8.25.11+-+Self+Study...+The+Back


 * OBJECTIVES:**


 * 1. Define the term “back.”**
 * 1) The posterieor aspect of the trunk, inferior to the neck and superior to the buttocks. The region of the body to which the head, neck, and limbs are attached.


 * 2. Identify the number of vertebrae forming the vertebral column.**
 * Cervical - 7
 * Thoracic - 12
 * Lumbar - 5
 * Sacral - 5
 * Coccygeal - 3 to 5 (think average = 4)


 * 3. Identify the five regions of the vertebral column. Name the regions formed by**
 * moveable vertebrae and the number of moveable vertebrae in each region. Write the**
 * abbreviations used for each region/**
 * Cervical - all 7 move
 * Thoracic - all 12 move
 * Lumbar - all 5 move
 * Sacral - unmoveable - fused to form sacram
 * 4 coccygeal fuse to form coccyx.


 * 4. Name the regions of the vertebral column formed by fused (unmovable) vertebrae**
 * and the number in each region.**
 * Sacram - 5 vertebrae
 * Coccyx - 4 vertebre


 * 5. Identify the four curvatures of the vertebral column. Name and describe the two**
 * primary and two secondary curvatures. Define the term “lumbosacral angle.” [COA 4th ed]**
 * Primary curvatures - thoracic and sacral - develop in the fetal period. Primary curvatures are caused by differences in height between anterior and posterior parts. Note: primary curvatures follow the same curve that a fetus would have (concave anteriorly). The secondary curvatures curve in the opposite direction.
 * Secondary curvatures - appear during fetal period but are not obvious until infancy - differences in thickness between the anterior and posterior parts of the IV discs. Sacral andLumbar curvatures
 * Lumbrosacral angle- end of the lumbar curvature--formed at the junction of the L5 vertebra with the sacrum.


 * 6. Define the following terms relative to the vertebral column: [COA 4th ed]**
 * Axial skeleton - 80 bones alone the central axis of the body, including the vertebral column
 * Intervetebral disc (IV disc) - provide strong attachments between the vertebral bodies. Also forms the inferior half of the anterior border of the IV foramen
 * Facet (zygopophyseal) joints - plane synovial joints between the superior and inferior articular processes of adjacent vertebrae. Permit gliding movements between the vertebrae; the shape and disposition of the articular surfaces determines the type of movement possible.
 * Extension - backwards (posterior) bend of the back
 * Flexion - forwards (anterior) bend of the back
 * Kyphosis - hunchback - abnormal increase in thoracic curvature--vertebral column curves posteriorly--resulting from erosion of the anterior part of one or more vertebrae
 * Scoliosis - crooked back - abnormal lateral curvature that is accompanied by rotation of vertebrae. Spinous processes turn toward the cavity of the abnormal curvature, and, when bending over, the ribs rotate posteriorly
 * Lordosis - hollow back - anterior rotation of the pelvis at hip joints, producing an abnormal increase in lumbar curvature--vertebral column curves anteriorly. Often caused by weakened trunk musculature, especially abdominal muscles.
 * Vertebra prominens - C7 - has a long spinous process
 * Vertebral canal - succession of vertebral foramina. Contains the spinal cord, minges, fat, spinal nerve roots, and vessels
 * Vertebral foramen - vertebral arch and the posterior surface of the vertebral body forms the walls of the vertebral foramen (THE hole)
 * Intervertebral foramen - the superior and inferior //vertebral// notches of adjacent vertebrae contribute to the formation of IV foramina, which give passage to spinal nerve roots and accompanying vessels, and contain the dorsal root ganglia.
 * Annulus fibrosus - forms the circumference of IV disk. Arranged in concentric layers of parallel fibers that crisscross those of the next layer. Made up of concentric lamellae of fibrocartilage. Anuli insert into smooth, rounded epiphyseal rings on articular surfaces of vertebral bodies. Allows some movement between adjacent vertebrae and provides a strong bond between them.
 * Nucleus pulposus - Located on the inside of the annulus fibrosis on the IV disc--contains fibrogelatinous pulp and occupies the center. More cartilaginous than fibrous and normally highly elastic. Located more posteriorly than centrally with high water content that decreases with age. Acts as a cushion and shock-absorbing mechanism. Acts like a semifluid ball bearing during flexion, extension, rotation, and lateral flexion of the vertebral column. Becomes broader when compressed. Avascular, receiving nourishment by diffusion from blood vessels at the periphery of the anulus fibrosus and vertebral body.
 * Sacral promontory - superiormost portion of the sacrum and is an important obstetrical landmark. It is the anterior projecting edge of the body of the S1 vertebra.
 * Sacral hiatus - results from the absence of laminae and spinous process of S5 vertebrae, and sometimes S4. The sacral hiatus leads into the sacral canal, the inferior end of the vertebral canal.

No, I think using the vertebra prominens is the best way.
 * 7. Describe the method used to count vertebrae in a living body (or cadaver).**
 * Does anyone have anything to say about this other than counting down from the vertebra prominens? //Clinically Oriented Anatomy// seems to say that you can't palpate or visualize any of the other cervical vertebrae, so that sounds like a good place to start counting, but I couldn't find anything else specific...


 * 8. Using a bony specimen, identify the following general features of a “typical**
 * vertebrae”:**


 * **body**
 * **vertebral (neural) arch**
 * **vertebral foramen**
 * **pedicles**
 * **laminae**
 * **superior articular processes and facets**
 * **inferior articular processes and facets**
 * **spinous process**
 * **transverse processes**
 * **intervertebral foramina**
 * **vertebral foramen**


 * 9.** Describe the following regional characteristics of vertebrae [COA 4th ed]
 * 1) Cervical vertebrae - form the bony skeleton of the neck (smallest of 24 movable vertebrae), between skull and thorax.
 * 2) Atlas - C1. atypical cervical vertebra. It is a ring-shaped bone and the widest of the cervical vertibrae. It supports the skull, and the kidney shaped concave superior articular surfaces of C1 receive the two large protuberances at the sides of the foramen magnum (the occipital condyles) . Weight of the head is transmitted to the verebral column. There is no spinous process or body and consists of anterior and posterior arches, each with a tubercle and lateral mass.
 * 3) Axis - C2. strongest of the cervical vertebrae because C1 rotates on it when a person is shaking the head. The axis has two large flat bearing surfaces, the **superior articular facets**, on which the atlas rotates. There is a blunt toothlike **dens** which projects superiorily from the body.
 * 4) **Foramen transversarri** - foramen of the transverse process is distinctive to the cervical vertebrae. These foremina are smaller in C7 than in othe rcervical vertebrae, and they are occasionally absent. Vertebral arteries pass through these, except in C7.
 * 5) Triangular vertebral foramina - typical cervical vertebrae (C3-C7) are characterized by a large triangular foramina (relative to rest of the vertebrae)
 * 6) Vertebra prominens - C7 - prominent vertebra characterized by a long spnious process
 * 7) Thoracic vertebrae
 * 8) **Costal facets -** characteristic features of thoracic veterbrae for articulation with ribs. One or more facets are on each side of the body for articulation with the head of the rib, and one facet is on each transverse process of the superior 10 thoracic vertebrae for the tubercle of the rib. Note: only thoracic vertebrae have costal facets because the other ones do not meet with ribs.
 * 9) Heart shaped bodies
 * 10) Circular vertebral foramina - circular and smaller than those of cervical and lumbar vertebrae
 * 11) Spinous processes - long and slopes posteroinferiorly; tip extends to level of vertebral body below.
 * 12) Lumbar vertebrae - in the lower back between the thorax and sacrum. Distinguished by massive bodies, sturdy laminae, and absence of costal facets.
 * 13) Largest vertebrae
 * 14) Massive bodies - kidney shaped when viewed superiorly (in order to bear the weight of all the vertebrae above it)
 * 15) Triangular vertebral foramina - larger than in thoracic vertebrae and smaller than in cervical vertebrae
 * 16) Sturdy laminae - thick, broad spinous process
 * 17) Sacram - large, triangular wedged shape bone composed of 5 fused sacral vertebrae in adults. Wedged between hip bones and forms the roof and posterosuperior wall of the posterior pelvic cavity.
 * 18) 5 fused vertebrae
 * 19) 4 pairs of foramina on ventral and dorsal surfaces
 * 20) Sacral promontory - superiormost portion of the sacrum and is an important obstetrical landmark. It is the anterior projecting edge of the body of the S1 vertebra.
 * 21) Sacral hiatus - results from the absence of laminae and spinous process of S5 vertebrae, and sometimes S4. The sacral hiatus leads into the sacral canal, the inferior end of the vertebral canal.
 * 22) Coccyx - tiny vertebrae - usually 3-5 fused. Remnant of the skeleton of the tail.


 * NOTE: At the point, focus your attention on the thoracic, lumbar, sacral and **
 * coccygeal vertebrae. The cervical vertebrae will be discussed in more depth in block **
 * 4 of this course. **


 * 10.Describe the following accessory ligaments of vertebral column: [COA 4th ed]**


 * ** Anterior longitudinal ligament ** - strong, broad fibrous band that covers and connects the anterolateral aspects of the vertebral bodies and IV discs. The ligament extends from the pelvic surface of the sacrum to the anterior tubercle of C1. Maintains stability of the joints between vertebral bodies and helps prevent hyperextension of the vertebral column. (all other ligaments prevents (hyper-)flexion)
 * ** Posterior longitudinal ligament ** - narrower, somewhat weaker band than the anterior longitudinal ligament. Runs within the vertebral canal along the posterior aspect of the vertebral bodies. Attached to the IV discs and the posterior edges of the vertebral bodies from C2 to the sacrum. Helps prevent hyperflexion of the vertebral column and herniation or posterior protrusion of the discs.
 * ** Nuchal ligament ** - broad, strong median ligament of the neck composed of thickened fibroelastic tissue, extending from the external occipital protuberance and posterior border of the foramen magnum (what's this?) to the spinous processes of the cervical vertebrae. Because of the shortness of the C3-C5 spinous processes, the nuchal ligament substitutes for bone in providing muscular attachments.
 * ** Interspinous ligament ** - connect adjoining spinous processes, attaching from the root to the apex of each process (weak, thin, membranous)
 * ** Supraspinous ligament ** **-** cordlike ligament connecting the apexes of the spinous processes from C7 to the sacrum, merges superiorly with the nuchal ligament.
 * ** Ligamenta flava ** - laminae of adjacent vertebral arches are joined by broad yellow elastic fibrous tissue. Extend almost vertically from lamina above to the lamina below. The ligaments bind the adjoining vertebrae together, forming part of the posterior wall of the vertebral canal. Long, thin, and broad in cervical region, thicker in thoracic region, thickest in the lumbar region. Legaments prevent separation of the vertebral lamina, arresting abrupt flexion of the vertebral column and usually preventing injury to IV discs. Strong elasticity help preserve the normal curvatures of the vertebral column and assist with straightening of the column after flexing.


 * 11.Describe a zygapophyseal (facet) joint.**


 * The zygapophyseal joint is the joint formed between the superior articular facet of one vertebra and the inferior articulating facet of a higher vertebra.


 * 12 Define the following movements of the vertebral column: **


 * ** flexion **
 * ** lateral flexion **
 * ** extension **
 * ** (axial) rotation **
 * ** axial compression **
 * ** axial distraction: ** opposite of compression?


 * 13.Identify the following extrinsic (superficial) muscles of the back. List the proximal **
 * attachments, distal attachments, innervation and main action(s) of these muscles: [ // Clinically Oriented Anatomy //(6th ed.) table 6.4. May be table 6.2 in other editions.] **


 * ** trapezius **
 * ** latissimus dorsi **
 * ** levator scapulae **
 * ** rhomboideus major **
 * ** rhomboideus minor **
 * Muscle || Proximal attachments || Distal attachments || Innervation || Main action ||
 * Trapezius || Medial third of superior nuchal line; external occipital protuberance, nuchal ligament, and spinous processes of the C7-T12 vertebrae || Lateral third of the clavicle, acromion, and spine of the scapula || Spinal root of the accessory nerve (CN XI) (motor) and cervical nerves C3 and C4 (pain and propioception) || Elevates, retracts, and rotates scapula; superior fiers elevate, middle fibers retract, and inferior fibers depress scapula; superior and inferior fibers act together in superior rotation of scapula ||
 * Latissiumus dorsi || Spinous processes of T7-T12, thoracolumbar fascia, iliac crest, and inferior 3 or 4 ribs. || Floor of intertubercular groove of the humerous || Thoracodorsal nerve (C6, C7, C8) || Extends, adducts, and medially rotates humerus; raises body toward arms during climbing ||
 * Lavator scapulae || Posterior tubercles of transverse processes of C1-C4 vertebrae || Superior part of medial border of scapula || Dorsal scapular (C5) and cervical (C3 and C4) nerves || Elevates scapula and tilts its glenoid cavity inferiorly by rotating scapula ||
 * Rhomboideus major || Spinous processes of T2-T5 vertebrae || Medial border of scapula from level of spine to inferior angle || Dorsal scapular nerve (C4 and C5) rotate || Retract scapula and rotate it to depress glenoid cavity; fix scapula to thoracic wall ||
 * Rhomboideus minor || Nuchal ligament, spinous ligament, and spinous process of C7 and T1 || Medial border of scapula || Dorsal scapular nerve, C5 || Retract scapula ||


 * 14.Identify the intrinsic (deep) muscles of the back. These muscles lie within a fascial **
 * compartment between layers of thoracolumbar fascia. Describe actions of splenius **
 * group and erector spinae group. Recognize that the innervation of these deep **
 * muscles is unusual in that they are innervated by the dorsal (posterior) rami of spinal **
 * nerves. [formatting nicely is a problem for me, sorry!] **
 * ** Splenius group (superficial layer) (table 4.4)
 * Origin: ligamentum nuchae and spinous processes of C7-T3 of T4 vertebre.
 * Insertion - spelnius capitus - fibers run superolaterally to mastoid process of temporal bone and lateral third of spuerior nuchal line of occipital bone splenius cervicis: tubercles of transverse processes of C1-C3 or C4 vertebrae
 * Nerve supply - dorsal rami of spinal nerves
 * Action: acting alone, they laterally bend and rotate head to side of active muscles; acting together, they extend head and nec
 * Erector spinae group (intermediate group)
 * Origin: arises by broad tendon from posterior part of iliac crest, posterior surface of sacrum, sacral and inferior lumbar spinous processes, and supraspinous ligament
 * Insertion:
 * Iliocostalis - lumborum, thoracis, and cervis: fibers run superiorly to angles of lower ribs and cervical transverse processes
 * Longissiumus - tracis, cervis, and 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, and capitus: fibers run superiorly to spinous processes in the upper thoracic reion and to the skull
 * Nerve supply - dorsal rami
 * Main action: acting bilaterally, they extend vertebral column and head; as back is flexesed they control movement by gradually lengthening their fibers; acting unilaterally, they laterally bend the vertebral column


 * 15.Identify the boundaries and clinical importance of the “triangle of auscultation” and **
 * “lumbar triangle.” **


 * ** Triangle of auscultation: **The borders are the trapezius, the latissimus dorsi, and the scapula. It is clinically significant because there is little tissue between the skin and the lung at this point, making it an ideal location to auscultate (listen to) the lungs during breathing.
 * **Lumbar triangle:** The border are the latissimus dorsi, the external obliques, and the iliac crest. It is clinically significant because a hernia can form here (rarely).


 * As a memory aid, it may help to remember that both triangles are bordered by the latissimus dorsi (although they are bordered by different sides of this muscle). It make also help to remember that each triangle is bordered by two muscles and one bone.


 * 16.Identify the serratus posterior inferior and serratus posterior superior muscles. **


 * Serratus posterior superior || Serratus posterior inferior ||
 * [[image:http://www.claudiafriedlander.com/.a/6a0133ec991857970b014e60e8098e970c-250wi]] || [[image:http://www.pilatespatio.com/serratus_posterior_inferior.jpg]] ||
 * [[image:http://www.claudiafriedlander.com/.a/6a0133ec991857970b014e60e8098e970c-250wi]] || [[image:http://www.pilatespatio.com/serratus_posterior_inferior.jpg]] ||


 * DISSECTION OBJECTIVES (PAGE 61-62 in Block 1 Handout)**


 * 1. After removing the intact dorsal portion of the vertebral laminae, turn it over and observe the ligamenta flava.**

> **epidural (extradural) space** > **dural sac (made of dura mater)** > **dura mater** > **arachnoid mater** > **subarachnoid space** > **pia mater** > **denticulate ligaments (made of pia mater)** > > **ventral root** > **dorsal root** > **lumbar enlargement (the cervical enlargement is not seen in this dissection)** > **conus medullaris** > **cauda equina** > **filum terminale** > > **dorsal root ganglion** > **spinal nerve** > **dorsal primary ramus** > **ventral primary ramus** > > **dorsal root** > **dorsal root ganglion** > **ventral root** > **spinal nerve** >> **dorsal (posterior) ramus** >>> **medial branch** >>> **lateral branch** >> **ventral (anterior) ramus** >>> **lateral cutaneous nerve** >>>> **anterior branch** >>>> **posterior branch** >>> **anterior cutaneous nerve** >>>> **medial branch** >>>> **lateral branch** >>>> Adapted from //Atlas of Human Anatomy, 5th edition,// (Frank Netter) plate 174: > > > **nerve plexus** > **dermatome** > **myotome** >
 * 2. Identify features associated with the spinal meninges:**
 * 3. Study the spinal cord and find:**
 * 4. Follow dorsal and ventral roots through intervertebral foramen and dissect:**
 * 5. Outside of lab, sketch and label the distribution of a spinal nerve:**
 * 6. Review the definitions of:**