Get documents about "B08
Description
Medicine
Document Sample
Structure of the spinal column · Main components of the spinal column · Anatomy B 08
The spinal column, our central axial organ, looks like a as a double-S-shaped column when viewed from the
side (in the sagittal plane). It has to perform both static and dynamic tasks. It provides the body with a stable,
Spine Surgery Information Portal · Prof. Dr. Jürgen Harms · www.harms-spinesurgery.com
yet mobile, supporting structure that carries the weight of the head, trunk and upper extremities while protecting
the spinal cord (medulla spinalis) and the roots of the emerging spinal cord nerves (nervi spinales).
Various bony processes on the vertebrae serve as spinal column insertions for back musculature.
Spinal column segments
The spinal column comprises
7 cervical vertebrae (vertebrae cervicales)
12 thoracic vertebrae (vertebrae thoracicae)
5 lumbar vertebrae (vertebrae lumbales)
5 sacral vertebrae (vertebrae sacrales), fused to the sacrum (os sacrum)
4-5 coccygeal vertebrae (vertebrae coccygeae), fused to the coccyx (os coccygeum)
• Side view of the spinal column (sagittal) and rear view (dorsal)
· Cervical spine (C1-C7)
· Thoracic spine (Th1-Th12)
· Lumbar spine (L1-L5)
· Sacrum (S1-S5)
· Coccyx (C1-5)
Seen from the side, the spinal column shows typical curves.
The curve toward the front in the cervical and lumbar segments is called lordosis, and the corresponding backward
curve in the thoracic spine segment is called kyphosis.
• Side view of the spinal column (sagittal profile)
· Lordosis of the cervical spine
· Kyphosis of the thoracic spine
· Lordosis of the lumbar spine
Prof. Dr. med. Jürgen Harms · Klinikum Karlsbad-Langensteinbach · Guttmannstraße 1 · 76307 Karlsbad
1
© www.harms-spinesurgery.com 2007. All rights reserved.
Structure of the spinal column · Main components of the spinal column · Anatomy B 08
Cervical spine
Spine Surgery Information Portal · Prof. Dr. Jürgen Harms · www.harms-spinesurgery.com
The cervical spine has 7 vertebrae (C1-C7). It is the segment of the spinal column with the greatest mobility, and
has special features that facilitate rapid movement along its whole length.
• Cervical spine, location
• Cervical spine, rear view
· Dens axis
· Atlas (C1)
· Axis (C2)
· 3rd cervical vertebra (C3)
· 7th cervical vertebra (C7)
Prof. Dr. med. Jürgen Harms · Klinikum Karlsbad-Langensteinbach · Guttmannstraße 1 · 76307 Karlsbad
2
© www.harms-spinesurgery.com 2007. All rights reserved.
Structure of the spinal column · Main components of the spinal column · Anatomy B 08
• Cervical spine, side view
Spine Surgery Information Portal · Prof. Dr. Jürgen Harms · www.harms-spinesurgery.com
· Atlas (C1)
· Axis (C2)
· 7th cervical vertebra (C7)
· 1st thoracic vertebra (Th1)
The first and second cervical vertebrae, the atlas (C1) and axis (C2), have forms that differ from those of all the
other vertebrae, enabling them to support and secure the head and ensure its mobility.
The ring-shaped atlas (C1) is the vertebra that directly bears the weight of the head. It consists of two lateral
elements, the massae laterales or lateral masses, connected by the anterior and posterior arches. The atlas
is connected to the occipital bone of the skull via articular processes (fovea articularis superior), forming the
atlantooccipital joint that allows the head to move forward and backward and incline to the side to a slight
degree as well.
• Atlas (C1) and axis (C2), rear view
· Atlas (C1) with fovea articularis superior (superior articular facet)
· Anterior arch (arcus anterior)
· Lateral mass (massa lateralis)
· Posterior arch (arcus posterior)
· Axis (C2)
· Dens axis
• Atlas (C1), from above
Prof. Dr. med. Jürgen Harms · Klinikum Karlsbad-Langensteinbach · Guttmannstraße 1 · 76307 Karlsbad
3
© www.harms-spinesurgery.com 2007. All rights reserved.
Structure of the spinal column · Main components of the spinal column · Anatomy B 08
• Axis (C2), from above
Spine Surgery Information Portal · Prof. Dr. Jürgen Harms · www.harms-spinesurgery.com
The special structure of the vertebral body of the 2nd cervical vertebra (axis), along with its peg-shaped
process, the dens axis, which extends into a gap in the 1st cervical vertebra, facilitates the transition between
the atlas and the rest of the cervical spine.
The dens axis is held in position by a tight ligament to prevent it from damaging the spinal cord. the 4
atlantoaxial joints between atlas and axis make it possible for the head to rotate, whereby the atlas rotates
eccentrically about the pivot of the axis.
The atlas, axis and occipital bone of the skull are connected by a complex ligamentous apparatus that, in
combination with the atlantooccipital joint, the atlantoaxial joints and the attached muscles, gives the head its
impressive mobility.
The cervical vertebrae feature large vertebral foramina to accommodate the spinal cord and are smaller than
the thoracic and lumbar vertebrae.
• Cervical vertebra, from above
· Spinous process (processus spinosus)
· Vertebral arch (arcus vertebrae)
· Vertebral articular process
· Vertebral foramen (foramen vertebrale)
· Transverse foramen (foramen transversale)
· Vertebral body (corpus vertebrae)
Additional special features of the cervical vertebrae are openings in the transverse processes (transverse
foramina, foramina transversaria), through which the vertebral arteries (arteriae vertebralis) that branch off from
the subclavian artery (arteria subclavia), run along both sides of the cervical spine to supply blood to the brain.
Prof. Dr. med. Jürgen Harms · Klinikum Karlsbad-Langensteinbach · Guttmannstraße 1 · 76307 Karlsbad
4
© www.harms-spinesurgery.com 2007. All rights reserved.
Structure of the spinal column · Main components of the spinal column · Anatomy B 08
• Course of the arteria vertebralis along the cervical spine, from the side
Spine Surgery Information Portal · Prof. Dr. Jürgen Harms · www.harms-spinesurgery.com
· 1st cervical vertebra (atlas, C1)
· Foramen transversum
· Arteria vertebralis
· Arteria carotis communis
· 7th cervical vertebra (C7)
· Arteria subclavia
· Clavicle (clavicula), partially removed
· 1st thoracic vertebra (Th1)
Thoracic spine
The thoracic spine has 12 vertebrae (Th1-Th12) and exhibits a characteristic backward curve or thoracic
kyphosis.
• Thoracic spine, location
• Thoracic spine, side view
· 1st thoracic vertebra (Th1)
· 12th thoracic vertebra (Th12)
Prof. Dr. med. Jürgen Harms · Klinikum Karlsbad-Langensteinbach · Guttmannstraße 1 · 76307 Karlsbad
5
© www.harms-spinesurgery.com 2007. All rights reserved.
Structure of the spinal column · Main components of the spinal column · Anatomy B 08
• Thoracic vertebra, side view
Spine Surgery Information Portal · Prof. Dr. Jürgen Harms · www.harms-spinesurgery.com
· Superior articular process
· Transverse process with fovea costalis transversalis
· Superior costal facet
· Vertebral arch
· Vertebral body
· Inferior articular process
· Incisura vertebralis inferior
· Spinous process
• Thoracic vertebra with ribs, from above
· Vertebral body
· Ligamentum costotransersarium
· Ribs
· Transverse process
· Vertebral arch
· Spinous process
The thoracic vertebrae are larger than the cervical vertebrae. They have a comparatively heavy body, with a
flat wedge shape somewhat lower at the front than at the back when seen from the side. The thick, three-sided
spinous processes point downward and backward. The vertebral foramen is round and smaller than in the
cervical vertebrae. A characteristic special feature of the thoracic vertebrae is the presence of the connection
points to the ribs of the ribcage. Each transverse process features three articular connections (fovea costalis
superior and inferior, and the fovea costalis transversalis), at which points each rib is connected to the thoracic
spine via the rib tubercle and head. These joints are protected and secured in position by a tight articular
capsule and ligaments.
The 12 thoracic vertebrae, the 12 rib pairs and the sternum form the ribcage (or thorax), which protects the
internal organs.
• Ribcage (thorax), rear view
Prof. Dr. med. Jürgen Harms · Klinikum Karlsbad-Langensteinbach · Guttmannstraße 1 · 76307 Karlsbad
6
© www.harms-spinesurgery.com 2007. All rights reserved.
Structure of the spinal column · Main components of the spinal column · Anatomy B 08
Lumbar spine
Spine Surgery Information Portal · Prof. Dr. Jürgen Harms · www.harms-spinesurgery.com
The lumbar spine has 5 vertebrae (L1-L5). The lumbar vertebral bodies are the largest vertebrae of all, since
the lumbar spine carries a large proportion of the body’s weight. The side view shows their slightly wedge-like
shape, similar to the thoracic vertebrae, although in this case the front or ventral side is thicker.
The transverse processes are much smaller that those of the thoracic vertebrae. The spinous processes
are thick and horizontally oriented. The vertebral foramina are triangular and smaller than in the thoracic
vertebrae. The special structure of the lumbar vertebrae facilitates a high degree of mobility for extension and
overextension of the trunk in this spinal segment.
• Lumbar spine, location • Lumbar vertebra, from above
· Spinous process
· Vertebral arch
· Articular process
· Transverse process
· Vertebral foramen
· Vertebral body
• Lumbar spine, side view
· 1st lumbar vertebra (L1)
· 5th lumbar vertebra (L5)
· 1st sacral vertebra (S1)
• Lumbar spine, rear view
· 1st lumbar vertebra (L1)
· 5th lumbar vertebra (L5)
· 1st sacral vertebra (S1)
Prof. Dr. med. Jürgen Harms · Klinikum Karlsbad-Langensteinbach · Guttmannstraße 1 · 76307 Karlsbad
7
© www.harms-spinesurgery.com 2007. All rights reserved.
Structure of the spinal column · Main components of the spinal column · Anatomy B 08
Sacrum/coccyx
Spine Surgery Information Portal · Prof. Dr. Jürgen Harms · www.harms-spinesurgery.com
The sacrum (os sacrum) consists of 5 vertebrae (S1-S5) fused together to form a triangular plate, providing a
broad upper base upon which the 5th lumbar vertebra rests, then narrowing toward the bottom. The sacrum has
4 openings (foramina sacralia) for nerves and vessels.
Articular processes are located on the sides of the sacrum (articulationes sacroiliacae) connecting it to the iliac
bones of the pelvis. This connection (the sacroiliac joint), is secured by a strong ligamentous apparatus and
allows only limited mobility.
The coccyx (os coccygeum) consists of 4-5 fused vertebrae and provides insertions for the ligaments and
muscles of the pelvis.
The pelvis, lower lumbar vertebrae and sacrum are subjected to considerable static loads, which is why the
various bony structures in this region are connected by a complex system of thick ligaments.
• Sacrococcyx, side view
· 5th lumbar vertebra (L5)
· Sacroiliac articular process
· Sacrum (os sacrum, S1-S5)
· Coccyx (os coccygeum)
• Sacrococcyx, rear view
· 5th lumbar vertebra (L5)
· Sacrum (os sacrum, S1-S5)
· Coccyx (os coccygeum)
Prof. Dr. med. Jürgen Harms · Klinikum Karlsbad-Langensteinbach · Guttmannstraße 1 · 76307 Karlsbad
8
© www.harms-spinesurgery.com 2007. All rights reserved.
Structure of the spinal column · Main components of the spinal column · Anatomy B 08
• Pelvis, lower lumbar spine, sacrococcyx, front view
Spine Surgery Information Portal · Prof. Dr. Jürgen Harms · www.harms-spinesurgery.com
· 5th lumbar vertebra
· Ilium, iliac bone (os ilium)
· Sacroiliac joint
· Sacrum
· Coccyx
· Pubic bone (os pubis)
· Ischium (os ischii)
· Symphysis
Prof. Dr. med. Jürgen Harms · Klinikum Karlsbad-Langensteinbach · Guttmannstraße 1 · 76307 Karlsbad
9
© www.harms-spinesurgery.com 2007. All rights reserved.
