Back of the neck

1. Back of the neck Muscles of the back- 4 layers from superficial to deep. • trapezius & latissimus dorsi • Levator scapulae, rhomboideus, serratus posterior superior, serratus posterior inferior, splenius cervicis and splenius capitis • Erector spinae or sacrospinalis( 3 columns) • iliocostalis- iliocostalis lumborum, iliocostalis thoracis & iliocostalis cervicis • Longissimus- longissimus thoracis, longissimus cervicis & longissimus capitis • Spinalis- spinalis lumborum, spinalis thoracis & spinalis cervicis 4. Multifidus

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5. Back of the neck Suboccipital triangle- Boundaries Superomedially- rectus capitis posterior major supplemented by rectus capitis posterior minor Superiolaterally-superior oblique muscle Inferiorly- inferior oblique muscle Roof- dense fibrous tissue covered by the semispinalis capitis Laterally-longissimus capitis & sometimes by the splenius capitis Floor- posterior arch of the atlas, posterior atlanto-occipital membrane Contents- • Third part of the vertebral a • Dorsal ramus of nerve C1- suboccipital nerve • Suboccipital plexus of veins

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7. Back of the neck Suboccipital muscles

8. Back of the neck Dorsal ramus of 1st cervical nerve- Emerges between posterior arch of the atlas & vertebral artery Supplies 4 suboccipital muscles & semispinalis capitis Nerve to inferior oblique gives off communicating branch to the greater occipital nerve

9. Back of the neck Greater occipital nerve- Medial branch of the dorsal ramus of the 2nd cervical nerve Winds round the middle of lower border of the inferior oblique muscle, & runs upwards and medially. Crosses the suboccipital triangle & pierces semispianlis capitis & trapezius muscles to ramify on the back of the head reaching the vertex Supplies the semispinalis and scalp

10. Back of the neck Third occipital nerve- Medial branch of the dorsal ramus of the 3rd cervical nerve After piercing the semispinalis capitis & trapezius, it ascends medial to the greater occipital nerve. Supplies- skin to the back of the neck to the external occipital protuberance

11. Back of the neck Vertebral artery- Branch from the 1st part of subsclavian artery 3part appears in the suboccipital triangle Foramen transversarium of the atlas, grooves the atlas leaves the triangle passing deep to lateral edge of the posterior atlanto-occipital membrane. It is separated from the posterior arch of the atlas by first cervical nerve & its dorsal and ventral rami

12. Back of the neck Occipital artery- Branch of ECA opposite to the origin of the facial artery Runs backwards & upwards deep to the lower border posterior belly of the digastric muscle, crossing the carotid sheath, accessory and hypoglossal nerves. Runs deep to mastoid process and sternocleidomastoid, digastric, splenius capitis , longissimus capitis. It crosses the rectus capitis lateralis, superior oblique and semispinalis capitis muscles at the apex of the posterior triangle Finally pierces the trapezius 2.5cm from the midline & comes to the lie along the greater occipital nerve. It is tortuous in the superficial of the scalp Branches- mastoid, meningeal & muscular

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14. Back of the neck Deep cervical artery- Branch of costocervical trunk of the subclavian a It passes into the back of the neck just above the neck of the 1st rib Ascends deep to the semispinalis & anastomoses with descending branch of the occipital artery Suboccipital plexus- Muscular veins, occipital veins, internal vertebral plexus & condylar emissary venous plexus. Finally drains into the deep cervical and vertebral plexus of the veins

15. Back of the neck Clinical anatomy- • Neck rigidity- • Cisternal puncture- • Neurosurgeons approach the posterior cranial fossa through this region