1. LATERAL CERVICAL TRIANGLE

2. Superficial Cervical Fascia
Contains:
Platysma muscle
Superficial veins
Cutaneous nerves

3. Prevertebral Fascia Covers: Extends: Muscles of the lateral triangle
Around anterior surface of the cervical vertebrae across anterior midline.

4. Boundaries of Triangle
Anterior:
Posterior border of the sternocleidomastoid
Posterior:
Anterior border of the trapezius
Inferior:
Clavicle
Moore: Fig. 6.29

5. Roof of Triangle Skin Superficial layer of deep cervical fascia:
Also called investing fascia.
Splits to enclose:
Trapezius
Sternocleidomastoid

6. Muscular Floor Triangle
Prevertebral fascia covers muscular floor consisting of:
Splenius capitis
Levator scapulae
Scalenus posterior
Scalenus medius
Scalenus anterior
Omohyoid

7. Nerves of Triangle Lesser occipital (C2) Supraclavicular (C3,4)
Accessory (CN XI):
To trapezius and sternocleidomastoid

8. Vessels of Triangle Occipital artery Transverse cervical artery
Subclavian vein:
Crosses first rib
Subclavian artery:
External jugular vein

9. Spinal Accessory Nerve
Spinal root
Arises from C1-C5.
Fibers pass superiorly through foramen magnum and join cranial root.
Cranial root
Arises from medulla.

10. Spinal Accessory Nerve
Both roots exit through jugular foramen and separate.
Spinal root innervates:
Sternocleidomastoid
Trapezius