| cranial epidural space | The intracranial dura mater, consisting of two layers: the outer periosteal layer which normally always adheres to the periosteum of the bones of the cranial vault; and the inner meningeal layer which in most places is fused with the outer. The two layers separate to accommodate meningeal vessels and large venous (dural) sinuses. The meningeal layer is also involved in the formation of the various dural folds, such as the falx cerebri and tentorium cerebelli and is comparable to and continuous with the dural mater of the spinal cord. The cranial epidural space is then a potential space between the bone and the combined periosteum/periosteal layer of the dura mater realised only pathologically and is neither continuous with or comparable to the vertebral epidural space. Synonym: dura mater cranialis, dura mater encephali, cerebral part of dura mater, cranial epidural space. (05 Mar 2000) |
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| cranial flexure | The sharp, ventrally concave bend in the developing midbrain of the embryo. Synonym: cerebral flexure, cranial flexure, mesencephalic flexure. (05 Mar 2000) |
| cranial fontanels | <anatomy> The membranous intervals between the angles of the cranial bones in the infant; they include the midline anterior fontanel and posterior fontanel, and the paired sphenoidal fontanel and mastoid fontanel. Synonym: fonticuli cranii. (05 Mar 2000) |
| cranial fossa, posterior | The posterior subdivision of the floor of the cranial cavity, lodging the cerebellum, pons, and medulla oblongata. It is formed by portions of the sphenoid, temporal, parietal, and occipital bones. (12 Dec 1998) |
| cranial index | The ratio of the maximal breadth to the maximal length of the skull, obtained by the formula: (breadth × 100)/length. (05 Mar 2000) |
| cranial irradiation | The exposure of the head to roentgen rays or other forms of radioactivity for therapeutic or preventive purposes. (12 Dec 1998) |
| cranial mononeuropathy III | (compression type) A disorder involving vision changes and eyelid drooping associated with a decreased functioning of cranial nerve III. Damage is usually caused by compression of the nerves from localised lesions or a swelling in the area of the nerve. Examples include cerebral aneurysms and tumours Symptoms include a drooping eyelid and double vision. (diabetic type) A disorder involving vision changes and eyelid drooping associated with a decreased functioning of cranial nerve III as a complication of diabetes. Symptoms include a drooping eyelid and double vision. Good control of blood sugars can reduce the incidence of this complication. (27 Sep 1997) |
| cranial mononeuropathy vi | A disorder involving vision changes that are associated with the decreased function of cranial nerve VI. Often this form of nerve damage is associated with diabetes, tumours of the VI nerve or increased intracranial pressure. Trauma and stroke may also damage the VI cranial nerve. Symptoms include double vision when looking to one side. (27 Sep 1997) |
| cranial mononeuropathy vii | A disorder which involves drooping of the face and the decreased ability to move one side of the face. Causes include isolated damage to the facial nerve, HIV infection, sarcoidosis and Lyme disease. Bell's palsy is a dysfunction of the facial nerve for reason unknown. (27 Sep 1997) |
| cranial nerves | <anatomy> There are 12 cranial nerves. The olfactory nerve, optic nerve, occulomotor nerve, trochlear nerve, trigeminal nerve, abducent nerve, facial nerve, vestibulocochlear nerve, glossopharyngeal nerve, vagus nerve, accessory nerve and the hypoglossal nerve. (18 Nov 1997) |
| cranial neuropore | The temporary opening at the extreme rostral (cephalic) end of the early embryonic forebrain; closes at the 20th somite stage. Synonym: anterior neuropore, cranial neuropore. (05 Mar 2000) |
| cranial roots | <anatomy, nerve> The roots of the accessory nerve which arise from the medulla; the nerve fibres of the cranial root join the intracranial portion of the vagus nerve and are distributed to the pharyngeal plexus, providing the motor innervation of the soft palate (except the tensor veli palati) and the pharynx. Synonym: pars vagalis nervi accessorii, radices craniales, accessory portion of spinal accessory nerve, cranial roots, vagal part of accessory nerve, vagal part. (05 Mar 2000) |
| cranial sinuses | Large endothelium-lined venous channels situated between the two layers of the dura mater; they are devoid of valves. (12 Dec 1998) |
| cranial sutures | A type of fibrous joint between bones of the head. (12 Dec 1998) |
| cranial synchondroses | The cartilaginous joints of the skull; these include sphenoethmoidal synchondrosis, spheno-occipital synchondrosis, sphenopetrosa synchondrosis, petro-occipital synchondrosis, anterior intraoccipital and posterior intraoccipital synchondrosis. Synonym: synchondroses cranii. (05 Mar 2000) |