The Posterior Triangle of the Neck

Question 1

What are the boundaries of the Posterior Triangle?

Answer 1

Anterior: Posterior Border of Sternomastoid Muscle
Posterior: Anterior Border of Trapezius Muscle
Base: Intermediate 1/3rd of Clavicle

Question 2

Roof of Posterior Triangle

Answer 2

Superficial to Deep:
Skin
Superficial Fascia (containing Platysma and External Jugular Vein)
Investing Layer of Deep Cervical Fascia

Question 3

Floor of Posterior Triangle

Answer 3

Scalenus Medius
Levator Scapulae
Splenius Capitis
Small part of Semispinalis Capitis

All covered by Prevertebral Fascia

Question 4

What are the Contents of the Posterior Triangle?

Answer 4

Nerves
Vessels
Muscles

Question 5

Contents of Posterior Triangle
What are the Nerves?

Answer 5

Spinal Accessory Nerves
Four Cutaneous Branches of Cervical Plexus
Roots and Trunks of Brachial Plexus

Question 6

Contents of Posterior Triangle
Spinal Accessory Nerve: Spinal Segments

Answer 6

C₁ - C₅

Question 7

Contents of Posterior Triangle: Spinal Accessory Nerve
Pathway

Answer 7

Appears at Posterior Border of Sternomastoid
Descends parallel to Levator Scapulae
Ends in Deep Surface of Trapezius Muscle

Question 8

Contents of Posterior Triangle: Spinal Accessory Nerve
Damage

Answer 8

Causes paralysis of Sternomastoid and Trapezius Muscles
Face turns towards paralysed side

Question 9

Contents of Posterior Triangle
Cervical Plexus: Cutaneous Branches

Answer 9

Lesser Occipital Nerve (C2)
Greater Auricular Nerve (C2, 3)
Transverse Cervical Nerve (C2, 3)
Supraclavicular Nerve (C3, 4)

Question 10

Contents of Posterior Triangle: Cervical Plexus
Lesser Occipital Nerve Pathway

Answer 10

Ascends along Posterior Border of Sternomastoid

Question 11

Contents of Posterior Triangle: Cervical Plexus
Lesser Occipital Nerve supplies …

Answer 11

Posterior Part of Scalp

Question 12

Contents of Posterior Triangle: Cervical Plexus
Greater Auricular Nerve Pathway

Answer 12

Crosses Sternomastoid towards Angle of Mandible

Question 13

Contents of Posterior Triangle: Cervical Plexus
Greater Auricular Nerve supplies …

Answer 13

Overlying Skin at Angle of Mandible

Question 14

Contents of Posterior Triangle: Cervical Plexus
Transverse Cervical Nerve Pathway

Answer 14

Crosses Sternomastoid towards Anterior Triangle

Question 15

Contents of Posterior Triangle: Cervical Plexus
Transverse Cervical Nerve supplies …

Answer 15

skin of front of neck

Question 16

Contents of Posterior Triangle: Cervical Plexus
Supraclavicular Nerve Pathway

Answer 16

Descend as Medial, Intermediate and Lateral Groups

Question 17

Contents of Posterior Triangle: Cervical Plexus
Supraclavicular Nerve supplies …

Answer 17

skin on front of upper chest

Question 18

Contents of Posterior Triangle
Brachial Plexus location

Answer 18

Lower Part of Posterior Triangle
Between Scalenus Anterior and Scalenus Medius

Question 19

Contents of Posterior Triangle
Vessels

Answer 19

3rd Part of Occipital Artery crosses Apex of Triangle
3rd Part of Subclavian Artery at Base of Triangle
Transverse Cervical Artery arising from Thyrocervical Trunk
Suprascapular Artery arising from Thyrocervical Trunk
Subclavian Vein which is a continuation of the Axillary Vein

Question 20

Contents of Posterior Triangle
Muscles

Answer 20

Inferior belly of Omohyoid

Question 21

Sternocleidomastoid
Origin

Answer 21

Sternal Head: Front of Manubrium Sterni
Clavicular Head: Medial 1/3rd of Clavicle

Question 22

Sternocleidomastoid
Insertion

Answer 22

Lateral Surface of Mastoid Process
Lateral 1/2 of Superior Nuchal Line

Question 23

Sternocleidomastoid
Nerve Supply

Answer 23

Spinal Accessory Nerve

Question 24

Sternocleidomastoid
Action

Answer 24

Acting Alone: Pulls Mastoid Process down on same side to Chin turns upwards on opposite side
Acting Together: Flexes Neck Forward and used in Elevation of Clavicle and Sternum during Deep Inspiration

Question 25

**Sternocleidomastoid** Torticollis

Answer 25

Spasm of muscle during Cold and Inflammation Ear tilts towards contracted muscle and chin faces opposite direction

Question 26

**Suboccipital Triangle** Boundaries

Answer 26

**Medial**: Rectus Capitis Posterior Major **Lateral**: Superior Obliquus Capitis **Inferior**: Inferior Obliquus Capitis **Floor**: Posterior Atlantoocipital Membrane and Posterior Arch of Atlas

Question 27

**Suboccipital Triangle** Contents

Answer 27

Suboccipital Nerve (C1) Third Part of Vertebral Artery

Question 28

**Suboccipital Triangle** Roof

Answer 28

Trapezius Sternomastoid Splenius Capitis Semispinalis Capitis

Question 29

Splenius Capitis Function

Answer 29

**Bilateral**: Extends Neck **Unilateral**: Rotates Face to same side

Question 30

Semispinalis Capitis Function

Answer 30

**Bilateral**: Extends Neck **Unilateral**: Lateral Flexion of Neck to same side

Question 31

**Rectus Posterior Major Capitis** Superior Attachment

Answer 31

Lateral Inferior Nuchal Line

Question 32

**Rectus Posterior Major Capitis** Inferior Attachment

Answer 32

Spine of Axis

Question 33

**Rectus Posterior Major Capitis** Nerve Supply

Answer 33

Suboccipital Nerve (C1)

Question 34

**Rectus Posterior Major Capitis** Action

Answer 34

Extends Head and Rotates to same side

Question 35

**Rectus Posterior Minor Capitis** Superior Attachment

Answer 35

Medial Inferior Nuchal Line

Question 36

**Rectus Posterior Minor Capitis** Inferior Attachment

Answer 36

Tubercle of Posterior Arch of Atlas

Question 37

**Rectus Posterior Minor Capitis** Nerve Supply

Answer 37

Suboccipital Nerve (C1)

Question 38

**Rectus Posterior Minor Capitis** Action

Answer 38

Extends Head

Question 39

**Obliquus Superior Capitis** Superior Attachment

Answer 39

Occipital Bone

Question 40

**Obliquus Superior Capitis** Inferior Attachment

Answer 40

Atlas Transverse Process

Question 41

**Obliquus Superior Capitis** Nerve Supply

Answer 41

Suboccipital Nerve (C1)

Question 42

**Obliquus Superior Capitis** Action

Answer 42

Extends Head Bends Head Laterally

Question 43

**Obliquus Inferior Capitis** Superior Attachment

Answer 43

Atlas Transverse Process

Question 44

**Obliquus Inferior Capitis** Inferior Attachment

Answer 44

Spine of Axis

Question 45

**Obliquus Inferior Capitis** Nerve Supply

Answer 45

Suboccipital Nerve (C1)

Question 46

**Obliquus Inferior Capitis** Action

Answer 46

Rotates Head to Same Side