MS1 Musculature of the Back- Intrinsic Flashcards
What do the intrinsic back muscles act on
the vertebral column and skull
What are intrinsic back muscles innervated by
posterior rami of spinal nerves
What covers the deep muscles of the back
thoracolumbar fascia
What superficial back muscle will attach to thoracolumbar fascia
latissimus dorsi
What muscles are covered by thoracolumbar fascia
intrinsic back muscles
What are the attachments of the thoracolumbar fascia
Superior: continuous with deep fascia of the neck
Inferior: lower border of Rib 12 and iliac crest
Medial: spinous and transverse processes
Lateral: angles of ribs and lateral abdominal wall muscles
What are the three layers of thoracolumbar fascia
anterior
middle
posterior
Where do the three layers of thoracolumbar fascia terminate
terminate at attachment of transversus abdominus muscle
Describe the location of the posterior layer of thoracolumbar fascia
most superficial
What is the function of the posterior layer of thoracolumbar fascia
covers deep muscles of the back
What is the function of the middle layer of the thoracolumbar fascia
separates deep back muscles from posterior abdominal wall
What is the function of the anterior layer of thoracolumbar fascia
separates abdominal cavity from posterior abdominal wall
How many layers are there of deep muscles
3
What muscles are included in the most superficial deep muscle layer
Spinotransversales
What is the proximal origin of the splenius capitis
nuchal ligament
spinous processes of C7-T4
What is the distal insertion of the splecius capitis
mastoid process
superior nuchal line
What is the proximal origin of the splenius cervicis
Spinous processes T3-T6
What is the distal insertion of the splenius cervicis
transverse processes of C1-C3
What muscles are included in the spinotransversales muscles
Splenius Capitis
Splenius Cervicis
What is the unilateral action of the Spinotransversales
rotate to ipsilateral side, lateral flexion
What is the bilateral action of the spinotransversales msucles
extension of the head and neck
What is the blood supply to the Spinotransversales muscles
Occipital and segmental arteries (come out at every level and supply body wall)
What muscles are included in the erector spinae muscles
Iliocostalis
Longissimus
Spinalis
What is the proximal origin of iliocostalis
ileum and sacrum
lumbar
Where is the distal insertion of iliocostalis
ribs
Where is the proximal origin of longissimus
ileum, sacrum, lumbar
Where is the distal insertion of longissimus
mastoid process and transverse process
What is the proximal origin of spinalis
ileum, sacrum, lumbar
What is the distal insertion of spinalis
spinous processes
What is the unilateral action of erector spinae
lateral flexion of the spine
What is the bilateral action of erector spinae
erect the spine
What muscle is the main extensor of the vertebral column
erector spinae muscle group
What muscle for transversospinales
Semispinalis
Multifidas
Rotatores
Where are the general origins and insertions of the transversospinales
transverse process to the spinous process
Where is semispinalis found
most prominent in thoracic region
How many vertebrae does semispinalis span
4-6 vertebral span
Where is multifidus found
most prominent in lumbar region
How many vertebrae does multifidus span
2-4 vertebrae
Where is rotatores located
entire spinal column
How many vertebrae does rotatores span
1-2
What is the unilateral action of transversospinales
rotation to the opposite side
What is the bilateral action of transversospinales
erection and support
What is the origin of semispinalis capitis
transverse processes of C7-T6
What is the insertion of semispinalis capitis
occipital bone
What are the intersegmental muscles
Intertransversarii and
Interspinales (true segmental)
Levatores costarum
What is the action of intertransversarii and interspinales muscles
support
What is the action of levatores costarum
elevates ribs (transverse process to ribs at thoracic region)
What type of muscle is the levatores costarum
an accessory respiratory muscles
Where is the suboccipital region found
associated with posterior aspects of C1 and C2
deep to semispinalis capitis
What is the proximal origin of rectus capitis posterior minor
inferior nuchal line
Where is the distal insertion of rectus capitis posterior minor
tubercle C1
What is the proximal origin of rectus capitis posterior major
inferior nuchal line
Where is the distal insertion of rectus capitis
spinous process C2
What is the proximal origin for obliquus capitis superior
between superior and inferior nuchal lines
Where is the distal insertion of obliquus capitis superior
transverse process of C1
What is the proximal origin of obliquus capitis inferior
transverse process C1
What is the distal insertion of obliquus capitis inferior
spinous process of C2
What is the function of the suboccipital muscles
support of the head
extension of the head on the neck
lateral flexion
What is the innervation of the suboccipital muscles
suboccipital nerve (C1 posterior ramus)
What is the vascular supply to the suboccipital muscles
vertebral and occipital arteries
What muscles form the suboccipital triangle
rectus capitis posterior major
obliqus capitis inferior
obliqus capitis superior
What are the contents of the suboccipital triangle
vertebral artery and suboccipital nerve (C1)
What is the function of the greater occipital nerve
strictly sensory to the back of the head
What is the clinical correlation for the function of the greater occipital nerve
transverses semispinalis capitis: dysfunction can lead to sensory issues on back of head
What is the function of the suboccipital nerve
motor to the muscles of the sub occipital triangle, no cutaneous or sensory branch
What is suboccipital release
place pressure on back of skull in order to release semispinalis capitis muscle and releave tension on greater occipital nerve (posterior rami C2)
What is the cervical myodural bridge
connection between cervical dura and CT of suboccipital muscles
What is the function of the cervical myodural bridge
implications in movements of CSF
What is a clinical correlation for cervical myodural bridge
possible cause of cervicogenic headaches
