Superficial Back Flashcards
External occipital protuberance
projection on the external surface of the squamous part of the occipital bone in the midline
Vertebra Prominens
Long spinous process of C7. Disappears when head is extended
T1 Spinous Process
Another prominent spinous process. Does not disappear when head is extended
Sacrum
Fusion of 5 sacral vertebrae. Large triangular bone
Iliac Crest
Superior lateral boundaries of pelvic girdle
Teres Major
medial rotator and adductor of the humerus and assists the latissimus dorsi in drawing the previously raised humerus downward and backward (extension, but not hyper extension). It also helps stabilize the humeral head in the glenoid cavity
Dermatome
Area of the skin innervated by fibers from a single spinal nerve or spinal cord segment. Dermatome maps have been developed from clinical studies. Adjacent dermatomes have some area of overlap. Dermatome maps can be used for clinical sensory testing.
Superficial Fascia
Subcutaneous tissue (tissue immediately below the skin). Found between the skin and the deep fascia. Covers most of the body, storage area for body fat. Not very well organized
Deep fascia
Strong, dense, well organized layer of connective tissue. Located deep to the superficial fascia and contains NO fat. Where muscles attach to bones the deep fascia becomes continuous with periosteum. Helps form compartments in the body. Divides into different layers: Investing layer of deep fascia, intermuscular septa, and retinaculum
Investing layer of deep fascia
AKA Superficial layer of deep fascia. Invests (covers) deeper structures. Extensions from the deep surface of the deep fascia invests deeper structures such as muscles and neurovascular bundles
Intermuscular septa
separates muscles into groups
Retinaculum
thickening of the deep fascia across tendons of muscles at joints
Muscles of the back
Three types of muscles of the back: superficial back muscles, intermediate back muscles, and deep back muscles
Superficial back muscles
Also known as axioappendicular muscles. Attach to upper limb (appendicular skeleton) to axial skeleton. muscles of the superficial group originate from the bony structures of the back and insert on the bones of upper limb. Since they act to move the upper limb and not the back, they are, therefore, EXTRINSIC back muscles. Since they are upper limb muscles they are supplied by the VENTRAL PRIMARY RAMI and not by the dorsal primary rami. Included in these are Trapezius, latissmus dorsi, levator scapulae, and rhomboid major and minor.
Intermediate back muscles
Extrinsic muscles. Involved in the act of respiration by acting on the chest wall. Innervated by ventral primary rami.
Deep back muscles
The deep back muscles are the true (intrinsic) muscles of the back. These muscles are the primary movers of the back. Innervated by the DORSAL primary ramus.
Trapezius
Superficial back muscle. Provides direct attachment of pectoral girdle to the axial skeleton (trunk). Flat triangular muscle. Helps to suspend the upper limb from the trunk. The two muscles, one on each side of the vertebral column, form a trapezoid (4 sided) structure. 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 origin
Occipital Bone, Ligamentum nuchae, Spinous process of C7 - T12
Trapezius Insertion
Clavicle (lateral 1/3), Acromion and spine of scapula
Trapezius Nerve Supply
Motor: Cranial nerve XI (spinal accessory nerve). Sensory: C3, C4 (ventral primary rami) - pain and proprioception
Trapezius Blood Supply
Superficial branch of the transverse cervical artery. Located on the deep surface of the muscle