Anatomy - Upper Respiratory Tract & Anterior Chest Wall Flashcards
What bones does the pectoralis major articulate with?
clavicle and sternum
What do the pectoralis minor attach to?
Part of scapula and then to the ribs
What are pectoralis major and minor known as?
Accessory respiratory muscles
What is the 1ary action of the pectoralis major and minor?
How do they contribute in times of respiratory distress?
On the upper limb
These muscles will contract to help elevate the thoracic cage during inspiration.
Where does the serratus anterior originate?
Muscle that originates on the surface of the 1st to 8th ribs at the side of the chest
What does the serratus anterior act to do?
Acts to pull the scapula towards the thorax.
As the external intercostals muscles approach anterior aspect, how do they change?
Lose muscle fibres and start to become membranous
Where is the intercostal neurovascular bundle found?
Between the internal and innermost intercostal muscles
Where does the intercostal neurovascular bundle sit?
In the costal groove
What is the order of the intercostal neurovascular bundle?
VAN - vein, artery, nerve (superior to inferior)
What does the intercostal nerve supply?
Supplies those intercostal muscles.
Also supplies the parietal pleura (lines thoracic cavity) which lies deep to intercostal muscles.
What does the intercostal vein drain?
Drains intercostal muscles of deoxygenated blood
What does the intercostal vein drain into?
Azygos system
Which arteries directly supply the thoracic wall?
- Posterior intercostal arteries
- Anterior intercostal arteries
- Internal thoracic arteries
Where does the internal thoracic artery originate from? (one on right and one on left)
Subclavian artery
What does the internal thoracic artery supply? (one on right and one on left)
intercostal muscles, skin and parietal pleura associated with the first 6 intercostal spaces.
Describe route of internal thoracic artery (left and right)
The arteries enter the thoracic cavity as they descend behind the clavicle and first costal cartilage. Upon entering the chest cavity, the vessel is crossed anteriorly by the phrenic nerve. It continues posteriorly to the first six costal cartilages, lateral to the sternum, and deep to the pectoralis major. The vessel passes behind the external intercostal membrane and internal intercostal muscles up to the level of the second or third costal cartilage. Beyond this level, it passes in front of the transversus thoracis muscles