12.2 Muscles of the Deep Back Flashcards Preview

Anatomy Exam 3 > 12.2 Muscles of the Deep Back > Flashcards

Flashcards in 12.2 Muscles of the Deep Back Deck (8)
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1
Q

What nerves innervate the intrinsic muscles of the back?

A

Posterior rami of spinal nerves.

2
Q

Identify the splenius capitis muscle, its attachments, function, and innervation.

A
  • Attachments: medially to nuchal ligament and spinous processes of C7-T3; superolaterally to mastoid process and superior nuchal line of occiput
  • Action: unilateral – laterally flexes neck, rotates head; bilateral – extends head/neck
  • Innervation: posterior rami of spinal nerves.
3
Q

Identify the Splenius cervicis muscle, its attachments, function, and innervation.

A

o Attachments: medially to nuchal ligament and spinous processes of C7-T4; superolaterally to posterior tubercles of C1-C4
o Action: unilateral – laterally flexes neck, rotates head; bilateral – extends head/neck
-Innervation: posterior rami of spinal nerves.

4
Q

Identify the 3 muscles that constitute the erector spinae muscles.
-Describe the attachments for each, as well as their general function and innervation.

A
  • 3 columns that attach to a broad tendon from the posterior iliac crest, posterior sacrum, sacroiliac ligaments, lumbosacral spinous processes, and supraspinous ligaments
  • Action: unilaterally, lateral flexion of vertebral column; bilaterally, extension of vertebral column and head
  • Innervation: posterior rami of spinal nerves.

o Spinalis (capitis, cervicis, thoracis)
• Medial column
• Fibers rise up to spinous processes in upper thorax and cranium
o Longissimus (capitis, cervicis, thoracis)
• Intermediate column
• Fibers rise up to ribs between angle and tubercle, transverse processes, and mastoid processes
o Iliocostalis (cervicis, thoracis, lumborum)
• Lateral column
• Fibers rise up to angles of ribs and cervical transverse processes

5
Q

Identify the semispinalis muscles (capitis, cervicis, and thoracis).

  • Describe the attachment plan and function of these muscles.
  • Innervation?
A

-Attachments: Rise from vertebral transverse processes to spinous processes of superior vertebrae
-Function: extension of head and cervical and thoracic vertebral column; rotates thoracic and cervical vertebral column contralaterally
Innervation: Posterior rami of spinal nerves.

6
Q

Identify the rotatores longus and brevis muscles, their attachments, function, and innervation.

A

• Spans 1-2 segments
• Attachments: inferiorly to articular processes of C4-C7, transverse processes of T1-T3, ilium, sacrum; superomedially to root of spinous process of superior 1 or 2 vertebrae
• Action: mainly proprioception, also stabilizing and rotating vertebral column
-Innervation: Posterior rami of spinal nerves.

7
Q

Identify the multifidus muscle, its attachments, function, and innervation.

A
  • Spans 2-4 segments
  • Attachments: sacrum, PSIS, aponeurosis of erector spinae, lateral neural arch to spinous processes
  • Action: unilaterally, rotation to contralateral side; bilaterally, stabilizes vertebrae during movements
  • Innervation: Posterior rami of spinal nerves
8
Q

Identify the lavatores long and brevis muscles, their attachments, function, and innervation.

A

Attachments: Tips of transverse processes of C7-T11; inferolaterally to rib between tubercle and angle

  • Action: Mainly proprioceptive. May elevates ribs, contributes to inspiration, contributes to lateral bending of VC
  • Innervation: posterior rami of C8-T11