Sagittal Section of Head and Neck with Infratemporal Fossa and Carotid Sheath Dissection - Erler Zimmer
This 3D model complements the H 11 and H 12 head and neck specimens by offering a view of the endocranial cavity without the brain, along with a lateral dissection that includes neck anatomy.
In the midsagittal section, the absence of the brain (with the medulla oblongata reflected inferiorly) provides a clear view of the dura mater lining the endocranial cavity. This view includes the tentorium cerebelli, extending from the transverse sinus to its attachment to the clinoid process of the sphenoid bone. Several cranial nerves, such as the optic (CN II), oculomotor (CN III), trigeminal (CN V), abducens (CN VI), and combined facial (CN VII) and vestibulocochlear (CN VIII) nerves, can be observed as they pierce the dura. The pituitary gland is visible in cross-section within the sella turcica, and the left vertebral artery ascends in the posterior cranial fossa.
The lateral dissection of the face retains some superficial structures while revealing the anatomy within the infratemporal fossa. The facial vein and facial artery are preserved but separated from any superficial fascia or facial expression muscles. They traverse the corpus of the mandible and the buccinator muscle. Most of the ascending ramus of the mandible and the zygomatic arch have been removed to showcase infratemporal fossa anatomy. This includes the inferior alveolar artery and nerve, lingual nerve (resting on the medial pterygoid), posterior deep temporal artery (resting on the lateral pterygoid), and the articulation of the mandibular condyle with the glenoid fossa. The terminal part of the external carotid artery, the initial portion of the maxillary artery, and the superficial temporal artery are visible.
Posterior to the infratemporal region, the facial nerve (CN VII) briefly appears adjacent to the posterior belly of the digastric muscle. The posterior belly of the digastric muscle runs superficially and obscures the internal and external carotid arteries and the internal jugular vein, all of which have been dissected from the carotid sheath (alongside the vagus nerve [CN X]). At the mandibular angle and along the inferior margin of the mandibular corpus, the hypoglossal nerve (CN XII) rests close to the central tendon of the digastric and the external carotid artery. In the anterior region, the facial artery is integrated into the submandibular gland before crossing the mandibular corpus, where you can observe the lingual artery and anterior belly of the digastric muscle. A set of superficial veins descends into the neck, forming a presumed external jugular vein (though displaced due to the removal of the retromandibular vein and sternocleidomastoid muscle). It lies too posteriorly to be considered an anterior jugular vein.
In the neck region of the specimen, the hyoid bone is situated just beneath the submandibular gland and receives infrahyoid muscles superficially, above a robust thyroid gland. At the cut section of the dissection, the underlying larynx can also be observed. Posterior to the carotid sheath structures, cutaneous branches from the cervical plexus extend over the scalene muscles, and near the lower margin of the specimen, the upper roots of the brachial plexus are preserved adjacent to the exposed internal jugular vein.
