anatomy of the head and neck

Question 1

What are the roots of the phrenic nerve?

Answer 1

C3 ,C4, C5 → C3,4,5 keeps the diaphragm alive

Question 2

What does the phrenic nerve do?

Answer 2

innervates the diaphragm.

Question 3

what does ansa cervicalis do?

Answer 3

Gives rise to 4 nerves that innervate the infrahyoids:

• Superior belly of the omohyoid muscle
• Inferior belly of omohyoid muscle
• Sternohyoid
• Sternothyroid

Question 4

What are the roots of ansa cervicalis?

Answer 4

C1-3

Question 5

What are the infrahyoids and what do they do and what is their innervation?

Answer 5

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

Question 6

What are the roots of the brachial plexus?

Answer 6

C5 - T1

Question 7

What are the roots of the cerviacle plexus?

Answer 7

C1 - C4

Question 8

What is the pneumonic to remember the way the brachial plexus is divided up?

Answer 8

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,

Question 9

What is the root of the musculocutaneous nerve?

Answer 9

C5, C6, C7

Question 10

What does the musculocutaneous nerve do?

Answer 10

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

Question 11

What are the roots of the axilliary nerve?

Answer 11

C5 + C6

Question 12

What does the axilliary nerve innervate?

Answer 12

Motor Functions: teres minor and deltoid muscles.

Sensory Functions: inferior region of the deltoid (“regimental badge area”).

Question 13

What are the roots of the median nerve?

Answer 13

C6 – T1

Question 14

What does the median nerve innervate?

Answer 14

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.

Question 15

What are the roots of the radial nerve?

Answer 15

C5 -T1 (all of them)

Question 16

What does the radial nerve do?

Answer 16

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.

Question 17

What are the roots of the Ulnar nerve?

Answer 17

C8 + T1

Question 18

What does the ulnar nerve do?

Answer 18

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.

Question 19

What is Erbs palsy?

Answer 19

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.

Question 20

How does Erbs palsy present?

Answer 20

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’

Question 21

Which roots are commonly affected in Erbs palsy?

Answer 21

C5 + C6

Question 22

Which muscles are normally affected in Erbs palsy?

Answer 22

• 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.

Question 23

What is Klumpke Palsy?

Answer 23

• A lower brachial plexus injury results from excessive abduction of the arm
• Falling from a tree and catching your arm on a branch.

Question 24

Which root is damaged?

Answer 24

T1 → everything ulnar!

Question 25

What 2 groups of muscles make up the extrinsic muscles of the larynx?

Answer 25

• Infrahyoid + suprahyoid

suprahyoid → stylohoid, Digastric, geniohyoid,mylohyoid

Infrahyoid → Sternohyoid, thyrohyoid, sternothyroid, omohyoid

Question 26

What do the intrinsic muscles of the larynx do?

Answer 26

Acting on the individual components of the larynx they control the shape of the rima glottidis (opening between the vocal folds and the arytenoid cartilages), and the length and tension of the vocal folds.

Question 27

What are the 5 arytenoid muscles called?

Answer 27

• Thyroaritenoid
• Transverse arytenoid
• Posterior arytenoid
• Oblique arytenoid
• Lateral cricoarytenoid