Muscles of the thoracic cage Flashcards
How many pairs of external intercostal muscles do you have?
11
In what direction do the external intercostals run?
Like your pockets, forwards and towards midline
Where do the external intercostals originate and insert?
Originate - lower border of rib above
Insert - Superior border of rib below
What is the action of external intercostals?
Elevate the ribs, increasing thoracic volume.
What is external intercostals innervation?
Intercostal nerves (T1 - T11)
Where do the internal intercostals lie?
Deep to the external intercostals.
In what direction do the internal intercostals run?
Perpendicular to external intercostals.
Where do the internal intercostals originate and insert?
Originate - Lateral edge of costal groove
Insert - Superior surface of rub below
What is the action of the internal intercostals?
The interosseous part reduces the thoracic volume by depressing ribcage while the interchondral part elevates the ribs.
What is the innervation of the internal intercostals?
Intercostal nerves (T1 -T11)
Where does the intercostal neuromuscular bundle lie?
Inbetween the internal intercostals and innermost intercostals.
Where do the innermost intercostals originate and insert?
Originate - Medial edge of costal groove
Insert - Superior surface of rib below
What is the action of the innermost intercostals?
Interosseous part reduces thoracic volume by depressing ribcage and interchondral part elevates ribs
What innervates the innermost intercostals?
Intercostal nerves (T1 - T11)
What are the transverse thoracics?
Continuous with transverse abdominis inferiorly
