Exam #3: Superficial Back Flashcards
What is a Dermatome?
An area of the skin innervated by a single spinal nerve
Clavicle Dermatome
C5
Thumb Dermatome
C6
Nipple Dermatome
T4
Umbilicus Dermatome
T10
Groin Dermatome
L1
Medial Foot Dermatome
L4
Lateral Foot Dermatome
L5
What is the superficial fascia?
- The subcutaneous tissue immediately below the skin
- It is located between skin and deep fascia & is not very organized
- Functions to store body fat
What is the deep fascia?
- A strong, dense, well organized layer of connective tissue located deep to the superficial fascia
- Does NOT store body fat
- Where muscles attach to bones it becomes continuous with the periosteum
- Compartmentalizes the body
What is the investing Layer of Deep Fascia?
Extensions from the deep surface of the deep fascia that invest in deeper structures e.g. muscles & neurovascular bundles
What is the Intermuscular Septa?
Part of the deep fascia that separates muscles into groups
What is the Retinaculum?
A thickening of deep fascia across tendons of muscles at joints
What are the three groups of muscles in the back?
1) Superficial Back Muscles (axioappendicular)
2) Intermediate Back Muscles
3) Deep Back Muscles
What are the superficial back muscles?
- Trapezius
- Latissimus Dorsi
- Levator Scapulae
- Rhomboid Major & Minor
Where do the superficial back muscles generally originate from and insert into?
- Originate from bony structures of the back
- Insert on the bones of the upper limb
What is an extrinsic back muscle?
Muscle in the back that do not move the back itself i.e. the superficial back muscles
What nerves supply the superficial muscles of the back?
Ventral Primary Rami (NOT Dorsal Primary Rami)
What are the intermediate back muscles?
- Serratus posterior superior
- Serratus posterior inferior
What is the general function of the intermediate back muscles?
Respiration i.e. like superficial back muscles, they are also extrinsic back muscles
What is the nerve supply to the intermediate back muscles?
Ventral Primary Rami (NOT Dorsal Primary Rami)
Which groups of back muscles are extrinsic?
Superficial & Intermediate Back Muscles
Which group of back muscles are intrinsic?
Deep Back Muscles
What is the nerve supply to the Deep Back Muscles
Dorsal Primary Rami
What is the general function of the Deep Back Muscles?
Movement of the back
What is the inferior angle of the scapula a landmark for?
T7
Which rib can be palpated just below the inferior angle of the scapula?
Rib 8
What lumbar vertebra is at the level of the iliac crest?
L4
What are the two muscles of the superficial group of superficial back muscles?
1) Trapezius
2) Latissimus Dorsi
What three muscles are part of the deep group of superficial back muscles?
1) Levator Scapulae
2) Rhomboid Minor
3) Rhomboid Major
Trapezius Origin
1) Occipital bone
2) Ligamentum Nuchae
3) Spinous process of C7 & all 12 thoracic vertebrae
Trapezius Insertion
1) Lateral 1/3 of the clavicle
2) Acromion and spine of scapula
Trapezius Nerve Supply
- Motor= CN XI (Spinal Accessory
- Pain & Priprioception= ventral primary rami of C3 & C4
Trapezius Blood Supply
Superficial Branch of the Transverse Cervical Artery
Trapezius Action
- Hold the upper limb to the trunk
- Middle fibers adduct (retract) the scapula
- Upper fibers raise the scapula
- Lower fibers depress the scapula
- Rotates the scapula so that the inferior angle is moved laterally for abduction of the upper limb above the horizontal position
What does CN XI injury result in?
Drooping of the scapula, which is known as a “shoulder drop”
How is the strength of the trapezius muscle tested?
Shoulder is shrugged against resistance
Latissimus Dorsi Origin
1) Spinous processes of the lower six thoracic vertebrae
2) Thoracolumbar fascia
3) Lower 3 or 4 ribs
4) Iliac Crest
Latissimus Dorsi Insertion
Intertubercular Groove of the Humerus, between the Teres Major & Pectoralis Major
Latissimus Dorsi Nerve Supply
Thoracodorsal Nerve (C6,7, & 8) from the brachial plexus
Latissimus Dorsi Blood Supply
Thoracodorsal Artery
Latissimus Dorsi Action
Adduction, extension, & medial rotation of humerus of the shoulder joint
Thoracodorsal Nerve Injury
Unable to raise the trunk with upper limbs when climbing
Triangle of Auscultation
A good place to listen for respiratory sounds with a stethoscope that is bounded by
1) Lateral Trapezius
2) Superior Latissimus Dorsi
3) Medial Border of the Scapula
Levator Scapulae Origin
Transverse processes of the first three to four cervical vertebrae
Levator Scapulae Insertion
Superior angle of the scapula along its upper medial border
Levator Scapulae Blood Supply
Dorsal Scapular Artery
Levator Scapulae Nerve Supply
Dorsal Scapular Nerve
Levator Scapulae Action
- Elevates the scapula
- Rotates the scapula to move the glenoid cavity and shoulder joint inferiorly
Rhomboid Major & Minor Origin
Spinous processes of C7- T5
Rhomboid Major & Minor Insertion
Medial Border of the Scapula
Rhomboid Major & Minor Blood Supply
Dorsal Scapular Artery
Rhomboid Major & Minor Action
- Adduct the scapula
- Rotate the scapula so the glenoid cavity moves inferiorly
Rhomboid Major & Minor Nerve Supply
Dorsal Scapular Nerve (ventral ramus of C5) & some fibers from C4
Dorsal Scapular Nerve Injury
Inability to adduct the scapula
Serratus Posterior Superior Origin
Ligamentum nuchae & spinous processes of C7-T3
Serratus Posterior Superior Insertion
2nd to 4th ribs
Serratus Posterior Superior Nerve Supply
First three thoracic spinal nerves
Serratus Posterior Superior Action
Elevates ribs in respiration
Serratus Posterior Inferior Origin
T11 to L2 spinous processes
Serratus Posterior Inferior Insertion
Lower four ribs
Serratus Posterior Inferior Action
Aids in respiration by holding ribs steady when the diaphragm moves up
Serratus Posterior Inferior Nerve Supply
Last four thoracic nerves
