anatomy of the head and neck Flashcards
(27 cards)
What are the roots of the phrenic nerve?
C3 ,C4, C5 → C3,4,5 keeps the diaphragm alive
What does the phrenic nerve do?
innervates the diaphragm.
what does ansa cervicalis do?
Gives rise to 4 nerves that innervate the infrahyoids:
- Superior belly of the omohyoid muscle
- Inferior belly of omohyoid muscle
- Sternohyoid
- Sternothyroid
What are the roots of ansa cervicalis?
C1-3
What are the infrahyoids and what do they do and what is their innervation?
They act to depress the hyoid bone; an important function for swallowing and speech.
- sternohyoid → ansa cervicalis
- sternothyroid → ansa cervicalis
- thyrohyoid → hypoglossal nerve
- omohyoid → ansa cervicalis
What are the roots of the brachial plexus?
C5 - T1
What are the roots of the cerviacle plexus?
C1 - C4
What is the pneumonic to remember the way the brachial plexus is divided up?
Read → Roots - C5-T1
That → Trunks - superior middle inferior
Damn → divisions (X,Y)
Cadaver → Chords - lateral, posterior, medial
Book → Branches - musculocutaneous, axillary, median, radial, ulnar,
What is the root of the musculocutaneous nerve?
C5, C6, C7
What does the musculocutaneous nerve do?
Motor Functions: Innervates the brachialis, biceps brachii and coracobrachialis muscles.
Sensory Functions: Gives off the lateral cutaneous branch of the forearm, which innervates the lateral half of the anterior forearm, and a small lateral portion of the posterior forearm
What are the roots of the axilliary nerve?
C5 + C6
What does the axilliary nerve innervate?
Motor Functions: teres minor and deltoid muscles.
Sensory Functions: inferior region of the deltoid (“regimental badge area”).
What are the roots of the median nerve?
C6 – T1
What does the median nerve innervate?
Motor Functions:
- Most of the flexor muscles in the forearm,
- The thenar muscles, and the
- Two lateral lumbricals that move the index and middle fingers.
Sensory Functions: → carpal tunnel syndrome.
Gives off the palmar cutaneous branch, which innervates the lateral part of the palm, and the digital cutaneous branch, which innervates the lateral three and a half fingers on the anterior (palmar) surface of the hand.
What are the roots of the radial nerve?
C5 -T1 (all of them)
What does the radial nerve do?
Motor Functions: Innervates the triceps brachii, and the extensor muscles in the posterior compartment of the forearm.
Sensory Functions: Innervates the posterior aspect of the arm and forearm, and the posterior, lateral aspect of the hand.
What are the roots of the Ulnar nerve?
C8 + T1
What does the ulnar nerve do?
Motor Functions: Innervates the muscles of the hand (apart from the thenar muscles and two lateral lumbricals), flexor carpi ulnaris and medial half of flexor digitorum profundus.
Sensory Functions: Innervates the anterior and posterior surfaces of the medial one and half fingers, and associated palm area.
What is Erbs palsy?
Erb’s palsy is an upper brachial plexus injury.
Occurs when the angle between the neck and shoulder increases –stretching or tearing the nerve roots.
• difficult birth or shoulder trauma.
How does Erbs palsy present?
Waiters tip!
The affected limb hangs limply, medially rotated by the unopposed action of pectoralis major. The forearm is pronated due to the loss of biceps brachii. This is position is known as ‘waiter’s tip’
Which roots are commonly affected in Erbs palsy?
C5 + C6
Which muscles are normally affected in Erbs palsy?
- Supraspinatus, infraspinatus, subclavius, biceps brachii, brachialis, coracobrachialis, deltoid and teres minor.
- Lost or weakened movements include: abduction at shoulder, lateral rotation of arm, supination of forearm, and flexion at shoulder.
What is Klumpke Palsy?
- A lower brachial plexus injury results from excessive abduction of the arm
- Falling from a tree and catching your arm on a branch.
Which root is damaged?
T1 → everything ulnar!
