure: expiration

Answer 18

1. diaphragm and external intercostals relax
2. rib cage moves in and down
3. thoracic cavity volume decreases
4. intrapulmonary volume decreases
5. intrapulmonary pressure increases
6. intrapulmonary pressure > atmospheric pressure = air leaves lungs down a pressure gradient until intrapulmonary pressure is 0

Question 19

Pulmonary compliance

Answer 19

Ease with which the lungs expand
Healthy lungs are stretchy = high compliance
Compliance is reduced by:
- scar tissue
- difficulty in expanding lungs
- blockages
- low levels of surfactant

Question 20

Partial pressure

Answer 20

The pressure exerted by each gas.

Directly proportional to its percentage in the total gas mixture

Question 21

Henry’s law

Answer 21

“amount of gas that dissolves in water is determined by its solubility in water and its partial pressure in air”

solubility in plasma = carbon dioxide > oxygen&raquo_space;nitrogen

Question 22

Detection systems

Answer 22

Peripheral chemoreceptors
> aortic bodies
> carotid bodies (main O2 sensors)
Central chemoreceptors
- monitor pH of CSF