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
The origin and insertion of longissimus muscle
Origin (Thoracis): Transverse processes of lumbar vertebrae.
Insertion (Cervicis): Posterior margin of Mastoid process.
The muscle of erector spinae that Most medially placed, smallest.
Attaches to the spinous processes of vertebrae.
Spinalis muscle
The origin and insertion of spinalis
Origin (Thoracis): Transverse processes of lumbar vertebrae.
Insertion (Capitis): Blends with semispinalis capitis.
Action of erector spinae
Action
Primary extensors of the vertebral column and head.
Bilaterally – Straighten the back, returning it to the upright position, pulls head posteriorly.
Unilaterally – Bends vertebral column laterally, turns head to actively contracting side.
Transversospinales
The action and name the muscles
extensor and rotator of vertebral column
Transversospinales how does its run
Run obliquely upward and medially from the transverse process to the spinous process filling the groove between the two vertebral projections.
Name the 3 major subgroups of tranversospinales
Has three major subgroups:
Semispinalis
Multifidus
Rotatores
Most superficial transversospinales
Semispinalis
Semispinalis
A. Begins where
B. Crosses where
C. Found where in the vertebral column regions
D. Division of semispinalis
A. Begins in lower thoracic region, ends by attaching to skull between nuchal lines.
B. Crosses 4-6 vertebrae from point of origin to point of insertion.
C. Found in thoracic and cervical regions.
D. Divided into semispinalis thoracis, semispinalis cervicis and semispinalis capitis.
A. where does the multifidus muscle best develop
B. Passes where?
C. Span where?
D. Start where and ends where?
A. Best developed in the lumbar region.
B. Passes from lateral origin upward to medially insert to the spinous process.
C. Spans 2-4 vertebrae from point of origin to point of insertion.
D. Starts at sacrum and ends at spinous process of axis (C2).
Muscles span length of vertebral column.
Multifidus
A. The rotatores is present where?
B. Fibers arrangement of rotatores?
C. Where does the rotatores crosses?
D. Division of rotatores
A. Present throughout vertebral column, most prominent in thoracic region.
B. Fibres pass upward and medially from transverse to spinous process.
C. Cross two vertebrae (Long rotators) or attach to adjacent vertebrae (Short rotators).
D. Divided into rotatores lumborum, rotatores thoracis and rotatores cervicis.
Deepest of the transverspinales
Rotatores
Name the segmental muscles
Levatores Costarum
Intertransversarii
Interspinales
Name the muscles of suboccipital group
Rectus capitis posterior Major
Rectus capitis posterior minor
Obliquus capitis inferior
Obliquus capitis superior
Small group of deep muscles in the upper cervical region at the base of the occipital bone.
Name the muscle group
Suboccipital muscles
What does the suboccipital muscles group connects
Connects C1 to C2 and both of these vertebrae to the base of the head.
Contraction of suboccipital muscle group results to what?
Contraction of these muscles results in extension and rotation of the head at the atlanto-occipital and atlanto-axial joints.
Suboccipital muscles are all innervated by the
posterior ramus of C1
The origin, insertion and action of rectus capitis posterior major
Origin: Spinous processes of axis (C2).
Insertion: Lateral part of skull, below the inferior nuchal line.
Action: Extension of head, rotation of head to face same side.
The origin, insertion and action of rectus capitis posterior minor
Origin: Posterior tubercle of atlas (C1).
Insertion: Medial part of skull, below the inferior nuchal line.
Action: Extension of head.
The origin, insertion and action of obliquus capitis superioris
Origin: Transverse process of atlas (C1).
Insertion: Occipital bone between nuchal lines.
Action: Extension of head, bends head to the side.
The origin, insertion and action of obliquus capitis inferior
Origin: Spinous process of axis (C2).
Insertion: Transverse process of atlas (C1).
Action: Rotation of head to face same side
Boundaries of suboccipital triangle
Medial: Rectus capitis posterior major and minor.
Lateral: Obliquus capitis superioris.
Inferior: Obliquus capitis inferioris.
Contents of suboccipital triangle
Posterior ramus of C1
Vertebral artery
Veins
What does the injury to accessory nerve can cause
DROOPING OF THE SHOULDER
What is drooping of the shoulder and affects which muscles
Weakness in the trapezius muscle, which is caused by an injury to the accessory nerve, can appear as drooping of the shoulder.
The drooping of the shoulder results to an inability to what?
Weakness in the trapezius muscle, which is caused by an injury to the accessory nerve, can appear as drooping of the shoulder.
The injury to the thoracolumbar fascia results to what? explain in details.
Injury to this fascia usually manifests as tightness and increased tone in the thoracic and lumbar spine which causes severe pains.
Poor posture and excessive strain can cause an injury
