The Back Flashcards
Dermatome
area of skin supplied by a single spinal nerve or spinal cord level
Myotome
muscle or group of muscles supplied by a specific spinal nerve or spinal cord level
How is herpes zoster relevant to dermatomes?
oCauses classically distributed skin lesions in a specific region due to viral infection reactivation in spinal ganglion
oClassic dermatomally distributed skin lesion- shingles
oViral disease of spinal ganglia
oCauses sharp burning pain in the dermatome, skin becomes red, vesicular eruption and possible muscle weakness in same myotome (affects specific myotome segment)
When is cervical curvature developed?
6 months
When is lumbar curvature developed?
1 year (walking age)
Excessive kyphosis
hunchback or increase in primary curvature
Excessive lordosis
swayback or increase in secondary curvature, weak anterior wall, pelvis moves back
Scoliosis
abnormal lateral curvature of the spine
posterior superior iliac spines (PSIS)
Surface anatomy in which dimples overlie it, common site for lumbar puncture (L4)
Extrinsic muscles
migrated to the ventral surface of the body & carried innervation with them.
Innervated by VENTRAL primary rami (or CN XI)
Intrinsic muscles
originated developmentally in the dorsum of the back and remained “true” or “intrinsic”
Innervated by DORSAL primary rami
Muscle layers of the back
oSuperficial: innervated by ventral rami (extrinsic)
oIntermediate: innervated by ventral rami (extrinsic)
oDeep: innervated by dorsal rami (intrinsic)
Trapezius Muscles
O: Along the midline
I: Lateral 1/3 clavicle, acromion, spine of scapula
Inn: Accessory n. (CN XI)
Action(s): Descending part: elevates
Ascending part: depresses
Middle/all parts together: retracts
Descending and ascending: rotate glenoid cavity superiorly
Latissimus Dorsi
O: along the midline
I: bicipital groove of the humerus
Inn: Thoracodorsal n.
Action(s): Extends, adducts, and medially rotates the humerus.
Raises body toward arms during climbing
Levator scapule
O: along the midline
I: Superior portion of the medial boarder of the scapula
Inn: dorsal scapular n.
Action (s): Elevates scapula
Rotates glenoid cavity inferiorly by rotating the scapula
Rhomboid minor
O: vertebrae
I: medial boarder of scapular spine
Inn: dorsal scapular n.
Action (s): Retract scapula
Rotates glenoid cavity inferiorly
Fix scapula to thoracic wall
Rhomboid major
O: vertebrae
I: medial border of scapula from spine to inferior angle
Inn: dorsal scapular n.
Action(s): retract scapula
Rotates glenoid cavity inferiorly
Fix scapula to thoracic wall
Triangle of Auscultation
a. Boundaries:
i. Superior: Trapezius
ii. Inferior: Latissimus dorsi m.
iii. Lateral: Rhomboid major m.
iv. Floor (deep): 6th intercostal space
b. Respiratory sounds since no muscles in way to hear lung sounds
Lumbar Triangle
a. Boundaries:
i. Medial: Latissimus dorsi m.
ii. Lateral: external oblique m.
iii. Inferior: Iliac crest
iv. Floor (deep): internal oblique m.
b. Can be site of an uncommon lumbar herniation
Serratus posterior superior
Elevates ribs
Serratus posterio inferior
Depresses ribs
Superficial Intrinsic (deep) back muscles)
- Superficial:
a. Spinotransversales mm.
i. Splenus capitis m.
ii. Splenius cervicis m. - Intermediate:
a. Erector Spinae mm.
i. Iliocostalis m.
ii. Longissimus m.
iii. Spinalis m. - Deep
a. Transversospinales mm.
i. Semispinalis group
ii. Multifidus group
iii. Rotatores group
Splenius capitis & Splenius cervicis (Spinotransversales mm.)
Inn: Posterior (dorsal) rami of spinal nn.
Action(s): Bilaterally: extends head and neck
Unilaterally: laterally flexes (bends) neck and rotates face to the side with active mm. (ipsilateral side)
Iliocostalis, Longissimus, Spinalis (Erector Spinae mm.)
Inn: Posterior (dorsal) rami of spinal nn.
Action(s): Bilaterally: extends vertebral column & head when back flexed and controls movement via eccentric contraction
Unilaterally: laterally flexes vertebral column
Semispinalis capitis, cervicis, and thoracis (Semispinalis group)
Inn: Posterior (dorsal) rami of spinal nn.
Action(s): Extends head, cervical, and thoracic regions of vertebral column
Rotates contralaterally
Multifidus group
Inn: Posterior (dorsal) rami of spinal nn.
Action(s): Stabilizes vertebrae during local movements of vertebral column
Rotatores Group
Inn: Posterior (dorsal) rami of spinal nn.
Action(s): Stabilize, extend, and rotates spine
Interspinales
aid in extension and rotation
Intertransversarii
aid in lateral flexion, stabilization (bilaterally)
Levatores costarum
Elevates ribs, assists with respiration and lateral flexion
Rectus capitis posterior minor and rectus capitis posterior major
Inn: suboccipital n.
Action(s): extension and rotation of the head
Obliquus capitis superior
Inn: suboccipital n.
Action(s): Extension and lateral flexion of head
Obliquus capitus inferior
Inn: suboccipital n.
Action(s): rotation of head
