VERTEBRAL ARTERY
- Vertebral artery
- First part
- Origin of artery to transverse process of 6 th cervical vertebra
- Course
- Runs upwards
- Scalenovertebral triangle
- Present at root of neck
- Boundaries
- Lateral Scalenus anterior
- Medial : oblique part of longus colli muscle
- Apex : transverse process of cervical vertebra
- Base : first part of subclavian artery
- Posterior wall : transverse process of C7 , ventral ramus of C8 nerve , neck of first rib
- Relations
- Anterior
- Carotid sheath with common carotid artery
- Vertebral vein
- Inferior thyroid artery
- Thoracic duct on left side
- Posterior
- Transverse process of 7 th cervical vertebra
- Stellate ganglion
- Ventral Rami of nerves C7 , C8
- Second part
- Runs through foramina transversria of upper 6 cervical vertebra
- Finally reaches foramen of atlas
- Relations
- accompanied by venous plexus and a large branch from stellate ganglion
- Ventral Rami of second to 6 th cervical nerves
- Third part
- Lies in suboccipital triangle
- Emerges from atlas
- Winds medially around posterior aspect of arch of atlas
- Relations
- Medial : ventral ramus of first cervical nerve
- Lateral : rectus capitis Lateralis
- Posterior : semispinalis capitis
- Anterior : lateral mass of atlas
- Fourth part
- Atlantooccipital membrane to pons
- Vertebral canal it pierces duramater
- At lower border of pons it joins to form basilar artery
- Branches
- Cervical branches
- Arise from 4 th part
- Anterior spinal artery
- Posterior spinal artery
- Posterior inferior cerebellar artery
- Meningeal branches