Respiratory Anatomy Flashcards
Describe the divisions of the respiratory tract and bronchial tree
Trachea:
- extension of larynx inferior to cricoid cartilage at level C6
- bifurcates at sternal angle into primary bronchi
Primary bronchi:
- right: wider, shorter, more vertical
- left: narrower, longer, more horizontal
Secondary bronchi:
- lobar bronchi
- 3 right
- 2 left
Tertiary bronchi:
- segmental bronchi
- 10 each lung
Terminal bronchioles:
- 20 each lung
Respiratory bronchioles:
- many in each lung
- have some alveolar sacs in the walls (so gas exchange can occur here)
- give off 2-5 alveolar ducts
Alveolar ducts:
- give off 5-6 alveolar sacs lined with alveoli
What is the difference between alveolar ducts, alveolar sacs, and alveoli?
Alveolar ducts:
- passageway from respiratory bronchioles to alveolar sacs
Alveolar sacs:
- bunches of alveoli
Alveoli:
- smallest unit in bronchial tree
- site of respiratory exchance
Describe the trachea
Location:
- from inferior end of larynx (C6) to sternal angle (T4/5 IVD)
- 10cm long
- part of conducting zone of respiratory tract
Structure:
- incomplete hyaline cartilaginous rings maintain patency of airway
- trachealis muscle on flat posterior surface
- lined with psuedostratified columnar ciliated epithelium (mucal escalator)
Innervation:
- CNX (PNS)
- T1-6 cardiopulmonary splanchnic (SNS)
Which primary bronchi is more likely to get obstructed by food?
Right - it is wider and more vertical than the left
Describe the structure of the lungs
Lobes:
- 2 lobes in left lung (superior and inferior)
- 3 lobes in right lung (superior, middle and inferior)
Fissures:
- both lungs have an oblique fissure
- right lung only has a horizontal fissure
Segments:
- 10 in each lung
- largest subdivision of lobes
- separated by connective tissue
- each supplied by a segmental bronchus and separate artery
Other:
- apex located superiorly
- hilum and root of lung on mediastinal surface
Surfaces:
- costal
- mediastinal
- diaphragmatic
Borders:
- anterior
- posterior
- inferior
Impressions:
- hilum
- cardiac impression
- groove for aortic arch and descending aorta
- groove for oesophagus
Describe the surfaces of the lungs
- Diaphragmatic
- inferior
- concave to receive domes of diaphragm - Costal
- anterior, lateral and posterior - Mediastinal
- medial
- concave
- hilum and root of lung
- cardiac impression (larger on the left)
- groove for aorta (left)
- groove for oesophagus (right)
Describe the pleural layers of the lung
Inner layer:
- visceral pleura
- lines lungs
Pleural space:
- between visceral and parietal layers
- filled with pleural fluid
Parietal layer:
- outer layer
- connective tissue
- lines Tx cage, diaphragm and mediastinum
(parietal and visceral layers become continuous at root of lung)
Describe the arteries supplying the lungs
- Pulmonary Arteries
- carry deoxygenated blood from the heart to the lungs for oxygenation at the respiratory membrane
- arise from pulmonary trunk at level of transverse thoracic plane
- one per lung - Bronchial Arteries
- supply root of lungs, connective tissue, and visceral pleura
Left bronchial arteries:
- 2
- from Tx aorta
Right bronchial arteries:
- 1
- from Tx aorta, posterior intercostal artery 3, or common trunk with left superior bronchial artery
Describe the venous drainage of the lungs
- Pulmonary veins
- 2 each side
- carry oxygenated blood from lungs to left atrium - Bronchial veins
- drain blood supplied to the lungs by bronchial arteries
Right bronchial vein
- drains into azygous vein
Left bronchial vein
- drains into accessory azygous vein
Do the bronchial arteries or bronchial veins follow the bronchial tree?
Bronchial arteries follow the bronchial tree; and bronchial veins follow their own path
