Posterior Triangle Flashcards
What is the anterior boarder of the posterior triangle of the neck?
Posterior boarder of sternocleidomastoid
What is the posterior boarder of the posterior triangle of the neck?
Anterior boarder of the trapezius muscle
What is the inferior boarder of the posterior triangle of the neck?
Middle 1/3 of the clavicle
What are the 2 sub triangles found within the posterior triangle of the neck?
- Supraclavicular triangle
2. Occipital triangle
What divides the posterior triangle into 2 sub triangles?
Inferior belly of omohyoid
What are the 3 things which form the roof of the posterior triangle?
- Skin
- Superficial fascia
- Investing layer of deep cervical fascia
What 3 things are found in the superficial fascia?
- Platysma muscle
- External jugular vein
- Cutaneous branches of cervical plexus
What are the 4 cutaneous branches of the cervical plexus?
- Lesser occipital nerve
- Greater auricular nerve
- Transverse cervical nerve
- Supraclavicular nerve
What are the 3 muscular branches of the cervical plexus?
- Phrenic
- Branches to prevertebral muscles
- Ansa cervicalis
What cervical nerves form the phrenic nerve?
C3 - C5
What does the phrenic nerve supply?
Diaphragm
What cervical nerves form the ansa cervicalis?
C1 - C3
Where do the cutaneous branches of the cervical plexus appear?
Middle of the posterior boarder of the sternocleidomastoid
What 3 areas of skin does the greater auricular nerve supply?
- Skin covering angle of mandible
- Lower part of the ear
- Skin behind the ear
What is the course of the greater auricular nerve after emerging from the middle of the posterior boarder of sternocleidomastoid?
Runs upward, superficial to the sternocleidomastoid
What area of skin does the lesser occipital nerve supply?
Skin behind the ear
What is the course of the lesser occipital nerve after emerging from the middle of the posterior boarder of sternocleidomastoid?
Ascends along posterior boarder of sternocleidomastoid
What are the 3 different supraclavicular nerves?
- Medial
- Intermediate
- Lateral
What 2 areas of skin does the supraclavicular nerve supply?
- Pectoral region
2. Skin covering deltoid (lateral supraclavicular only)
What is the course of the supraclavicular nerve after emerging from the middle of the posterior boarder of sternocleidomastoid?
Arise by a common trunk which divides and the branches then cross the clavicle
What area of the skin does the transverse cervical nerve supply?
Anterolateral part of the neck
What is the course of the transverse cervical nerve after emerging from the middle of the posterior boarder of sternocleidomastoid?
Runs forward superficial to sternocleidomastoid before dividing into ascending and descending branches
What 4 muscles form the floor of the posterior triangle?
- Scalenus medius
- Levator scapulae
- Splenius capitis
- Semispinalis capitis
What are the 3 major nerves found in the posterior triangle?
- Brachial plexus
- Spinal part of accessory nerve
- Cutaneous branch of cervical plexus
What is the major muscle found in the posterior triangle?
Inferior belly of omohyoid muscle
What are the 5 major vessels found in the posterior triangle?
- Third part of subclavian artery
- Occipital artery
- Suprascapular artery
- Subclavian vein
- External jugular vein
What is the course of the spinal part of accessory nerve?
- Crosses posterior triangle obliquely lying on levator scapulae
- Disappears under trapezius muscle
Describe the position of the third part of the subclavian artery
- Lies on upper surface of first rib
2. Lies behind subclavian vein
What is the only tributary of the subclavian vein?
External jugular vein
What are the 3 branches of the first part of the subclavian artery?
- Vertebral artery
- Internal thoracic artery
- Thyrocervical trunk
What are the 3 branches of the thyrocervical trunk?
- Inferior thyroid artery
- Transverse cervical artery
- Suprascapular artery
What is the trunk given from the second part of the subclavian artery?
Costocervical trunk
What artery is given from the third part of the subclavian artery?
Dorsal scapular artery
What surgery can put the spinal part of accessory nerve at risk?
Surgery of deep cervical lymph nodes
What can occur if the spinal part of accessory nerve is damaged?
Paralysis of the trapezius muscle so arm cannot be abducted beyond 90 degrees
What are 2 clinical things of importance of the external jugular vein?
- Jugular venous pressure can be examined
2. If cut, it cannot close and air is sucked in causing air embolism
What are the 2 types of torticollis?
- Congenital muscular
2. Acquired acute
What can cause congenital muscular torticollis?
A mass in the sternocleidomastoid
What are 2 types of brachial plexus block?
- Interscalene block
2. Supraclavicular block
What are 3 differences between an interscalene block and supraclavicular block?
- Onset of block is earlier in supraclavicular block
- All of the dermatome is anesthetised in the interscalene block
- Duration of sensory block is prolonged in supraclavicular block
