Superficial Back Flashcards
What are dermatomes?
area of skin innervated by fibers from a single spinal nerve or spinal cord segment
- not definitive, overlap between segments
What are the different types of fascia?
superficial and deep
Where is superficial fascia found?
subcutaneous tissue (just below the skin) - between skin and deep fascia
What is the function of superficial fascia?
- storage area for body fat
- covers most of the body
- not well organized
Where is deep fascia?
strong, dense, well organized layer of connective tissue
- becomes continuous with periosteum where muscles attach to bones
- helps form compartments
What are the different types of deep fascia?
investing layer
intermuscular septa
retinaculum
Investing layer
- covers deeper structures
- invests deeper structures such as muscles and neurovascular bundles
Intermuscular septa
separates muscles into groups
Retinaculum
thickening of deep fascia across tendons of muscles at joints
What is another name of superficial back muscles (extrinsic layer)?
axioappendicular muscles
What’s the function of superficial back muscles?
movement of upper limb
What are the superficial back muscles?
Trapezius
Latissimus dorsi
Levator scapulae
Rhomboid major and minor
What is the origin of trapezius?
occipital bone
ligamentum nuchae
spinous process of C7-T12
What is the insertion of trapezius?
lateral 1/3 of clavicle
acromion and spine of scapula
What are the actions of trapezius?
1) holds upper limb to trunk
2) adducts (retract) scapula - middle fibers
3) raises scapula - upper fibers
4) depresses scapula - lower fibers
5) rotates scapula so that inferior angle is moved
6) laterally for abduction of upper limb above horizontal position
What is the motor innervation of trapezius?
CN XI (spinal accessory nerve)
What is the sensory innervation of trapezius?
C3, C4 (ventral primary rami)
- pain and proprioception
What is the blood supply to trapezius?
superficial branch of transverse cervical artery
- located on deep surface of muscle
What happens to trapezius when there’s nerve injury ?
drooping of scapula (shoulder)
- shoulder drop
How do you test the strength of trapezius?
shrug against resistance
What is the origin of latissimus dorsi?
- spinous process of lower 6 thoracic vertebrae
- thoracolumbar fascia
- iliac crest and lower 3 or 4 ribs
What is the insertion of latissimus dorsi?
humers (intertubercular groove)
- between Teres major and pectoralis major
What innervates latissimus dorsi?
thoracodorsal nerve (C6,7,8 level of spinal cord) from brachial plexus
What vessel provides blood supply to latissimus dorsi?
thoracodorsal artery
What is the action of latissimus dorsi?
- adducts upper limb
- extends upper limb
- medial rotatation of upper limb (butterfly stroke)
What happens to latissimus dorsi when its nerve supply sustains injury?
unable to raise the trunk with the upper limbs during climbing
What is the triangle of auscultation?
small triangular gap between muscles near the inferior angle of scapula
- bounded by trapezius, latissimus dorsi and medial border of scapula
- good place to listen for respiratory sounds with stethoscope (less muffled)
What is the origin of levator scapulae?
transverse processes of first 3 or 4 cervical vertebrae
What is the insertion of levator scapulae?
superior angle of scapula and along its upper medial border
What innervates levator scapulae?
dorsal scapular nerve (C5) and 3rd and 4th cervical nerves
What is the action of levator scapulae?
raises scapula
What is the origin of rhomboid major and minor?
spines of lower cervical (C7) and upper thoracic (T1 - T5) vertebrae
What is the insertion of rhomboid major and minor?
medial border of scapula
What is the blood supply to rhomboid major and minor?
dorsal scapular artery
What is the action of rhomboid major and minor?
- adduct scapula
- rotate scapula so the glenoid cavity moves inferiorly
What innervates rhomboid major and minor?
dorsal scapular nerve (ventral ramus of C5) and some fibers of C4
What happens to rhomboid major and minor if the nerve supplying is injured?
dorsal scapular nerve results in inability to adduct scapula
What are the intermediate back muscles?
serratus posterior superior
serratus posterior inferior
What is the origin of serratus posterior superior?
ligamentum nuchae and spines of C7 to T3 vertebrae
What is the insertion of serratus posterior superior?
2nd to 4th ribs
What innervates serratus posterior superior?
first 3 thoracic spinal nerves
What is the action of serratus posterior superior?
elevates ribs
What is the origin of serratus posterior inferior?
T11 to L2 vertebral spines
What is the insertion of serratus posterior inferior?
lower 4 ribs
What innervates serratus posterior inferior?
last 4 thoracic nerves
What is the action of serratus posterior inferior?
aids in respiration by holding ribs steady when diaphragm moves up
What is the primary function of intermediate back muscles?
respiration
Name this muscle:
- very broad flat muscle, covers inferior half of the back (T6 to iliac crest), attaches the upper limb to the trunk and acts on the shoulder joint
Latissimus dorsi
Name this muscle:
- flat triangular muscle, provides direct attachment of pectoral girdle to the axial skeleton, helps to suspend upper limb from the trunk, covers back of neck and upper half of the trunk, attaches the pectoral girdle to the skull and vertebral column, muscle fibers are divided into three parts
trapezius
What is the primary action of deep back muscles?
movement of vertebral column
