MIDTERM IBS - VERTEBRAL COLUMN AND THORAX

Hyoid bone, axial or appendicular?

axial skeleton

Hyoid bone, special feature:

does not articulate with any other bone

How is the hyoid bone suspended?

Suspended from the styloid processes by ligaments and muscles

Where is hyoid bone located? attachment site for what?

• anterior neck between the mandible and larynx

• attachment site of muscles of the neck and pharynx

Hyoid bone structure:

horizontal body, lesser horns and greater horns

Vertebral column makes up ____ of total height

2/5th

Vertebral column composed of series of bone called…

vertebrae

Vertebral column functions:

✓ strong, flexible rod

✓ encloses and protect the spinal cord

✓ supports the head

✓ attachment point for the ribs, pelvic girdle + muscles of the back and neck

Vertebrae # during development:

33 vertebrae

Vertebrae # when adult:

26 vertebrae

How many cervical vertebrae are there and where are they located?

7 – Cervical vertebrae in the neck region

How many thoracic vertebrae are there and where are they located?

12 - Thoracic vertebrae posterior to the thorax

How many lumbar vertebrae are there and what do they support?

5 – Lumbar vertebrae support the lower back

What does the sacrum consist of?

1 – Sacrum consists of five fused sacral vertebrae

What do the sacral vertebrae articulate with?

hip bones

What does the coccyx consist of?

1 – Coccyx consists of four fused coccygeal vertebrae

What does the coccyx form?

terminus of the vertebral column

What are the cervical vertebrae numbered?

C1–C7

What are the first two cervical vertebrae called?

Atlas - C1

Axis - C2

What are the thoracic vertebrae numbered?

T1–T12

What are the lumbar vertebrae numbered?

L1–L5

What are the coccygeal vertebrae numbered?

Co1–Co4

Which curves of the vertebral column are convex?

Cervical and lumbar curves

Which curves of the vertebral column are concave?

Thoracic and sacral curves

What type of curve does a fetus have?

single anteriorly concave curve

What are the primary curves?

thoracic and sacral curves

What do the primary curves retain?

original curvature of fetal life

What are the secondary curves?

cervical and lumbar curves

When do the secondary curves begin to form?

after birth

What are the functions of the curves of the vertebral column?

increase strength, maintain balance, absorb shocks, protect from fracture

What is scoliosis?

Lateral bending of the thoracic region

What causes scoliosis?

congenitally malformed vertebrae

What is kyphosis?

Increase in the thoracic curve (elderly)

What causes kyphosis?

Degeneration of the intervertebral discs

What is lordosis?

Increase in the lumbar curve

What causes lordosis?

Increased weight of the abdomen

Where do the anterior and posterior longitudinal ligaments run?

continuous bands down the front and back surfaces of the vertebrae

neck to the sacrum

What is the anterior ligament strongly attached to?

Bony vertebrae and the discs

What does the anterior ligament prevent?

Hyperextension of the spine

What does the posterior ligament attach more firmly to?

The discs

What does the posterior ligament resist?

Hyperflexion of the spine.

What is the ligamentum flavum?

short ligaments connecting laminae of adjacent vertebrae

What does the ligamentum flavum contain?

Strong elastic connective tissue

How does the ligamentum flavum respond to posture?

Stretches and recoils according to posture

What is the vertebral body?

Thick, disc-shaped anterior portion

The vertebral body is the ____-_____ part of a vertebra

the vertebral body is the weight-bearing part of a vertebra

What are the roughened superior and inferior surfaces of the vertebral body for?

attachment of cartilaginous intervertebral discs

What are pedicles?

Two short, thick processes

Where do pedicles project from?

Posteriorly from the vertebral body

How is the vertebral arch formed?

union of pedicles with the flat laminae

Where does the vertebral arch extend?

Posteriorly from the body of the vertebra

How is the vertebral foramen formed?

vertebral body and the vertebral arch together

What does the vertebral foramen surround?

spinal cord

What does the vertebral foramen contain

• adipose tissue

• areolar connective tissue

• blood vessels

How is the vertebral (spinal) canal formed?

vertebral foramina stacked one on top of the other

What are vertebral notches?

Superior and inferior indentations of pedicles

What do vertebral notches form?

opening between adjoining vertebrae

What is the intervertebral foramen?

Opening between adjoining vertebrae.

What does the intervertebral foramen permit?

passage of spinal nerve

How many processes arise from the vertebral arch?

7

What is the transverse process?

extends laterally on each side

What is the spinous process?

projects posteriorly from the junction of the laminae.

What is the function of the transverse and spinous processes?

serve as points of attachment for muscles

How many superior and inferior articular processes are there?

two of each

What is the function of the four articular processes?

form joints with other vertebrae above or below

What are facets?

articulating surfaces of the articular processes

What covers the facets?

Hyaline cartilage

Where are intervertebral discs found?

Between the bodies of adjacent vertebrae

From which vertebra to which vertebra are intervertebral discs found?

second cervical vertebra to the sacrum

What do the superior and inferior surfaces of the intervertebral disc consist of?

thin plate of hyaline cartilage

What are the two regions of an intervertebral disc?

Annulus fibrosus and nucleus pulposus

What is the annulus fibrosus?

outer fibrous ring of fibrocartilage

What is the nucleus pulposus?

inner soft, pulpy, highly elastic substance

What are the functions of intervertebral discs?

form strong joints
permit flexion, extension, and lateral bending of spine
absorb vertical shock during walking, jumping, running

What causes a herniated (slipped) disc?

Injury to the anterior and posterior ligaments

What happens to the nucleus pulposus during a herniated disc?

built up pressure

What does increased pressure in the nucleus pulposus lead to?

rupture of the annulus fibrosus

What happens when the annulus fibrosus ruptures?

nucleus pulposus herniates (protrudes) posteriorly

What does a herniated disc exert pressure on?

spinal nerves

What are the effects of a herniated disc?

Local weakness and acute pain

Where do herniated discs most often occur?

lumbar area

Which nerve may be compressed by a herniated disc?

sciatic nerve

Where does pain from sciatic nerve compression radiate?

calf → posterior thigh → even to the foot

What is flexion?

Anterior bending of the spine

What is extension?

Posterior straightening of the spine

What is lateral flexion?

Bending upper body to the right or left

What is rotation?

Vertebrae rotate on one another, longitudinal axis of spine

Which region of the spine has the greatest range of movement?

Cervical region

How does the size of cervical, thoracic, and lumbar vertebrae compare?

Cervical: Small
Thoracic: Larger
Lumbar: Largest

What foramina are present in cervical vertebrae?

1 vertebral, 2 transverse

What foramina are present in thoracic vertebrae?

1 vertebral formamen

What are the spinous processes of cervical vertebrae like?

Slender, often bifid

What are the spinous processes of thoracic vertebrae like?

Long, fairly thick, project inferiorly

What are the spinous processes of lumbar vertebrae like?

Short, blunt, project posteriorly

What are the transverse processes of cervical vertebrae like?

Small

What are the transverse processes of thoracic vertebrae like?

Fairly large

What are the transverse processes of lumbar vertebrae like?

Large and blunt

Are articular facets for ribs present in cervical vertebrae?

Absent

Are articular facets for ribs present in thoracic vertebrae?

Present

Are articular facets for ribs present in lumbar vertebrae?

Absent