Anatomy of the Canine Spine: Difference between revisions
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== Thoracic spine == | == Thoracic spine == | ||
The thoracic vertebrae differs from other vertebrae due to it's distinct feature. The thoracic vertebrae articulates with the rib that corresponds in the number. It has short bodies and flattened extremities. It has short articular processes and the long spinous process. The caudal articular processes of the thoracic vertebrae face ventrally and at the base of spinous process whereas the cranial articular processes of the thoraic vertebrae are oval facets on arch of vertebrae and face dorsally. All the thoracic vertebrae has a pair of costal facets on dorsal body (except T13) forming costal fovea. There are costal facets on the transverse processes of the vertebrae and cranial and caudal fovea on the extremities of the vertebral bodies. <ref>IMAIOS.Vet Anatomy. Thoracic vertebrae - ''Vertebrae thoracicae. Accessed on: 2021/03/10. available from'' | |||
https://www.imaios.com/en/vet-Anatomy/Vet-Anatomical-Part/Thoracic-vertebrae | |||
</ref> The 11th thoracic vertebra is also known as the anticlinal vertebra. The anticlinal vertebra is a point at which vertebral anatomic features change and the spinous process becomes perpendicular to the body and the preceeding vertebra incline caudally. <ref>IMAIOS. Vet Anatomy. Anticlinal vertebra - ''Vertebra anticlinalis. Accessed on 2021/03/10. Available from:'' https://www.imaios.com/en/vet-Anatomy/Vet-Anatomical-Part/Anticlinal-vertebra</ref> | |||
The costovertebral joint has two artculation between rib and the vertebral column | |||
== References == | == References == | ||
<references /> | <references /> |
Revision as of 09:00, 10 March 2021
Introduction[edit | edit source]
The anatomy of the canine spine is almost similar to the human spine. The spine of the canine also supports weight and encloses the spinal cord. The spine is located along the dorsal/top side of the canine's body and runs from the base of the head to the end of the tail. [1]
The canine spine is divided into five regions: cervical, thoracic, lumbar, sacral, and caudal. There are 7 cervical vertebrae, 13 thoracic vertebrae, 7 lumbar vertebrae, 3 sacral vertebrae and the number of caudal vertebrae varies according to the species.[2]
Cervical spine[edit | edit source]
Atlas and axis are the first two cervical vertebrae respectively.
The atlanto-occipital joint is a condylar modified synovial hinge joint. The capsule of the joint is strengthened by three thickenings: dorsal, ventral, and lateral.[3]The transverse process of the atlas is the wing that allows the articulation of the occipital condyles and the spine.The atlas and axis are fused in embryonic life.[2]The transverse atlantal ligament is the one that holds the dens of the axis against the ventral arch of the atlas. [3]
Axis is the second cervical vertebra and is the longest vertebra. The atlantoaxial joint is the pivot joint and has a loose joint capsule. The dens of the axis is connected to the occipital bone through the apical ligament.[3]
The cervical vertebrae are obliquely oriented in the transverse plane. The cranial articular processes face dorsomedially whereas the caudal articular processes face ventrolaterally. [3]
Nuchal ligament is a paired band of connective tissue that spinous process of cervical vertebrae to the spinous process of thoracic vertebra (from axis to T1).[2][3] The ligamentum flavum, dorsal longitudinal ligament and ventral longitudinal ligament are similar to that of human being. The ligamentum flavum connects the lamina of adjacent lamina. The anterior longitudinal ligament attaches to the front of each vertebra and posterior longitudinal ligament runs at the posterior aspect of spine and inside of the spinal cord.[3]
Muscle | Origin | Insertion | Innervation | Action |
---|---|---|---|---|
Omotransversarius | Lower spine of scapula | Wing of Atlas | Ventral branches of local cervical spinal nerve | Advances limb
Moves neck laterally |
Brachiocephalicus | (the clavicle divides the muscle into two
namely cleidobrachialis and cleidomastoideus) |
|||
Cleidobrachialis | Clavicular intersection | Crest of the humerus | Axillary nerve | Advances limb
Adducts Limb |
Cleidomastoideus | Clavicular intersection | Mastoid process of the temporal bone | Ventral branch of the accessory nerve
(cranial nerve XI) |
Forms dorsal border of jugular groove
Advances limb Flexes neck Turns head |
Sternocephalicus
(sternomandibularis) |
Manubrium of the sternum | Mastoid part of temporal bone
Nuchal crest |
Ventral branch of Accessory nerve (Cranial nerve XI) | Forms ventral border of jugular groove
Flexes neck Turns head Opens mouth |
Omohyoideus | Subscapular Fascia | Lingual process of basihyoid bone | Spinal nerve C1 | Forms medial border of jugular groove
Retracts basihyoid bone and tongue |
Trapezius(cervical and thoracic parts) | Nuchal Ligament and supraspinous ligament of C2-10 | Cervical part: entire scapular spine
Thoracic part: rsal third of scapular spine |
Dorsal branch of accessory nerve (cranial nerve XI) | Advances thoracic limb
Abducts thoracic limb Elevates shoulder |
Rhomboiudeus muscle (cervical and thoracic) | Nuchal ligament and dorsoscapular ligaments of C2-T8 | Scapular cartilage | Local thoracic nerve
Local cervical nerve |
Elevates neck
Draws scapula cranially and dorsally |
Serratus ventralis cervicis | Transverse processes of C4-7 | Scapular cartilage and medial scapula | Ventral branches of local cervical nerve | Supports trunk between forelimbs
Raises neck when the limb is fixed |
Splenius (capitis and cervicis) | Nuchal ligament and spinous processes of T3-5 via the thoracolumbar fascia | Nuchal crest and the mastoid process of temporal bone | Dorsal branch of accessory nerve(cranial nerve XI) and dorsal branch of local spinal nerve | Extends neck
Elevates neck Bends neck laterally |
Longissimus
(cervicis,capitis, atlantis) |
Transverse processes of cervical and thoracic vertebrae | Wing of atlas and mastoid process of temporal bone | Dorsal branches of local spinal nerve | Elevates head and neck
Bends head and neck laterally Stabilizes and extends vertebral column |
Semispinalis capitis | Articular processes of C2/3-7 and transverse processes of T1-6/7 | Occipital bone | Dorsal branches of local spinal nerve | Elevates head and neck
Bends head and neck laterally |
Longus capitis | Transverse processes of C3-5 | Mastoid process | Ventral branch of local spinal nerve | |
Longus colli | ||||
cervical part | Transverse processes of C3-7 | Ventral tubercle of atlas and bodies of cervical vertebrae | Ventral branches of local spinal nerve | Flexes head |
thoracic part | Bodies of T1-6 | Transverse processes of C6-7 | Ventral branches of local spinal nerve | Flexes head
Bends head laterally |
Obliquus capitis caudalis | Spinous process of the axis | Wings of the atlas | Dorsal branch of C2 | Rotates atlas and head |
Rectus capitis dorsalis muscle | ||||
major | Spinous process of the axis | Nuchal crest | Dorsal branch of C1 | Elevates head |
minor | Dorsal arch of the atlas | Occipital bone | Dorsal branch of C1 | Elevates head |
Scalenes
(composed of two unequal parts and the lower one is larger) |
From the transverse process of the last four cervical vertebrae | Into the anterior border and outer surface of the first rib | Assists inspiration by drawing the first rib forward
With rib fixed draws the neck downward and to one side |
Thoracic spine[edit | edit source]
The thoracic vertebrae differs from other vertebrae due to it's distinct feature. The thoracic vertebrae articulates with the rib that corresponds in the number. It has short bodies and flattened extremities. It has short articular processes and the long spinous process. The caudal articular processes of the thoracic vertebrae face ventrally and at the base of spinous process whereas the cranial articular processes of the thoraic vertebrae are oval facets on arch of vertebrae and face dorsally. All the thoracic vertebrae has a pair of costal facets on dorsal body (except T13) forming costal fovea. There are costal facets on the transverse processes of the vertebrae and cranial and caudal fovea on the extremities of the vertebral bodies. [4] The 11th thoracic vertebra is also known as the anticlinal vertebra. The anticlinal vertebra is a point at which vertebral anatomic features change and the spinous process becomes perpendicular to the body and the preceeding vertebra incline caudally. [5]
The costovertebral joint has two artculation between rib and the vertebral column
References[edit | edit source]
- ↑ Cuteness. Canine Spine Anatomy.(Accessed on 2021/03/06). Available from https://www.cuteness.com/article/anatomy-dog-brain
- ↑ 2.0 2.1 2.2 Wikivet. Spinal Column - Anatomy & Physiology. Accessed on:2021/03/06. Available from: https://en.wikivet.net/Spinal_Column_-_Anatomy_%26_Physiology
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Van der Walt A.Canine Spine Anatomy.Handout.
- ↑ IMAIOS.Vet Anatomy. Thoracic vertebrae - Vertebrae thoracicae. Accessed on: 2021/03/10. available from https://www.imaios.com/en/vet-Anatomy/Vet-Anatomical-Part/Thoracic-vertebrae
- ↑ IMAIOS. Vet Anatomy. Anticlinal vertebra - Vertebra anticlinalis. Accessed on 2021/03/10. Available from: https://www.imaios.com/en/vet-Anatomy/Vet-Anatomical-Part/Anticlinal-vertebra