Growth of the Cranial Base HHiH
D. Dixon Andrew, A.N. Hoyte David, Ronning Olli in Fundamentals of Craniofacial Growth, 2017
The cranial base is derived from the primitive chondrocranium (De Beer, 1937), and comprises the midline bones and the cranial fossae — anterior, middle and posterior — which in large part also originate in the chondrocranium, with additions, in certain bones, ossifying in membrane. The midline bones are the basioccipital, sphenoid — comprising at various stages in different animals and man a basisphenoid (or postsphenoid) and a presphenoid — and the ethmoid at the junction of base and face. The anterior cranial fossa is roofed-in in front by the frontal bone, whose orbital plates form most of the floor of the fossa, meeting the cribriform plate of the ethmoid in the midline, and the lesser wings of the sphenoid behind. The sphenoid bone could be said to be the linch-pin of the middle fossa, with its greater wing extending laterally to floor the fossa, anteriorly to wall in the orbit posterolaterally, and further laterally to share with the squamosal the wall of the temporal fossa. Separating the middle from the posterior fossa is the obliquely lying petrous part of the temporal bone (see Chapter 12). The parts of the occipital bone derived from the chondrocranium complete the floor and walls of the posterior fossa, surrounding the foramen magnum — the basioccipital, here forming with the posterior aspect of the sphenoid bone the clivus, the exoccipitals, and the supraoccipital. The membranous interparietal bone which joins with supraoccipital to form the occipital squama belongs more properly to the skull vault, and will not be considered here.
Head and Neck
Bobby Krishnachetty, Abdul Syed, Harriet Scott in Applied Anatomy for the FRCA, 2020
Carotid systemOriginThe right common carotid artery arises from a bifurcation of the brachiocephalic trunk (the right subclavian artery is the other branch).The left common carotid artery branches directly from the arch of aorta.The left and right common carotid arteries ascend up the neck, lateral to the trachea and the oesophagus. They do not give off any branches in the neck.CourseAt the level of the superior margin of the thyroid cartilage (C4), the carotid arteries split into the external and internal carotid arteries. The internal carotid arteries do not supply any structures in the neck, entering the cranial cavity via the carotid canal in the petrous part of the temporal bone.
Physical Recovery
Stijn Geerinck in Reconstructing Identity After Brain Injury, 2022
Partial paralysis of my body prevented me from closing my left eye. This didn’t get any better, contrary to my arm and leg. I continuously had to use eye-drops and to apply ointment before going to sleep. My right eye socket was shattered and had been removed, which made my eye sink away into my face. My left ear was beyond the help of even a hearing aid. It had lost its function to a fracture of the petrous part of the temporal bone and to a severely damaged cochlea. They only broke the news to me 14 months after the accident. From now on, I had to make do with my right ear, so I wanted extra protection. I ordered custom earplugs to continue to play music and do my job as a teacher, afraid of losing my hearing entirely.
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.
Clinical characteristics of petrosal cholesteatoma and value of MRI-DWI in the diagnosis
Published in Acta Oto-Laryngologica, 2020
Wenjing Zuo, Fangyuan Wang, Shiming Yang, Dongyi Han, Pu Dai, Weidong Shen, Zhaohui Hou, Weiju Han
Petrous cholesteatoma of the temporal bone refers to cholesteatoma caused by various causes that invades the petrous part of the temporal bone and reaches the medial range of the inner ear. It was rare in the past, but now the incidence rate is higher than before [11]. Because of its deep location and lack of specific clinical symptoms, it is not easy to get an early diagnosis. And it is adjacent to important structures, such as internal carotid artery, facial nerve, labyrinth, sigmoid sinus, jugular bulb, posterior and middle fossa dura mater, posterior cranial nerves and etc [12]. Cholesteatoma is divided into congenital cholesteatoma and acquired cholesteatoma. Congenital cholesteatoma is the development of embryonic ectodermal tissue in the skull. The pathological features are squamous epithelium and keratocytes which gathered in the middle ear mastoid cavity, petroclival apex or cerebellopontine angle. Although it is a benign lesion, it can also destroy the normal structure of the surrounding area and cause serious complications, even death. At present, the exact incidence, etiology and pathogenesis of the disease are not clear [13]. The pathological features of acquired cholesteatoma of middle ear are mainly as follows: the lamellar squamous epithelium invades the middle ear cavity, forms the capsule bag, and abnormal proliferates, which results in the excessive keratosis of the squamous epithelium falling off and accumulating, gradually expanding and involving the surrounding tissues and structures. It can cause serious bone resorption damage and leading to hearing loss, vertigo, tinnitus, hemifacial spasm, facial paralysis, diplopia, ear leakage, and even threaten the lives of patients [1].
Foramen caecum medullae oblongatae in the history of anatomical terminology
Published in Journal of the History of the Neurosciences, 2020
František Šimon, Florian Steger
The term foramen caecum itself was used several times in different ways within anatomical terminology, meaning not only an extension of the spinal cord but also the frontal bone (foramen caecum ossis frontalis) and the tongue (foramen caecum linguae) and it did, in fact, occur in anatomical terminology prior to Soemmerring. According to Galen (See Galenos 1821, II 838 K., and Mayo 1966, 330) the ancient anatomists called the hollow in the petrous part of the temporal bone (today foramen stylomastoideum) tyflon (i.e. caecum), because they were “not able to perfectly bore out the helix through which the facial nerve penetrates to the exterior behind the external ear.”
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