Lab Unit 04: The Back Flashcards
Latissimus Dorsi – (Moore 700)
• Origin (PA):
SP T7-T12
+ thoracolumbar fascia
+ iliac crest
+ inferior 4 ribs.
• Insertion (DA):
Floor of intertubercular groove of humerus.
Posterior surface of inferior angle of scapula.
• Nerve: Thoracodorsal nerve (C6, C7, C8).
• Action: Extends, adducts, and internally rotates humerus.
Multifidus
• Origin: Sacrum + TP C4-L5.
• Insertion: SP C, T, L vertebrae (spanning 2-4 segments).
• Nerve: DR.
• Action:
- Bilaterally: Extension of vertebrae.
- Unilaterally: Contralateral rotation.
Quadratus Lumborum
• Insertion (SA): Medial half of inferior border of 12th ribs \+ lumbar TP. • Origin (IA): Iliolumbar ligament \+ internal lip of iliac crest. • Nerve: AR T12-L4. • Action: - Extends and laterally flexes vertebral column. - Flexes 12th rib during inspiration.
Psoas Major
• Origin (SA): Sides of T12-L5 and IV discs \+ TP of all lumbar vertebrae. • Insertion (IA): Lesser trochanter of femur. • Nerve: AR L1, L2, L3. • Action: Flexes hip.
Splenius Capitis – ID & Action
• Origin: SP C7-T4. • Insertion: Mastoid process \+ lateral 1/3rd of superior nuchal line. • Nerve: DR. • Action: - Bilaterally: Extend head. - Unilaterally: Ipsilateral lateral flexion + ipsilateral rotation.
Splenius Cervicis – ID & Action
• Origin: SP T3-T6.
• Insertin: TP C1-C3.
• Nerve: DR.
• Action:
- Bilaterally: Extend cervical spine.
- Unilaterally: Ipsilateral lateral flexion + ipsilateral rotation.
Rotatores – ID & Action
• Origin: TP C2 to sacrum.
• Insertion: Lamina of vertebrae 1-2 segments above origin.
• Nerve: DR.
• Action:
- Bilaterally: Extension of vertebrae.
- Unilaterally: Contralateral rotation.
Longissimus Thoracis & Cervicis – ID & Action
- Origin: TP of lumbar vertebrae, TP T1-5.
- Insertion: TP of all thoracic vertebrae, TP C2-6.
- Nerve: DR.
- Action: Extends thoracic & cervical spine.
Longissimus Capitis – ID & Action
- Origin: TP T1-5, C4-C7.
- Insertion: Mastoid process.
- Nerve: DR.
- Action: Extend head.
Iliocostalis Lumborum, Thoracis & Cervicis
– ID & Action
• Origin: Sacrum \+ iliac crest \+ lumbar SP T11/12 \+ ribs 3-12. • Insertion: Ribs, TP C4-7. • Nerve: DR. • Action: Extends lumbar, thoracic & cervical spine.
Spinalis Thoracis, Cervicis & Capitis
– ID & Action
• Origin: SP of upper lumbar & lower thoracic vertebrae \+ ligamentum nuchae \+ SP C7. • Insertion: SP of upper thoracic vertebrae \+ SP of axis \+ SP of C3 & C4. • Nerve: DR. • Action: Extends thoracic & cervical spine \+ Extends the head.
(can not separate from Semispinalis Capitis)
Semispinalis Thoracis, Cervicis – ID & Action
- Origin: TP T1-T12.
- Insertion: SP C2-T4.
- Nerve: DR.
- Action: Extends cervical spine.
Semispinalis Capitis – ID & Action
- Origin: TP C7-T7.
- Insertion: Occipital bone.
- Nerve: DR.
- Action: Extend head.
C1 - Atlas
• Anterior tubercle • Posterior tubercle • Articular facet for dens • Anterior arch • Posterior arch • Lateral mass • Superior articular facet (of lateral mass for occipital condyle) • Inferior articular facet (of lateral mass for axis) • Transverse foramen • Transverse process (TP) • Groove for vertebral artery • Vertebral foramen
C2 - Axis
• Body • Dens / odontoid process • Anterior articular facet (for articulation with anterior arch of atlas) • Pedicle • Superior articular process and facet (for atlas) • Inferior articular process and facet (for C3) • Lamina • Transverse process (TP) • Transverse foramen • Spinous process (SP) • Vertebral foramen
C3 - C7
- Body
- Uncinate processes
- Pedicle
- Transverse process (TP)
- Anterior tubercle of the transverse process
- Posterior tubercle of the transverse process
- Transverse foramen
- Superior articular process and facet
- Inferior articular process and facet
- Lamina
- Vertebral foramen
- Spinous process (SP)
Thoracic Vertebra
- Body
- Pedicle
- Lamina
- Spinous process (SP)
- Transverse process (TP)
- Vertebral foramen
- Superior articular process and facet
- Inferior articular process and facet
- Superior costal facet
- Inferior costal facet
- Transverse costal facet
Lumbar Vertebra
- Body
- Pedicle
- Lamina
- Spinous process
- Transverse process
- Vertebral foramen
- Superior articular process and facet
- Mammillary process
- Inferior articular process and facet
Sacrum
- Superior articular process and facet
- Lumbosacral articular process
- Base
- Promontory
- Ala
- Median crest
- Intermediate crest
- Lateral crest
- Sacral tuberosity
- Auricular surface
- Anterior sacral foramina
- Posterior sacral foramina
- Sacral canal
- Sacral hiatus
- Apex
Nutation – Definition
• = Sacral flexion
(anterior rotation of the sacrum in relation to
the ilium)
• Base of sacrum moves anteriorly + inferiorly
• Occurs WITH trunk flexion or hip extension
Counternutation – Definition
• = Sacral extension
(posterior rotation of the sacrum in relation
to the ilium)
• Base of sacrum moves posteriorly + superiorly
• Occurs WITH trunk extension or hip flexion
Coccyx
• Transverse process of cocyx
Common characteristics of ALL vertebrae
- Spinous process (SP) (except C1)
- Superior articular facets
- Inferior articular facets
- Transverse process (TP) (2 of them)
- Pedicles (except C1)
- Lamina (except C1)
- Body (except C1)
Unique characteristics of CERVICAL vertebrae
- Bifurcated SPs
* Transverse foramen
Unique characteristics of THORACIC vertebrae
- Costal facets on body & TPs
- Heart shaped body
- Long, downward sloping SPs
Unique characteristics of LUMBAR vertebrae
- Massive body
* Blunt, horizontally projecting SPs
Ligaments
• Apical ligament • Alar ligament • Transverse (cruciform) ligament • Ligamentum Nuchae (nuchal ligament) • Supraspinous ligament • Interspinous ligament • Intertransverse ligament • Anterior longitudinal ligament (ALL) • Posterior longitudinal ligament (PLL) • Ligamentum Flavum • Sacrotuberous ligament • Sacrospinous ligament • Iliolumbar ligament • Sacroiliac (SI) ligaments - Anterior sacroiliac ligament - Posterior sacroiliac ligament - Interosseous sacroiliac ligament • Sacrococcygeal ligaments - Anterior sacrococcygeal ligament - Posterior sacrococcygeal ligament - Interosseous sacrococcygeal ligaments
Nerves
- Posterior horns (Dorsal)
- Anterior horns (Ventral)
- Posterior nerve roots and rami (Dorsal)
- Anterior nerve roots and rami (Ventral)
- Posterior Root Ganglion (Dorsal)/(DRG)
Posterior horns (dorsal)
•
Anterior (ventral)
•
Posterior nerve roots and rami (dorsal)
•
Anterior nerve roots and rami (ventral)
•
Posterior rot ganglion DRG (dorsal)
•
Cauda equina
•
Tracts
- Dorsal Column
- Spinothalamus
- Corticospinal
Dorsal Column (DC)
- receptors on cutaneous proprioception
- discriminative touch and “body awareness”.
- Cross midline at caudal medulla
Spinothalamus Tract (ST)
- sensory - ascending
- Pain, temperature + light touch + pressure.
- Crosses midline at segmental level.
Corticospinal Tract (CS)
• Descending (Motor) Pathway
– from brain to periphery
• major motor pathway for voluntary movements
(especially skilled or precise movement).
• Motor cortex-internal capsule-cerebral peduncle-deep projection fibers-pyramids.
• Crosses over at the caudal medulla
(decussation of the pyramids)-synapse w/ grey matter in ant. horn
Brown Sequard Syndrome – Definition
• incomplete spinal cord lesion
• loss of sensation and motor function
(paralysis and anesthesia)
• caused by the lateral hemisection (cutting) of the
spinal cord, often in the cervical cord region
• Light touch, pain and temperature fibers are carried in the spinothalamic tract. These fibers decussate at the level of the spinal cord. Therefore, a hemi-section lesion to the spinal cord will
• loss of these modalities on the contralateral side of the lesion, while preserving them on the ipsilateral side.
• Interruption of the lateral corticospinal tracts:
–> Ipsilateral spastic paralysis below the level of
the lesion
–> Babinski sign ipsilateral to lesion
–>Abnormal reflexes and Babinski sign may not
be present in acute injury.
• Interruption of posterior white column:
–>Ipsilateral loss of tactile discrimination,
vibratory, and position sensation below the
level of the lesion
• Interruption of lateral spinothalamic tracts:
–> Contralateral loss of pain and temperature
sensation. This usually occurs 2-3 segments
below the level of the lesion.
Anterior Spinal Artery
•
Posterior Spinal Arteries
•
General Spine Ligaments
- Supraspinous ligament
- Interspinous ligament
- Intertransverse ligament
- Anterior longitudinal ligament (ALL)
- Posterior longitudinal ligament (PLL)
- Ligamentum Flavum
Suprasinous Ligament
- connects tips of SPs
* continous superiorly as ligamentum nuchae
Interspinous Ligament
• connects vertebral spines
deep to supraspinous lig
Intertransverse Ligament
• connects TPs
separates anterior & posterior spinal muscles
Anterior Longitudinal Ligament (ALL)
- connects anterior surface of vertebral bodies
* helps limit excessive extension b/n vertebral segments
Posterior Longitudinal Ligament (PLL)
- connects posterior vertebral bodies
* resists felxion
Ligamentum Flavum
“yellow ligament”
• connects lamina
• limits flexion
• 80% elastin (yellow color), 20% collagen
Cervical Ligaments
- Alar ligament
- Cruciform ligament (Transverse & Longitudinal)
- Apical ligament
- Ligamentum nuchae
Alar Ligament
- Dens of C2 –> medial surface of occipital condyles
* Limits Atlanto-Axial rotation
Cruciform ligament
–> composed of 2 ligs:
• Transverse ligament
- between the lateral masses of C1
- prevents anterior displacement of C1 on C2
- very strong, dens will fracture before transverse ligament tears
• Longitudinal ligament (don’t need to know)
- Foramen magnum –> axis (C2)
Apical ligament
Dens of C –> foramen magnum
Ligamentum Nuchae
(nuchal ligament)
• C7 –> external occipital protuberance
• Continuation of supraspinous ligament
• Origin of upper trapezius, rhomboid minor
Sacroiliac (SI) Joint stability provided by
- Primary Sacroliliac ligaments
- Wedging (bony fromations)
- Articular surface irregularities
- Accessory Sacroiliac ligaments
Nutation
sacral promontory moves anteriorly & inferiorly
Ligaments preventing nutation
- Interosseous SI ligaments
- Sacrotuberous ligament
- Sacrospinous ligament
Counternutation
sacral promontory moves posteriorly & superiorly
Ligaments that prevent prevent counternutation
Posterior SI ligaments
Lower Lumbar & Sacrum
Anterior view
• Iliolumbar ligament
- TP L4-5 –> iliac crest
- Insertion of quadratus lumborum
• Sacroiliac ligaments
- Anterior:
- -> Ala and pelic surface of sacrum –> auricular surface of ilium
- Posterior:
- -> Prevents counternutation
- Interosseous:
- -> Prevents nutation
Lower Lumbar & Sacrum
• Sacrotuberous ligament
- Sacrum, ilium, coccyx –> ischial tuberosity
- prevents nutation
- origin of gluteus maximus & assoc. w/ long head of biceps femoris
• Sacrospinous ligament
- Sacrum and coccyx –> ischial spine
- prevents nutation
- deep to sacrotuberous ligament
• Sacrococcygeal ligaments
- anterior
- posterior
- interosseous
