Muscle of the back and thorax Flashcards
What are the 3 groups of muscles in the back and what are there general functions
- Extrensic back muscles= superficial group that produce and control limb movements
- Intermediate group= muscles involved in respiration
- Intrinsic back muscles= the true back muscles that act on the vertebral column producing its movements and maintaining posture
Name the 2 intrinsic muscle groups of the back
- Erector spinae
2. Transverospinal
Where is the origin and function of the erector spinae
origin=sacrum and iliac crest
fxn=extension of the spine, flexion, lateral bending
What are the 3 muscular columns of the erector spinae
Spinalis (medial)
Longissimus (intermediate)
Illiocostalis (lateral)
True or False the transverospinal muscles are superficial to the erector spinae
False, the transverospinal muscles are deep to the erector spinae
Describe the location and function of the transverospinal muscles
function=rotate the vertebrae
location= almst look like they wrap around the spine
What is the Mnemonic for remembering the names of the transverospinal muscles from superficial to deep
Spine= semispinal muscles May= multifidus muscles Rotate= rotatores muscles
Define anterior median line
aka midsternal
reference line that indicates the intersection of the median plane with the anterior chest wall
Define midclavicular line
reference lines that pass through the midpoints of the clavicles, parallel to the anterior median line
Define anterior axillary line
reference line that runs vertically along the anterior axillary fold, it is formed by the border of the pectoralis major
Define midaxillary line
reference line that runs from the apex of the axilla, parallel to the anterior line
Define posterior axillary line
reference line that is parallel to the anterior axillary line vertically along the posterior axillary fold, my the latissimus dorsi and teres major
Define scapular line
lines parallel to the posterior median line and cross the inferior angles of the scapula
midclavicular lines but on the back
Posterior median line
vertical line described by the tips of the spinous processes of the vertebrae
What 2 groups of muscles make up the muscles of the thoracic wall
- thoracoappendicular
2. Muscles of breathing
What is the fxn of the thoracoappendicular muscles
-upper limb muscles that attach to the thoracic cage, and produce/control limb movements
What muscles comprise the muscles of breathing
- Diaphragm
- Scalenes
- intercostal muscles
- some thoracoappendicular muscles
Name the 3 layers of intercostal muscles from superficial to deep
- outer layer=External intercostals
- middle layer= internal intercostals
- innermost = 3 layers
Describe the external intercostal muscles in terms of the direction they run, origin and attachment, their function and innervation
- travels obliquely from lateral to medial
- originate inferior border of the rib above
- insertion is the superior border of the rib below
- fxn=elevate the rib cage/muscle of inspiration
- innervation=segmental intercostal nerve, which is a branch of the posterior rami of spinal nerves
Describe the internal intercostal muscles in terms of the direction they run, origin and attachment, their function and innervation
- travels obliquely from medial to lateral, at right angles to the external intercostals
- originate from the superior border of the rib below
- insertion is the inferior border of the rib above
- fxn=depress the rib cage/muscle of forced expiration
- innervation=segmental intercostal nerve, which is a branch of the posterior rami of spinal nerves
What are the 3 layers of the innermost intercostal muscles from anterior to posterior and what do they do
- Transversus thoracis =depress the ribs
- Subcostal =bridge intercostal space, prob elevate ribs
- Innermost intercostal =bridge intercostal space, prob depress ribs
What ribs have transverse thoracic muscles
2-6
