Sternomastoid Muscle Flashcards
1
Q
Sternomastoid muscle
A
Important landmark between anterior and posterior triangles
2
Q
Origin
A
- Sternal head
- Clavicular head
3
Q
Sternal head
A
Round and tendinous from front of upper part manubrium sterni
4
Q
Clavicular head
A
Broad and fleshy
From upper surface medial 1/3 clavicle
5
Q
Insertion
A
- Lateral surface mastoid process
- Lateral half superior nuchal line
6
Q
Nerve supply
A
- Motor: spinal root accessory nerve
- Sensory: anterior ramifications C2,3
7
Q
Action
A
One muscle:
1. Bends head same side
2. Rotates face to opposite side
Two muscles:
Flexes neck by:
1. Projecting head forwards
2. Raising head from supine
8
Q
Relations
A
- Spinal root accesory nerve
- Superficial
- Deep
9
Q
Spinal root accessory nerve
A
- Pierces muscle at junction of upper and middle thirds
- Runs within it about its middle
10
Q
Superficially
A
- Skin and fascia (with Platysma)
- EJV (crosses it obliquely)
- Posterior auricular vessels
- Great auricular nerve
- Transverse cutaneous nerve neck
- Parotid Posteromedial surface
11
Q
Deep
A
- Carotid sheath and its contents
- Cervical plexus
- Deep cervical lymph nodes
- Eight muscles
- Scalenus anterior muscle
- Subclavian artery
- Anterior jugular vein
- Thyroid gland lobe
- Mastoid process
12
Q
Carotid sheath and its contents
A
- Common and internal carotid arteries
- Vagus nerve
- IJV
13
Q
Deep cervical lymph nodes
A
Along IJV
14
Q
Subclavian artery
A
1st and 2nd parts
15
Q
Anterior jugular vein
A
In lower part
