6 Triangles of Neck Flashcards
A surgical procedure is performed and a tumor is removed from the larynx. The right ansa cervicalis is anastomosed with the right recurrent laryngeal nerve to reinnervate the muscles of the larynx and restore phonation. Which muscle is most likely paralzed?
Because of the surgical division of the ansa cervicalis, the sternohyoid muscle is most likely paralyzed. The ansa cervicalis innervates the strap muscles: sternohyoid, sternothyroid and omohyoid muscles
An abscess is removed from the middle of the posterior cervical triangle on the right side. Patient notices her shoulder droops and can no longer raise her right hand above her head. Which nerve is injured?
The spinal accessory nerve (CN XI) passes across the posterior triangle of the neck and innervates the trapezius muscle and SCM.
Patient has a stab wound in superior region of neck. Examination reveals patient has lost sensation from the skin over the angle of the jaw. Which nerve is injured?
The area over the angle of the jaw and posteroinferior to the auricle of the ear is innervated by the great auricular nerve.
transverse cerival innervates the anterior and lateral aspects of the neck.
The lesser occipital nerve innervates skin in the area of the back of the neck and posterior occipit.
The supraclavicular nerves innervate the inf. aspects of the neck, upper deltoid region and skin inf. to clavicles
Child has continuously tilted head posture, with right ear near right shoulder and face turned upward and to the left. Which muscle was most likely damaged during birth?
The sternocleidomastoid muscle is injured especially during birth. When acting alone, the action of SCM is to turn the head to the opposite side and bend it toward the ipsilateral shoulder.
Midline tracheostomy inferior the thyroid isthmus is performed. Which vessel are most likely to be present at the site of incision and will need to be cauterized?
The thyroidea ima artery (NOT inf. thyroid artery) and inf. thyroid vein.
Following a thyroidectomy in which the inf. thyroid artery was ligated, the patient speaks with a hoarse voice and has difficulty in breathing on exertion. Which nerve was injured during the surgery?
The recurrent laryngeal nerve was most likely injured bc it runs in close proximity to the inf. thyroid artery. The recurrent laryngeal n. innervates the majority of the vocal muscles and open and close the rima glottidis, in addition to providing sensory supply to the larynx below the vocal folds
After surgery, patient has hoarseness of voice. Examination shows a permanently adducted vocal fold on the right side. Surgical trauma to the innervation of which muscle is responsible for the position of the right vocal fold?
The recurrent laryngeal nreve is often at risk of being damaged during a thyroidectomy. The posterior cricoarytenoid is supplied by the recurrent laryngeal n. The post. cricoarytenoid is the only muscle responsible for abduction of the vocal cords and paralysis would result in a permanently adducted position of the involved vocal cord.
An emergency tracheostomy is performed and arterial bleeding suddenly occurs from the midline incision over the trachea. Which vessel was most likely cut?
The thyroidea ima artery supplies the thyroid gland and ascends in front of the trachea.
Patient suffers from odynophagia and hoarseness of voice. Examination reveals tumor at the tracheoesophageal groove. Which nerve is affected by tumor?
The right and left recurrent laryngeal nerves loops around the right subclavian artery and the arch of the aorta, respectively. These nerves then travel superioly in the tracheoesophageal groove to the larynx.
The external laryngeal nerve (damage can occur during thyroidectomy) will result in loss of innervation to the cricothyroid muscle with resultant vocal weakness.
Cardiac pain is referred in some cases to the mandible and the region of the TMJ. Cutaneous sensation over the angle of the mandible is normally supplied by which nerve?
The great auricular nerve is derived from C2 and C3 and supplies the skin over the angle of the mandible up to the level of the TMJ.
Patient has enlarged cervical lymph nodes. Which lymph nodes of the neck is most frequently associated with malignant tumors of the GI tract?
The supraclavicular lmph node on the left side is associated with the thoracic duct. The thoracic duct receives lymph from below the diaphragm, including the GI tract.
Patient has DiGeorge syndrome. Failure of neural crest cells to migrate normally into which areas best explains the recurrent infections and hypocalcemia?
DiGeorge syndrome occurs due to failure of differentiation of the 3rd and 4th pouches.
Patient has soft, midline mass on his neck. CT reveals a fluid-filled mass. Persistence of which embryologic structure most likely accounts for this mass?
Thyroglossal duct cysts are due to the failure of obliteration of the thyroglossal duct. The thyroglossal duct is formed as the thyroid primordium descends from the posterior aspect of the tongue to its usual location.
Patient was unable to shrug his shoulder on the right side and turn his head to the left. A CT scan showed a large aneurysm of an artery compressing the nerve responsible for his symptoms. in which artery was the aneurysm?
SCM and trapezius muscles are supplied by the spinal accessory nerve, which enters the skull via the foramen magnum. The posterior inferior cerebellar artery is the artery nearest the accessory nerve.
