General Anatomy, lung mechanics Flashcards
What three structures make up the sternum?
Manubrium, body and xiphoid process
How are ribs 8-10 connected to the sternum?
They are not - they are connected to the costal cartilage above.
Which four ribs are considered atypical and why?
1 - shortest, broadest, most curved, single articular facet, two superior grooves for subclavian vessels
2 - poorly marked costal groove, serratus anterior attaches to superior surface
11/12 - single articular facet, no tubercle, tapering anterior end
What are the two types of joint between ribs and vertebrae?
Costotransverse joint and costovertebral joint
Describe the costotransverse joint.
Between the tubercle of the rib and the transverse process of vertebrae
Describe the costovertebral joint.
Between the head of the rib, the superior costal facet of the corresponding vertebra and the inferior costal facet of the superior vertebra
What are the three layers of the intercostal muscles?
External intercostal - inferoanteriorly
Internal intercostal - inferioposteriorly
Innermost intercostal
What is the function of the external intercostal muscle?
Elevates ribs to increase thoracic volume
What thin strips of muscle are similar in structure, function and innervation to the innermost intercostal muscles?
Subcostals
Does elevation of the upper ribs increase AP diameter or lateral diameter?
AP diameter
What movement increases lateral diameter of the thorax?
Bucket handle type movement of lower ribs
Which muscles depress the ribs during forced expiration?
Innermost and internal intercostal muscles
What separates the internal intercostal muscles and innermost intercostal muscles?
Neurovascular bundle
Describe the arterial supply to intercostal muscles.
Posterior intercostal arteries from thoracic aorta and anterior intercostal arteries from internal thoracic artery anastomose to supply muscles, parietal pleura and overlying skin.
Where does venous return drain into?
Azygous system
What are the three peripheral attachments of the diaphragm?
- Xiphoid process
- Costal cartilages of ribs 7-12
- Lumbar vertebrae and arcuate ligaments
What forms the central tendon and where does it fuse to?
Muscles of the diaphragm combine to form central tendon and fuse with inferior fibrous pericardium
Which muscle accounts for the majority of chest expansion during inspiration?
Diaphragm
At what level does the oesophagus pass through the diaphragm?
T10
At what level does the IVC pass through the diaphragm?
T8