Anatomy

Question 1

upper respiratory tract

Answer 1

includes the nose and nasal passages, paranasal sinuses, the pharynx, and the portion of the larynx above the vocal folds (cords).
soft palate
hard palate
epligottis closes over larynx during swallowing to prevent aspiration.

Question 2

lower respiratory tract

Answer 2

The lower airways or lower respiratory tract includes the portion of the larynx below the vocal folds, trachea, bronchi and bronchioles.

Question 3

lungs

Answer 3

Each lobe is divided into bronchopulmonary segments

10 bronchopulmonary segments in the left lung

8 bronchopulmonary segments in the right lung

The anatomical knowledge of this segments is used to perform gravity positioning to promote drainage of excess secretions; position the segmental bronchi perpendicular to gravity in order to drain the affected segment

Question 4

Bronchial tree

Answer 4

left and right bronchus 
L: 
3 lobar bronchi 
segmental bronchi
bronchi and bronchioles of decreasing size 
terminal bronchioles 
respiratory bronchioles 

R: 2 lobar bronchi

Question 5

Respiratory zone

Answer 5

Site of gaseous exchange
- 300 million alveoli/ lung
- Rich blood supply – capillaries form sheet over alveoli
- Type I alveolar cells – make up wall of alveoli
Type II alveolar cells – secrete surfactant
- Alveolar macrophages

Question 6

Alveoli

Answer 6

The walls are lined by a thin film of water, which creates a force at their surface called surface tension.
Surface tension tends to collapse the pulmonary alveoli.
Alveolar cells produce surfactant to counteract surface tension.
Our body makes surfactant at 26 weeks gestation, premature babies suffer may from respiratory distress syndrome.
Treated with surfactant replacement therapy
Covid-19 destroys surfactant making cells

Question 7

collateral channels of ventilation

Answer 7

The phenomenon ofcollateral ventilationin the human lung is defined as “the ventilationof alveolar structures through passages or channels that bypass the normal airways”.
None of these channels present at birth
Pores of Kohn 1-2 years
Canal of Lambert 4-6 years
Channels of Martin: Develop in pathology (Interbronchial)

Question 8

Pleura

Answer 8

Lungs are covered in a thin double layered membranous sac
Outer layer: parietal pleura
Inner layer: visceral pleura
Pleural cavity: space between the pleura
Pleura secret pleural fluid, this acts as a lubricant to allow friction free movement of the two layers.
The pleural fluid also acts to increase surface tension and “locks” the two layers together so that they cling to the chest wall throughout inspiration and expiration

The visceral pleura is innervated by the autonomic nervous system and so is not sensitive to pain.
The parietal pleura is innervated by the phrenic and intercostal muscles and is highly sensitive to pain.
Pleuritic pain can cause severe sharp stabbing pain.
Pneumothorax occurs when there is air in the pleural space

Question 9

Respiratory muscles

Answer 9

Diaphragm:
right hemidiaphragm sits higher (1-2cm) than the left because of the liver
Diaphragm has 3 openings: oesophageal, aortic and vena cava.
Innervated by the phrenic nerve (C3, 4, 5 keep the diaphragm alive)

Intercostal muscles
-11 pairs, innervated by T1-T11

Accessory muscles: scalenes, sternocliedomastoids (also can use pec major and minor)
- Use of the accessory muscle is a sign of respiratory distress

Question 10

Thoracic cage

Answer 10

Protects the heart, lungs and great vessels

• Ribs 1-7 true ribs
• Ribs 8-10, false ribs
• Ribs 11-12 floating ribs

Question 11

Flail chest

Answer 11

Results in a segment of the chest wall flailing back and forth in the opposite direction of the rest of the chest wall.
- Breathing movements in which the chest wall moves in on inspiration and out on expiration, in reverse of the normal movements are know as paradoxical breathing.

Question 12

Respiratory mechanics

Answer 12

Atmospheric pressure =760 mmHg
Respiratory pressures are always described in relation to atmospheric pressure
Intrapulmomary pressure or intra-alveolar pressure (Palv) is the pressure within the alveoli: Decreases with inspiration and increases with expiration- always returns to 0mmHg (equalises with atmospheric pressure) at the end of inspiration and end of expiration

Question 13

movement of the ribs

Answer 13

Pump handle - increase diameter antero-posterior

bucket handle- increase diameter laterally