The occipital condyles are undersurface protuberances of the occipital bone in vertebrates, which function in articulation with the superior facets of the atlas vertebra. The inferior nuchal line is a transverse ridge on the external surface of the occipital bone between the superior nuchal line and the foramen magnum. For questions regarding business inquiries. The occipital bone (latin: os occipitale) is a single bone and consists of four parts that surround the foramen magnum. The structures that pass through the foramen magnum are: The foramen magnum is divided into four parts: one basilar part, two condylar parts, and a squamous part. The hypoglossal canal is a bony passage that originates from the lateral part of the occipital bone anterior to the foramen magnum and ends on the outer surface anterior to the occipital condyle. For example, if the occipital bone is misaligned, this also causes misalignment of the spine, causing pain. Its boundary is formed by all the three parts of the occipital bone. The foramen magnum is curved externally and hollow inside. The superior nuchal line is a transverse ridge on the external surface of the occipital bone at the level of the external occipital protuberance. Healy J, Varacallo M. Anatomy, Head and Neck, Foramen Magnum. This website proves to be a great platform for the medical enthusiast and also for those medicos searching to outgrowth their knowledge about the medical field. The articular surfaces of the condyles are convex from before backward and from side to side, and look downward and lateralward. The anteriomedial wall of the condylar canal thickens to join the foramen magnum rim and connect to the occipital condyle. World of Medical Saviours (WOMS) is a website formed by a group of medicos who are embarking to provide facts, tips and knowledge related to health and lifestyle. It is composed of the endocranium and the lower parts of the skull roof. Transmits: an emissary vein connecting sigmoid sinus with veins of the suboccipital triangle. The occipital bone has a variety of functions. It is larger than the upper extremity of femur, is somewhat cuboid in form, but its transverse diameter is greater than its antero-posterior; it consists of two oblong eminences known as the condyles. The hypoglossal canal is a foramen in the occipital bone of the skull. It contains the brainstem and cerebellum. Veins joining the venous plexus of medulla oblongata downward with vertebral plexus of veins. Each lateral part of the occipital bone has an internal and an external surface. Your Scorecard. The occipital bone houses the back part of the brain and is one of seven bones that come together to form the skull. The superior sagittal sinus allows blood to drain from the adjacent parts of the anterior hemisphere to the sinuses. Occipital condyles face downwards. The condyles are oval or reniform (kidney-shaped) in shape, and their anterior extremities, directed forward and medialward, are closer together than their posterior, and encroach on the basilar portion of the bone; the posterior extremities extend back to the level of the middle of the foramen magnum. Wikibuy Review: A Free Tool That Saves You Time and Money, 15 Creative Ways to Save Money That Actually Work. No cookie for you. It is a thick part, quadrilateral in shape and extends upward and forward from the foramen magnum. The posterior and anterior condylar foramina are generally located in front of and behind the condyles. Parts of occipital bone: Squamous part: Expanded part above and behind foramen magnum. The groove for the superior sagittal sinus is a shallow depression on the frontal, parietal, and occipital bones forming a channel for the sagittal superior sinus; its margins come together as it passes downward and become continuous with the frontal crest. This may include: As your brain’s protector, your occipital bone plays an important role in your overall health and life quality. The identification of the location of the fetal occiput is important in delivery. The union of the transverse and sagittal sinuses— the confluence of the sinuses—is indicated by a depression on either side of the protuberance. The posterior section of the bone is often triangular in shape, with the apex pointing upwards. The external surface of the squama of the occipital bone features: The external occipital protuberance is a palpable bony projection in the middle of the occipital bone. The scorecard of a champion. Score . The condyloid process or condylar process is the process on the human mandible and some other species' mandibles that ends in a condyle, the mandibular condyle. The occipital bone is a cranial dermal bone and the main bone of the occiput.It is trapezoidal in shape and curved on itself like a shallow dish. At the upper part is the internal occipital crest, which houses the transverse sinuses. The squamous part of occipital bone, is situated above and behind the foramen magnum, and is curved from above downward and from side to side. The base of the occipital bone articulates with the first cervical vertebra â atlas or C1 â thanks to the condylar part of occiput that anatomically ressambles the processus articularis inferior of cervical vertebra. The hypoglossal nerve (the 12th cranial nerve) spears through the condylar part of the occipital bone. The basilar part is at the front of the foramen magnum and sits next to the dense area of the temporal bone of your skull surrounding the inner ear. Laterally the jugular process presents a rough quadrilateral or triangular area which is joined to the jugular surface of the temporal bone by a plate of cartilage; after the age of twenty-five this plate tends to ossify. On either side of the opening for the brain stem, known as the foramen magnum, two large, bony protuberances, generally known to anatomists as the condyles, allow the muscles of the neck to connect with the back of the skull. The ascending pharyngeal artery is an artery in the neck that supplies the pharynx, developing from the proximal part of the embryonic second aortic arch. Lateral parts of occipital bone shown in red. Chris (from Montreal). It is located next to five of the cranium bones. It also plays a part in your ability to see and interact with the world. Basilar part of occipital bone has two Lateral borders: one on either side; articulates with the petrous part of the temporal bone. The occipital bone overlies the occipital lobes of the cerebrum. I've seen numerous ER doctors, Neurologists and Osteopaths. It also transmits the spinal component of the accessory nerve into the skull. The groove for the sigmoid sinus is located in the posterior cranial fossa, found on the lateral part of the occipital bone, then curving around the jugular process on the mastoid part of the temporal bone, finally, turning sharply on the inner surface of the parietal bone, continuing as the transverse groove. Michael Menna, DO, is a board-certified, active attending emergency medicine physician at White Plains Hospital in White Plains, New York. Resection of the rectus capitis posterior major and minor muscles reveals the bony recess leading to the condylar canal, which is situated posterior and lateral to the occipital condyle. It is the passageway of the central nervous system through the skull that connects the brain to the spinal cord.. The occipital condyles allow the head and neck to move together. They run laterally in a groove along the interior surface of the occipital bone. forms an important bony landmark and is easy. The anterior margin of the foramen gives attachment to the anterior atlantooccipital membrane while the posterior margin to the posterior atlantooccipital membrane. (Squamous part is top half, portion above foramen magnum ... TA98: A02.1.04.010: TA2: 565: FMA: 52860: Anatomical terms of bone [edit on Wikidata] The squamous part of occipital bone, is situated above and behind the foramen magnum, and is curved from above downward and from side to side. The greater wing of the sphenoid bone, or alisphenoid, is a bony process of the sphenoid bone; there is one on each side, extending from the side of the body of the sphenoid and curving upward, laterally, and backward. StatPearls Publishing; 2019 Jan. Ⓒ 2020 About, Inc. (Dotdash) — All rights reserved. Your doctor can recommend a variety of treatments, from medications to physical therapy and surgery. This groove lodges the terminal part of the transverse sinus, and opening into it, close to its medial margin, is the orifice of the condyloid canal. The occipital is generally made up of three distinct parts. The external surface of the lateral part of the occipital bone features the following structures: The occipital condyle is a process on the occipital bone for articulation with the atlas. This begins on the cranial surface of the bone immediately above the foramen magnum, and is directed lateralward and forward above the condyle. They drain from the confluence of sinuses to the sigmoid sinuses, which ultimately connect to the internal jugular vein. It may be partially or completely divided into two by a spicule of bone; it gives exit to the hypoglossal or twelfth cerebral nerve, and entrance to a meningeal branch of the ascending pharyngeal artery. Best of luck. It is immediately superior to the extradural vertebral artery, which makes a loop above the posterior C1 ring to enter the foramen magnum. The condyles are convex and articulating, making them capable of movement. I've been having the same problem for years, pressure and cracking in my occipital bone. It is located next to five of the cranium bones. The foramen magnum is a large oval opening (foramen) in the occipital bone of the skull in humans and various other animals. This opening allows for passage of the spinal cord. Place # 0. The basilar part of the occipital bone has an internal and an external surface. An inferior curved line is typically located below the superior curved line. Condylar parts: Lateral parts lying horizontally, one on each side of foramen magnum bearing the occipital condyles. Trauma to occiput can cause a fracture to a base of the skull, called a basilar skull fracture. The under surface of the jugular process is rough, and gives attachment to the Rectus capitis lateralis muscle and the lateral atlanto-occipital ligament; from this surface an eminence, the paramastoid process, sometimes projects downward, and may be of sufficient length to reach, and articulate with, the transverse process of the atlas. The lower end of medulla oblongata with its meanings. gives attachment to the highest point of the ligamentum nuchae. As a person ages, their occipital bones will fuse to the other bones of their skull. The occipital bone joins with the temporal and parietal bones to make up the back part of the skull. The occipital bone is slightly articulative with the bones around it. It is therefore important to investigate the cause of head and spine symptoms you may be experiencing, especially pain and problems with function and movement. IX (Glossopharyngeal), X (vagus) and Xl (Accessory) cranial nerves. From its borders the mastoid part articulates with two other bones. Jugular tubercle (Tuberculum jugular) : an oval eminence overlying the hypoglossal canal; its posterior part presents a shallow groove for the passage of the glossopharyngeal, vagus and accessory cranial nerves to thc jugular foramen. Because of its location, the occipital bone affects all your body’s movements, as well as your flexibility, stability, and balance. opposite this level, the superior sagittal sinus ends and transverse sinus begins. The condylar canal is a bony passage located in the lateral part of the occipital bone posterior to the occipital condyle transmitting a vein from the sigmoid sinus.