Cervical Neuro Flashcards
what is the brachial plexus?
a complex network of nerves that originate from the spinal cord in the neck
what is the brachial plexus formed by?
the ventral rami (anterior branches) of the spinal nerves C5-T1
where can the brachial plexus be found?
deep between scalene and feels like chords
(the chords go under the clavicle)
what are the 6 sections in the brachial plexus?
Spinal cord
Roots
Trunks
Divisons
Cords
Terminal branches
what is the Root part of the brachial plexus?
the ventral rami from C5-T1 that emerge from the spinal cord between anterior and posterior nerve roots.
what is the Trunks part of the brachial plexus?
as the roots emerge from the spinal cord they converge to form 3 trunks:
Superior (C5-C6)
Middle (C7)
Inferior (C8-T1)
what does each trunk divide into?
each trunk divides into anteiror and posterior DIVISIONS
how many cords are there in the brachial plexus?
3 chords in total, lateral medial and posterior
what does each cord give rise to?
multiple peripheral nerves that innervate various muscles and provide sensory information to the upper limb
what are the main nerves that derive from the brachial plexus?
-musculocutaneous nerve
- axillary nerve
- radial nerve
- median nerve
- ulnar nerve
where does the musculocutaneous nerve come from?
C5-C7
where does the axillary nerve come from?
C5 +C6, branches from radial nerve
where does the radial nerve come from?
C5-C8 (T1)
where does the ulnar nerve come from?
C8-T1
Describe the course/formation of the ulnar nerve
Originates for C8-T1 (part of the Brachial plexus/ BP)
It is formed from the medial part of of the BP
Once it leaves the BP is travels down the arm, passing behind the medial epicondyle of the humerus at the elbow.
It then goes onto supply motor function of the flexor carpi ulnaris and flexor digitorium profundus.
Describe the course/formation of the medial nerve
Originates from the nerve roots C5-T1 (part of the BP)
It is one of the terminal branches on the BP and originates from both lateral and medial cords.
It travels through the axilla and down the anterior humerus, staying close to the brachial artery, then through the cubital fossa (triangular shape on front of elbow) without inervating any muscles in the upper arm.
It then travels down the forearm where it innervates severeal muscles (flexor digitorum superficialis, flexor carpi radialis, palmaris longus etc.).
Finally it enteres the hand via the carpal tunnel where it inervates several hand muscles.
Describe the course/formation of the radial nerve
It originates from nerve roots C5-C8
It is a terminal branch of the BP and arises from the posterior cord.
It begins at the axilla and moves down the posterior humerus before giving off a branch called the interosseus nerve at the elbow.
It then divides into 2 branches near the elbow;
-the deep branch- which provides motor innervation to the extensor muscles of the forearm
-the superficial branch- which provides sensory innervation to the dorsal thumb, index finger & middle finger.
What makes up the cervical plexus?
It originates from the ventral rami of spinal nerves C1-C4
What does the cervical plexus give rise to?
several cutaneous branches that provide sensory innervation to differnet areas of the head neck and shoulders
What is a cutaneous nerve?
a peripheral nerve thats role is to rely sensory information from parts of the skin
*it directly inervates specific regions of the skin
what nerve does the micky mouse/dumbo/ ULTTD test?
the ulnar
what are the 5 D’s?
Dizziness
Drop attack- whilst still conscious
Dysarthria- swallowing difficulty
Dysphasia- language disorder
Diplopia- double vision
what are the 3 N’s?
Nausea
Numbness
Nystagmus- involuntary eye movements
what are the components of the CNS?
brain and spinal cord
what are the components of the PNS?
all the nerves that extend from the brain and the spinal cord to the rest of the body
(including cranial and spinal nerves)
what are the main functions of the CNS?
- processing and interperating sensory information
- controlling and co-ordinating voluntary and involuantry bodily functions
- interppetating information from the PNS
what are the main functions of the PNS?
- connects the CNS to the rest of the body
- carries sensory information form the body to CNS
- transmits motor commands from CNS to muscles and glands
describe the course/formation of the musculocutaneous nerve
-originates from nerve roots C5-C7
-comes from a lateral cord in the BP
-travels through the axilla to the anteiror compartment of the arm
-innervates the coracobrachialis, biceps brachii and brachioradilais muscles
-travels down the arm until it becomes the lateral cutaneous nerve of the forearm at the lateral elbow
-the lateral cutaneous nerve of the forearm provides sensory innervation to the lateral foraem and wrist.
Describe the formation/course of axillary nerve
-originates from nerve roots C5 and C6
-arieses from a posterior cord in the BP
-travels inferiorly and laterally in the axilla through the quadrangular space.
-provides motor inervation to the deltoid, teres minor and lateral head of the tricep brachi muscles
-gives rise to the superior lateral cutaneous nerve of the forearm
-this nerve provides sensory innervation to the skin over the lower part of the deltoid and upper lateral arm
what makes up the quadrangular space?
teres minor superiorly
long head of triceps medially
teres major inferiorly
surgical neck of humerus laterally
