242. Sternocleidomastoid region · Anatomy (Topographic) · MU Sofia

242. Sternocleidomastoid region.

Covers the sternocleidomastoid region, beginning with its boundaries and the surface anatomy of the superficial layers, including the skin, platysma, external jugular vein, cervical plexus and the muscles lying in the region. It then describes how the space behind the muscle divides into the antescalene, interscalene and scaleno-vertebral spaces, listing the structures in each.

Inside: 4 sections · 2 labelled pictures · 14 flashcards · 1 min

Topic 13 of 40 in the MU Sofia syllabus for Anatomy (Topographic) (Medicine, Year 2). The free AceMed note covers it in 4 sections, about 195 words (1 min of reading), with 14 flashcards.

Boundaries :

The boundaries of SCM muscle.

Surface Anatomy :

1. Skin
2. Subcutanous tissue

Contains → Platysma m.
↳ Enclosed by superficial fascia.
→ External jugular vein.
→ Cervical plexus

3. SCM m.

↳ Enveloped in the split of investing layer of deep cervical fascia.

4. Cervical neurovasicular bundle.
5. Omohyoid m. (in the lower part).
6. Sternothyroid m.

Subdivisions :

In the inferior part of SCM region, the space behind the muscle is subdivided into several spaces :

1. Antescalane Space:

Enclosed btw. SCM & ant. scalenus m.
Content:

1. Venous angle

↳ Accepts:

1. Supperficial veins of the neck.
2. Thoracic duct (on the left)
3. Right lympathic duct (on the right)
2. Internal jugular v. ↶ runs medial
3. Common Carotid art.
4. Vagus n.

2. Interscalene space

Between ant. & middle scaleni m. & the first rib.
Content:

1. Subclavian art.

↳ gives only one br.
→ costocervical trunk.

2. Brachial plexus,

3. Scaleno-vertebral triangle:

*Deepst & most inf. part of the SCM region.
Boundaries :
Later. - ant. scalene m.
Medi - trachea, esophagus
Inf. - Dome of pleura
Contant :
Subclavian art & v.
↳ gives vertebral art.
Sympathetic trunk
Vagus n & Phrenic n.