Anatomy: back - muscles Flashcards
HYPAXIAL MUSCLES
- What are they?
- How did these end up in the back (an epaxial location)?
They developed ventrally and are innervated by ventral rami (hence, hypaxial). But, the muscle + nerves have migrated dorsally to the back
HYPAXIAL MUSCLES
Trapezius:
- Attachments
- Innervation
Skull, nuchal ligament, spinous processes in cervical and thoracic regions
Cranial nerve 11
HYPAXIAL MUSCLES
Levator scapulae
- Innervation
- Actions
Cervical innervation (including the dorsal scapular nerve)
Draws scapula superomedially - elevates and retracts the scapula
HYPAXIAL MUSCLES
Rhomboideus major and minor
- Attachments?
- Innervation
- Actions
Nuchal ligament, spinous processes C7-T5, medial border of the scapula
Dorsal scapular nerve
Draws scapula superomedially - elevates and retracts the scapula
HYPAXIAL MUSCLES
Latissimus dorsi
- Attachments
- Innervation
- Actions
Thoracolumbar fascia, humerus
Thoracodorsal nerve
Arm extension, internal rotation, adduction
HYPAXIAL MUSCLES
2 inferior hypaxial muscles of the back?
Quadratus lumborum and transversus abdominus
TRIANGLE OF AUSCULTATION
- What are its borders?
- Under what circumstances is it exposed? Why would you want to expose it?
Trapezius, latissimus dorsi, medial morder of scapula
When the arm is lifted. Makes it easier to hear lung sounds - as no muscles are covering it
EPAXIAL MUSCLES
Describe their development and innervation
The muscles have developed dorsally
They are innervated by dorsal rami
SUPERFICIAL EPAXIAL MUSCLES
What are the 2 groups?
- Erector spinae group
- Splenius muscles
SUPERFICIAL EPAXIAL MUSCLES
Erector spinae muscles
- Mnemonic
- What are the muscles, and their subdivisions?
I like standing (from lateral to medial)
Iliocostalis lumborum/thoracis/cervicis (attaches at iliac crest (ilio) and ribs (costalis))
Longissimus thoracis/cervicis/capitis
Spinalis
SUPERFICIAL EPAXIAL MUSCLES
Erector spinae muscles
- Common attachment?
- Innervation?
- Actions (bilaterally and unilaterally?)
Thoracolumbar fascia
Dorsal rami of spinal nerves, sequentially
Bilaterally: extension of spine (keeps the spine erect - name)
Unilaterally: laterally bending of the spine
SUPERFICIAL EPAXIAL MUSCLES
Splenius muscles
- What does splenius mean?
- What direction are the fibres orientated?
- What are the two splenius muscles?
Bandage
Superolaterally
Splenius capitis and splenius cervicis
SUPERFICIAL EPAXIAL MUSCLES
Splenius capitis
- Attachments
- Innervation
- Actions (unilaterally and bilaterally)
Mastoid process of temporal bone, spinous processes of C7-T3
Segmental innervation by the dorsal rami of spinal nerves
Bilaterally: extends the head
Unilaterally: rotates the head
SUPERFICIAL EPAXIAL MUSCLES
Splenius cervicis
- Attachments
- Innervation
- Actions (bilaterally and unilaterally)
Transverse processes of C1-C3, T3-T6
Segmental innervation by the dorsal rami of spinal nerves
Bilaterally: extends the neck, unilaterally: rotates the neck
INTERMEDIATE EPAXIAL MUSCLES
What are the 6 intermediate epaxial muscles?
TRANSVERSOSPINALIS GROUP
- Rotatores
- Multifidus
- Semispinalis thoracis/cervicis/capitis
- Levatores costarum
OTHER MUSCLES
- Interspinalis
- Intertransversarius muscles
INTERMEDIATE EPAXIAL MUSCLES
Transversospinalis group
- What structures do they run between?
- What is the direction of the muscle fibres?
Run from the transverse processes to spinous processes, superomedially
INTERMEDIATE EPAXIAL MUSCLES
How many segments do the following muscles span across?
- Rotatores brevis
- Rotatores longus
- Multifidus brevis
- Multifidus longus
- Semispinalis thoracis/cervicis/capitis
- Rotatores brevis: runs across 1 segment
- Rotatores longus: runs across 2 segments
- Multifidus brevis: runs across 2 segments
- Multifidus longus: runs across 4 segments
- Semispinalis thoracis/cervicis/capitis: runs across 6 segments
TRANSVERSOSPINALIS GROUP
Levatores costarum
- What actions does it perform?
- Is it technically a part of the transversospinalis group? Why/why not?
Elevates (levatores) the ribs (costarum)
Technically not part of the transversospinalis group – as attachments from the angles of ribs to tranverse process
INTERMEDIATE EPAXIAL MUSCLES
Label the following
THORACOLUMBAR FASCIA
The anterior layer is found around what muscle?
The middle layer is found around what muscles?
The posterior layer is found around what muscles?
Anterior layer: around the quadratus lumborum
Middle layer: between the quadratus lumborum and erector spinae/multifidus muscles
Posterior layer: around the erector spinae and multifidus muscles
DEEP EPAXIAL MUSCLES
What is the muscle group involved?
How many muscles are there (per side?)
Suboccipital muscles
4 (per side)
DEEP EPAXIAL MUSCLES
Label the suboccipital muscles
DEEP EPAXIAL MUSCLES
Rectus capitis posterior minor:
- Attachments
- Innervation
- Actions
DEEP EPAXIAL MUSCLES
Rectus capitis posterior major:
- Attachments
- Innervation
- Actions
DEEP EPAXIAL MUSCLES
Obliquus capitis superior:
- Attachments
- Innervation
- Actions
DEEP EPAXIAL MUSCLES
Obliquus capitis inferior:
- Attachments
- Innervation
- Actions
DEEP EPAXIAL MUSCLES
Suboccipital triangle
- Label the additional structures
SUBOCCIPITAL TRIANGLE
- What are the muscular borders?
- What are the contents?
Rectus capitis major, obliquus capitis superior + inferior
Suboccipital nerve (dorsal ramus of C1) and the vertebral artery
