Lecture Module 1: Back Flashcards
(38 cards)
What are the back muscles?
- Extrinsic muscles
– superficial: limb to trunk, deep to skin and superficial fascia
— vertebral column to humerus: Latissimus dorsi
— vertebral column to scapula: Rhomboid minor/major, trapezius, and levator scapulae
– intermediate
— serratus posterior superior/inferior - Intrinsic muscles
– deep
— erector spinae: iliocostalis, longissimus, spinalis - Muscular triangles of the back: Auscultatory and lumbar
What are the three groups of muscles of the back and what do they do?
- Extrinsic: superficially on structure, supplied by anterior rami of spinal nerves
1) Superficial group: movement of shoulder and upper limb & stabilize scapula
2) Intermediate group: attached to ribs & serve respiratory functions - Intrinsic: within/deeper in structure: true back muscles
3) Deep group: Movement vertebral column and head, supplied by posterior rami
What comprises the skeleton?
- Axial skeleton (80 bones): skull bones, auditory ossicles, hyoid bone, ribs, sternum, vertebrae, & sacrum
- Appendicular skeleton (126): upper & lower extremities including pectoral & pelvic girdle
What is the curvature of the adult spine?
- Cervical (7) and Lumbar (5): Convex/lordosis
- Thoracic (12) and Pelvic (5,4) : Concave. kyphosis
What are the bony landmarks of the pectoral girdle and humorous?
- Acromion process
- Acromial end (clavicle)
- Head of the humerus
- Greater tubercle
- Lesser tubercle
- Intertubercle sulcus
- Deltoid tuberosity
*glenoid cavity**
What are the regions of the scapula?
Anterior
- Supraglenoid tubercle
- Coracoid process
- Glenoid cavity
- Infraglenoid tubercle
- Subscapular fossa
- Lateral border
- Inferior angle
- Medial border
- Superior angle
- Superior border
- Scapular notch
Posterior
- Acromion
- Coracoid process
- Infraspinous fossa
- Spine
- Supraspinous fossa
What are the movements of the scapula?
- Elevation/depression
- Adduction/abduction
- Upward/downward rotation
What is the surface anatomy of the back?
- Deltoid: clavicular part (top when arm 90* abducted), middle part, spinal part
- Scapula: spine and medial border
- Trapezius: Descending, middle, and ascending parts
- Triangle of auscultation: lateral trapezius, medial scapula, superior border of latissimus dorsi (stethoscope for lungs)
- Rhomboids: deep to trapezius
- Latissimus dorsi: Superior & Lateral border
- Ilium: Iliac crest, posterior iliac spine
Trapezius: regions, origin, insertion, action, innervation, injury
Regions:
- superior: descending fibers origin to insertion
- middle: horizontal fibers
- lower: inferior fibers, ascending to scapula
Origin: Occiput (bone & prominins) of skull, ligamentum nuchae, spinous processes C7-T12
Insertion: Clavicle, acromion, scapular spine
Action: move scapula
- superior: s. elevation & neck extension
- middle: s. adduction (retraction)
- lower: s. depression
Innervation: CN XI (Spinal Accessory Nerve)
Injury:
- strains: accident, exercise, overuse, nerve damage, poor posture (hunched)
- limited mobility, dec ROM, muscle weakness, neck/shoulder/between blades pain —> cramps/spasms
The spinal accessory nerve pathway and injury
- Only motor
- Anterior gray horn of first 5 cervical segments
- Axons exit laterally through foramen magnum and jugular foramen with vagus and glossopharyngeal
- Injury: neck surgery trauma (lymph node biopsy), traction injury (whiplash) –> “winged” scapula, weakened trapezius and sternocleidomastoid
Latissimus Dorsi: origin, insertion, action, innervation,
Origin: T6-12 spinous processes, iliac crest, thoracolumbar fascia, inferior 3 ribs
Insertion: near intertubercular sulcus of humorous (w/ teres maj) as common tendon
Action: Humerus/shoulder joint - shoulder extension, adduction, medial rotation, pulls truck upward & forward (arms overhead), flexion of lumbar and extension spine “swimmer’s muscle”
Innervation: thoracodorsal nerve
Thoracodorsal nerve: origin and injury
- Off of brachial plexus (posterior cord), ventral rami from C6-8
- Injury: surgery at axillary region, paralysis latissimus dorsi - unable raise trunk w/ upper limbs (Breast cancer: surgery to axillary nodes)
Levator Scapulae: origin, insertion, action, innervation
Origin: C1-C4 transverse processes (most covered Splenius capitis)
Insertion: scapula superior medial border
Action: scapula elevation
Innervation: dorsal scapular nerve (C5 only - also Rhomboids)
Rhomboid Major: origin, insertion, action, innervation,
Origin: T2-5 spinous processes
Insertion: scapula medial border (b/w spine & inferior angle)
Innervation: Dorsal scapular nerve
Action: scapular retraction & downward rotation
Rhomboid Minor: origin, insertion, action, innervation,
Origin: C7-T1 Spinous processes
Insertion: scapula medial border (@spine)
Innervation: Dorsal scapular nerve
Actions: Scapular adduction/retraction & downward rotation
Intermediate group of back muscles: origin, insertion, action,
- Origin: vertebral column
- Insertion: ribs
- Action: rib movement for respiration
Serratus posterior superior (rib elevator)
Serratus posterior inferior (rib depressor) - Separated from deep by thoracolumbar fascia (fibrous tissue)
Dorsal scapular nerve entrapment:
- Common body builders/heavy overhead lifting
- Compression of nerve
- Upper back & shoulder pain
- Possible winged scapula
- Weakness rhomboid and levator scapulae
What are the general aspects of a vertebrae?
- Spinous process
- Lamina
- Superior/inferior articular process
- Transverse process
- Pedicle
- Body
- Vertebral arch: v. foramen
- Vertebral foramen: spinal cord
- Intervertebral foramen: for spinal nerves formed by superior and inferior vertebral notches
What is the difference between a facet and a process/
- Facet: smooth surface where bones contact
- Process: extension (outgrowth) of bone
What are the unique aspects of cervical vertebrae 1 and 2?
- Atlas (C1)
– no body or spinous process,
– large articular facets (w/ occipital condyles),
– atlanto-occipital joint “yes” - Axis (C2)
– Pivot rotating atlas & skull
– atlanto-axial joints (3) “no”
– Dens: large upright process
What are the unique aspects of cervical vertebrae?
- Smallest, lightest vertebrae
- Short spinous process C2-6 may be bifid
- Transverse p. have foramina for vertebral arteries
- small bodies
- Uncovertebral joints: on each side of cervical disks for flexion and extension of the neck (limited lateral)
– by body & uncinate process in superior surface of vertebral body
What are the unique aspects of the thoracic vertebrae?
- Articulate with ribs: costovertebral joint
– costal facets (rib heads): complete in 1, 10, 11, 12. 2-9 demifacets
– transverse costal facets (rib tubercles) - Heart-shaped body
- Long, thick, downward spinous process
- Sup/inf articular process –> facet/zygopophysial joint
What are the unique aspects of the lumbar vertebrae?
- Large, thick bodies
- Heavy, rectangular spinous process
What is unique about the sacrum and coccyx?
- Sacrum: fused mid-late adolescence, nerves through foramina
- Coccyx, fused, 1 coccygeal nerve
