Extrinsic muscles are supplied nerves by the anterior rami (branch of a spinal nerve that exits the vertebral canal (opening in the vertebrae) of spinal nerves
extrinsic muscles consist of two layers of the back and their functions
superficial connects the axial skeleton (skeleton that contains head and trunk of vertebrae) to the superior appendicular skeleton (portion of skeleton consisting of bone or cartilage that support appendages (external projection from body)
intermediate is only apart of the axial skeleton, controls respiratory/proprioceptive (a stimuli produced and perceived by organism) movements
intrinsic muscles function 3
associated with axial skeleton
act on vertebral column to control movements and maintain posture
supplied nerves from the posterior rami (branch of spinal nerve that forms the dorsal root) of spinal nerves
axio-appendicular musculature function and location
are muscles that extend between axial and appendicular (portion of skeleton consisting of bones or cartilage that support appendages) skeletons
insert on the upper limb
innervated by anterior rami of spinal nerves (except trapezius)
name the muscles of the superficial extrinsic 5
trapezius
levator scapulae
rhomboid minor
rhomboid major
latissimus dorsi
trapezius actions 4
descending - elevation of scapula
middle - retracts scapula (push arms bag)
ascending - depress scapula
descending + ascending - superior rotation of scapula (swinging of arm 360)
trapezius innervate the cranial nerve XI spinal accessory nerve
insertion at the acromion and spine of the scapular
trapezius palsy cause and effect
a weakness in the trapezius muscle due to the result of injury to the CN XI spinal accessory nerve that innervates it
weakness of superior rotation of the shoulder (glenhumeral joint (ball and socket joint))
how is trapezius treated
surgically with muscle transfers of the levator scapulae and rhomboids
latissimus dorsi broadest part of back ations 2
extends, adducts and medially rotates the humerus at the ball and sock joint
helps raise body toward arms while climbing
innervation of the latissimus dorsi
insertion
thoracodorsal nerve (branch of the brachial plexus (branch or network of vessels or nerves)) (think where brachial pulse is)
intertubercular sulcus of humerus (a groove separating the larger and smaller nodes of the humerus)
origin of latissimus doris
spinous processes of T6-T12 (protrution at the posterior of the vertebrae (pokes out if too skinny)), thoracolumbar fascia (a deep membrane throughout the posterior thorax and abdomen)
levator scapulae actions 2
elevates scapula
rotates glenoid cavity inferiorly
levator scapulae innervation
insertion
dorsal scapular nerve (branch of brachial plexus)
medial border of scapula, superior root of scapular spine (neck to shoulder area muscle)
origin of levator scapulae
transverse processes of C1-C4 (same bones but side protrusions inside of middle main)
rhomboid minor and major actions 3
**minor is above and major is below**
retract scapula (pull arm back)
inferior rotation of scapula (praise with arms up)
fix scapula to thoracic wall
rhomboid minor and major innervation
insertion
dorsal scapular nerve (branch of brachial plexus)
MI-medial end of scapular spine
MJ-medial border of scapula
rhomboid minor and major origin
MI-nuchal ligament & spinal processes C7/T1
MJ-spinous processes of T2-T5
actions
controls respiratory/proprioceptive (produced and sensed stimuli) movements
intrinsic back muscles name and actions
erector spinae (group of 3)
extends vertebral column
some roation of vertebral column
act on vertebral column to control movements and maintain posture
paraspinous muscles actions
act on vertebral column to control movements and maintain posture
back sprain
normal
grade 1 sprain
grade 2 sprain
grade 3 sprain
normal looking tissue
1 - stretching with some tears
2 - larger tear
3 - complete tear
back sprain defined and cause
injury where only ligamentous tissue or a ligament attached to the bone is dislocated
due to strong contractions from movements of the vertebral column
back strain definition, cause, muscles involved
injury due to stretching or microscopic tearing of muscle fibers
results from overly strong muscle contraction
erector spinae muscles are often involved **muscle spams may response to inflammation)
ramus
any part or organ that branches from another part
rami spinal nerve description
muscle nerves go to intrinsic muscles of the back which help with sensation
spinal nerve emerges laterally from the IV foramen
spinal nerve then divides into 2 major branches ventral (anterior) and dorsal (posterior) primary rami
posterior go to back intrinsic muscles
anterior go to body wall and limbs (extrinsic back muscles)
4 innervations of the back
spinal accessory nerve
cutaneous branches of posterior rami
dorsal scapular nerve
thoracodorsal nerve
spinal accessory nerve (cranial nerve XI) location and possible injury
this is front it runs down the back between scapula and spine
travel from cranium through the neck and back deep to trapezius
superficial nerve
penetrating or blunt injury
cutaneous branches of posterior rami function
provides cutaneous sensory innervation (GSA) to the back
dorsal scapular nerve C5
location
innervation
emerges between anterior and middle neck muscles posteriorly deep through levator and rhomoids
innervates rhomboid minor and major and levator through separate branch
thoracodorsal innervation
latissimus dorsi (C6-C8)
cutaneous branches of posterior rami function
provides cutaneous sensory innervation (GSA) to the back
(the branch of nerves running out of the middle of the back from neck to mid back)
dermatomes defined
use
number
location
unilateral area of skin innervated by (GSA) fibers of a single spinal nerve
helps find site of damage in neurology
30
7 cervical C2-C8
12 thoracic (T1-T12)
5 lumbar (l1-l5)
5 sacral (S1-5)
1 coccygeal
cutaneous nerves
function
supplies an area of the skin that is related to a peripheral nerve
**nerve contains fibers from several individual spinal nerves
**are broader and wider than an area supplied by only a single spinal nerve
suboccipital triangle is bounded (demarcated) by what 3 muscles
contains
rectus capitis posterior major on superomedial margin
obliquus capitis inferior on inferolateral margin
obliquus capitis superior on superolateral margin
suboccipital n (c1)
vertebral artery
vertebral artery
location
travels through transverse foramen C6-1 passes medially along posterior arch of C1 then passes superiorly through the foramen magnum to supply brain
**c7 has a transverse foramina but vertebral arteries dont run through then**
*** when blood flow is reduced like prolong turning of head may cause reduced flow of blood to brain***
deep posterior neck muscle actions 2
use of atlanto-occipital joint (synovial joint)
extension
lateral flexion
head rotation using the atlanto-axial joint
rotation of muscles contract
right?
left?