Superficial Back

Question 1

Dermatomes

Answer 1

• Area of skin innervated by fibers from a single spinal nerve or spinal cord segment
• Maps have been developed from clinical studies
• adjacent dermatomes overlap
• maps can be used for clinical sensory testing

Question 2

Superficial Fascia

Answer 2

• Subcutaneous Tissue (immediately below skin)
• found between skin and deep fascia
• covers most of body
• storage area for body fat
• not very well organized

Question 3

Deep fascia

Answer 3

• strong, dens, well organized layer of connective tissue
• Located deep to superficial fasica
• contains no fat
• At the locations where muscles attach to bones, the deep fascia becomes continuous with periosteum
• Helps form compartments in the body

Question 4

Layers of Deep Fascia

Answer 4

• Investing layer of deep fascia
  
  • covers deeper structures
  • extensions from deep surface of dep fascia invests deeper structures such as muscles and neurovascular bundles
• Intermuscular septa
  
  • separates muscles into groups
• Retinaculum
  
  • thickening of the deep fascia acros tendons of muscles at joints

Question 5

Superficial Back Muscle Characteristics

Answer 5

• Extrinsic Layer of muscles
• Known as the axioappendicular muslces
• Attach upper limb to axial skelteon
• Originate from bony strucutres of back & insert on bones of upper limb
• act to move upper limb & not back, therefore extrinsic

Question 6

Innervation of Superficial Back Muscles

Answer 6

• Ventral primary rami (because they are upper limb muscles - NOT dorsal primary rami)

Question 7

Intermediate Back Muslces

Answer 7

• Extrinsic Back Muscles
  
  • Serratus posterior superior
  • Serratus posterior inferior
• involved in respiration by acting on chest wall
• also innervated by ventral primary rami

Question 8

Deep Back Muscles

Answer 8

• Intrinsic Back muscles
• primary movers of back
• innervated by dorsal primary rami

Question 9

Trapeziu

Question 10

List of Superificial Back Muscles

Answer 10

• trapezius,
• latissimus dorsi,
• Levator scapulae,
• Rhomboid major & minor

Question 11

Trapezius Characteristics

Answer 11

• provides direct attachment of pectoral girdle to axial skelton
• flat triangular muscle
• helps to suspend upper limb from the trunk
• two muscles - one on each side of vertebral column
  
  • form a trapezoid (4 sided) structure
• 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

Question 12

Origin of Trap

Answer 12

occipital bone

ligamentum nuchae

spinous process of C7-T12

Question 13

Insertion of Trap

Answer 13

clavical (lateral 1/3)

Acromion and spine of scapulae

Question 14

Nerve supply to Trap

Answer 14

CN XI - motor

C3, C4 (ventral primary rami) - pain & proprioception

• Nerve injury results in drooping scapula (shoulder) also known as shoulder drop

Question 15

Blood Supply to Trap

Answer 15

superficial branch of transverse cervical artery

located on the deep surface of muscle

Question 16

Action of Trap

Answer 16

• hold upper limb to trunk
• adducts (retracts) scapula - middle fibers
• raises scapula - upper fibers
• depresses scapula - lower fibers
• Rotates scapula so that inferior angle is moved laterally for abduction of upper limb above horizontal postion
• Test strength by shrugging against resistance

Question 17

Latissimus Dorsi Characteristics

Answer 17

• Very broad flat muscle
• covers inferior half of back (T6 - iliac crest)
• Attaches the upper limbe to the trunk
• acts on the shoulder joint

Question 18

Origin of Lat

Answer 18

Spinous process of lower 6 thoracic vertebrae

thoracolumbar fascia

iliac crest and lower 3 or 4 ribs

Question 19

Insertion of Lat

Answer 19

Humerus (intertubercular groove) - between teres major and pectoralis major

Question 20

Nerve supply of lat

Answer 20

Thoracodorsal Nerve (C6,7,8 level of spinal cord) from brachial plexus

• Nerve injury results in inability to raise the trunk with the upper limbs during climbing

Question 21

Blood supply to Lat

Answer 21

Thoracodorsal artery

Question 22

Action of Lat

Answer 22

• Pulls arm posteriorly (extends) 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 the pectoralis major, it is a powerful adductor of the arm

Question 23

Triangle of Auscultation

Answer 23

• small triangular gap between muscles near the inferior angle of scapula
• Bounded by Trap, lat, and medial border of scapula
• good place to listen for respiratory sounds
• respiratory sounds here are less muffeled

Question 24

Levator Scapulae Characteristics

Answer 24

• Strap-like muscle located in the neck and upper part of the thorax
• upper part lies deep to SCM and the inferior part lies deep to trap

Question 25

Origin of Lev Scap

Answer 25

Transverse processes of C1-4

Question 26

Insertion of Lev Scap

Answer 26

Superior angle of scapula and along it's upper medial border

Question 27

Blood supply of Lev Scap

Answer 27

Dorsal Scapular artery (branch of axillary a) deep branch of transverse cervical a

Question 28

Nerve innervation of Lev Scap

Answer 28

Dorsal Scapular nerve (C5) and 3rd & 4th cervical nerves

Question 29

Action of Lev Scap

Answer 29

* Elevates Scapula * rotates scapula to move the glenoid cavity and shoulder joint inferiorly

Question 30

Rhomboid Major & Minor Characteristics

Answer 30

* One sheet of muscle * lies deep to trap * upper part is called rhomboid minor * Lower, bigger part is called rhomboid major

Question 31

Origin of Rhomboids

Answer 31

Spines of C7 and T1-T5

Question 32

Insertion of Rhomboids

Answer 32

medial border of scapula

Question 33

Blood Supply of Rhomboids

Answer 33

Dorsal Scapular Artery

Question 34

Action of Rhomboids

Answer 34

Adduct Scapula Rotate scapula so the glenoid cavity moves inferiorly

Question 35

Nerve innervation of Rhomboids

Answer 35

Dorsal scapular nerve (ventral ramus of C5) and some fibers from C4 Injury to the dorsal scapular nerve results in inability to adduct scapula

Question 36

List of intermidiate Back Muscles

Answer 36

Serratus Posterior Superior Serratus Posterio Inferior

Question 37

Serratus Posterior Superior

Answer 37

* Located deep to rhomboids * Origin - ligamuntum nuchae and spines of C7-T3 * Insertion - 2nd to 4th ribs * Nerve - first three throacic spinal nerves * Action - elevates ribs

Question 38

Serratus Posterior Inferior

Answer 38

* Origin - T11-L2 vertebral spines * Insertion - Lower 4 ribs * Action - aids in respiration by holding ribs steady when diaphragm moves up * Nerves - last 4 thoracic nerves

Question 39

If during a surgical proceduer, T9-12 nerves are damaged, which one of the following muscles would be affected? Rhomboid Major Trap Lev Scap Serratus posterior superior serratus posterior inferior

Answer 39

Serratus posterior inferior

Question 40

During a physical exam, you notice that the patient has one shoulder lower than the other (drooping of the shoulder). This condition can result from damage to the _____ muscles Lev Scap Lat Serratus anterior Trap Lev Scap AND Trap

Answer 40

Lev Scap AND Trap

Question 41

You notice that the patient is unable to extend his arm at the shoulder joint. You expect nerve damage to the muscle responsible for this action. Which group of nerves might be involved? T1-L1 C6-C8 T8-T11 C1-C6

Answer 41

C6-C8

Question 42

Rhomboid Major and minor act to ____ the scapula Rotate Adduct Depress Abduct Rotate and Adduct

Answer 42

Rotate and Adduct