Suboccipital Triangle

Question 1

Suboccipital triangle

Answer 1

The suboccipital triangle is a region at the back of the neck bounded by the suboccipital group of muscles:

-Rectus Capitis Posterior Major muscle = forms the medial border
F- Extension and rotation of the neck

-Obliquus Capitis Superior muscle = forms the
lateral border
F- Lateral bending of the neck

-Obliquus Capitis Inferior muscle = forms the
inferior border
F- Neck rotation

-The roof of the suboccipital triangle is
formed by the semispinalis capitis and longissimus capitis muscles

-The region has a floor formed by the
posterior arch of the atlas and the posterior atlanto-occipital membrane

Question 2

Rectus capitis posterior major

Answer 2

NERVE Suboccipital

ACTION Extends, rotates, and flexes the head laterally

ORIGIN Spine of axis

INSERTION Inferior nuchal line

Question 3

Rectus capitis posterior minor

Answer 3

NERVE: Suboccipital

ACTION: Extends and flexes the head laterally

ORIGIN: Posterior tubercle of atlas

INSERTION: Nuchal line

Question 4

Obliquus capitis superior

Answer 4

NERVE: Suboccipital

ACTION: Extends, rotates, and flexes the head laterally

ORIGIN: Transverse process of atlas

INSERTION: Nuchal line

Question 5

Obliquus capitis inferior

Answer 5

NERVE: Suboccipital n.

ACTION: Extends and rotates the head laterally

ORIGIN: Spine of the axis

INSERTION: Transverse process of atlas

Question 6

Contents of suboccipital triangle

Answer 6

• Vertebral artery
• Suboccipital nerve (C1) and vessels
• Suboccipital venous plexus

-Vertebral artery
• Branch off the subclavian artery • Travels through the transverse foramina of the upper six cervical vertebrae • Gives off an anterior spinal and two posterior spinal arteries

-Suboccipital nerve (C1) and vessels
• Derived from the dorsal ramus of C1
• Emerges between the vertebral artery above
and the posterior arch of the atlas below
• Supplies the muscles of the suboccipital triangle and the semispinalis capitis muscle

Question 7

Suboccipital triangle joints

Test Question

Answer 7

• Atlanto-occipital joint = flexion, extension, and lateral flexion of the head
• Atlantoaxial joints = rotation of the atlas and the head as a unit on the axis

Question 8

Components of the Occipitoaxial Ligament

Answer 8

1-Cruciform Ligament (under tectorial)
a-Transverse ligament
b-Longitudinal ligament

2-Apical Ligament (under cruciate lig.)

3-Alar Ligament (under cruciate lig.)

4-Tectorial Membrane (top layer)