Back muscles attachments Flashcards
What are the muscles of the back divided into? (2)
- superficial (extrinsic)
2. deep (intrinsic)
What are the extrinsic muscles of the back innervated by?
ventral rami of spinal nerves
accessory nerve
What are the extrinsic muscles divided into?
superficial and intermediate groups
What are the muscles in the superficial group of extrinsic back muscles?
- rhomboid major and minor
- levator scapulae
- trapezius
- latissimus dorsi
What is the origin of rhomboid major?
spinous process of TIII to TV
What is the insertion of rhomboid major?
medial border of scapula between spine and inferior angle
What is the innervation of rhomboid major?
dorsal scapular nerve
What is the function of rhomboid major?
- retracts (adducts)
2. elevates scapula
What is the origin of rhomboid minor?
- the lower portion of ligamentum nuchae
2. spinous processes of CVII and TI
What is the insertion of rhomboid minor?
medial border of scapula at spine of scapula
What is the innervation of rhomboid minor?
dorsal scapular nerve (C4,C5)
What is the function of rhomboid minor?
- retracts (adducts)
2. elevates scapula
What is the origin of levator scapulae?
transverse processes of CI to CIV
What is the insertion of levator scapulae?
upper portion of medial border of scapula
What is the innervation of levator scapulae?
- C3 to C4
2. dorsal scapular nerve
What is the function of levator scapulae?
elevates scapula
What is the origin of trapezius?
- superior nuchal line
- external occipital protuberance
- ligamentum nuchae
- spinous processes of CVII to TXII
What is the innervation to trapezius?
motor
- accessory nerve
proprioception
- C3 and C4
What is the function of trapezius?
- assists in rotating the scapula during abduction of the humerus above horizontal
- upper fibres - elevate
- middle fibres - adducts
- lower fibres - depress scapula
What is the origin of latissimus dorsi?
- spinous processes of TVII to LV
- spinous processes of sacrum
- iliac crest
- ribs X to XII
What is the insertion of latissimus dorsi?
floor of inter tubercular sulcus of humerus
What is the innervation to latissimus dorsi?
thoracodorsal nerve (C6 to C8)
What is the function of latissimus dorsi?
- extends the humerus
- adducts the humerus
- medially rotates the humerus
What muscles are in the intermediate group of the extrinsic back muscles and what do these muscles act as?
- serratus posterior superior
- serratus posterior inferior
weak accessory muscles for respiration
What is the origin of serratus posterior superior?
- lower portion of ligamentum nuchae
- spinous processes of CVII to TIII
- supraspinous ligaments
What is the insertion of serratus posterior superior?
- upper border of ribs II to V
- just lateral to their angles
What is the innervation to serratus posterior superior?
anterior rami of upper thoracic nerves (T2 and T5)
What is the function of serratus posterior superior?
elevates ribs II to V
What is the origin of serratus posterior inferior?
- spinous processes of TXI to LIII
2. supraspinous ligaments
What is the insertion of superior posterior inferior?
- lower border of ribs IX to XII
- just lateral to their angles
What is the innervation of superior posterior inferior?
anterior rami of lower thoracic nerves (T9 - T12)
What is the function of superior posterior inferior?
- depresses ribs IX and XII
2. prevent lower ribs from being elevated when diaphragm contracts
What are in intrinsic or deep/ intrinsic muscles of the back innervated by?
posterior rami of spinal nerves
What 3 groups can the deep/intrinsic muscles of the back be divided into?
- superficial
- intermedial
- deep
What muscles are in the superficial group of the deep/intrinsic muscles of the back?
- splenius capitus
2. splenius cervicus
What is the origin of splenius capitus?
- lower half of ligamentum nuchae
2. spinous processes of CVII to TIV
What is the insertion of splenius capitus?
- mastoid process
2. skull below lateral 1/3 of superior nuchal line
What is the innervation of splenius capitus?
posterior rami of middle cervical nerves
What is the function of splenius capitus?
together
- draw head backwards
- extends neck
individually
- draw and rotate head to one side - turn face to same side
What is the origin of splenius cervicis?
spinous processes of TIII to TVI
What is the insertion of splenius cervicis?
transverse processes of CI to CIII
What is the innervation of splenius cervicis?
posterior rami of lower cervical nerves
What is the function of splenius cervicis?
together
- extend the neck
Individually
- draw and rotate head to one side - face turned to the same side
What is the intermediate group of muscles of the intrinsic to deep muscles of the back?
large erector spinae muscles - lie either side of the vertebral column
What is the main function erector spinae?
chief extensor vertebral column
What 3 muscles does the erector spinae muscle consist of from medial to lateral?
- spinalis
- longissimus
- iliocostalis
NOTE
DO NOT NEED TO KNOW THE ATTACHMENTS OF ERECTOR SPINAE MUSCLES
What are the muscles of the deep group of the intrinsic muscles of the back and what is their origin and insertion and what they also known as?
- semispinalis
- multifidis
- rotares
origin - transverse processes of the vertebrae
insert - spinous process of more superior vertebrae
know as - transversospinalis group