Advanced Cervical Plexus Quiz

Q1. Why is the midpoint of the posterior border of sternocleidomastoid clinically important?

• The brachial artery begins there
• The internal carotid artery becomes superficial there
• The recurrent laryngeal nerve enters the larynx there
• The major cutaneous branches emerge near this point

Q2. What is the anatomical basis of a superficial cervical plexus block?

• Anesthetic is injected directly into the spinal cord
• The vagus nerve is blocked within the carotid sheath
• Anesthetic targets superficial cutaneous branches near the posterior sternocleidomastoid border
• The facial nerve is blocked inside the parotid gland

Q3. Why can a deep cervical plexus block affect diaphragmatic function?

• The block interrupts the thoracic sympathetic chain only
• The block directly paralyzes the recurrent laryngeal nerve in every case
• The diaphragm is supplied by the ansa cervicalis
• Local anesthetic may spread to the phrenic nerve

Q4. Which pattern best describes sensory loss after injury to the great auricular nerve?

• Loss over the entire scalp above the vertex
• Loss limited to the tongue
• Loss over the tip of the nose only
• Loss over the lower auricle, parotid region, and nearby mandibular angle

Q5. Why does a lesion of the ansa cervicalis not usually paralyze thyrohyoid?

• Thyrohyoid has no motor innervation
• Thyrohyoid is supplied by the recurrent laryngeal nerve
• Thyrohyoid receives C1 fibers through the hypoglossal nerve pathway
• Thyrohyoid is supplied by the facial nerve

Q6. Which anatomical arrangement explains why C1 fibers can be mistaken for hypoglossal motor fibers in the neck?

• The ansa cervicalis is a branch of CN XII
• C1 fibers hitchhike temporarily along the hypoglossal nerve
• The hypoglossal nerve originates from the C1 spinal cord
• C1 fibers pass through the hypoglossal canal independently beside CN XII

Q7. How does the cervical plexus relate to the prevertebral muscular plane?

• It is contained entirely within the carotid artery
• It lies inside the retropharyngeal space anterior to the pharynx
• It lies deep to sternocleidomastoid over the prevertebral muscular region
• It lies superficial to platysma throughout

Q8. Why can supraclavicular nerve injury produce sensory symptoms over the shoulder despite the shoulder also receiving brachial plexus innervation?

• The brachial plexus does not supply any shoulder structures
• The supraclavicular nerves supply the deltoid muscle motor fibers
• Cervical plexus supraclavicular nerves supply skin over part of the shoulder region
• The supraclavicular nerves arise from the radial nerve

Q9. Which feature best distinguishes the cervical plexus from the brachial plexus anatomically?

• The brachial plexus lies only inside the cranial cavity
• The cervical plexus uses posterior rami while the brachial plexus uses anterior rami
• The cervical plexus is mainly C1-C4, while the brachial plexus is mainly C5-T1
• The cervical plexus is entirely sympathetic

Q10. Which statement best integrates cervical plexus anatomy?

• It is a sympathetic plexus surrounding the carotid artery
• It is a C1-C4 plexus combining superficial cutaneous and deep motor pathways in the neck
• It is a cranial nerve network supplying only the pharynx
• It is a C5-T1 plexus devoted entirely to the upper limb