A
Name the superficial muscles of the back
Trapezius, Latissimus dorsi, Rhomboids, Levator Scapulae
What innervates Trapezius?
CN XI the Spinal Accessory Nerve
(also, spinal nerves C3 and C4)
What is the function of deep back muscles?
Maintain posture and move vertebral column and head
Between which muscles does the VAN sit?
Internal and innermost intercostal muscles
What makes up the rectus sheath?
The apeneuroses of the three flat muscles (external oblique, internal oblique, and transversus abdominus)
What are extrinsic back muscles?
Muscles that originate from locations other than the back, i.e. the superficial and intermediate back muscles
What is the function and innervation of latissimus dorsi?
Innervated by the thoracodorsal nerve
Extends, adducts, and medially rotates humerus
Name the Erector Spinae Muscles from most medial to most lateral
Spinalis
Longissimus
Iliocostalis
Which of the intercostal muscles depresses the rib above?
Internal and innermost
Which innervation differentiates the internal oblique and transversus abdominis?
Spinal nerve L1
As with the other abdominal muscles, they are also innervated by the thoracoabdominal nerves T7-T11 and the subcostal nerve (T12)
What is the innervation of superficial vs. deep back muscles?
Superficial back muscles are innervated by ventral (anterior) rami of spinal nerves, deep back muscles are innervated by dorsal (posterior) rami of spinal nerves
What does the dorsal scapular nerve innervate?
Rhomboid major/minor and levator scapulae
Name the Transversospinales muscles and their function
Stabilizing role during movement of vertebral column, extend head and cervical/thoracic spine, rotate contralaterally
Semispinalis capitis, semispinalis cervicis, multifidius
What is the direction of fibers of the three flat muscles?
External Oblique- inferiomedial
Internal oblique- Superiolateral
Transversus Abdominus- Horizontal
What is the arcuate line?
A division of the rectus sheath- above this line there is both a posterior and anterior sheath, but below this line there is only anterior sheath.
The arcuate line is halfway between the umbilicus and the pubic symphysis and inferior to it is the fibrous transversalis fascia
Name the functions and innervations of pectoralis major and pectoralis minor
Pectoralis major is INN by the medial and lateral pectoral nerve, running deep to the muscle.
Pectoralis minor is INN by the medial pectoral nerve.
Pec major rotates, flexes, and adducts the humerus
Pec minor tilts and depresses the scapula
What does the lateral thoracic artery and long thoracic nerve supply/innervate?
Serratus Anterior
Where do the inferior epigastric vessels enter the rectus sheath?
At the level of the arcuate line and then they run deep to the rectus abdominus muscle
What attaches the rectus sheath to the rectus abdominus?
Tendinous intersections
Between which muscles would you find the ilioinguinal nerve?
External and internal oblique
Name the suboccipital muscles and their innervation
Rectus capitis posterior major
Rectus capitis posterior minor
Obliquus capitis superior
Obliquus capitis inferior
Innervated by Suboccipital n. (posterior ramus C1)
*Minor & Superior attach to C1, Major & Inferior attach to C2
*Extend head
Where would you find the superficial inguinal ring and what runs through it?
It's formed in the apeneurosis of the external oblique and contains either the spermatic cord or the round ligament of the uterus.
The erector spinae muslces function to...
Unilaterally flex the vertebral column to the same side and bilaterally extends and stabilizes the vertebral column
What deep back muscle does the Greater Occipital Nerve nerve run through?
Semispinalis capitis
What is the arterial supply of the superficial back muscles?
Trapezius is supplied by transverse cervical artery, latissimus dorsi is the throacodorsal artery, and the rhomboids and levator scapulae are supplied by the dorsal scapular vessels