Thoracic Wall Muscles Flashcards
Define Axioappendicular muscles and their purpose
extend from thoracic cage to upper limb bone.
help elevate ribs in respiration
Which muscles are the accessory muscles in respiration?
Scalene muscles, pectoralis major, pectoralis minor, serratus anterior
Name the attachment and function of scalene muscles.
Attachment from neck vertebrae to 1st and 2nd ribs. Fixes the ribs and elevates lower ribs
Which muscles are the true thoracic wall muscles?
Serratus Posterior Anterior, Serratus Posterior Interior, Levator Costarum, External Intercostal Muscles, Internal Intercostal Muscles, Innermost Intercostal Muscles, Subcostal, Tranversus Thoracis
Describe the Levator Costarum
12 fan shape muscles
What is the purpose of the intercostal muscles? Where are they located?
They keep the intercostal spaces rigid so that there’s no bulging during expiration and no drawing in during inspiration. They occupy the intercostal muscles
How many pairs in the external intercostal muscles? Most active during?
11 pairs. Most active during inspiration
External intercostal muscles are replaced anteriorly by? What’s unique about them?
external intercostal membranes. they run continuously with oblique muscles
Internal intercostal muscles are replaced posteriorly by? What’s unique about them?
internal intercostal membranes. they are continuous with internal oblique muscles
internal intercostals are weaker than? most active during?
weaker than external intercostal muscles and are most active during expiration.
the innermost intercostal muscles are separated by?
intercostal nerves and vessels.
subcostal muscles are located where?
lower thoracic wall
describe the features of the transversus thoracis muscles.
4 or 5 slips. continuous with transversus abdominis.
What is the main purpose of the diaphragm?
Describe its features
primary muscle of inspiration. shared wall separating thorax and abdomen
What is passive unless one is exhaling against resistance?
Expiration
superior attachment of the serratus posterior superior?
nuchal ligament, spinous processes of C7-T3 Vertebrae
inferior attachment of the serratus posterior superior?
superior borders of 2nd to 4th ribs
innervation of the serratus posterior superior?
2nd to 5th intercostal nerves
main action of the serratus posterior superior?
proprioception - elevate ribs
superior attachment of the serratus posterior inferior?
spinous processes of T11 to L2
inferior attachment of the serratus posterior inferior?
inferior borders of 8th to 12th ribs near their angles
innervation of the serratus posterior inferior?
anterior rami to T9 to T12 thoracic spinal nerves
action of the serratus posterior inferior?
proprioception - depress ribs
superior attachment of levator costarum.
transverse processes of T7-11
inferior attachment of levator costarum.
subjacent ribs between tubercle and angle
innervation of levator costarum
posterior primary rami of C8-T11
action of levator costarum.
elevate ribs
superior attachment of external, internal and innermost intercostal muscles.
inferior border of ribs
inferior attachment of external, internal, innermost intercostal muscles
superior border of ribs below
innervation of the external, internal, innermost intercostal muscles
intercostal nerve
action of the external intercostal muscles.
elevate ribs during forced inspiration
action of the internal intercostal and innermost intercostal muscles.
interosseous part: depresses ribs
interchondral part: elevates ribs
during active respiration
superior attachment of the subcostal muscles.
internal surface of lower ribs near their angles
inferior attachment of the subcostal muscles.
superior borders of 2nd or 3rd ribs below
innervation of the subcostal muscles.
intercostal nerve
action of the subcostal muscles
probably the same as internal intercostal muscles
superior attachment of the transversus thoracis
posterior surface of the lower sternum
inferior attachment of the transversus thoracis
internal surface of costal cartilages 2-6
innervation of the transversus thoracis
intercostal nerves
action of the transversus thoracis
weakly depress ribs. proprioception