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Fontanelles
A fontanelle (or fontanel) (colloquially, soft spot) is an anatomical feature of the infant human skull comprising soft membranous gaps ( sutures) between the cranial bones that make up the calvaria of a fetus or an infant. Fontanelles allow for stretching and deformation of the neurocranium both during birth and later as the brain expands faster than the surrounding bone can grow. Premature complete ossification of the sutures is called craniosynostosis. After infancy, the anterior fontanelle is known as the bregma. Structure An infant's skull consists of five main bones: two frontal bones, two parietal bones, and one occipital bone. These are joined by fibrous sutures, which allow movement that facilitates childbirth and brain growth. * Posterior fontanelle is triangle-shaped. It lies at the junction between the sagittal suture and lambdoid suture. At birth, the skull features a small posterior fontanelle with an open area covered by a tough membrane, where the two pari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Skull
The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent parts: the neurocranium and the facial skeleton, which evolved from the first pharyngeal arch. The skull forms the frontmost portion of the axial skeleton and is a product of cephalization and vesicular enlargement of the brain, with several special senses structures such as the eyes, ears, nose, tongue and, in fish, specialized tactile organs such as barbels near the mouth. The skull is composed of three types of bone: cranial bones, facial bones and ossicles, which is made up of a number of fused flat and irregular bones. The cranial bones are joined at firm fibrous junctions called sutures and contains many foramina, fossae, processes, and sinuses. In zoology, the openings in the skull are called fenestrae, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parietal Bone
The parietal bones ( ) are two bones in the skull which, when joined at a fibrous joint known as a cranial suture, form the sides and roof of the neurocranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named from the Latin ''paries'' (''-ietis''), wall. Surfaces External The external surface [Fig. 1] is convex, smooth, and marked near the center by an eminence, the parietal eminence (''tuber parietale''), which indicates the point where ossification commenced. Crossing the middle of the bone in an arched direction are two curved lines, the superior and inferior temporal lines; the former gives attachment to the temporal fascia, and the latter indicates the upper limit of the muscular origin of the temporal muscle. Above these lines the bone is covered by a tough layer of fibrous tissue – the epicranial aponeurosis; below them it forms part of the temporal fossa, and affords attachment to the temporal mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Body
The human body is the entire structure of a Human, human being. It is composed of many different types of Cell (biology), cells that together create Tissue (biology), tissues and subsequently Organ (biology), organs and then Organ system, organ systems. The external human body consists of a human head, head, hair, neck, torso (which includes the thorax and abdomen), Sex organ, genitals, arms, Hand, hands, human leg, legs, and Foot, feet. The internal human body includes organs, Human tooth, teeth, bones, muscle, tendons, ligaments, blood vessels and blood, lymphatic vessels and lymph. The study of the human body includes anatomy, physiology, histology and embryology. The body Anatomical variation, varies anatomically in known ways. Physiology focuses on the systems and organs of the human body and their functions. Many systems and mechanisms interact in order to maintain homeostasis, with safe levels of substances such as sugar, iron, and oxygen in the blood. The body is st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulsating Fontanelle
A pulse, in physiology, is the throbbing of arteries resulting from heartbeat. Pulse, The Pulse or Pulses may also refer to: Botany * Pulse (legume), any agriculturally significant annual leguminous food crop, such as peas, beans, lentils, and chickpeas Electronics and physics * Pulse (physics), a single disturbance through a transmission medium * Pulse (signal processing), a brief change from a baseline value ** Pulse dialing, of a telephone Books and publications * ''Pulse'' (magazine), a medical professional's magazine * ''Pulse!'' (magazine), a music magazine * Pulse (Augustus), a character in the Marvel Comics universe * ''Pulse'' (short story collection), a short story collection by Julian Barnes * ''Pulse'', a book by Robert Frenay * The Pulse, the signal transmitted from cell phones that made people go crazy in Stephen King's novel ''Cell'' * ''The Pulse'' (comics), a Marvel Comics series * ''Pulse'' (webtoon), a Lezhin Comics series Film, television and games F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenoidal Fontanelle
The pterion is the region where the frontal bone, frontal, parietal bone, parietal, temporal bone, temporal, and sphenoid bone, sphenoid bones join. It is located on the side of the skull, just behind the temple (anatomy), temple. It is also considered to be the weakest part of the skull, which makes it clinically significant, as if there is a Bone fracture, fracture around the pterion it could be accompanied by an epidural hematoma. Structure The pterion is located in the temporal fossa, approximately 2.6 cm behind and 1.3 cm above the posterolateral margin of the frontozygomatic suture. It is the junction between four bones: * the parietal bone. * the Squamous part of temporal bone, squamous part of temporal bone. * the Greater wing of sphenoid bone, greater wing of sphenoid bone. * the frontal bone. These bones are typically joined by five cranial sutures: * the sphenoparietal suture joins the sphenoid and parietal bones. * the coronal suture joins the frontal bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mastoid Fontanelle
The asterion is a meeting point between three sutures between bones of the skull. It is an important surgical landmark. Structure In human anatomy, the asterion is a visible ( craniometric) point on the exposed skull. It is just posterior to the ear. It is the point where three cranial sutures meet: * the lambdoid suture. * parietomastoid suture. * occipitomastoid suture. It is also the point where three cranial bones meet: * the parietal bone. * the occipital bone. * the mastoid portion of the temporal bone. In the adult, it lies 4 cm behind and 12 mm above the center of the entrance to the ear canal. Its relation to other anatomical structures is fairly variable. Clinical significance Neurosurgeons may use the asterion to orient themselves, in order to plan safe entry into the skull for some operations, such as when using a retro-sigmoid approach. The asterion marks the junction of the transverse and the sigmoid sinuses Etymology The asterion receives its name from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleidocranial Dysostosis
Cleidocranial dysostosis (CCD), also called cleidocranial dysplasia, is a congenital disorder, birth defect that mostly affects the bones and teeth. The collarbones are typically either poorly developed or absent, which allows the shoulders to be brought close together. The front of the skull often does not close until later, and those affected are often shorter than average. Other symptoms may include a prominent forehead, wide set eyes, abnormal teeth, and a flat nose. Symptoms vary among people; however, cognitive function is typically unaffected. The condition is either heredity, inherited or occurs as a new mutation. It is inherited in an autosomal dominant manner. It is due to a defect in the RUNX2 gene which is involved in bone formation. Diagnosis is suspected based on symptoms and X-rays with confirmation by genetic testing. Other conditions that can produce similar symptoms include mandibuloacral dysplasia, pyknodysostosis, osteogenesis imperfecta, and Hajdu-Cheney synd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronal Suture
The coronal suture is a dense, fibrous connective tissue joint that separates the two parietal bones from the frontal bone of the skull. Structure The coronal suture lies between the paired parietal bones and the frontal bone of the skull. It runs from the pterion on each side. Nerve supply The coronal suture is likely supplied by a branch of the trigeminal nerve. Development The coronal suture is derived from the paraxial mesoderm. Clinical significance If certain bones of the skull grow too fast then premature fusion of the sutures, craniosynostosis, may occur. This can result in skull deformities. These deformities include: * Brachycephaly (both sides) * Plagiocephaly (one side only) * Oxycephaly (both sides) References * "Sagittal suture." ''Stedman's Medical Dictionary, 27th ed.'' (2000). * Moore, Keith L., and T.V.N. Persaud. ''The Developing Human: Clinically Oriented Embryology, 7th ed.'' (2003). Additional images File:Coronal suture - ani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anterior Fontanelle
The anterior fontanelle (bregmatic fontanelle, frontal fontanelle) is the largest fontanelle, and is placed at the junction of the sagittal suture, coronal suture, and frontal suture; it is lozenge-shaped, and measures about 4 cm in its antero-posterior and 2.5 cm in its transverse diameter. The fontanelle allows the skull to deform during birth to ease its passage through the birth canal and for expansion of the brain after birth. The anterior fontanelle typically closes between the ages of 12 and 18 months. Clinical significance The anterior fontanelle is useful clinically. Examination of an infant includes palpating the anterior fontanelle. A sunken fontanelle indicates dehydration whereas a very tense or bulging anterior fontanelle indicates raised intracranial pressure Intracranial pressure (ICP) is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue. ICP is measured in millimeters of mercury ( mmHg) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambda (anatomy)
The lambda is the meeting point of the sagittal suture and the lambdoid suture. This is also the point of the occipital angle. It is named after the Greek letter lambda. Structure The lambda is the meeting point of the sagittal suture and the lambdoid suture. It may be the exact midpoint of the lambdoid suture, but often deviates slightly from the midline. This is also the point of the occipital angle. Development In the foetus, the lambda is membranous, and is called the posterior fontanelle. Etymology The lambda is named after the Greek letter lambda Lambda (; uppercase , lowercase ; , ''lám(b)da'') is the eleventh letter of the Greek alphabet, representing the voiced alveolar lateral approximant . In the system of Greek numerals, lambda has a value of 30. Lambda is derived from the Phoen ..., whose lowercase form (λ) resembles the junction formed by the sutures. References External links * Skull {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Membrane
A biological membrane, biomembrane or cell membrane is a selectively permeable membrane that separates the interior of a cell from the external environment or creates intracellular compartments by serving as a boundary between one part of the cell and another. Biological membranes, in the form of eukaryotic cell membranes, consist of a phospholipid bilayer with embedded, integral and peripheral proteins used in communication and transportation of chemicals and ions. The bulk of lipids in a cell membrane provides a fluid matrix for proteins to rotate and laterally diffuse for physiological functioning. Proteins are adapted to high membrane fluidity environment of the lipid bilayer with the presence of an annular lipid shell, consisting of lipid molecules bound tightly to the surface of integral membrane proteins. The cell membranes are different from the isolating tissues formed by layers of cells, such as mucous membranes, basement membranes, and serous membranes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambdoid Suture
The lambdoid suture, or lambdoidal suture, is a dense, fibrous connective tissue joint on the posterior aspect of the skull that connects the parietal bones with the occipital bone. It is continuous with the occipitomastoid suture. Structure The lambdoid suture is between the paired parietal bones and the occipital bone of the skull. It runs from the asterion on each side. Nerve supply The lambdoid suture may be supplied by a branch of the supraorbital nerve, a branch of the frontal branch of the trigeminal nerve. Clinical significance At birth, the bones of the skull do not meet. If certain bones of the skull grow too fast, then craniosynostosis (premature closure of the sutures) may occur. This can result in skull deformities. If the lambdoid suture closes too soon on one side, the skull will appear twisted and asymmetrical, a condition called "plagiocephaly". Plagiocephaly refers to the shape and not the condition. The condition is craniosynostosis. The lambdoid s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
