Back Osteology, Arthrology, Fascia, and Muscles

What are the differences in C1, aka Atlas?

- Carries cranium, which means the lateral masses bear the weight of the cranium -Nobody - Articular facet for dens: on the posterior surface of the anterior arch - super and inferior articular facet - tubercle for transverse ligament - groove for vertebral artery

What are the limitations to the mobility of the vertebral column?

- Compressibility and elasticity of the IV discs - Shape and orientation of the zygapophysial joints - Resistance of back muscles and ligaments - Attachment to thoracic cage - Bulk of surrounding tissue

What are the veins of the vertebral column?

- Internal anterior and posterior vertebral venous plexuses - External anterior and posterior vertebral venous plexuses

What are the functions of the vertebral column?

- Protect spinal cord and spinal nerves - Supports the weight of the body superior to the pelvis - Involved in posture and locomotion

What are the parts of the back?

- Skin and subcutaneous tissue - Muscles: superficial (axioappendicular) and deep (intrinsic back muscles) - Vertebral column - Ribs (medial to the angle of ribs) - Spinal cord and meninges - Segmental nerves and vessels

What is the ligamenta flava?

- broad, pale yellow band of elastic tissue joining the laminae of adjacent vertebrae. - Form posterior wall of vertebral canal. -Limit flexion and separation of vertebral laminae, protecting IV disks

How long is the vertebral column?

- it is 72-75 cm long in the adult , and 1/4 is formed by the IV disc

What does the sacral vertebrae include?

- sacral canal, sacral hiatus, sacral cornua, sacral promontory -ala, apex, base of sacrum, median sacral crest, anterior and posterior sacral foramina

Characteristics of thoracic vertebrae and Lumbar : •General Features

-Have bodies -Vertebral arches -Seven processes for muscular and articular connections

What is the nuchal ligament?

-strong, broad, and thickened fibroelastic tissue. -Extends from occipital protuberance and posterior border of FM to spinous processes of cervical vertebrae. - Muscle attachment

What are the general characteristics of the vertebrae?

-vertebral body, vertebral arch, vertebral foramen, vertebral notch -lateral masses -7 processes

What are the atlanto-axial joints?

1.Lateral atlanto-axial joints (2) 2.Median atlanto-axial joint (1): pivot type of synovial joint between the dens of C2 and the anterior arch of C1

How many ribs are they?

12 ribs

Where is the articular process located?

2 superior & 2 inferior, project from the junction of pedicles and laminae. Each bears an articular surface (or facet)

Where is the sacral vertebrae located?

5 fused sacral vertebrae in the adult between the hip bones

What are the characteristic features of the coccygeal cornua?

: rudimentary articular process of Co 1 vertebra that articulate with the sacral cornua

What are the ligaments of the craniovertebral joints?

Anterior and Posterior atlanto-occipital membrane

What is the craniovertebral joint?

Atlanto-occipital joint: synovial joint, with thin, loose capsule between superior articular facets of the Atlas and the condyles of the occipital bone. -Flexion & extension (e.g. nodding). Anatomical equivalent of zygapophysial joint

Where is the back located?

Between the neck and buttocks

What is the spine made up of?

C7, T12, L5, 5S 4C =33 vertebrae Lumbar is huge

What are the typical features of thoracic vertebrae?

Costal facets (bilateral demifacets): articulate with head of ribs, usually occur in superior and inferior pairs Transverse costal facets: articulate with tubercles of ribs Spinous processes: long and sloped inferiorly

What are the general features of the lumbar vertebrae?

Have bodies Vertebral arches Seven processes for muscular and articular connections

What are the general features of thoracic vertebrae?

Have bodies Vertebral arches Seven processes for muscular and articular connections

What is kyphosis?

Humpback in the thoracic area

What are the joints of the vertebral bodies?

IV discs ligament support: Anterior longitudinal ligament Posterior longitudinal ligament

Where are the lumbar vertebrae located?

In the lower back, between thorax and sacrum

What is true about cervical vertebrates?

It bears less weight. •Greatest range and variety of movement of all vertebral regions Relative thickness of discs compared to the vertebral bodies Nearly horizontal orientation of facets Small amount of surrounding body mass

What does the back comprise of?

It it comprises of the posterior aspect of the trunk

What is the vertebral body?

Large and cylindrical in shape, weight bearing, anterior portion of vertebra

What is cervical lordosis?

Pushes your neck further forward than it should be or usually is

What is known about vertebral column?

Reduced to the superior 24 vertebrae. The 5 sacral vertebrae are fused, and the 4 coccygeal vertebrae fuse after age 30, limiting the movement of these vertebrae.

What are the 7 process of the vertebrae?

Spinous process Transverse process (2) Articular process (4)

What is the initial increase in size in the vertebral column due to?

The initial increase in size is due to increased body weight bearing, which is transferred from cervical > thoracic > lumbar > sacrum > pelvis > legs

What does the succession of the vertebral foramina form?

The succession of vertebral foramina forms the vertebral canal

What are vertebral notches?

These are the notches above and below the pedicle. There are superior and inferior notches

What does the anterior and posterior atlanto-occipital have in common?

These two membranes are strong sheets of connective tissue that extend laterally towards the atlanto-occipital joint, and help prevent excessive movement of atlanto-occipital joint

What does C1 and C2 have in common

They both have lateral masses, transverse foramen, C1 has a articular facet for C2 dens which creates a synovial joint -Embryologically, the dens represent the remnant of the body of the Atlas.

What are the differences in C3-C7?

They have anterior and posterior tubercle, Uncus of the body: raised lateral margins of the superior surface of cervical vertebrae C3 - C7 vertebral foramen: triangular and large, contains a large portion of the spinal cord •Transverse foramina: vertebral artery goes through C3 - C6, but no C7

What are the two cruciate ligaments?

Transverse ligament of atlas Superior and inferior longitudinal bands

What are the massive bodies of the lumbar vertebrae?

account for much of the thickness of the lower trunk in the median plane

What is the groove for vertebral artery in C1?

allows passage for vertebral artery into cranium

What is the sacral promontory?

anterior projection of the edge of the body of S1 vertebra

What is the vertebral size?

become larger from cervical to sacrum and then become smaller from sacrum to coccyx.

What is the supraspinous ligament?

connects tips of spinous processes from C7 to sacrum; merge superiorly with the nuchal ligament

What is the sacral canal?

continuation of the vertebral canal in the sacrum

What is lumbar lordosis?

excessive curvature of lower back, more pronounced in women than males

What is the anterior and posterior sacral foramina?

exit for the anterior and posterior rami of spinal nerves

What are the alar ligaments?

extend superolaterally from each side of dens to lateral margin of FM. - Check ligaments, prevent excessive rotation of the joints

What is the anterior atlanto occipital membrane?

extends from anterior arches of Atlas to anterior margin of FM. Merges with anterior longitudinal ligament in the center

What is the posterior atlanto-occipital membrane?

extends from posterior arches of Atlas to posterior margin of FM. Perforated to allow passage for the vertebral artery

Where does the vertebral column extends from?

extends from the cranium to apex of coccyx

What are the laminae of the vertebrae?

flat plates continuous with pedicles that join posteriorly in the midline

What is the vertebral foramen?

formed by vertebral arch and posterior surface of vertebral body.

What are the superior and inferior longitudinal bands?

from transverse ligament to occipital bone superiorly and to body of C2 inferiorly

What os the median sacral crest?

fused rudimentary spinous processes of sacral vertebrae

What is the sacral hiatus?

inverted U-shape, resulting from lack of laminae and spinous processes of S5 vertebra

What is vertebra L5?

largest of the moveable vertebrae

What are the typical features of the lumbar vertebrae?

massive bodies, accessory process, and mamillary process

Where is the spinous process located?

medinan and posterior

What do the anterior and posterior tubercles do in C3-C7?

muscle attachment

What is the lumbosacral angle?

occurs at the junction of the long axis of the lumbar and sacral region

What is the accessory process of the lumbar vertebrae?

on posterior surface of the base of the transverse processes and provides attachment for the intertransversarii muscles

What are the mamillary processes of the lumbar vertebrae?

on posterior surface of the superior articular process and provide attachments for the multifidus and intertransversarii muscles

What is the transverse foramen in C1?

passage for vertebral arteries and accompanying veins

Where is the transverse process located?

project postero-laterally from the junction of pedicles and laminae

What does the sacral hiatus provide?

provides access to the sacral epidural space for administration of anesthetics (caudal nerve block)

What is the sacral cornua?

represents inferior articular process of S5 vertebra. Helps in the anatomical location of the sacral hiatus

What is the ala?

represents the fused transverse processes of sacral vertebrae

What are the pedicles of the vertebrae?

short, cylindrical projecting posteriorly from body

What is the transverse ligament of the atlas?

strong band extending between tubercles on lateral masses of C1

What are anterior longitudinal ligaments?

strong, broad fibrous band covering and connecting the anterolateral aspects of vertebral bodies and IV disks. Extends from anterior aspect of FM to pelvic surface of sacrum. Limits extension (only ligament that limits extension)

What is the tectorial membrane?

superior continuation of posterior longitudinal ligament, starting at the body of Axis (C2) until anterior aspect of FM

What is the base of the sacrum?

superior surface of S1 vertebrae

What does the nutrient branch supply?

supply bone marrow

What does the equatorial branch supply?

supply central core

What does the periosteal branch supply?

supply the periosteum

What are zygapophyseal joints?

synovial joint between superior and inferior articular facets of adjacent vertebrae. Allows gliding movements.

What is the tubercle for transverse ligament of Atlas?

the ligament helps to hold the dens of C2 in place

What does C1, C2, C3-7 have in common?

transverse foramina

Where is the coccygeal located?

usually 4 fused coccygeal vertebrae

What is the posterior longitudinal ligament?

weaker, narrower band than ALL. Runs within vertebral canal along posterior aspect of vertebral bodies. Extends from body of C2 to sacrum. Limits flexion

What are the joints of the vertebral arches?

zygapophysial joints Accessory ligaments supporting the vertebral arches: ligamenta flava interspinous ligaments nuchal ligament

What are the interspinous ligaments?

üweak ligaments joining adjacent spinous processes. Inconsequential in the cervical region

What is the apex?

• inferior end that articulates with coccyx

When is the primary curvature developed?

•Develop during the fetal period, related to fetal (flexed) position

When does the secondary curvature develop?

•Develop from extension from the fetal position •Begin to develop during late fetal period, and truly become obvious in infancy

What do the coccygeal vertebrae not participate in?

•Does NOT participate in body weight bearing

What does the sacral vertebrae form?

•Forms the roof and posterosuperior wall of the pelvic cavity

Where are the 7 cervical vertebrae located?

•Located between cranium and thoracic vertebrae. C1=atlas, C2=axis, C3-7

What does curvature of the vertebral column provide?

•Provide additional flexibility to that of the IV discs

What is the coccygeal vertebrae remnant of?

•Remnant of the skeleton of the embryonic tail-like caudal eminence

What are the movements of the cervical portion of the vertebral column?

•Rotation • Lateral bending • Flexion/lateral flexion • Extension/ lateral extension

What does C2 and C3-7 have in common?

•Spinous process: bifurcated in whites, but not as common in blacks or females •Body - superior and inferior articular facet, pedicles, lamina,

What are the differences in C2?

•Strongest of cervical vertebrae • rotates on the Axis (C2) • Anterior articular facet: articulates with the posterior surface of the anterior arch of Atlas (C1) • Posterior articular facet: where the dens is supported by the transverse ligament of the atlas •Superior articular facet: where the atlas (C1) rotates •Inferior articular facet: articulates with C3

What is the superior and inferior articular facet of C1?

•Superior articular facet: articulates with occipital condyle •Inferior articular facet: articulates with axis (C2)

What are IV discs?

•cartilaginous joints, connecting articulating surfaces of adjacent vertebral bodies

What does the superior and inferior notches of adjacent vertebrae form?

•form the intervertebral foramina (exit for spinal nerves and accompanying vessels)

What do the superior and inferior articulate facets do in C3-C7?

•more transverse plane to allow more articulation, gliding movement

What is the vertebral arches and what does it consist of?

•posterior to vertebral body and consist of the pedicles (2) and laminae (2)

What is the function of the sacral vertebrae?

•provides strength and stability to the pelvis, and transmits the weight of the body to the pelvic girdle