Head and Neck Muscles
Eve K. Boyle, Vondel S. E. Mahon, Rui Diogo in Handbook of Muscle Variations and Anomalies in Humans, 2022
Macalister (1875) notes that Luschka considered constrictor pharyngis superior a composite muscle comprised of four parts: pterygo-pharyngeus, bucco-pharyngeus, mylo-pharyngeus, and glosso-pharyngeus. The buccopharyngeal part may connect with buccinator (Macalister 1875; Shimada and Gasser 1989). The extent of the origin from the pterygoid hamulus may vary (Macalister 1875). It may have an origin from the medial pterygoid plate (Standring 2016) or the petrous part of the temporal bone (Bergman et al. 1988; Sakamoto 2009, 2016a). Stylopharyngeus may course transversely and join the superior pharyngeal constrictor (Choi et al. 2020). A portion of the superior constrictor may run longitudinally and pass between the superior and middle constrictors, or merge with the middle constrictor and the contralateral constrictor muscles (Choi et al. 2020). An accessory muscle, petropharyngeus, may also be joined with the superior constrictor (Macalister 1875; Knott 1883a; see the entry for this muscle). A slip from genioglossus to constrictor pharyngis superior is referred to as geniopharyngeus (Winslow) (Macalister 1875; Knott 1883a; Bergman et al. 1988; Patel and Loukas 2016). Pterygopharyngeus externus, which attaches to the pterygoid hamulus, may be present as a distinct muscle (Sakamoto 2016a).
Examine the cranial nerves
Hani TS Benamer in Neurology for MRCP PACES, 2019
Q: What are the causes of LMN VIIth nerve palsy? Bell’s palsy.Ramsey–Hunt syndrome due to herpes zoster infection.Cerebello-pontine angle lesion such as acoustic neuroma (if nerves V and/or VIII are affected).Head injuries involving the petrous bone.Middle ear infection.Parotid tumour.Parotid gland or ear surgery.Pontine lesion such as tumour if nerves V and/or VI are involved.Rarely caused by multiple sclerosis and neurosarcoid.If it is bilateral, consider Guillain–Barré syndrome, neurosarcoid and Lyme disease.
Imaging of the nasopharynx, face and neck
Sarah McWilliams in Practical Radiological Anatomy, 2011
Fig. 2.21 Axial and coronal petrous bone. (a) Axial CT shows the basal turn of the cochlea (1). The incudomalleolar complex in the epitympanic recess (2); aditus or opening to the mastoid air cells (3); vestibule with horizontal semicircular canal (4). (b) Axial T2-weighted MRI: basal turn of cochlea (1). Nerves VII and VIII in internal auditory canal (5). (c) Coronal T2-weighted MRI: cochlea (1), third ventricle (6), basilar artery (7), internal capsule (8) and insula (9). (d) Diagram of the inner and middle ear.
Anatomical study of presigmoid-retrolabyrinthine approach based on temporal bone high-resolution CT
Published in Acta Oto-Laryngologica, 2019
Xinping Hao, Yongxin Li, Danmo Cui, Biao Chen, Yunfu Liu, Bentao Yang
The retrolabyrinthine space of the petrous bone is a small three-dimensional space. The boundary of the space that can be identified in the surgery with the presigmoid retrolabyrinthine approach: the anterior border is the posterior semicircular canal plane, and the posterior border is the posterior edge of the petrous bone. The upper border is the middle cranial fossa meninges, the lower border is the vestibular aqueducts, the shallow interface is the apex of the posterior semicircular canal, and the deep interface is the posterior edge of the inner auditory canal. The volume of the retrolabyrinthine space matches the actual surgical cavity during the surgery. The larger the volume that can be removed, the larger the operative field will be. The larger the operative field, the more likely it is to increase the inclination of the instrument because changes in the small distance between the structures of the skull base can lead to significant movement restrictions on the surgeon, lead to retraction of the brain tissue, and even lead to incomplete removal of the tumor. The space behind the petrous bone is very narrow, and not all patients with acoustic neuromas are suitable for this approach. Before deciding whether to implement the approach, it is necessary to examine the patient’s anatomy and possible anatomical variations. Compared with MRI, high-resolution CT(HRCT) might be an optimal preoperative assessment for complicated skull base specimen [3].
Petrous bone cholesteatoma: our experience of 51 patients with emphasis on cochlea preservation and use of endoscope
Published in Acta Oto-Laryngologica, 2019
Zhen Gao, Gang Gao, Wei-Dong Zhao, Xian-Hao Jia, Jing Yu, Chun-Fu Dai, Bing Chen, Fang-Lu Chi, Jing Wang, Ya-Sheng Yuan
Petrous bone cholesteatoma (PBC) is defined as cholesteatomas developed in the petrous portion of temporal bone. PBC can be congenital or, more frequently acquired. As a benign disease with slow growth, there may be no symptoms of PBC at its early onset. However, for its deep location in the petrous bone which is surrounded by several important structures such as inner ear, facial nerve, internal carotid artery and dura, as PBC gradually enlarges, it can bring disastrous consequences. With the erosive and expansile properties of PBC [1], it can erode ossicles, fallopian canal or labyrinthine, leading to facial paralysis and hearing decline. It even has the chance to penetrate the petrous bone and invade into the region of cerebellopontine angle which will cause much severer symptoms [2].
Ciliated cell observation by SEM on the surface of human incudo-malleolar-joint articular cartilage: are they a new chondrocyte phenotype?
Published in Acta Oto-Laryngologica, 2019
Michela Relucenti, Selenia Miglietta, Edoardo Covelli, Pietro Familiari, Ezio Battaglione, Giuseppe Familiari, Maurizio Barbara
The middle ear cavity is a bony space in the petrous part of the temporal bone where the ossicular chain (malleus, incus, stapes) is also accommodated. It communicates with the nasopharynx via the Eustachian tube and with the mastoid air–cell complex via the antrum cell. In addition, the mucosa lining the tympanic cavity, consisting in a flattened squamous epithelium with a thin lamina propria, closely adherent to the underlying bone, is in continuation with those of the Eustachian tube and of the mastoid air cells. This mucosal lining envelops the ossicular chain, including the incus, the middle component of the ossicular chain which articulates with the malleus by means of a saddle joint containing an intra-articular disc. The human incudo-malleolar joint is a non-weight-bearing joint described in detail by Gussen [1] and Stockwell [2] using light microscopy.
Related Knowledge Centers
- Inner Ear
- Occipital Bone
- Skull
- Sphenoid Bone
- Temporal Bone
- Endocranium
- Squamous Part of Temporal Bone
- Mastoid Part of The Temporal Bone
- Greater Wing of Sphenoid Bone
- Basilar Part of Occipital Bone