Thorax 3 - GA Flashcards
What are the main muscles of inspiration?
→ external intercostal muscle
→ scalene muscles
What are the origins of the external intercostal muscles?
originates from the sharp inferior costal border of one rib
What are the insertions of the external intercostal muscles?
insert along the outer lip of the superior border of the immediate rib below
What is the innervation for external intercostal muscles?
intercostal nerves
What are the different parts of the scalene muscles?
→ anterior
→ middle
→ posterior
What is the origin of the anterior scalene muscle?
anterior tubercles of transverse processes of cervical vertebrae C3-C6
What is the insertion of the anterior scalene muscle?
scalene tubercle of 1st rib
What innervates the anterior scalene muscle?
anterior rami of 4th-6th cervical nerves
What is the origin of the middle scalene muscle?
posterior tubercles of transverse processes of C2-C7
What is the insertion of the middle scalene muscle?
superior surface of 1st rib
What innervates the middle scalene muscle?
anterior rami of 3rd-8th cervical nerves
What is the origin of the posterior scalene muscle?
posterior tubercles of transverse processes of C4-C6
What is the insertion of the posterior scalene muscle?
external surface of 2nd rib
What innervates the posterior scalene muscle?
anterior rami of 4th-6th cervical nerves
What do the external intercostal muscle do?
contraction moves ribs up + out
What do the scalene muscles do?
contraction raises 1st + 2nd ribs up in deep inspiration
What are the muscles of expiration?
→ internal intercostal muscles
→ abdomen muscles
What are the origins of the internal intercostal muscles?
inferior border of the ribs
What are the insertions of the internal intercostal muscles?
superior borders of the ribs immediately below
What innervates the internal intercostal muscles?
intercostal nerves
What do the internal intercostal muscles do?
→ depresses ribs at their costovertebral joints
→ moves ribs down + in
What are the different abdomen muscle involved in expiration?
→ rectus abdominis
→ transversus abdominis
→ internal oblique
→ external oblique
What do the abdominal muscles do in expiration?
→ helps move ribs down + in expiration
→ assists in forced expiration e.g. coughing + sneezing
What artery is the main supply for the thorax? Where does it stem from?
thoracic arteries, stem from the respective subclavian arteries