Functions of the spine
-protects spinal cord and nerves
-supports weight of body superior to pelvis
-supports head and provides stiff yet flexible axis
... [Show More] for the body
-supports body posture and allows locomotion
Cervical vertebra (how to differentiate)
-bifid spinus process
-smallest
-foramen transversarium
Thoracic vertebra (how to differentiate)
-long spinous process
-costal facets
Lumbar vertebra (how to differentiate)
-large body
-thick, blunt spinous process
Anterior longitudinal ligament
anterior side of vertebral body; limits extension
widens as it descends; maintains joint stability
Posterior longitudinal ligament
-very strong
-supports posterior vertebra and discs
-limits flexion
Ligamentum flavum (yellow ligament)
-connects the laminae of adjacent vertebra
-helps straighten vertebral column after flexion
Ligamentum nuchae
-attaches to C2-C6
-triangular shaped median fibrous septum between muscles on two sides of posterior neck to support back of skull
-formed by thickened supraspinous ligaments
Superficial Extrinsic Back Muscles
-Latissimus Dorsi
-Trapezius
-Rhomboids (major and minor)
-Levator Scapulae
Intermediate extrinsic back muscles
-serratus posterior superior
-serratus posterior inferior
Serratus posterior superior
Inserts on upper border of ribs 2-5
Elevates the ribs
intermediate extrinsic muscle
Serratus posterior inferior
Inserts on lower border of ribs 9-12
Depresses the ribs
intermediate extrinsic muscle
Intermediate Intrinsic back muscles
-spinotransverse group
-sacrospinalis group
Spinotransverse group
-Splenius capitis and splenius cervicis
-Extends, rotates, and laterally flexes head and neck
-intermediate intrinsic muscle
Sacrospinalis group
-aka Erector spinae
-Iliocostalis, longissimus, spinalis muscles
-Extension and control of flexion (head, spine), side bending
-Long fibers, covers top to bottom
-intermediate intrinsic muscle
intrinsic deep muscles
transversospinal group
transversospinal group
-Semispinalis, Multifidus, Rotatores
-Short fibers, segmental
-Very small muscles (interspinales, intertransversarii, levatores costarum)
-intrinsic deep muscles
cervical arterial supply
Occipital, vertebral, deep cervical, and ascending intercostal arteries
Thoracic arterial supply
posterior intercostal arteries
lumbar arterial supply
subcostal and lumbar arteries
sacral arterial supply
iliolumbar and lateral sacral arteries
vertebral venous system
-internal vertebral venous plexus
-external vertebral venous plexus
-intervertebral vein
internal vertebral venous plexus
-in epidural space b/w dura mater and vertebral canal
-4 major veins (2 anterior, 2 posterior) w/ lots of tributaries and communications
-tributaries from spinal cord and vertebra
-route of early metastasis of lung, breast, and prostate cancer
lymphatic drainage of the back-superficial
-axillary nodes (above iliac crest)
-superficial inguinal nodes (below iliac crest)
lymph drainage of the back-deep
-deep cervical
-posterior mediastinal
-lateral aortic
-sacral nodes
denticulate ligaments
-lateral extensions of pia mater
-helps hold the spinal cord in position in the subarachnoid space
L3-L4 herniation (from chart)
-pain- lower back, hip, posterolateral thigh, anterior leg
-numbness- anteromedial thigh and knee
-weakness- quadriceps
-atrophy- quadriceps
-reflexes- knee jerk diminished
L4-L5 herniation (from chart)
-pain- above sacroiliac joint,hip, lateral thigh, and leg
-numbness- lateral leg, first 3 toes
-weakness- dorsiflexion of great toe and foot, difficulty walking on heels; foot drop may occur
-atrophy- minor or nonspecific
-reflexes-posterior tibial reflex diminished or absent, changes uncommon in knee and ankle jerks [Show Less]