The spinal cord starts at the foramen magnum, where it is continuous with the medulla oblongata, which is the most caudal portion of the brainstem.

It then extends inferiorly through the vertebral canal. In adults, it usually ends at the level of the first or second lumbar vertebra.

The auriculotemporal nerve is irritated by mumps, which results in significant discomfort due to inflammation and swelling of the parotid gland, as well as the stretching of its capsule. Compression caused by swallowing or chewing exacerbates pain.

The tonsils are collections of lymphatic tissue located within the pharynx. They collectively form a ringed arrangement, known as Waldeyer’s ring: pharyngeal tonsil, 2 tubal tonsils, 2 palatine tonsils, and the lingual tonsil.

Lymphatic fluid from the lingual tonsil drains into the jugulodigastric and deep cervical lymph nodes.

Lymphatic fluid from the pharyngeal tonsil drains into the retropharyngeal nodes (which empty into the deep cervical chain), and directly into deep cervical nodes within the parapharyngeal space.

The retropharyngeal and the deep cervical lymph nodes drain the tubal tonsils.

The palatine tonsils drain to the jugulodigastric node, a node of the deep cervical lymph nodes, located inferior to the angle of the mandible.

The fifth cervical nerve passes between the fourth and fifth cervical vertebrae, and the fourth thoracic nerve passes between the fourth and fifth thoracic vertebrae. Therefore, when the cancer metastasizes in this area, they are most likely affected.

The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:
Muscles: thyrohyoid, sternothyroid, sternohyoid muscles
Organs: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid gland
Arteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteries
Veins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veins
Nerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerve

The posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.
Contents:
Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodes
Nerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus

A blowout fracture is an isolated fracture of the orbital walls without compromise of the orbital rims. The common mechanisms are falls, high-velocity ball-related sports, traffic accidents, and interpersonal violence.

The frontal, ethmoidal, sphenoid, zygomatic, and lacrimal bones form the bony structures of the orbit. Medially, the maxillary and the lacrimal bone form the lacrimal fossa. Together with the lamina papyracea of the ethmoid bone, they form the medial wall. The sphenoid bone forms the posterior wall and houses the orbital canal. Lateral to the orbital canal lies the superior orbital fissure housing cranial nerves III, IV, V, and VI. The zygomatic bone forms the lateral wall. Superior and inferior borders are the frontal and maxillary bones. Located around the globe of the eye and attached to it are 6 extraocular muscles; the 4 rectus muscles and the superior and inferior oblique muscles. The fat and connective tissue around the globe help to reduce the pressure exerted by the extraocular muscles.

The goal of treatment is to restore aesthetics and physiological function. The problem with orbital blowout fractures is that the volume of the orbit can be increased, resulting in enophthalmos and hypoglobus. In addition, the orbital tissue and inferior rectus muscle can become trapped by the bony fragments leading to diplopia, limitation of gaze, and tethering. Finally, the orbital injury can lead to retinal oedema, hyphema, and significant loss of vision.

While some cases may be managed with conservative care, others may require some type of surgical intervention.

A cricothyrotomy involves making an opening in the median cricothyroid ligament (the medial part of the cricothyroid membrane), between the cricoid cartilage below and the thyroid cartilage above.

Sensory innervation to the external ear is supplied by both cranial and spinal nerves. Branches of the trigeminal, facial, and vagus nerves (CN V, VII, X) are the cranial nerve components, while the lesser occipital (C2, C3) and greater auricular (C2, C3) nerves are the spinal nerve components involved. The lateral surface of the tympanic membrane, the external auditory canal, and the external acoustic meatus are all innervated by nervus intermedius (a branch of CN VII), the auriculotemporal nerve (CN V3), and the auricular branch of the vagus nerve. The concha receives split innervation from nervus intermedius, the auricular branch of the vagus nerve, and the greater auricular (spinal) nerve. Beyond the concha, the anteromedial and anterosuperior parts of the pinna are innervated by the auriculotemporal nerve, and a portion of the lateral helix by the lesser occipital nerve. The greater auricular nerve provides innervation to the area of the pinna inferolateral to the lobule.

The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:
Muscles: thyrohyoid, sternothyroid, sternohyoid muscles
Organs: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid gland
Arteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteries
Veins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veins
Nerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerve

The posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.
Contents:
Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodes
Nerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus
Of the muscles listed in the options, only the anterior scalene is situated within the posterior triangle of the neck.

At birth, the conus medullaris lies at L3. By the age of 21, it sits at L1/L2.