Advanced Infrahyoid Muscles Quiz

Q1. Why can injury to the ansa cervicalis weaken several infrahyoid muscles while sparing thyrohyoid?

• Thyrohyoid is supplied by the facial nerve
• Thyrohyoid has no motor innervation
• Thyrohyoid is supplied by the recurrent laryngeal nerve
• Thyrohyoid receives C1 fibers outside the ansa cervicalis loop

Q2. Why is sternothyroid unable to depress the hyoid directly?

• It is a suprahyoid muscle
• It attaches to the thyroid cartilage rather than the hyoid
• It inserts on the mandible
• It has no attachment to the sternum

Q3. How can sternothyroid and thyrohyoid act sequentially on the laryngeal framework?

• Both muscles act exclusively on the tongue
• They form a sphincter around the trachea
• Both muscles only rotate the head
• They can move the thyroid cartilage relative to the sternum and hyoid in complementary directions

Q4. Why is the omohyoid an important surgical landmark in the neck?

• It passes through the jugular foramen
• It encloses the internal carotid artery
• Its course helps define cervical triangles and orient regional anatomy
• It forms the entire floor of the mouth

Q5. What is the functional importance of stabilizing the hyoid bone?

• It fixes the cervical vertebrae together
• It closes the carotid arteries
• It prevents all laryngeal movement
• It provides a stable base for muscles acting on the tongue, floor of mouth, and mandible

Q6. Why may C1 fibers associated with the hypoglossal nerve be mistaken for fibers originating from CN XII?

• C1 and CN XII share the same motor nucleus
• CN XII originates from the C1 spinal cord
• The hypoglossal nerve is a branch of the cervical plexus
• They hitchhike along CN XII before leaving it for cervical targets

Q7. Which infrahyoid relationship is most relevant when approaching the thyroid gland from the anterior neck?

• Thyrohyoid surrounds the carotid bifurcation
• Omohyoid lies inside the thyroid capsule
• All infrahyoid muscles lie posterior to the vertebral column
• Sternohyoid and sternothyroid overlie the thyroid region

Q8. Why can the term strap muscles include more than one anatomical layer?

• The group contains superficial and deep muscles despite their shared strap-like organization
• The muscles are layers of one continuous muscle
• The term refers only to sternohyoid
• All four muscles occupy exactly the same fascial plane

Q9. Which action would be most impaired if sternohyoid, sternothyroid, and omohyoid were all denervated?

• Abduction of the vocal folds
• Elevation of the soft palate
• Protraction of the mandible
• Depression and stabilization of the hyoid-laryngeal complex

Q10. Which statement best integrates infrahyoid muscle anatomy?

• They are layered anterior neck muscles that coordinate hyoid and laryngeal movement through cervical motor innervation
• They are pharyngeal constrictors supplied entirely by the vagus nerve
• They are posterior neck extensors supplied by dorsal rami
• They are muscles of mastication supplied by the mandibular nerve