Muscle Origin/Insertion/Nerve/Blood Supply Flashcards
What do extrinsic muscles of the back do?
Superficial group: movements of the upper limb.
Intermediate group consists of muscles attached to the ribs and may serve a respiratory function.
What do intrinsic muscles of the back do?
Maintain posture and move the vertebral column and head; movements include extension, lateral flexion, and rotation
If there is not much mobility between each vertebra, how does the vertebral column allow for such extensive motion?
Movement is additive
How is back musculature divided?
Superficial, intermediate and deep
What muscle groups within the back are extrinsic?
Superficial and intermediate
What innervation supplies the extrinsic muscles of the back?
Anterior rami of spinal nerves
What innervation supplies the intrinsic muscles of the back?
Posterior rami of the spinal nerves
What parts of the skeleton do superficial muscles attach?
Superior part of appendicular skeleton to the axial skeleton
What is the origin of the trapezius muscles?
Descending: Superior occipital nuchae and ligamentum nuchae, and spinous process of C1-C7
Transverse: Spinous processes of T1-T4
Ascending: Spinous processes T5-T12
What is the insertion of the trapezius muscles?
Descending: Lateral one third of the clavicle
Transverse: medial side of the acromion
Ascending: upper crest of the scapular spine
How many muscle sections make up the trapezoid muscle?
6- 2 Descending, 2 transverse, 2 ascending
What motor nerve innervates the trapezius muscles?
anterior rami of accessory nerve XI
Where do proprioceptive fibres of the trapezius move through?
Move through cervical plexus to C3 and C4 vertebra
Where is blood supply to the trapezius from?
Superficial branch of the transverse cervical artery
Acromial branch of the suprascapular artery
Dorsal branches of posterior intercostal arteries.
What movements does the trapezius muscle perform?
Assists in rotating the scapula during abduction of humerus above horizontal; upper fibers elevate, middle fibers adduct, and lower fibers depress scapula
What movements does the latissimus dorsi perform?
Extends, adducts, and medially rotates humerus
What is the origin of latissimus dorsi?
Spinous processes of T7 - L5 and sacrum, iliac crest, ribs 10-12
What is the insertion of latissimus dorsi?
Floor of intertubercular groove of humerus
What innervation supplies latissimus dorsi?
Thoracodorsal nerve (C6 to C8)
What is the origin of the Levator Scapula?
Transverse process of C1-C4
What is the insertion of the Levator Scapula?
Upper portion of medial border of scapula
What nerve(s) innervates the levator scapula?
C3-C4 and dorsal scapular nerve
What movements does the levator scapula perform?
Elevates scapula
What is the origin of Rhomboid Major?
Spinous process of T2-T5
What is the insertion of Rhomboid Major?
Medial border of scapula between scapular spine and inferior angle
What nerve(s) innervate Rhomboid Major?
Dorsal Scapular Nerve (C4, C5)
What nerve(s) innervate Rhomboid Minor?
Dorsal Scapular Nerve (C4, C5)
What is the origin of Rhomboid Minor?
Lower portion of ligamentum nuchae and spinour process of C7-T1
What is the insertion of Rhomboid Minor?
Medial border of scapula at scapular spine
What movements does Rhomboid Minor perform?
Retracts (adducts) and elevates scapula
What movements does Rhomboid Major perform?
Retracts (adducts) and elevates scapula
What are the most superficial of the intrinsic back muscles?
Splenius Muscles
Splenius capitis, and splenius cervicis
Where does Splenius Capitis originate?
Spinous Processes of C7-T3 and lower half of Nuchal Ligament
Where does Splenius Capitis insert?
Base of skull- Occipital bone and mastoid process
What action do the Splenius Muscles aid in?
Bilateral neck extension
Unilateral rotation of head (towards muscle)
Where does Splenius Cervicis originate?
Spinous processes and bottom of nuchale ligaments (T3-T6)
Where does Splenius Cervicis Insert?
Transverse processes of C1-C3
What nerves supply the splenius muscles?
Posterior rami of spinal nerves
What is the name of the intermediate layer of the intrinsic back muscles?
Erector spinae muscles
What is the common origin of the intermediate intrinsic back muscles?
Broad tendon attached to sacrum, spinous processes of the lumbar and lower thoracic, and ileac crest
What are the 3 grouping of the intermediate intrinsic back muscles?
Iliocostal, Longissimus, and Spinalis
What is the insertion of the Iliocostal muscles?
Inserts angles of ribs, and transverse processes of cervical spine
What is the insertion of the longissimus muscles?
Insert at cervical and thoracic transverse processes and mastoid process
What is the insertion of the spinalis muscles?
Thoracic spinous processes and skull base
What are the different muscle sections in the ileocostalis muscle group?
Lumbar, thoraces, and cervicis
What are the types of muscles found in longissimus muscle group?
Thoracis, cervicis, capitis
What are the divisions of the spinalis muscle?
Thoracis, cervicis, capitis
What action does the erector spinae muscles aid in?
Extend the spine (straighten back and lean back)
Main muscles that work to extend the spine.
Independent unilateral contraction aids in rotation
What muscle groups are found in the deep intrinsic back muscles?
Transversospinalis muscles and additional muscles
What are the muscle types that make the deep transversospinalis muscles as well as the amount of vertebrae that the muscle types cross?
Semispinalis (cross 4-5 vertebrae)
Mutifidis (lower region, crosses 3-4 vertebrae)
Rotatores (deep, pass 1-2 vertebrae to connect transverse with spinous processes)
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What movement do the transversospinalis muscles aid in?
Rotation of spine primarily and back extension
What are the additional intrinsic muscles?
Levator costarum, interspinalis and intertransversirii
What is the origin and insertion of levator costarum?
Transverse process down to posterior aspect of ribs, inferior to vertebra of origin
What motion does the levator costarum aid in?
Lifting the ribs
What is the origin and insertion of the interspinalis muscle?
Cross 1 vertebra to connect spinous processes of vertebrae.
What is the origin and insertion of the intertransversirii muscles?
Cross 1 vertebra to attach the transverse processes of vertebrae.
What do the tiny muscle spindles in the intrinsic additional back muscles aid in?
Proprioception
What are some examples of things that may cause back pain?
Muscle spasm, strained muscles, poor posture, ligament injury (sprain), nerve pain (prolapsed disc applying pressure to nerves, sciatica), synovial joint arthritis, kidney stones, pancreatic pain, enlarged lymph nodes, enlarged aortic (i.e. aneurism)
Moving from lateral to medial, name the intermediate intrinsic back muscles.
Iliocostalis, longisimus, spinalis
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What are the intrinsic back muscles, moving from most dorsal to most ventral?
Splenius Muscles (splenius cervical/capitate)
Intermediate Erector Muscles (Ileocostalalis, Longissimus, Spinalis)
Deep Transversospinalous Muscles (Semispinalous, Multifidus, Rotatores)
Additional Deep Muscles (Interspinous, Intertransverous, Levator costalis)
What muscles are found within the transversospinalis group?
Multifidus, Rotatores, and semispinalis
