Anatomy of the Thorax

  • Course Information
  • Thoracic Wall
    • Thoracic Vertebral Column
      30 min
  • Neurovasculature
  • The Heart
    • Valves
      30 min
  • Lungs, Trachea, Bronchi and Esophagus
  • Mediastinum

Anatomy of the Thorax

0

Thoracic Vertebral Column

Vertebral column and related bones (Credit: Sobotta)

The thoracic vertebral column consists of 12 vertebrae. In this lesson, we will discuss its functions, curvatures, the vertebrae themselves, its joints and ligaments.

Functions

  1. Protection
  2. Suspension of the body
  3. Shock absorbance and weight carrying
  4. Allow mobility
  5. Provide attachment to the ribs and the muscles

Curvatures

Generally, the two physiological types of curvatures within the entire vertebral column are kyphotic and lordotic.

The thoracic vertebral column curvature is considered to be kyphotic.

  • Kyphotic — Bent forward
    • Thoracic and sacral curves
    • Primary — Develop during gestation
  • Lordotic –Bent backward
    • Cervical and lumbar curves
    • Secondary — Develop shortly after birth
Curvatures of the vertebral column (Credit: OpenStax, CC BY-SA 4.0)

Thoracic vertebrae

The vertebrae can be divided into typical and atypical vertebrae:

  • T2- T9 are typical vertebrae and consist of the following:
    • 7 Processes:
      • 1 Spinous process
      • 2 Transverse processes
      • 2 Articular processes
      • 2 Demifacets for the head of the rib (superior and inferior)
    • Vertebral body
    • 2 Laminae
    • 2 Pedicles
    • 2 Facets for articular part of tubercle of the rib (on the transverse processes)
  • Generally, atypical vertebrae contain a costal facet (single) instead of demifacets (couple):
    • T1:
      • Does not contain demifacets, but rather superior costal facets, because there are no demifacets on the C7 vertebra above it.
      • The first rib articulates only with T1 vertebra and not with any other vertebrae
      • T1 has a typical inferior costal demifacet which articulates with the 1st rib
    • T10 has only one pair of costal facets on its lateral surfaces, located partially on its body and partially on its pedicle
    • T11 and T12 have only a single pair of costal facets, located on their pedicles only
Structure of vertebrae and the vertebral column (Credit: OpenStax, CC BY-SA 4.0)

 

Structure of vertebrae and the vertebral column (Credit: OpenStax, CC BY-SA 4.0)

 

Structure of vertebrae and rib articulations (Credit: OpenStax, CC BY-SA 4.0)

 

Animation of the thoracic vertebra (Credit: Anatomography, CC BY-SA 4.0)

 

Typical thoracic vertebra (inferior view)

 

Atypical thoracic vertebra, notice the single costal facet (superior view)

Joints of the vertebral column

In the vertebral column, there are three types of joints which are responsible for the articulation between the between the different parts of the vertebrae:

  1. Intervertebral discs —  Located between the vertebral bodies. It is a symphysis type of joint consisting of the nucleus pulposus (gel) and anulus fibrosus (fibrous ring) around it
  2. Uncovertebral joints (also known as joints of Luschka) — Located at the cervical portion and only in the T1 between the uncinate processes of the lower vertebral to the uncus of the upper one
  3. Zygapophyseal joints (also known as facet joints) — Located between the superior and inferior articulating processes. These are the synovial plane type of joints which permit gliding movements

    Intervertebral disc (Credit: OpenStax, CC BY-SA 4.0)

Ligaments of the vertebral column

  1. Anterior longitudinal ligament — Covers the vertebral bodies from the anterior surface
  2. Posterior longitudina ligament — Covers the vertebral bodies from the posterior surface
  3. Ligamentum flava (or flavum) — Attaches within the vertebral foramen on the spinous process surface
  4. Interspinous ligament — Connects between the spinous processes of the inferior vertebra to the superior one
  5. Supraspinous ligament — Connect the spinous processes from the posterior of the tip of each spinous process
Ligaments of the vertebral column — lateral view (Credit: Beatricebalciunaite, CC BY-SA 4.0)

 

Ligaments of the vertebral column — posterior view (Credit: Beatricebalciunaite, CC BY-SA 4.0)

References

1. Moore, Keith L., et al. Clinically Oriented Anatomy. Wolters Kluwer, 2018.
2. Standring, Susan, and Henry Gray. Gray’s Anatomy: The Anatomical Basis of Clinical Practice. Elsevier, 2016.
3. Bertalan, Csillik, et al. Regional Anatomy. Medicina, 2008.

0
0
Copyright © 2020 Meddists.com. All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including printing, copying, recording, or other electronic or mechanical methods.