Resp1&2 - Anatomy of the Respiratory System

Question 1

5 features of the structure of the nose and paranasal sinuses

Nasal Cavity
Lateral Walls
Paranasal Sinuses
Nostrils

Answer 1

1. ) Nasal cavity divided by the median nasal septum
2. ) Lateral walls contain 3 bony projections (turbinates/conchae)
3. ) 4 paranasal sinuses: frontal, ethmoidal, sphenoidal, maxillary
4. ) Paranasal sinuses are lined by pseudostratified ciliated columnar epithelium
5. ) Nostrils are lined with coarse hairs, trapping large particles in inhaled air

Question 2

3 features/function of the turbinates

Answer 2

1. ) large surface area
2. ) allow inhaled air to be warmed and humidified
3. ) cause turbulence and slow down airflow to increase time available for warming and humidification

Question 3

3 features of the larynx

Answer 3

1. ) links the pharynx to the trachea
2. ) contains vocal cords/folds/ligaments which act as a sphincter to close off the entrance to the trachea
3. ) movements of the vocal cords are caused by the intrinsic laryngeal muscles, supplied by the recurrent laryngeal nerve

Question 4

Why is a voice change the first sign of a serious intra-thoracic disease?

Answer 4

• The recurrent laryngeal nerve on the left side is present inside the thoracic cavity.
• intra-thoracic disease (e.g. aortic aneurysm, lung cancer etc.) compressing the nerve results in a hoarse voice due to paralysis of the left vocal cord

Question 5

What is aspiration?

What is the cough reflex?

Answer 5

If larynx/vocal cords is dysfunctional, trachea wont be properly closed off during swallowing, leading to aspiration of food/liquid

Cough reflex is the quick opening and closing the vocal cords. It is a protective mechanism for disposal of excessive secretions from the airways

Question 6

What are the 3 intercostal muscles and their actions?

Answer 6

External - chest expansion during quiet inspiration, it increases the antero-posterior and transverse diameters of the thoracic cavity (brings ribs up and out)
Internal - forced expiration, pulls ribs down and in
Innermost - similar to internal but less developed,

Question 7

4 features of the diaphragm

Function
Innervation
Openings x3
Level

Answer 7

1. ) responsible for chest expansion in quiet inspiration, it increases the vertical diameter of the thoracic cavity
2. ) Innervated by the phrenic nerves (C3,4,5)
   - phrenic nerve lies in front of the hilum
3. ) Has openings for the IVC (T8), the oesophagus (T10), the aorta (T12)
   - vena cava passes through the central tendon of the diaphragm
4. ) Right dome lies at 5th rib level, left dome lies in the 5th intercostal space
   - the liver can be percussed on the right side from the 5th ICS

Question 8

3 movements of the thoracic wall and diaphragm in inspiration

Answer 8

1. ) Elevation of lateral aspect of ribs in inspiration (bucket handle)
2. ) Sternum moves forward in inspiration due to rib elevation (pump handle)
3. ) Diaphragm descends to increase thoracic capacity in inspiration

Question 9

What are the 2 accessory muscles of respiration?

Answer 9

Pectorals (hands on knees after running)

SCM (seen in COPD patients)

Question 10

4 features of neurovasculature of the intercostal muscles/thorax

Intercostal Arteries
Azygous System
Intercostal Nerves
Chest Drain

Answer 10

1. ) Intercostal Arteries - supply the parietal pleura
   - located between the internal and innermost intercostal muscles
   - each intercostal space has an anterior and posterior intercostal artery originating from the back (aorta) and front (internal thoracic arteries)
2. ) Azygous System - venous drainage of the thorax
   - azygous vein = right side, hemiazygous and accessory hemiazygous vein = left side of the thorax
   - the azygous vein drains into the SVC
3. ) Intercostal Nerves - supply the intercostal muscles, parietal pleura, and the skin overlying each intercostal space
4. ) Chest Drain - insert the tube above the rib rather than below to avoid hitting the major neurovasculature

Question 11

4 features of the pleura

Parietal
Visceral
Cavity
Recess

Answer 11

1. ) Parietal Pleura - lines the inside of each hemi-thorax and is continuous at the hilum of the lung
2. ) Visceral Pleura - lines the outside of the lung, extends between lobes of the lung into the oblique and horizontal fissures
3. ) Costo-diaphragmatic Recess - peripheral gutter around the outer edge of the diaphragm which only the parietal pleura extends
4. ) Pleural Cavity - space between parietal and visceral pleura containing pleural fluid.

Question 12

6 features of the trachea and bronchial tree

Location
Structure
Divisions
Carina
Lodging of Foreign Bodies
Bronchopulmonary Segment

Answer 12

1. ) Location - lower border of cricoid cartilage —> sternal angle
   - anterior to the oesophagus
2. ) Structure - has C shaped cartilages
3. )Trachea –> main(primary) bronchus –> lobar(secondary) bronchi –> segmental(tertiary) bronchi
4. ) Carina - angle between the the R and L main bronchus
5. ) Right main bronchus is wider, shorter, and more vertical hence inhaled foreign bodies more likely lodge there
6. ) Bronchopulmonary Segment - area of lung supplied by a segmental bronchus and segmental branch of the pulmonary artery

Question 13

5 features of the basic anatomy of the lungs

Lobes
Apex 
Hilum
L Side Associations x7
R Side Associations x7

Answer 13

1.) Lobes - 3 lobes on the right (horizontal and oblique fissure). 2 lobes on the left (oblique fissure)

2. ) Apex - above the level of the 1st rib into the root of the neck
   - 2nd rib articulates with the sternal angle
3. ) Hilum - found in the mediastinal surface, contains the main bronchi, branches of the pulmonary artery, veins, lymphatics and pulmonary plexuses
4. ) L Side Associations - heart, aortic arch, descending aorta, oesophagus, nerves: phrenic, vagus, recurrent laryngeal
5. ) R Side Associations- SVC, azygous vein, RA, oesophagus, nerves: phrenic, vagus, sympathetic trunk

Question 14

4 features of the neurovasculature of the lungs

Arteries, veins, lymph, nerves

Answer 14

1. ) Dual Blood Supply - bronchial and pulmonary arteries
   - bronchial artery supplies the bronchial tree and visceral pleura
   - pulmonary arteries supply the alveoli
   - some anastomoses present at precapillary and capillary level
2. ) Pulmonary Veins - run in the intersegmental septa. 2 veins leave each hilum
3. ) Lymphatic Drainage - vessels drain to the hilar (bronchopulmonary) nodes and tracheobronchial nodes
4. ) Nerve Supply - vagus nerves (parasympathetic) cause bronchoconstriction and nerves from the sympathetic trunk cause bronchodilation and vasoconstriction

Question 15

What is the conducting zone and respiratory zone

Answer 15

Conducting Zone - zone that does not take part in gas exchange (divisions 1-16)

Respiratory Zone - made up by the respiratory bronchioles, alveolar ducts and sacs (divisions 17-23)