This document provides information about muscles in the back and suboccipital region. It begins with multiple choice questions then provides details about: - Muscles of the back including the superficial group (trapezius, levator scapulae) and deep group (erector spinae, semispinalis, suboccipital muscles) - Structures in the suboccipital region such as the suboccipital triangle bounded by the atlas, occiput and mastoid process - Nerves that supply muscles including the suboccipital nerve, a branch of C1 - Procedures like cistern puncture that are done through the suboccipital triangle

1. Muscles of back and
Suboccipital region
Dr. Laxman Khanal
Assistant professor
Department of anatomy, BPKIHS
To BDS 2nd year
21-11-2016

2. Q. Main artery of suboccipital triangle is
a. External carotid artery b. internal carotid artery
c. Vertebral artery d. occipital artery.
Q. Which part of the vertebral artery lies in suboccipital triangle?
a. First part b. second part c. third part d. fourth part
Q. Suboccipital nerve is the branch of.
a. C1 dorsal ramus b. C1 ventral ramus
c. C2 dorsal ramus d. C2 ventral ramus
Q. Which procedure is done through suboccipital triangle?
a. Lumbar puncture b. cistern puncture
c. Surgical approach to ant cranial fossa d. all of the above

3. Identify the landmark.
Identify the bone.
Identify the muscle.
Identify it.
EOC
C1
Trapezius
Ligamentum
nuchae

4. Introduction
• The back of the neck is limited above by external occipital
protuberance and superior nuchal lines, and below by spine of C7
vertebra and horizontal lines extending on either side from it to the
acromial process of scapula.
• The important structures on the back of the neck include ligamentum
nuchae, extensor muscles of the neck, suboccipital triangle and
arterial anastomosis around the semispinalis capitis.
• Suboccipital region lies between occiput and spine of axis vertebra.

5. • Skeletal framework of back
consists of 33 vertebrae.
Atlas
Atlas & Axis
Typical cervical vertebra

6. 1. Ext occipital protuberance
2. Ext occipital crest
3. Sup nuchal line
4. Inferior nuchal line

7. Ligamentum nuchae
• It is a triangular sheet of fibroelastic
tissue that forms the median fibrous
septum between the muscles of the
two sides of the back of the neck.
Post free border
Ant border
Apex
Spine and post
tubercles of C1-C6
Spine of C7
EOP and external
occipital crest

8. • The musculatures of the back
are arranged in a series of
layers.
1. Superficial group of muscles
2. Deeper group of muscles
• Only the deeper muscles are
true back muscles which are
supplied by dorsal rami of spinal
nerves.
• Superficial muscles are
innervated by ventral rami of
spinal nerves.

10. Erector spinae muscle
1. Spinalis
2. Longissimus
3. Iliocostalis
Levator scapulae
Rhomboid minor
Rhomboid major
Splenius capitis
Splenius cervicis
Splenius=bandage

11. Semispinalis capitis
Semispinalis cervicis
Suboccipital musclesAnastomosis around the
semispinalis capitis
Splenius
Erector
spinae

12. Muscles of back of neck
• The muscles of the back of the neck on either side of midline are
arranged into superficial and deep groups
Superficial group
First layer: Trapezius
Second layer: levator scapulae
rhomboid major
rhomboid minor
Deep group
First layer: splenius capitis
splenius cervicis
Second layer: Erector spinae
Third layer: semispinalis capitis
semispinalis cervicis
Fourth layer: suboccipital muscles

13. Neck rigidity
• Occurs in meningitis.
• Spasm of extensor muscles on
the back of the neck occurs.
• Caused by irritation of nerve
roots of cervical spinal nerves
• Trapezius
• Levator scapulae and rhomboids
• Splenius- layer 1
• Erector spinae- layer 2
• Semispinalis- layer 3 # SESS
• Sub-occipital group of muscles- layer 4

14. Nerve supply
Spinal accessory nerve (motor).
Ventral rami of C3 and C4 (sensory)
Action
Upper fibers: elevate the shoulder
Middle and lower fibers: retract shoulder

15. Suboccipital region
Above:
Inferior nuchal line
Below:
Spine and lamina of C2
Lateral:
Mastoid process and transverse
process of C1 and C2

16. Cistern puncture:
• Needle is introduced in the
midline just above the spine
of the axis vertebra.
• Utmost care should be taken
as medulla lies only 1 inch
anterior to the posterior
atlanto-occipital membrane
which, if damaged, may be
fatal.

17. Muscles of suboccipital triangle
1. Rectus capitis posterior major.
2. Rectus capitis posterior minor.
3. Oblique capitis inferior.
4. Oblique capitis superior.
All these muscles are supplied by the dorsal ramus of
C1 spinal nerve (suboccipital nerve).
Unique feature of C1 nerve
no cutaneous branches.

18. C1
C2
Rectus capitis posterior major
Rectus capitis posterior minor
Oblique capitis inferior
Oblique capitis superior
Suboccipital traingle

19. Floor
posterior arch of the atlas
atlanto-occipital membrane
Boundaries
• Superomedial
• Superolateral
• Inferior

20. Suboccipital nerve
Vertebral artery
Greater occipital nerve
Suboccipital venous plexus

21. The connection between suboccipital venous plexus and internal vertebral
venous plexus serves as a path of intracranial infection in carbuncles of the
neck.
Suboccipital venous plexus