Superficial Back Flashcards
Surface Anatomy
External occipital protuberance Spinous process of C7 T1 Spine of scapula Sacrum Iliac crest Inferior angle of scapula Latissimus dorsi, trees major, trapezius
Skin Innervation
Dermatomes
- area of skin innervated by fibers from a single spinal nerve or segment
- dermatome maps used for sensory testing and surgical incisions
Superficial Fascia
Subcutaneous tissue (immediately below the skin) Found between the skin and deep fascia Covers most of the body Storage area for body fat Not well organized
Deep Fascia
Strong, dense, well organized layer of CT
Located deep to superficial fascia and contains no fat
Where muscle attaches to bone, deep fascia becomes continuous with periosteum
Helps form compartments in the body
Different layers of the deep fascia
Investing layer of the deep fascia - incests and covers deeper structures like muscles and neuromuscular bundles
Intermuscular Septa - separates muscles into groups
Retinaculum - thickening of deep fascia across tendons of muscles at joints
Superficial Back Muscles
AKA axioappendicular muscles or Extrinsic back muscles Attach upper limb to axial skeleton Trapezius Latissimus Dorsi Levator Scapulae Rhomboid Major and Minor
Upper Limb muscles are supplied by…
Ventral primary rami
Intermediate Back Muscles
AKA Extrinsic back muscles Serratus posterior superior Serratus posterior inferior Involved in act of respiration innervated by ventral primary rami
Deep Back Muscles
AKA Intrinsic Back Muscles
Primary movers of the back
Innervated by the dorsal primary rami
Trapezius Info
Provides direct attachment of pectoral girdle to axial skeleton
Flat triangular muscle
Helps suspend the upper limb from the trunk
Covers back of neck and upper half of trunk
Attaches the pectoral girdle to the skull and vertebral column
Muscle fibers are divided into 3 parts
Trapezius Origin
Occipital bone
Ligamentum Nuchae
Spinous Process of C7-T12
Trapezius Insertion
Clavicle (lateral 1/3)
Acromion and spine of scapula
Trapezius Nerve Supply
Cranial nerve XI (accessory) - motor innervation
C3, C4 - central primary rami - pain and proprioception
Nerve injury would result in drooping of scapula
Trapezius Blood Supply
Superficial branch of the transverse cervical artery
Located on deep surface of the muscle
Trapezius Action
Holds upper limb to trunk
Adducts (retract) scapula
Raises scapula
Depreses scapula
Rotates scapula so that inferior angle is moved laterally for abduction of upper limb above horizontal position
To test its strength - shoulder shrugged against resistance
Latissimus Dorsi Info
Very broad flat muscle
Covers inferior half of the back (T6 to iliac crest)
Attaches the upper limb to the trunk
Acts on the shoulder joint
Latissimus Dorsi Origin
Spinous process of lower six thoracic vertebrae
Thoracolumbar fascia
Iliac crest and lower 3 or 4 ribs
Latissimus Dorsi Insertion
Humerus (intertubular groove) between Teres major and Pectorals Major
Latissimus Dorsi Nerve Supply
Thoracodorsal nerve (C6, C7, C8 level of spinal cord) from brachial plexus If injured unable to raise the trunk with the upper limbs during climbing
Latissimus Dorsi Blood Supply
Thoracodorsal artery
Latissimus Dorsi Action
Pulls arm posteriorly (extends arm) and rotates medially
Used in chopping wood or crawl stroke in swimming
It adducts, extends and medially rotates the humerus at the shoulder joint
Along with pectorals major, it is an adductor of the arm
Triangle of Auscultation
Small triangular gap between muscles near the inferior angle of the scapula
Bounded by the trapezius, latissimus doors, and medial border of the scapula
Good place to listen for respiratory sounds because they will be less muffled
Levator Scapulae Info
Strap like muscle located in the neck and upper part of the thorax
Upper part lies deep to the sternocleidomastoid and the inferior part lies deep to the trapezius muscle
Levator Scapulae Origin
Transverse processes of the first three or four cervical vertebrae
