Lecture 1.1: Anatomy of the Respiratory System Flashcards
What are the 2 parts of the Respiratory System?
Upper and Lower
What makes up the Upper Respiratory Tract? (4)
- Nasal cavity
- Paranasal sinuses
- Pharynx
- Larynx above vocal cords
What makes up the Lower Respiratory Tract? (4)
- Larynx below the vocal cords
- Trachea
- Bronchi
- Bronchioles
What anatomical structures do the lungs contain? (4)
- Respiratory Bronchioles - Transitional
- Alveolar Ducts
- Alveolar Sacs Respiratory
- Alveoli
How do the Ribs 1-7 articulate with the sternum anteriorly?
• Ribs 1 - 7 connected to sternum via costal cartilages
How do the Ribs 8-10 articulate with the sternum anteriorly?
• Ribs 8 - 10 connected to the costal cartilage above
How do the Ribs 11-12 articulate with the sternum anteriorly?
• Ribs 11 & 12 end free in the abdominal muscles (`floating ribs’)
What are the Typical Ribs?
• Ribs 3-9
• Head: 2 articular facets
• Neck
• Tubercle: 1 articular facet for articulation with transverse process of the
corresponding thoracic vertebra
• Shaft: costal groove under lower border which protects the intercostal vessels
& nerve
Structure of 1st Rib (Atypical)
- Forms upper border of superior thoracic aperture
- Short and thick
- Single articular facet for the costovertebral joint
- Flattened from top to bottom
- Grooves for: subclavian artery, subclavian vein, lowest trunk of brachial plexus
Where do Rib Fractures usually occur? Why?
- Usually Middle Ribs
* Crush Injuries/Direct Trauma
Complications of Rib Fractures?
- Soft tissue injury from broken fragments
* Risk of damage to lungs, spleen or diaphragm
When is the affected area in a rib fracture not under control of the thoracic muscles?
• If 2+ fractures occur in 2+ adjacent ribs
What is Flail Chest?
Defined as two or more contiguous rib fractures with two or more breaks per rib
What Intercostal Muscles are used in Inspiration?
• External Intercostal Muscles
What Intercostal Muscles are used in Expiration?
- Internal Intercostal
* Innermost Intercostal
Diaphragm Structure and Position?
- Double-domed musculotendinous sheet
* Inferior aspect of the rib cage
Functions of the Diaphragm
• Separates thoracic cavity from abdominal cavity
• Contraction and Relaxation alters volume of thoracic cavity and lungs
• Primary muscle of inspiration and expiration (70% chest expansion in quiet
respiration)
What does the Diaphragm attach to?
- Anteriorly to xiphoid process and costal margin
- Laterally to ribs 11 and 12
- Posteriorly to lumbar vertebrae
What are the 3 Openings in the Diaphragm?
- Vena Caval Hiatus (Foramen Venae Cavae)
- Oesophageal Hiatus (Hiatus Oesophagus)
- Aortic Hiatus (Hiatus Aorticus)
Caval Aperture/Hiatus
- Level: T8
- Central area of the central tendon
- Inferior vena cava
- Branches of right phrenic nerve
Oesophageal Aperture/Hiatus
- Level: T10
- Formed by fibres of the right crus, around oesophagus, to left of the midline
- Oesophagus
- Right and left vagus nerves (Gastric nerves)
- Oesophageal branches of Left Gastric vessels
- Lymphatics
Aortic Aperture/Hiatus
- Level: T12
- Between the right and the left crura, bounded by the median arcuate ligament
- Aorta
- Thoracic duct
- Azygous and Hemiazygous vein
What Nerves supply the Diaphragm?
- Right and left Phrenic Nerve
- Cervical plexus
- C3, C4, C5 (these keep the diaphragm alive!)
Why is Diaphragmatic pain often felt at the Shoulder Tip?
- Shoulder and diaphragm share common nerve supply - C3, C4
- Phrenic nerve
- Supraclavicular nerves