Connection lost. Please refresh the page.
Online
Get help How to study Login Register
Ready to learn?
Pick your favorite study tool

Thoracic vertebrae

Recommended video: Thoracic spine [03:26]
Anatomy, location and general features of the thoracic spine.

The twelve thoracic vertebrae are strong bones that are located in the middle of the vertebral column, sandwhiched between the cervical ones above and the lumbar vertebrae below. Like typical vertebrae, they are separated by intervertebral discs. However, they are various anatomical features that make them quite dinstinct compared to other groups of vertebrae.

In addition, several thoracic vertebrae are 'special' in a way, either in terms of its structure or by providing an important landmark that physicians use to orientate themselves and locate other anatomical structures. Two muscles also interact with those twelve vertebrae, these being the spinalis and longissimus.

Key facts
Main characteristic 12 vertebrae connected with intervertebral discs (nucleus pulposus + anulus fibrosus)
Anatomical characteristics Body: heart-shaped massive that increase in size as descending to the lumbar vertebrae
Spinous process: dorsal bony prominence
Costal facets (superior, inferior, transverse): articulation surfaces for head of the rib
Transverse process: bony process that arises from the vertebral arch, intended for the attaching of the rib tubercle
Superior and inferior articular facets: articulation surfaces for adjacent (superior and inferior) vertebrae
Lamina: bony imbrication that covers the subjacent vertebrae and connect with pedicles to protect the spinal cord
Intervertebral foramen: paired foramina (one left, one right) intended for the exiting nerve roots
Vertebral foramen: large opening posterior to the body that forms spinal canal through which the spinal cord passes
Distinguishing features Presence of facets for the joints with the ribs (all except the 11th and 12th vertebra)
Spinous processes are more pointed than other vertebrae and angle sharply downward
The body is smaller than in lumbar, but larger than in the cervical vertebrae
Muscles associated with the vertebrae Spinalis muscle (part of the erector spinae), longissimus muscle
Clinical importance Herniated discs, scoliosis

This article will elucidate all the mysteries surrounding the thoracic vertebrae and will describe both their typical and atypical features.

Contents
  1. Anatomy
    1. Intervertebral discs
  2. Bones
    1. Distinguishing features
  3. Individual thoracic vertebrae
  4. Muscles affecting thoracic vertebrae function
  5. Clinical notes
    1. Herniated discs
    2. Scoliosis
  6. Sources
+ Show all

Anatomy

The thoracic vertebrae are located in the middle section of the vertebral column, specifically inferior to the cervical vertebrae and superior to the lumbar vertebrae. These vertebrae span the large majority of the chest cavity area.

Intervertebral discs

The vertebrae are separated by intervertebral discs of fibrocartilage, which are flexible cartilage discs located between the bodies of two adjacent vertebrae that allow movement in the spine and have a shock absorbing or cushioning function as well. An intervertebral disc consists of an inner gelatinous nucleus pulposus surrounded by a ring of fibrocartilage, the annulus fibrosus.

In total, the adult human body typically has 23 discs, with the first found between cervical vertebrae 2 and 3, and the last one is found between the lumbar vertebra and the sacrum. In addition to providing shock resistance and cushioning, the discs also help bind adjacent vertebrae together.

Bones

There are 12 thoracic vertebrae (denoted as T1-T12) found in adult humans, and they are situated in between the cervical and lumbar vertebrae, with a general sizing larger than the cervical but smaller than the lumbar vertebrae. For each of the 12 thoracic vertebrae, there is a corresponding pair of ribs attached to them. This is unique since no other vertebrae have ribs attached to them. Thoracic vertebrae increase in size as they descend towards the lumbar vertebrae; this is because the lower vertebrae must be able to support more of the body’s weight when a person is standing due to the effects of gravity.

To summarize, the main anatomical components of a thoracic vertebra are:

  • Body
  • Spinous process
  • Costal facets: transverse costal facet, superior costal facet, and inferior costal facet
  • Transverse process
  • Superior and inferior articular facets
  • Lamina
  • Intervertebral foramen
  • Vertebral foramen

Now you know the bones of the thoracic vertebrae - but what about the other regions of the body? Use our skeletal system quizzes and free worksheets to learn all the bones quickly and easily. 

Distinguishing features

Distinguishing features of the thoracic vertebrae include the presence of facets on the sides of the bodies for articulation with the heads of the ribs, and facets on the transverse processes of all, except the 11th and 12th vertebrae, for articulation with the tubercles of the ribs. In addition, the spinous processes are relatively more pointed than other vertebrae, and angle sharply downward.

The body of a thoracic vertebra is somewhat “heart-shaped,” and is larger than the cervical but smaller than the lumbar vertebrae in size. The body also has small, smooth, and somewhat concave costal facets for the attachment of the ribs. Ribs are generally inserted between two vertebrae, such that each vertebra contributes to articulating with half of the articular surface. Each vertebra therefore has a pair of superior articular facets that face posteriorly and a pair of inferior articulating facets that face anteriorly (except for T12). This means that the rib will articulate with the inferior costal facet of the upper vertebrae and the superior costal facet of the lower vertebrae. Transverse processes arise from the arch found behind he superior articular processes and pedicles, and are thick and strong with a clubbed end and a small concave surface for the articulation with the tubercle of a rib. These processes are directed obliquely backward towards the spinous process and lateralward.

Body of thoracic vertebra (cranial view)

It is important to note that the superior and inferior facets are named relative to their position on the vertebral body, and not for which part of the articular they provide for the rib. The costal facets are also slightly different between the vertebrae. Vertebrae T1, T10, T11, and T12 have complete costal facets on the bodies for ribs 1 and 10-12, which articulate on the vertebral bodies instead of between vertebrae. On the other hand, vertebrae T11 and T12 have no transverse costal facets. Similarly, ribs 11 and 12 articulate with the bodies of T11 and T12, but since the ribs do not have tubercles they also cannot attach to the non-existent transverse costal facets of T11 and T12. These ribs also lack a cartilaginous connection to the sternum and higher costal cartilages, and are only embedded in the lumbar muscle, therefore, T11 and T12 are known as the floating ribs.

Inferior articular process (lateral left view)

Superior articular processes are thin plates of bone, which project upward from the junctions of the pedicles and laminae, with facets that are nearly flat and directed backward, lateralward, and upward. Inferior articular processes are mostly fused with the laminae, with the facts directed forward, medialward, and downward. The lamina of the thoracic vertebrae are broad, thick, and imbricated (which means their adjacent sides overlap similar to roof tiles or scales of a fish); lamina function to connect with the pedicles to surround and protect the spinal cord. The spinal cord runs through the vertebral foramen of a vertebra where is it thus protected since it is encased throughout the vertebrae. The nerve roots from the spinal cord exit from intervertebral foramen, where there are two at each intervertebral level, one for each the right and left side.

Learn everything about the vertebral column and the different types of vertebrae with the following study units: 

You can also have a look at the following quiz about the bones that form the vertebral column.

Individual thoracic vertebrae

  • First thoracic vertebrae (T1): Has on either side of the body, an entire articular fact for the head of the first rib, and a demi-facet for the upper half of the head of the second rib. The spinous process is thick, long, and almost horizontal. The transverse processes are long, with the upper vertebral notches deeper than any of those found on the other thoracic vertebrae. The thoracic spinal nerve 1 passes through underneath T1.
  • Second thoracic vertebrae (T2): The T2 vertebra is larger than T1 vertebra. The thoracic spinal nerve 2 passes through underneath T2.
  • Third thoracic vertebrae (T3): The thoracic spinal nerve 3 passes through underneath T3.
  • Fourth thoracic vertebrae (T4): The T4 and T5 vertebrae are at the same levels as the sternal angle. The thoracic spinal nerve 4 passes through underneath T4.
  • Fifth thoracic vertebrae (T5): The T5 and T4 vertebrae are at the same levels as the sternal angle. The trachea branches into the two main bronchi at the level of T5. The thoracic spinal nerve 5 passes through underneath T5.
  • Sixth thoracic vertebrae (T6): The thoracic spinal nerve 6 passes through underneath T6.
  • Seventh thoracic vertebrae (T7): The thoracic spinal nerve 7 passes through underneath T7.
  • Eighth thoracic vertebrae (T8): The T8 and T9 vertebrae are found at the same level as the xiphoid process. The thoracic spinal nerve 8 passes through underneath T8.
  • Ninth thoracic vertebrae (T9): The T9 vertebra may have no demi-facts below it, but some people do have two demi-facets on either side, which subsequently means T10 will not have facets below it. The xiphoid process of the sternum is at the same level as T9 in the axial plane. The thoracic spinal nerve 9 passes through underneath T9.
  • Tenth thoracic vertebrae (T10): T10 has an entire articular facet (not demi-facet) on either side, which is located on the lateral pedicle surface. However, it will not have any type of facet below it, since the ribs following only have a single facet on their heads. The thoracic spinal nerve 10 passes through underneath T10.
  • Eleventh thoracic vertebrae (T11): At this level, the T11 begins to resemble the size and structure of a lumbar vertebrae. The articular facets for the heads of the ribs are large and primarily on the pedicles, which are thicker and stronger in T11 and T12, than in T1-T10. The spinous process in T11 is short and nearly horizontal. The transverse processes are very short, tuberculated at its extremities, and devoid of articular facets. The thoracic spinal nerve 11 passes through underneath T11.
  • Twelfth thoracic vertebrae (T12): T12 is similar to T11, but can be distinguished by its inferior articular surfaces, which are convex and directed lateralward, similar to those of lumbar vertebrae. This vertebrae will most closely resemble a lumbar vertebra also by its transverse process that is subdivided into 3 elevations—the superior, inferior, and lateral tubercles. The superior and inferior tubercles correspond to mammillary and accessory processes of the lumbar vertebrae. T12 is accordingly a logical anatomical progression into lumbar vertebrae structure and function. The thoracic spinal nerve 12 passes through underneath T12.

Test and consolidate your knowledge about the thoracic spine with the following quiz!

Muscles affecting thoracic vertebrae function

  • Spinalis muscle: This is a long muscle that is part of the erector spinae bundle of muscles and tendons, which helps the spine with movement and also helps in maintaining posture. The ligaments of the spinalis muscle attach to multiple thoracic vertebrae, and while it is narrow near the first thoracic vertebra and the lumbar vertebrae, the muscle is wide in the middle.
  • Longissimus muscle: This is a long muscle lateral from the semispinalis, which travels upwards the spine from the middle of the lumbar spine and is found to run along both sides of the spinalis muscle.

Thoracic vertebrae: want to learn more about it?

Our engaging videos, interactive quizzes, in-depth articles and HD atlas are here to get you top results faster.

What do you prefer to learn with?

“I would honestly say that Kenhub cut my study time in half.” – Read more.

Kim Bengochea Kim Bengochea, Regis University, Denver
© Unless stated otherwise, all content, including illustrations are exclusive property of Kenhub GmbH, and are protected by German and international copyright laws. All rights reserved.

Register now and grab your free ultimate anatomy study guide!