Superficial Back Flashcards
Dermatomes
area of skin innervated by fibers from single spinal nerve or spinal cord segment C5 clavicle C6 thumb T4 nipple T10 umbilical L1 groin L4 medial foot S1 outer foot
Superficial fascia
subcutaneous tissue - immediately below skin
covers most of body
storage area for body fat
Deep fascia
strong, dense deep to superficial fascia
contains no fat
Investing layer of deep fascia
covers deeper structures like muscles and neurovascular bundles
Intermuscular septa
separates muscles into groups
Retinaculum
thickening of deep fascia across tendons of muscles at joints
Superficial back muscles include
trapezius, latissimus dorsi, levator scapulae, rhomboid major/minor
(Attach upper limb to axial skeleton, move arms not back - extrinsic back muscles)
Superficial back muscles are supplied by
ventral primary rami (because they are upper limb muscles)
Intermediate back muscles include
Serratus posterior superior, serratus posterior inferior
Deep back muscles
true muscles of back, primary movers of back, innervated by dorsal primary rami
Trapezius muscle
attach pectoral girdle to axial skeleton
Flat triangular muscles
2 muscle, cover back of neck and upper half of trunk
Trapezius origin
Occipital bone, ligamentum nuchae, spinous process of C7-T12
Trapezius insertion
lateral 1/3 of Clavicle, acromion and spine of scapula
Trapezius nerve supply
Cranial nerve XI (spinal accessory nerve) - motor
C3, C4 (ventral primary rami) - pain and proprioception
Trapezius blood supply
Superficial branch of transverse cervical artery (on deep surface)
Trapezius action
hold upper limb to trunk
adduct (retract) scapula, raises scapula, depresses scapula, rotates scapula so inferior angle is moved laterally for abduction of upper limb above horizontal position
Nerve injury to trapezius causes
drooping of scapula - shoulder drop
Latissimus dorsi
broad, flat muscle
covers inferior half of back (T6 to iliac crest)
Acts on shoulder joint
Latissimus dorsi origin
spinous proccess of lower 6 thoracic vertebrae
thoracolumbar fascial
iliac crest and lower 3 or 4 ribs
Latissimus dorsi insertion
humerus (intertubercular groove) - between teres major and pectoralis major
Latissimus dorsi nerve supply
Thoracodorsal nerve (C6-8) from brachial plexus
Latissimus dorsi blood supply
Thoracodorsal artery
Latissimus dorsi action
pulls arm posteriorly and rotates medially
adducts, extends, and medially rotates humerus at shoulder joint
Nerve injury to Latissimus dorsi causes
inability to raise trunk with upper limbs during climbing
Triangle of ausculation
small triangular gap between muscles at inferior angle of scapula
bounded by trapezius, latissimus dorsi, and medial border of scapula
respiratory sounds here are less muffled - good place to listen
Levator scapulae
strap muscle located in neck and upper throax
lies deep to SCM and trapezius muscle
Levator scapulae origin
transverse processes of first 3 or 4 cervical vertebrae
Levator scapulae insertion
superior angle of scapula on upper medial border
Levator scapulae blood supply
Dorsal scapular artery (branch of axillary a) or deep branch of transverse cervical a.
Levator scapulae nerve supply
Dorsal scapular nerve (C5) and 3rd or 4th cervical nerves
Levator scapulae action
Elevates scapula
Rotates scapula to move glenoid cavity and shoulder joint inferiorly
Rhomboid major and minor origin
spines of lower cervical (C7) and upper thoracic (T1-T5) vertebrae
Rhomboid major and minor insertion
medial border of scapula
Rhomboid major and minor blood supply
dorsal scapular artery
Rhomboid major and minor nerve supply
Dorsal scapular nerve (ventral ramus of C5) and some fibers from C4
Rhomboid major and minor action
Adduct scapula
Rotate scapula so glenoid cavity moves inferiorly
Nerve injury to Rhomboid major and minor cause
inability to adduct scapula
Serratus posterior superior
lies deep to rhomboid muscles
Serratus posterior superior origin
Ligamentum nuchae and spines of C7-T3 vertebrae
Serratus posterior superior insertion
2nd to 4th ribs
Serratus posterior superior nerve
first 3 thoracic spinal nerves (T1-T3)
Serratus posterior superior action
elevates ribs (aids in respiration)
Serratus posterior inferior origin
T11 to L2 vertebral spines
Serratus posterior inferior insertion
lower 4 ribs
Serratus posterior inferior nerves
Last 4 thoracic spinal nerves (T8-T12)
Serratus posterior inferior action
aids in respiration by holding ribs steady when diaphragm moves up