Chapter 2: BACK

Anulus fibrous of disc

(L. anus, a ring) bulging fibrous ring consisting of concentric lamelle (layer) of fibrocartilage.

Of the 33 vertebrae in the spinal column, there are: A) 5 lumbar. B) 5 thoracic. C) 7 sacral. D) 12 cervical.

5 lumbar

33 vertebrae in the spinal column

7 cervical, 12 thoracic, 5 lumbar, 5 sacral, 4 coccygeal

posterior longitudinal ligament

Connects all the posterior surfaces of the vertebral bodies

superior notches

above

Anterior Longitudinal Ligament (ALL)

*a strong fibrous ligament that courses along the anterior surface of the vertebral bodies from the base of the skull to the sacrum.

Occyx

*also called "tailbone" *Made of/consists 4 fused vertebrae * Provide attachment points for ligament muscles of the pelvic floor -Muscles: gluteus Maximus and coccygeal muscles -Ligament: anococcygeal ligaments

Atlanto-axial joint (AA joint)

*articulation between the atlas and axis *three Atlanto-axial joint -Dens of axis -median and lateral Atlanto-axial joints *pg. 100 book

atlanto-occipital joint

*articulation between the atlas and the cranium -or form between atlas (C1 and cranium) *anterior and posterior Atlanta-occipital membrane connects cranium and C1

2. Joints of vertebral arches

*zygapophysical joints (facet joints)

joint capsule

The fibrous sac that encloses a joint.

vertebral canal (spinal cavity) (pg. 73)

canal contains the spinal cord and roots of the spinal nerves along with the membranes of (meninges)

laminae of vertebrae

make up vertebral arch; flattened plates that fuse in the median plate, completing the arch posteriorly and unite in the midline

what form the wall of the vertebral foremen?

posterior surface of the vertebral body and vertebral arch

Uncovertebral "joints" or clefts (of Luschka)

* cause neck pain

Cervical Vertebrae (C1-C7)

* contain transverse foramen, small oval body, triangular vertebral foramen *supports head *C1 (atlas) and C2 are specialized vertebrae -allows greatest range of motion for all vertebrae

sacral vertebrae

*5 vertebrae which are fused to form the sacrum in the pelvis *They fused together, and with hipbone they form the pelvic girdle. -connects spine to hip bones *provides strength and stability to the pelvic and transmits the weight of the body to pelvic girdle

C2 (axis) vertebrae

*C2 called "axis" -served as an axis around which C1 pivots (pin) -allowing you to shake your head while saying "no" , specialized process called dens or odontoid process

Joints of Vertebral bodies: Symphyses (Cartilaginous Joint)

*Fibrocartilage sandwiched between hyaline cartilage *Strong & flexible (weight bearing and strength) *Amphiarthrotic: slightly movable joints Ex. Pubic symphysis, intervertebral joints *connected by IV discs and ligaments.

zygapophysical joints

*articulations are plane synovial joints between superior and inferior articular process *each joint is surrounded by thin joint capsule *permit gliding movements between the articular process; the shape and disposition of the articular surfaces that determine the types of movement possible. *innervated (supply by nerve) by articular branches that arise from the medial branches of the posterior rami of spinal nerves.

REGIONAL CHARACTERISTICS OF VERTEBRAE

*cervical vertebrae *thoracic vertebrae *lumbar vertebrae *Sacral vertebrae *occygeal

intervertebral (IV) discs

*fibrocartilage pads that separate and cushion the vertebrae *provide strong attachments between vertebral bodies *and permits movement between adjacent vertebrae *each IV discs consists of an anulus fibrous *contribute 20-25% of spinal length (height)

1 - Vertebral Body

*gives strength to the vertebral column and supports body weight *epiphysial rim (ring of smooth bone) *centrum

Vertebral column (spine)

*is also called backbone. *composed of 33 bones called vertebrae *function: provide body with support and protect spinal cord from injury. *divided into five columns: Cervical, thoracic, lumbar, sacral, and coccygeal. *Cervical, thoracic, and lumbar vertebrae are articulating and separated by intervertebral discs * Sacral and bones of coccyx are fused

(C1) atlas vertebrae individual view

*supports head, has no body or spine, the two transverse processes have superior facets which the occipital condyles articulate *C1 is ring shaped and directly attached to skull -allows head to nod * lacks body and spinous process

Thoracic Vertebrae (T1-T12)

*the 12 bones of the vertebral column (midspine) and upper back. *holds the rib cage and protect heart and lungs *has limited range of motion

nucleus pulposus

*the soft, fibrocartilaginous, central portion of intervertebral disk * semifluid nature is responsible for much of the flexibility and resilience of the IV disc of the vertebral column

Lumbar Vertebrae (L1-L5)

*third set of five larger vertebrae, which forms the concave (inward curve) of the spine *vertebrae of lower back *bear the weight of upper body *And are larger to support the stress, especially when lifting something heavy

Intervertebral foramina

*when two vertebral notches join together *openings providing for exit of spinal nerves

Joints of the Vertebral Column

1. Joints of the vertebral bodies (body: bears weight) 2. Joints of the vertebral arches (Arches: houses the spinal cord, process: allows muscle attachment) 3. Craniovertebral (atlanto-axial and atlanto-occipital) joints 4. Costovertebral joints (chapter 4, thorax) 5. Sacro-iliac joints (chapter 6. pelvis and perineum)

Three types of seven processes

1. spinous process 2. transverse process 3. Articular process

pedicles of vertebrae

2 short stalks projecting laterally Connect the body of vertebrae to transverse processes

3. Two types of craniovertebral joints

Atlanto-occipital joints Atlanto-axial joints

articular process

Function: restriction of movement *assist in keeping adjacent vertrebrae aligned, specially it prevents one vertebra from slipping anteriorly on the vertrebra below * bear weight temporally

transverse process

Function: same as spinous process

Joints capsule

an envelope, attached to the end of each bone at the joint, enclosing the cavity of a synovial joint

3. Seven processes

arise from the vertebral arch

alar ligaments (paired)

attach to the sides and posterior surface of the dens and run laterally with a superior band attaching to the occipital bone, a middle band attaching to the lateral mass of the atlas and an inferior band attaching to the axis *p.g., 100 in text book

inferior notches of the vertebrae

below

Meninges

dura mater, arachnoid mater, pia mater

What is this starred region that wraps around the entire vertebral body?

epiphysial rim: derived from an anular epiphysis, is fused to the body

Spinous and transverse processes provide attachment

for deep back muscles and serves as levers

spinous process

function: muscle attachment and movement

"Accessory ligaments" of intervertebral joints

https://youtu.be/_GHzD4ZDM6A *Interspinous ligaments: connect adjoining spinous process *supraspinous ligaments: "Supra" means on top up and spinous means spinous process -SL, goes all the way down to sacrum, but when it goes up it terminate at C7 -connects all tip of spinous process from C1 to C7 *Nuchal ligament (back of neck): Above C7 which connects all spinous process and sheet like ligament *Intertransverse ligaments: connect adjoining transverse process

vertebral notches

indentations that are superior and inferior to the pedicles, they are seen on the lateral views of the vertebrae

2) Vertebral arch

posterior to the vertebral body and consists of two (right and left) pedicles and laminae *function: protect the spinal cord

centrum: center where superior(above) and inferior (below) epiphyses usually unite

primary ossification center for the central mass of vertebral body

1. joints of vertebral bodies

symphyses: secondary cartilage joints

STRUCTURE

typical vertebra consists of a vertebral body, vertebral arch, and seven process

What form the vertebral canal?

vertebral foramina in the articulated vertebral column