Anatomy Back

What kind of ligament limit motion of the ribs relative to the vertebrae

"costo" ligaments

Describe how a bulging disk at L2/L3 will affect the spinal nerves.

A herniated lumbar nucleus pulposus generally affects the spinal nerve at the level below because the nerve exits superiorly to the disc bulging so L2 will be fine, but the L3 spinal nerve will be affected.

Dermatome: L5

Anterior ankle and foot

Innervation of Latissimus Dorsi

Thoracodorsal nerve

Extrinsic muscles of the back

Trapezius, Latissimus dorsi, Rhomboid major, Rhomboid minor, Levator scapulae

Ischemia of Spinal Cord

Deficiency of spinal blood supply, through medullary arteries, that can lead to muscle weakness and paralysis.

Name several muscles that contract during extension of the trunk.

Erector spinae, splenius capitus, splenius cervicis, multifidis lumborum, rotatores, semispinalis capitus and cervicis, suboccipital muscles, gluteus maximus, hamstring muscles.

What is innervated by posterior rami?

Everything is considered "true" back.

Describe Type 1 Mechanics

Example, scoliosis.

In regards to active and passive action, what do the erector spinae muscles cause?

Cause unilateral side-bending and lateral flexion; bilateral extension. They resist flexion.

In regards to active and passive action, what does the splenius do?

Causes extension and resists flexion

Which part of the spine do Fryette's laws not apply to?

Cervical spine

Which planes are thoracic vertebral articular facets primarily oriented?

Coronal plane

Innervation of Trapezius

Cranial Nerve XI or spinal accessory nerve

Describe Type 2 Mechanics

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What are the principle muscles producing movement of the cervical intervertebral joints? What are the limiting structures?

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What are the principle muscles producing movement of the thoracic and lumbar intervertebral joints? What are the limiting structures?

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Overall and individual function of extrinsic muscles

Overall function is to produce and control limb and respiratory movements. Trapezius - elevator and rotate scapulae Lats - swimmers muscle Rhomboids - retract and rotate scapular to depress the genoid cavity; Rhomboids also hold the scapula close to he posterior thoracic wall. Levator scapulae - elevates and rotates the scapula to depress the glenoid cavity.

Dermatome: C6

Pollex (thumb)

Dermatome: S2

Posterior lower limb

Causes of excessive lumbar lordosis

Pregnancy, carrying excess belly fat, descrese in abdominal muscle tone. The disappearance of lumbar lordosis (flattening of back) is seen when muscles spasm in back.

Function of posterior vertebral segment (arch etc)

Primarily determines range of motion

What is the relationship of the posterior rami to the posterior roots in the cervical region? Is there a difference in the thoracic region?

Rami have both sensory and motor fibers within them (roots do not)

The IV disc is innervated by what branches of the spinal nerve?

Recurrent meningeal nerve - innervate the facet joints, the annulus fibrosus of the intervertebral disc, and the ligaments and periosteum of the spinal canal, carrying pain sensation. The nucleus pulposus of the intervertebral disk has no pain innervation.

What is the primary motion permitted by thoracic vertebra?

Rotation

Describe tri-planar motion of the spine

Sagittal, side-bending, rotation.

SAP

Sensory-afferent-posterior

Intermediate extrinsic back muscles

Serratus posterior superior (lies just deep to Rhomboids and is sometimes reflected with them) and serratus posterior anterior (lies just deep to the latissimus dorsi and is also sometimes reflected with it)

Overall and individual function of intermediate extrinsic muscles

Serratus; superficial respiratory muscles, but more likely proprioceptive (sensory) rather than motor, possibly stretch receptors.

Define the structure and space a needle might pass through if inserted through the skin to the subarachnoid space at the level of T12-L1.

Skin, subcutaneous fat, thoracolumbar fascia, supraspinous ligament, interspinous legament, no ligamentum flavum on the midline, dura mater, arachonid mater, and subarachnoid space.

Explain breakdown of function for vertebral segments

Anterior supports body weight. Posterior is for movement. Transverse processes are for attachment. Facet are to restrict movement. Neural arches are for protection.

How is the spinal cord anchored within the vertebral column?

The pia mater of the spinal cord has a pair of denticulate ligaments (one on each side of the spinal cord) with 21 attachments per side which attach it to the arachnoid and dura maters. Named for their tooth-like appearance, the denticulate ligaments are traditionally believed to provide stability for the spinal cord against motion within the vertebral column.

Once the semispinalis capitis muscle is removed, which muscle and what landmark are easily seen?

The semispinalis cervicis muscles which attaches to the spinous process of the axis (C2)

Describe how a bulging disk in the cervical area will affect the spinal nerves.

The spinal nerves in the cervical region travel horizontally and the space between vertebrae is tighter. A cervical HNP will affect the nerve exiting at the same level, but due to nomenclature C1-C7 nerves exist superior to their corresponding vertebra. There is no C8 vertebra, so the C8 spinal nerve exist the intervertebral foramen btw C8 and T1 vertebrae.

What are the boundaries of the lumbar triangle?

The superior border of the iliac crest, the latissimus dorsi (posteriorly ish), and the external obliques (anteriorly ish)

Disc Prolapse

Very common injury. With age, the anulus fibrosus (the fibrous outer rings of fibrocartilage) may degenerate and develop teras that allow radial extrusion of the pressurized liquid nucleus (nucleus pulposis, acts a s a shock-absorber). Extrusion may reach longitudinal ligament and the nerve roots and cause impingement leading to neurological symptoms. 95% of lumbar disc herniations occur btw L4-L5 and L5-S1.

2nd Fryette Law

When you flex or hyperextend your spine and you laterally bend/ flex or side bend to the RIGHT. Your spine will ROTATE to the RIGHT (same side). Referring to a single vertebral segment.

3rd Fryette Law

When you side bend or forward flex or you do any movement in one plane. Simply put, there won't be as much motion in the other planes.The first two solely apply to the lumbar and thoracic spinal regions, and the third applies to the spinal region.

1st Fryette Law

When you're standing in a neutral position (no bending or hyperextension) and you laterally bend/ flex or side bend to the RIGHT. Your spine will ROTATE to the LEFT (the opposite side). Referring to a group of vertebrae.

Function of soft tissue (muscle and ligament) in spine

Works to cause and resist motion.

Nuchal ligament

a fibrous membrane, which, in the neck, represents the supraspinal ligaments of the upper part of the spine. As it is required for running, not all animals have a nuchal ligament. It extends from the external occipital protuberance on the skull and median nuchal line to the spinous process of the seventh cervical vertebra in the lower part of the neck. From its anterior border a fibrous lamina is given off, which is attached to the posterior tubercle of the atlas, and to the spinous processes of the cervical vertebrae. The trapezius and Splenius capitis muscle attach to the nuchal ligament.

Intertransverersarii

a series of small muscles connecting the transverse processes of contiguous vertebrae and most highly developed in the neck; mainly involved in proprioception and resists flexion.

Spondylolisthesis

after a spondylolysis is present causing the more superior vertebra to slip anteriorly; this can put pressure on the cauda equina.

Iliolumbar ligament

connect the transverse processes of L4 and L5 to the Ilium.

Spinal ganglia cells

derived from neural crest and have ONLY sensory root axons to posterior hron

Insertion of Latissimus dorsi

intertubercular groove of the humerus

Ligamentum flavum

is only on the neural arch (medial side) of the lamina, not the spinous process. It is very elastic and doesn't function much as a ligament.

Posterior Longitudinal Ligament

is within the vertebral canal, and extends along the posterior surfaces of the bodies of the vertebræ, from the body of the axis, where it is continuous with the membrana tectoria, to the sacrum. It is thicker in the thoracic region. It is what an extrusion in a herniation bumps into before it hits the spinal nerves. Helps prevent hyperflexion of spine.

Dermatome: L4

knee

Great Anterior Segmental Medullary Artery of Adamkiewicz

much larger than other segmental medullary arteries and seen on left side at low T or L levels. If obstructed by obstructuve arterial disease, it can have a great impact on spinal circulation.

Myotome

muscle fibers supplied by a single spinal nerve

Rachischisis

neural tube itself didn't form properly; usually 100% fatal; many different types.

Dura Mater

tough, fibrous membrane that surrounds the brain, spinal cord, and nerve roots. The dural connection btw the foramen magnum of the occiput to S2 and coccyx explains why injury to the sacrum may manifest in other areas of the spine.

What is the primary motion permitted by the lower cervical vertebra?

Flexion and extension

What are the major motion of the lumbar and thoracic spine?

Flexion and extension. Side-bending and rotation, which are coupled motions.

Describe how extension and flexion manipulate the nucleus pulposus.

Flexion of the back pushes the nucleus pulposus posteriorly while extension pushes it anteriorly.

Dermatome: C3

Neck

Dermatome: T4

Nipple

Explain development of the intervertebral disc

Notochord is surrounded by sclerotomal mesenchym, which condense to intervertebral disc with the annulus fibrosis; The nototchord leaves no trace except as the NUCLEUS PULPOSUS.

Where to type II dysfunction occurs in relation to Type I?

Type II (non-neutral) somatic dysfunctions are usually found at the apex of a type 1 (neutral curve, or else where the curve transition back to the normal spine (crossover).Somatic dysfunction occurs when the spine does not return to its usual neutral psition after compelting an activity (in flexion, facet locked open; and in extension, facets are locked closed).

Dermatome: T10

Umbilicus

Dermatome: C8

5th digit of hand

Anterior Longitudinal Ligament

A ligament that runs down the anterior surface of the spine. It traverses all of the vertebral bodies and intervertebral discs. The ligament actually has three layers: superficial, intermediate and deep. The superficial layer traverses 3 - 4 vertebrae, the intermediate layer covers 2 - 3 and the deep layer is only between individual vertebrae.

What is the first thing we usually check for in somatic dysfunctions?

A rotated vertebral segment. Think of riding a bicycle and turning left and right. However, be aware of paraspinal "fullness" which may be due to the erector spinae muscles and not a rotated vertebra. Use motion testing to differentiate.

Definition of Scoliosis

Abnormal lateral curvature of the spine. Cause due to poor pasture, excess weight, short leg, or genetic bone pathologies. Remember, S curve occurs because head wants to be kept upright.

Function of erector spinae group

Bilateral contraction of these muscles pull the trunk into extension or hold the trunk stable at any degree of flexion. unilateral contraction side-bends the torso to the ipsilateral side.

Importance of Vertebral Venous Plexuses

Can return blood from pelvis or abdomen to superior vena cava in heart when the inferior vena cava is blocked. These veins also provide a route for metastasis of cancer cells to the vertebrae or brain from an abdominal or pelvic tumor (ex. prostate cancer).

Denticular ligament

Divides the posterior and anterior roots; made of pia mater and anchors the pia mater to the dura mater for stability.

Innervation of rhomboid major and minor

Dorsal Scapular nerve, runs with dorsal scapular artery on anterior aspect of rhomboids at medial border of the scapula.

What types of signal pass through the posterior rami of the spinal nerves?

Dorsal rami carry visceral motor, somatic motor, and sensory information to and from the skin and deep muscles of the back; mixed nerves. Posterior divisions usually larger than anterior.

Intrinsic intermediate back muscles

Erector Spinae Muscles: - Iliocostalis - Longissimus - Spinalis Responsible for extension and lateral flexion of back/trunk (postural). Cross many vertebral segments as compared to the transversiospinalis group which cross 2-4 vertebral segments.

Basal plates

From neural tub thickening and differentiation of mantle layer. Basal plates become anterior horn (motor neuron cell bodies). And the intermediate horn forms between the basal and alar plates.

Alar plate

From neural tube thickening and differentiation of mantle cells. Alar plates become posterior horn (sensory neurons)

Neuroepithelial layer

Gives rise to all spinal neurons and some support cells

Functions of Intervertebral disc and anterior vertebral segment

IV disc cushion and distribute stress. AVS (vertebral body) is primarily devoted to load bearing.

Spinal Meningitis

Inflammation of the spinal meninges (dura, arachoid, pia mater and CSF) can occur due to infection. Spinal meninges are continuous with those of the brain and so infection can spread to the cranium. Can test with Kernig's Sign (back pain with straightening elevated leg while supine) and will stretch the lumbosacral meninges.

Dermatome: L1

Inguinal line

What is the course of the thoracodorsal nerve? And, if it were injured, how would the symptoms present?

It innervates the latissimus dorsi. It originates from the posterior brachial plexus from C6-8 nerves and follows the subscapular artery and supplies the deep surface of the latissimus dorsi. Injury or compression of the nerve leads to paralysis of the latissums dorsi meaning that the person cannot raise the trunk with the upper limbs, such as in climbing.

What is the importance of the lumbar triangle?

It is often the site of herniatrions

Sclerotomal mesenchyme

It surrounds the neural tube and notochord to become the vertebrae and ribs; mesenchyme will condense into cartilage and then bond. The spinous process is the last to form. If spinous process doesn't form you have Spina bifida.

Intrinsic superficial Back Muscles

Splenius muscles - splenius capitis and splenius cervicis.

Insertion of trapezius

Stable origins are the cervical and thoracic spinous processes and the occiptal region of the skull while the insertion site on the spine of the scapula is more mobile.

Movement of the trapezius

Superior fibers - elevation of scapula Middle fibers - retraction of scapula Inferior fibers - depression of scapula and inferior rotation of glenohumeral joint.

During flexion, what are several ligaments that will be stretched.

Supraspinous ligaments, linterspinous ligaments, ligamentum flavum, and nuchal ligament.

Compare the lumbar triangle to the triangle of auscultation.

The borders of the triangle of auscultation are the superior border of the latissimus dorsi, lateral border of the trapezius, and the medial borders of the rhomboid muscles. This is a site with less muscle and so lung sounds may be heard more distinctly here. Also heard better if pt leans forward while crossing arms.

In regards to active and passive action, what do the transversospinalis muscles cause?

The cause rotation and extension, but resist flexion.

Posterior and anterior rami in embryological development

The collective neurons of the spinal nerve split to form the posterior and anterior rami. The posterior rapi penetrate the somite (epimere) and will supply the derivatives of the skin and true muscles of the back. The anterior rami will grow into the lateral mesoderm (hypomere) and will supply the skin and muscles of the rest of the body, except for the head.

What muscles are innervated by the dorsal scapular nerve? And if this nerve were injured, how would the symptoms present.

The dorsal scapular nerve originates from the brachial plexus from C5 nerve root and innervates the rhomboid muscles and the levator scapulae. Injury to this nerve results in weakness of those muscles, usually related to shoulder dysfunction.

Meningocele

The least common form of spina bifida is a posterior meningocele (or meningeal cyst). In this form, the vertebrae develop normally, but the meninges are forced into the gaps between the vertebrae. As the nervous system remains undamaged, individuals with meningocele are unlikely to suffer long-term health problems

What are uncovertebral or Luschka's joints?

They are located C3-C7 and limit some rotation and side bending; meant to keep the vertebral bodies on top of each other so no sliding. These are synovial joints and therefore have articular cartilage and can develop osteoarthritis.

Meningomyelocele

This type of spina bifida often results in the most severe complications. In individuals with myelomeningocele, the unfused portion of the spinal column allows the spinal cord to protrude through an opening. The meningeal membranes that cover the spinal cord form a sac enclosing the spinal elements.

Causes of excessive kyphosis

over accentuation of the thoracic kyphosis is often the result of osteoporosis and compression fractures of vertebrae.

Radiculopathy

pain that frequently radiates along a dermatome.

Marginal layer

region that will contain white matter

Function of splenius muscles

unilateral contraction of the splenius muscles will turn the head to the same side and elevate it slightly. Biltateral contraction extends the neck and head.

What is the clinical connection btw the internal vertebral venous plexus and prostate cancer?

vertebral venous system as the route of metastasis of cancer from the prostate to the spine. Cerebrospinal venous system was bi-directional due to n etwork of valveless veins in the human body that connect the deep pelvic veins and thoracic veins (draining the inferior end of the urinary bladder, breast and prostate) to the internal vertebral venous plexuses.

Name several muscles that contract during flexion of the trunk

Abdominal muscles, psoas major, sternocleidomastoid, infrahyoid muscles.

What ligament will be stretched during extension (will resist extension?

Anterior longitudinal ligament.

Innervation of Levator scapulae

Anterior rami, C3-C5. Its blood supply is the dorsal scapular artery and its innervation is the dorsal scapular nerve.

Lumbar triangle

Area where there is less muscles keeping the abdominal organs in their cavity; borders are the external obliques, latissimus dorsi, and iliac crest

Origin and insertion of splenius cervicis

Origin is T3-T6 Insertion is transverse processes of C1-C3 Innervated by posterior rami. Function is to extend, rotate, and laterally flex the head.

Origin and insertion of splenius capitus

Origin is lower nuchal ligament and C7-T3 or T4 Insertion is to the mastoid process of the temporal bone and rough surface on occipital bone. Innervated by posterior rami. Function is to extend, rotate, and laterally flex the head.

Overall and individual functions of the Intrinsic back muscles

Overall the maintain posture and control movements of the vertebral column.

Supraspinous ligament

a strong fibrous cord, which connects together the apices of the spinous processes from the seventh cervical vertebra to the sacrum. The most superficial fibers of this ligament extend over three or four vertebræ; those more deeply seated pass between two or three vertebræ while the deepest connect the spinous processes of neighboring vertebræ. Between the spinous processes it is continuous with the interspinal ligaments.

Zygapophyseal joint

a synovial joint between the superior articular process of one vertebra and the inferior articular process of the vertebra directly above it. The biomechanical function of each pair of facet joints is to guide and limit movement of the spinal motion segment. In the lumbar spine, for example, the zygapophysial joints function to protect the motion segment from anterior shear forces, excessive rotation and flexion. Zygapophyseal joints appear to have little influence on the range of side bending (lateral flexion).

Mantle layer

formed by neuroepithelial cell that divide an differentiate into neuroblast cells

Spondylolysis

fracture of the interarticular parts (the weakest link) of the lamina; most common btw L5 and S1

Anterior horn cells

give rise to ONLY motor root axons (to myotome)

Intermediate horn

gives rise to sympathetic cells (autonomic nervous system)

Spina bifida occulta

hair and skin where spinous process would be. In occulta, the outer part of some of the vertebrae is not completely closed. The splits in the vertebrae are so small that the spinal cord does not protrude. The skin at the site of the lesion may be normal, or it may have some hair growing from it; there may be a dimple in the skin, or a birthmark. Many people with this type of spina bifida do not even know they have it, as the condition is asymptomatic in most cases

Describe the internal vertebral venous plexus. Where is it found?

lie within the vertebral canal in the epidural space (outside the dura mater but within the vertebral column) and receive tributaries from the bones and from the medulla spinalis. the internal vertebral venous plexuses (anterior and posterior) lying within the spinal canal but external to the dura; the external vertebral venous plexuses (anterior and posterior), which surround the vertebral column; and the basivertebral veins, which run horizontally within the vertebrae. Both the internal vertebral venous plexus and the external vertebral venous plexus course longitudinally along the entire length of the spine, from the sacrum to the cranial vault

Intrinsic Deep back muscles or the transversospinales muscle group

semispinalis capitis (must reflect splenius capitus to see it) and semispinalis cervicis (inserts to C2), multifidus (most visible in lumbar region), rotatores (most visible in thoracic region). They occupy the "gutter" between the transverse and spinous processes. Rotatores are deepest to multifidus then semispinalis.

Dermatome

sensory region (area of the skin) supplied by a single spinal nerve

Function of the latissimus Dorsi

slight extension (backward), adduction (towards the body), medial rotation (behind, towards body) rotation of the arm. Important to balance the pectoral muscles on the anterior thorax.

Function of transversoplinalis muscles

the semispenalis capitis, semispenalis cerivicis, rotatores, and multifidus lumborum. The all run obliquely from transverse process to spinous process so they all have some rotational component. Semispinalis muscles are the longest and ave the lest rotational component; they act as extensors of the neck and skull. Multifidus lumborum - the major extensor and posterior stabilizer of the lumbar vertebrae; is acts with the longissimus and the oblique angle of the multifisu fibers give them some rotary role. Rotatores - the deepest and have the most rotary action, but the are the smallest and so can't give much muscular force; perhaps more proprioceptive sensory bc of higher concentration of muscle spindle fibers.