Cervical Plexus Flashcards
What is the cervical plexus formed by?
Anterior primary rami of C1-4
What is the loop formed by motor branches of the cervical plexus called?
Ansa cervicalis
C1-3
What does the ansa cervicalis supply?
Motor supply to infrahyoid muscles
Sensory innervation of cervical plexus
Skin of neck
Part of scalp + ear
Superior thorax (C2-4 dermatomes)
What is the ansa cervicalis?
What roots of cervical plexus contribute to it?
Loop formed by motor branches of the cervical plexus
C1-3
What anatomical structure does the ansa cervicalis overlie anteriorly?
Internal jugular vein
What are the nerve roots of the phrenic nerve?
C3-5
What does the phrenic nerve innervate?
Diaphragm
Location of the cervical plexus
In posterior triangle in neck
Halfway up SCM
Within prevertebral fascia
Describes the route of the phrenic nerve
- Arises from C3-5
- Travels down anterior scalene muscle
- Enters thorax
- Descends anterior to lung to reach diaphragm
What is the nerve point of the neck/Erb’s point?
Midway up the posterior border of SCM where the sensory branches of cervical plexus pierce the skin
Where do the sensory branches of the cervical plexus enter the skin?
Midway up the posterior border of SCM
‘Erb’s area’
Clinical use of Erb’s point/nerve point of the neck
Examples of when its used
Site of administering regional anaesthesia or nerve blocks in neck + upper limbs
e,g, carotid endarterectomy, thyroidectomy + cervical lymph node excision
Describe cervical plexus block
- Provides regional anaesthesia for neck surgery
- into Erb’s area/nerve point of neck
- midway up posterior border of SCM
- needle inserted + injected 3 times in fan like fashion
Who should cervical plexus block not be used on?
Those with co-existing cardiac or resp disease due to risk of affecting phrenic nerve
