Muscle of the back and thorax

Question 1

What are the 3 groups of muscles in the back and what are there general functions

Answer 1

1. Extrensic back muscles= superficial group that produce and control limb movements
2. Intermediate group= muscles involved in respiration
3. Intrinsic back muscles= the true back muscles that act on the vertebral column producing its movements and maintaining posture

Question 2

Name the 2 intrinsic muscle groups of the back

Answer 2

1. Erector spinae

2. Transverospinal

Question 3

Where is the origin and function of the erector spinae

Answer 3

origin=sacrum and iliac crest

fxn=extension of the spine, flexion, lateral bending

Question 4

What are the 3 muscular columns of the erector spinae

Answer 4

Spinalis (medial)

Longissimus (intermediate)

Illiocostalis (lateral)

Question 5

True or False the transverospinal muscles are superficial to the erector spinae

Answer 5

False, the transverospinal muscles are deep to the erector spinae

Question 6

Describe the location and function of the transverospinal muscles

Answer 6

function=rotate the vertebrae

location= almst look like they wrap around the spine

Question 7

What is the Mnemonic for remembering the names of the transverospinal muscles from superficial to deep

Answer 7

Spine= semispinal muscles
May= multifidus muscles 
Rotate= rotatores muscles

Question 8

Define anterior median line

Answer 8

aka midsternal

reference line that indicates the intersection of the median plane with the anterior chest wall

Question 9

Define midclavicular line

Answer 9

reference lines that pass through the midpoints of the clavicles, parallel to the anterior median line

Question 10

Define anterior axillary line

Answer 10

reference line that runs vertically along the anterior axillary fold, it is formed by the border of the pectoralis major

Question 11

Define midaxillary line

Answer 11

reference line that runs from the apex of the axilla, parallel to the anterior line

Question 12

Define posterior axillary line

Answer 12

reference line that is parallel to the anterior axillary line vertically along the posterior axillary fold, my the latissimus dorsi and teres major

Question 13

Define scapular line

Answer 13

lines parallel to the posterior median line and cross the inferior angles of the scapula

midclavicular lines but on the back

Question 14

Posterior median line

Answer 14

vertical line described by the tips of the spinous processes of the vertebrae

Question 15

What 2 groups of muscles make up the muscles of the thoracic wall

Answer 15

1. thoracoappendicular

2. Muscles of breathing

Question 16

What is the fxn of the thoracoappendicular muscles

Answer 16

-upper limb muscles that attach to the thoracic cage, and produce/control limb movements

Question 17

What muscles comprise the muscles of breathing

Answer 17

• Diaphragm
• Scalenes
• intercostal muscles
• some thoracoappendicular muscles

Question 18

Name the 3 layers of intercostal muscles from superficial to deep

Answer 18

• outer layer=External intercostals
• middle layer= internal intercostals
• innermost = 3 layers

Question 19

Describe the external intercostal muscles in terms of the direction they run, origin and attachment, their function and innervation

Answer 19

• 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

Question 20

Describe the internal intercostal muscles in terms of the direction they run, origin and attachment, their function and innervation

Answer 20

• 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

Question 21

What are the 3 layers of the innermost intercostal muscles from anterior to posterior and what do they do

Answer 21

1. Transversus thoracis =depress the ribs
2. Subcostal =bridge intercostal space, prob elevate ribs
3. Innermost intercostal =bridge intercostal space, prob depress ribs

Question 22

What ribs have transverse thoracic muscles

Answer 22

2-6