bones, part 1: the axial skeleton

of 14 /14
PowerPoint ® Lecture Slides prepared by Leslie Hendon University of Alabama, Birmingham C H A P T E R Copyright © 2011 Pearson Education, Inc. Part 4 7 Bones, Part 1: The Axial Skeleton

Upload: noel-sweet

Post on 31-Dec-2015

62 views

Category:

Documents


3 download

DESCRIPTION

7. Bones, Part 1: The Axial Skeleton. The Vertebral Column. Formed from 26 bones in the adult Transmits weight of trunk to the lower limbs Surrounds and protects the spinal cord. The Vertebral Column. Serves as attachment sites for muscles of the neck and back Held in place by ligaments - PowerPoint PPT Presentation

TRANSCRIPT

PowerPoint® Lecture Slides prepared by Leslie HendonUniversity of Alabama, Birmingham

C H A P T E R

Copyright © 2011 Pearson Education, Inc.

Part 4

7

Bones, Part 1:The Axial Skeleton

Copyright © 2011 Pearson Education, Inc.

The Vertebral Column

• Formed from 26 bones in the adult• Transmits weight of trunk to the lower limbs• Surrounds and protects the spinal cord

Copyright © 2011 Pearson Education, Inc.

The Vertebral Column

• Serves as attachment sites for muscles of the neck and back

• Held in place by ligaments• Anterior and posterior longitudinal ligaments • Ligamentum flavum

Copyright © 2011 Pearson Education, Inc.

The Vertebral Column

Figure 7.18

Cervical curvature(concave)

7 vertebrae, C1 – C7

Thoracic curvature(convex)

12 vertebrae,T1 – T12

Lumbarcurvature(concave)

5 vertebrae, L1 – L5

Sacralcurvature

(convex) 5 fusedvertebrae sacrum

Coccyx4 fused vertebraeAnterior view Right lateral view

C1

T1

2

3

4

5

6

7

8

9

10

11

12

L1

2

3

4

5

2

3

4

567

SpinousprocessTransverseprocesses

Intervertebraldiscs

Intervertebralforamen

Copyright © 2011 Pearson Education, Inc.

Regions and Normal Curvatures

• The Vertebral column has five major regions• 7 cervical vertebrae of the neck region• 12 thoracic vertebrae• 5 lumbar vertebrae• Sacrum—five fused bones• Inferior to lumbar vertebrae

• Coccyx—inferior to sacrum

Copyright © 2011 Pearson Education, Inc.

Regions and Normal Curvatures

• Curvatures of the spine• Cervical and lumbar curvatures• Concave posteriorly

• Thoracic and sacral curvatures• Convex posteriority

Copyright © 2011 Pearson Education, Inc.

Regions and Normal Curvatures

• Curvatures increase resilience of spine• Thoracic and sacral curvatures• Primary curvatures• Present at birth

• Lumbar curvature• Develops when baby begins to walk

Copyright © 2011 Pearson Education, Inc.

Ligaments of the Spine

• Major supporting ligaments• Anterior longitudinal ligament• Attaches to bony vertebrae and

intervertebral discs• Prevents hyperextension

• Posterior longitudinal ligament• Narrow and relatively weak• Attaches to intervertebral discs

Copyright © 2011 Pearson Education, Inc.

Posterior longitudinalligament

Anterior longitudinalligament

Body of a vertebra

Intervertebral disc

(b) Anterior view of part of the spinal column

Ligaments of the Spine

Supraspinous ligamentIntervertebraldisc

Anteriorlongitudinalligament

Intervertebral foramenPosterior longitudinalligament

Anulus fibrosus

Nucleus pulposus

Sectioned bodyof vertebra

Transverse process

Sectionedspinous process

Ligamentum flavum

Interspinousligament

Inferior articular process

(a) Median section of three vertebrae, illustrating the compositionof the discs and the ligaments

Figure 7.19a, b

Copyright © 2011 Pearson Education, Inc.

Ligaments of the Spine

Figure 7.19c, d

Vertebral spinous process(posterior aspect of vertebra)

Spinal nerve root

Anulus fibrosusof disc

Herniated portionof disc

Nucleuspulposusof disc

Spinal cord

(c) Superior view of a herniated intervertebral disc

Transverseprocess

(d) MRI of lumbar region of vertebral column in sagittal section showing normal and herniated discs

Nucleus pulposus of intact disc

Herniated nucleuspulposus

Copyright © 2011 Pearson Education, Inc.

Intervertebral Discs

• Are cushion-like pads between vertebrae• Composed of• Nucleus pulposus• Anulus fibrosus

Copyright © 2011 Pearson Education, Inc.

Intervertebral Discs

• Nucleus pulposus• Gelatinous inner sphere• Absorbs compressive stresses

• Anulus fibrosus• Outer fings formed of ligament• Inner rings formed of fibrocartilage• Contain the nucleus pulposus

Copyright © 2011 Pearson Education, Inc.

General Structure of Vertebrae

PLAY Spine (horizontal)

Figure 7.20

Posterior

Anterior

Lamina

Superior articularprocessandfacet

Transverseprocess

Pedicle

Spinousprocess

Vertebralarch

Vertebralforamen

Body(centrum)

Copyright © 2011 Pearson Education, Inc.

General Structure of Vertebrae

• Common structures to all regions• Body• Vertebral arch• Vertebral foramen• Spinous process• Transverse process• Superior and inferior articular processes• Intervertebral foramina