Deep BackAndres S. Javier M.D.

Department of AnatomyCollege of Medicine

UERMMMC

Objectives

To introduced the back and vertebral column structures

To be familiarized with:I. VERTEBRAII. JOINTS AND LIGAMENTSIII. MUSCLESIV. BLOOD SUPPLY AND DRAINAGESV. NERVE SUPPLY

Overview of Back and Vertebral Column

BACK Skin Muscles: a superficial layer and deeper layers

(“true back muscles”) Vertebral column: the vertebrae, intervertebral

(IV) discs, and associated ligaments. Ribs (in the thoracic region): particularly their

posterior portions, medial to the angles of the ribs.

Spinal cord and meninges Various segmental nerves and vessels.

FUNCTION OF VERTEBRAL COLUMN Protects the spinal cord and spinal

nerves. Supports the weight of the body

superior to the level of the pelvis. Provides a partly rigid and flexible

axis for the body and an extended base on which the head is placed and pivots.

Plays an important role in posture and locomotion

Typical Vertebra

Consists of : Vertebral body Vertebral arch Seven processes

1 spinous process 2 transverse processes 4 articular processes (G. zygapophyses)

Cervical Vertebrae

Thoracic Vertebrae

Lumbar Vertebrae

Sacrum and Coccyx

Joints of the Vertebral Column

The joints of the vertebral column include the: Joints of the vertebral bodies. Joints of the vertebral arches. Craniovertebral (atlanto-axial and

atlanto-occipital) joints. Costovertebral joints Sacroiliac joints

Joints of Vertebral Bodies

Joints of the Vertebral Arches

CRANIOVERTEBRAL JOINTS

are synovial joints that have no IV discs

Atlanto-Occipital Joints Articulations between the superior

articular surface of the lateral masses of the atlas and occipital condyles

Cranium and C1 vertebra are also connected by ▪ ANTERIOR and POSTERIOR ATLANTO-

OCCIPITAL MEMBRANES

Atlanto-Axial Joints(3 articulations) 2 Lateral Atlanto-Axial Joints 1 Median Atlanto-Axial Joints

Notable ligaments and membrane Transverse Ligament of the Atlas Cruciate Ligament of the Atlas Alar ligaments Tectorial Membrane

Vasculature of Vertebral Column

Nerves of the Vertebral Column

Muscles of the Back(Major Groups)

Extrinsic Back Muscles Superficial▪ Trapezius▪ Latissimus dorsi▪ Levator Scapulae▪ Rhomboids

Intermediate▪ Serratus Posterior Superior▪ Serratus Posterior Inferior

Intrinsic Back Muscles Superficial ▪ Splenius capitis and cervicis

Intermediate (Erector spinae)▪ Iliocostalis (cervicis, thoracis, lumborum)▪ Longissimus(capitis, cervicis, thoracis)▪ Spinalis(capitis, cervicis, thoracis)

Deep (Transversospinales)▪ Semispinalis▪ Multifidus▪ Rotatores

Splenius

Nuchal ligament and spinous processes of C7-T3 or T4 vertebrae

Splenius capitis: fibers run superolaterally to mastoid process of temporal bone and lateral third of superior nuchal line of occipital bone Splenius cervicis: tubercles of transverse processes of C1-C3 or C4 vertebrae

Acting alone: laterally flex neck and rotate head to side of active muscles Acting together: extend head and neck

Erector spinae

Arises by a broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacroiliac ligaments, sacral and inferior lumbar spinous processes, and supraspinous ligament

Acting bilaterally: extend vertebral column and head; as back is flexed, control movement via eccentric contractionActing unilaterally: laterally flex vertebral column

Iliocostalis

Lumborum, thoracis, cervicis; fibers run superiorly to angles of lower ribs and cervical transverse processes

Longissimus

thoracis, cervicis, capitis; fibers run superiorly to ribs between tubercles and angles to transverse processes in thoracic and cervical regions, and to mastoid process of temporal bone

Spinalis

thoracis, cervicis, capitis; fibers run superiorly to spinous processes in the upper thoracic region and to cranium

Transversospinales

Semispinalis

arises from transverse processes of C4-T12 vertebrae

thoracis, cervicis, capitis; fibers run superomedially to occipital bone and spinous processes in thoracic and cervical regions, spanning 4-6 segments

extends head and thoracic and cervical regions of vertebral column and rotates them contralaterally

Multifidus

arises from posterior sacrum, posterior superior iliac spine of ilium, aponeurosis of erector spinae, sacroiliac ligaments, mammillary processes of lumbar vertebrae, transverse processes of T1-T3, articular processes of C4-C7

Multifidus

fibers pass obliquely superomedially to entire length of spinous processes, located 2-4 segments superior to proximal attachment

stabilizes vertebrae during local movements of vertebralcolumn

Rotatores

arise from transverse processes

fibers pass superomedially to attach to junction of lamina and transverse process or spinous process of vertebra immediately (brevis) or 2 segments (longus) superior to vertebra of attachment

Rotatores

stabilize vertebrae and assist with local extension and rotatory movements of vertebral column; may function as organs of proprioception

Suboccipital & Deep Neck Muscles

Compartment deep to the superior of the posterior cervical region, underlying the trapezius, sternocleidomastoid, and splenius

Pyramidal space inferior to the external occipital prominence of head

Supplied by posterior ramus of C1, the suboccipital nerve

Suboccipital Triangle

 Whom have I in heaven but you?And earth has nothing I desire besides

you.My flesh and my heart may fail, but God is the strength of my heart and

my portion forever.Psalm 73:25-26

God bless you!

References

Clinically-Oriented Anatomy by Moore 6th ed.