Muscles of the Back Flashcards
The muscles of the back are divided into 3 groups, name those groups and functions.
Back muscles are organized into three groups:
1. SUPERFICIAL – Movement of the upper limb.
2. INTERMEDIATE – Attached to ribs, has respiratory function.
3. DEEP – movement of vertebral column and head.
name the group of muscles that are extrinsic and their innervation
The superficial and intermediate groups are extrinsic muscles that are innervated by the anterior rami of the spinal nerves.
name the group of muscle that are intrinsic and their innervation.
The deep group of muscles are intrinsic muscles that are innervated by the posterior rami of the spinal nerves.
Name the muscles of the intermediate group in the muscle of the back
serratus posterior superior
serratus posterior inferior
The innervation, action, origin and insertion of serratus posterior superior
Origin: Lower portion of ligamentum nuchae, spinous processes of C7-T3
Insertion: Upper border of Rib 2-5, Lateral to the angle
Innervation: Anterior rami of T2-T5
Action: Elevates Ribs 2-5
The innervation, origin, insertion and action of serratus posterior inferior
Origin: Spinous processes of T11-L3, Supraspinous ligament.
Insertion: Lower border of Ribs 9-12, Lateral to angle.
Innervation: Anterior rami of T9-T12.
Action: Depresses Ribs 9-12, may prevent lower ribs from elevating during diaphragm contraction.
The muscle of the intermediate of the back that Deep to rhomboid muscles.
Serratus posterior superior
the fibers of the serratus posterior superior
Fibers descend.
The muscles of the intermediates back that Immediately deep to latissimus dorsi.
serratus posterior inferior
The fibers of serratus posterior inferior
Fibres ascend
Name the muscle of the back of the superficial group
Trapezius
rhomboid major and minor
latissimus dorsi
levator scapulae
What is thoracolumbar fascia
Covers deep muscles of back and trunk.
Where does the thoracolumbar fascia pass in posterior, what does it covers in thoracic region, where does it attach in medially and laterally?
Superiorly – Passes anteriorly to serratus posterior superior, continuous with deep fascia of neck.
Thoracic Region – Covers and separates deep muscles from other groups.
Medially – Attaches to spinous processes of vertebrae.
Laterally – Attaches to angle of ribs.
In lumbar region the thoracolumbar fascia has three layers, name those layers.
Posterior – Thick, attached to spinous process of lumbar vertebrae and sacrum, extends to cover erector spinae.
Middle – Attached medially to tips of transverse processes of lumbar vertebrae. Inferiorly attached to iliac crest, superiorly attached to lower border of Rib 12.
Anterior – Covers anterior aspect of quadratus lumborum. Medially attached to transverse processes of lumbar vertebrae, inferiorly attached to iliac crest and superiorly forms lateral arcuate ligament.
The function of spinotransversales muscles and name those muscles
Extensor and rotator of the head and neck
splenius cervicis
splenius capitis
The origin, insertion, innervation and action of splenius capitis.
Origin: Lower half of ligamentum nuchae, spinous processes of C7-T4.
Insertion: Mastoid process, skull below Lateral ⅓ of Superior nuchal line.
Innervation: Posterior rami of Middle Cervical Nerves.
Action:
Together – Draws head backward, extend neck.
Individually – Draw and rotate head to one side
The origin, insertion, innervation and action of splenius cervicis
Origin: Spinous processes of T3-T6.
Insertion: Transverse processes of C1-C3.
Innervation: Posterior rami of Lower Cervical Nerves.
Action:
Together – Extend neck.
Individually – Draw and rotate head to one side
The function of erector spinae and name the muscles of erector spinae
Extensor and rotator of the vertebral column
Largest group of intrinsic back muscles which lies posterolaterally to the vertebral column.
Name this group
Erector spinae
Where does the muscle of the erector spinae arise from
Mass of muscle arises from a broad, thick tendon which is attached to the sacrum, spinous processes of thoracic and lumbar vertebrae as well as the iliac crest.
Explain the division of the erector spinae
This muscle mass is divided into three vertical columns.
Each of these are further divided into regional subdivisions:
Capitis, Cervicis, Thoracis, Lumborum
The muscle of erector spinae that Most laterally placed.
Attaches to the angle of the ribs.
iliocostalis
The insertion and origin of iliocostalis muscle
Origin (Lumborum): Sacrum and spinous processes of lumbar and lower two thoracic vertebrae, and the iliac crest.
Insertion (Cervicis): Transverse processes of C4-C6.
The muscle of erector spinae that Middle column, largest.
Attaches to the transverse processes of vertebrae.
longissimus muscle
