GA Back Muscles, Vasculature and Innervation Flashcards
Trapezius Muscle
O- Medial 1/3 superior nuchal line, external occipital protuberance, nuchal lig., SP’s of C7-T12
I- Lateral 1/3 clavicle, acromion and spine of scapula
A- Superior - elevation of scapula, Middle - retraction of scapula, Inferior - depression of scapula, Superior and Inferior fibres together - upward rotation of scapula
N- Motor - CN XI (Spinal Accessory), Sensory - C3, C4
B - Transverse cervical artery
Latissimus Dorsi Muscle
O- SP’s of T6-12, thoracolumbar fascia, iliac crest and inferior 3 or 4 ribs
I- Floor of intertubercular (IT), groove (sulcus) of humerus
A- Extension, ADD, and MR of Humerus, downward rotation of scapula; raises body towards arm when climbing
N- Thoracodorsal nerve (C6,C7,C8)
B - Thoracodorsal artery
Levator Scapulae Muscle
O- Posterior tubercles of TP’s C1-4
I- Medial border of scapula, superior to root of scapular spine
A- Elevation and downward rotation of scapula; bilaterally, extension of neck
N- Dorsal scapular nerve (C5)
B- Dorsal scapular artery
Rhomboid Major
O- SP’s T2-5
I- Medial border of scapula from level of spine to inferior angle
A- Retraction and downward rotation of scapula; fix scapula to thoracic wall
N- Dorsal scapular nerve C4,C5)
B- Dorsal scapula artery
Serratus Posterior Superior
O- Nuchal lig., SP’s C7-T3
I- Superior borders of 2nd and 4th ribs
A- Proprioception (elevation of ribs); considered accessory muscle of respiration
N- 2nd-5th Intercostal nerves
Rhomboid Minor
O- Nuchal lig. and SPs of C7 and T1
I- Smooth triangular area at base of scapular spine
A- Retraction and downward rotation of scapula; fix to thoracic wall
N- Dorsal scapular nerve (C4,C5)
B- Dorsal scapular artery
Serratus Posterior Inferior
O- SPs T11-L2
I- Inferior borders of 8th-12th ribs nears their angles
A- Proprioception (depress ribs); considered accessory muscle of respiration
N- Ventral rami of T9-T12 thoracic spinal nerves
Splenius Cervicis
O- Nuchal lig., and SP’s of C7-T3 or T4
I- Tubercles of TP’s C1-C3 or C4
A- Lateral flexion of neck to side of active muscle
N- Dorsal rami of spinal nerve
Splenius Capitis
O- Nuchal lig., and SP’s of C7-T3 and T4
I- Mastiod process and later 1/3 of superior nuchal line
A- Rotation of head to side of active muscle
N- Dorsal rami of spinal nerve
Iliocostalis
O- Posterior part of iliac crest, posterior surface of sacrum, sacroiliac lig., sacral and inferior lumbar SP’s and supraspinous lig.
I- Lumborum- angles of lower rib, Thoracis- angles of upper rib, Cervicis- cervical TP’s
A- Bilateral- extension of vertebral column; unilateral- lateral flexion of vertebral column
N- Dorsi rami of spinal nerve
Longissimus muscle
O- Posterior part of iliac crest, posterior surface of sacrum, sacroiliac lig, sacral and inferior lumbar SP’s and supraspinous lig.
I- Thoracis- ribs b/w tubercles and angles and TP’s in thoracic region, Cervicis - cervical TPs, Capitis- Mastoid process
A- Bilateral- ext of vertebral column and head; unilateral- lat flexion of vertebral column
N- Dorsi rami of spinal nerve
Spinalis muscle
O- Posterior part of iliac crest, posterior surface of sacrum, sacroiliac lig., sacral and inferior lumbar SP’s and supraspinous lig.
I- Thoracis- SP’s in thoracic region, Cervicis- SP’s in cervical region, Capitis- Cranium
A- Bilateral- ext of vertebral column and head; unilateral- lat flex of vertebral column
N- Dorsi rami of spinal nerve
Semispinalis
O- TP’s of C4-T12 vertebrae
I- Thoracis- SP’s 4-6 vertebral segements superior, Cervicis- SP’s 4-65 vertebral segments superior, Capitis- Occipital bone
A- Bilateral ext of all regions; contralateral rotation of all regions
N- Dorsi rami of spinal nerve
Multifidus
O- Posterior sacrum, PSIS, sacroiliac lig., aponeurosis of erector spinae muscle, mamillary process of lumber vertebrae, TP’s of T1-3 and articular processes of C4-7
I-SP’s 2-4 segments superior
A- Stabilize vertebrae during local movements of vertebral column
N- Dorsal rami of spinal nerve
Rotatores
O- TP’s of vertebrae
I- Longus- SP 2 segments superior; brevis - SP1 segments superior
A- Stabilize vertebrae and assist with extension and roptary movements; proprioception
N- Dorsi rami of spinal nerve
Interspinalis
O- Superior surfaces of SP’s of cervical and lumbar vertebrae
I- Inferior surfaces of SP’s of vertebrae superior
A- Aid in ext and rotation of vertebral column
N- Dorsi rami of spinal nerve
Intertransversarii
O- TP’s or cervical and lumbar vertebrae
I -TP’s of adjacent vertebrae
A- Aid in lateral flexion of vertebral column; bilaterally- stabilize vertebral column
N- Dorsal and ventral rami of spinal nerve
Levatores Costarum
O- Brevis and Longus - TP’s of C7-T11
I- Ribs b/w tubercle and angle
A- Elevates ribs in inspiration, assist with lateral flexion of vertebral column
N- Dorsal rami of spinal never
Rectus Capitis Posterior Major
O- SP of C2 I- Lateral part inferior nuchal line A- Ext of head; rotation of same side N- suboccipital nerve B- Vertebral and occipital artery
Rectus capitis posterior minor
O- Posterior tubercle of posterior arch of C1
I- Medial part inferior nuchal line
A - Extension of head; Rotation to same side
N- Sub occipital nerve
B- Vertebral and occipital artery
Obliquus capitis Inferior
O- SP of C2 I- TP's of C1 A- Rotation of atlas and face to same side N- Suboccipital nerve B- Vertebral and occipital artery
Obliquus Capitis Superior
O- TPs of C1
I- Occipital bone between superior and inferior nuchal lines
A- Extension of head and lateral flexion of head and neck
N- Suboccipital nerve
B- Vertebral and occipital artery
Vasculature of back
Transverse cervical artery, Dorsal Scapular artery, Thoracodorsal artery, Posterior intercostal Arteries, Occipital artery, Vertebral artery
Transverse Cervical Artery
originates from the thyrocervical trunk.
superficial cervical branch deep to trapezius, runs with CN XI
dorsal scpular atery deep branch supplies levator scapulae and rhomboid muscles, artery does not branch from here
Dorsal Scapular Artery
originates from subclavian artery
passes through trunk of brachial plexus, supplies levator scapulae and rhomboid muscles and runs with dorsal scapular nerve
Thoracodorsal artery
originates from 1 of 2 terminal branches of subscapular artery
supplies latissimus dorsi muscle and runs with thoracodorsal nerve
Posterior Intercostal ateries
originates from descending thoracic aorta
dorsal cutaneous branches that supply deep back muscles
Occipital artery
originates from external carotid artery
supplies posterior scalp and suboccipital muscles
Vertebral Artery
originates from subclavian artery
enters neck at C6, passes thru transverse foramin and exits C1. supplys suboccipital region, enter foramen magnum with help of circle of willis
Innervation of Back
Dorsal Rami of Spinal Nerve, Spinal Accessory, Thoracodorsal Nerve, Dorsal Scapular nerve
Dorsal Rami of Spinal Nerve
fixed from spinal nerve, some unique rami; C1 - larger dorsal ramus exits b/w occiput and C1 vertebrae and is called suboccipital nerve
C2 - larger doral ramus, exits b/w C1 and C2, medial division of this nerve is the greater occipital nerve
supplies intrinsic back muscles
Spinal Accessory Nerve
CN XI, supplies trapezius muscles
origin is the spinal cord and the brain stem
Thoracodorsal Nerve
branch of posterior cord of brachial plexus C6-8, supplies latissimus dorsi muscle
origin is the posterior cord of the brachial plexus (C6-C8)
Dorsal Scapular Nerve
branch of ventral rams of C5, supplies the levator scapulae and rhomboid muscles
origin is the brachial plexus
C1
larger than ventral C1 nerve, large dorsal rams, exits between the occiput and C1, call suboccipital nerve, supplies the suboccipital trianngle muscles
C2
larger dorsal ramus, exits b/w C1 and C2, medial division of this dorsal ramus called greater occipital nerve
Vertebral Column and functions
approx 72-75 cm long
functions: protect spinal cord and nerves, support body weight, provides and axis for body and head, important for posture and locomotion
Curvatures of Vertebral Column
four curvatures in adults, occur in cervical, thoracic, lumbar and sacral regions
Primary curvature which is formed during the fetal period and secondary which are formed due to an extension from fetal position.
Excessive lordosis
anterior lifting of the pelvis with increased extension of lumbar vertebrae
causes: weakened trunk musculature, obesity
Excessive Kyphosis
abnormal increase in thoracic curvature in which the vertebrae curve posteriorly
causes: erosion of the anterior part of one or more vertebrae
Scoliosis
abnormal lateral curvature accompanied by rotation of vertebrae, SP’s rotate toward the cavity of abnormal curvature, ribs protrude on side of increased convexity
Types: structural, myophatic, functional, habit
Typical vertebrae
body, arch, pedicles, laminae, foramen, canal, notches, intervertebral foramen, spinous processes, transverse processes, articular processes
Ligaments
Supraspinous lig - connects tips of SP’s from C7-Sacrum, merges with
Nuchal Lig. - extends from external occipital protuberance and posterior border of foramen magnum to SPs of cervical vertebrae, accommodates the short C3-5 SP’s providing attachment for muscles
Triangle of Auscultation
Borders: Medial - trapezius, Lateral - medial border of scapula, Inferior - Latissimus Dorsi, Floor - Erector Spinae and rhomboid major
provides a good area to hear posterior lungs, to expose you need to protract scap and flex back, makes space in 6th rib b/w 6th and 7th ribs
Lumbar Triangle
Borders: Medial - Erector Spinae, Lateral - External Oblique, Inferior - Iliac Crest, Floor - Internal Oblique
important b/c it is a common place of lumbar hernia
Suboccipital Triangle
Superomedial - Rectus Capitus Posterior Major, Superolater - Obliquus Capitis Superior, Superoinferior - Obliquus Capitis Inferior, Roof - Semispinalis Capitus, Floor - posterior atlanto-occipital membrane
contains: vertebral artery and suboccipital artery
Two major groups of back muscles
Extrinsic - divided into superficial and intermediate, produce and control limb and respitory movements respectively
Intrinsic - Deep Back muscles, divided into superficial, intermediate and deep and minor deep layers, specifically act on vertebral column
Superficial Deep Back Muscles
Trapezius, Latissimus Dorsi, Levator Scapulae, and Rhomboid Major and Minor,
also known as posterior axioappendicular muscles
produce and control upper limb movements
receive innervation from vetral rami of cervical nerves
Intermediate Extrinsic Back Muscles
Serratus Muscles
designated as superficial respiratory muscles but are more likely for proprioception all innervated by ventral rami
Intermediate Intrinsic Back Muscles
collectively know as erector spinae muscles, lie in a groove between SP’s and angle of ribs, chief extensors of vertebral column and is divided into 3 columns based on superior attachment
Deep Intrinsic Back Muscles
collectively known as transversospinalis group, deep to erector spinae muscle, occupy gutter between the SP’s and the TP’s, having the laminae and ligaments linking them together
Minor Deep Intrinsic Back Muscles
relatively sparse in thoracic region
interspinalis, intertransversarii, levators costarum
Suboccipital Region
muscle compartment beep to superior part of posterior cervical region, pyramidal space inferior to external occipital protuberance, contains 4 small muscles
contains: greater occipital nerve, occipital nerve, 3rd occipital nerve and lesser occipital nerve
