Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer ). See the entire definition of Abnormal
Amino acid: One of the 20 building blocks of protein . The sequence of amino acids in a protein and, hence, the function of that protein are determined by the genetic code in the DNA . See the entire definition of Amino acid
Autosomal: Pertaining to a chromosome that is not a sex chromosome; relating to any one of the chromosomes save the sex chromosomes. See the entire definition of Autosomal
Autosomal dominant: A pattern of inheritance in which an affected individual has one copy of a mutant gene and one normal gene on a pair of autosomal chromosomes. (In contrast, autosomal recessive diseases require that the individual have two copies of the mutant gene.) Individuals with autosomal dominant diseases have a 50-50 chance of passing the mutant gene and therefore the disorder onto each of their children. Examples of autosomal dominant diseases include Huntington disease, neurofibromatosis, and polycystic kidney disease.
Bone density: Bone density is the amount of bone tissue in a certain volume of bone. It can be measured using a special x-ray called a quantitative computed tomogram.
Brachycephaly: A short head, one that is short in diameter from front to back. See the entire definition of Brachycephaly
Cartilage: Firm, rubbery tissue that cushions bones at joints. A more flexible kind of cartilage connects muscles with bones and makes up other parts of the body, such as the larynx and the outside parts of the ears.
Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane . See the entire definition of Cell
Cleidocranial dysostosis: A genetic (inherited) disorder of bone development characterized by: - Absent or incompletely formed collar bones (the "cleido-" part refers to the clavicles, the collar bones) The child with this disorder can bring its shoulders together or nearly so; and
- Typical cranial and facial abnormalities with square skull, late closure of the sutures of the skull, late closure of the fontanels (the soft spots), low nasal bridge, delayed eruption of the teeth, abnormal permanent teeth, etc.
See the entire definition of Cleidocranial dysostosis
Cleidocranial dysplasia : A genetic (inherited) disorder of bone development characterized by: - Absent or incompletely formed collar bones (the "cleido-" part refers to the clavicles, the collar bones) The child with this disorder can bring its shoulders together or nearly so; and
- Typical cranial and facial abnormalities with square skull, late closure of the sutures of the skull, late closure of the fontanels (the soft spots), low nasal bridge, delayed eruption of the teeth, abnormal permanent teeth, etc.
See the entire definition of Cleidocranial dysplasia
Cysts: Cysts are abnormal, closed sac-like structures within a tissue that contain a liquid, gaseous, or semisolid substance. Cysts can occur anywhere in the body and can vary in size. The outer, or capsular, portion of a cyst is termed the cyst wall.
DNA: Deoxyribonucleic acid. One of two types of molecules that encode genetic information. (The other is RNA . In humans DNA is the genetic material; RNA is transcribed from it. In some other organisms, RNA is the genetic material and, in reverse fashion, the DNA is transcribed from it.) See the entire definition of DNA
Dysplasia: Abnormal in form. From the Greek dys- (bad, disordered, abnormal) and plassein (to form). For example, retinal dysplasia is abnormal formation of the retina during embryonic development. See the entire definition of Dysplasia
Ear: The hearing organ. There are three sections of the ear, according to the anatomy textbooks. They are the outer ear (the part we see along the sides of our head behind the temples), the middle ear, and the inner ear. But in terms of function, the ear has four parts: those three and the brain. Hearing thus involves all parts of the ear as well as the auditory cortex of the brain. The external ear helps concentrate the vibrations of air on the ear drum and make it vibrate. These vibrations are transmitted by a chain of little bones in the middle ear to the inner ear. There they stimulate the fibers of the auditory nerve to transmit impulses to the brain. See the entire definition of Ear
Flat feet: A condition of the feet in which the arch of the instep is flattened and the entire sole touches the ground. See the entire definition of Flat feet
Fracture: A break in bone or cartilage. Although usually the result of trauma, a fracture can be caused by an acquired disease of bone such as osteoporosis or by abnormal formation of bone in a disease such as osteogenesis imperfecta ("brittle bone disease"). Fractures are classified according to their character and location as, for example, a greenstick fracture of the radius. See the entire definition of Fracture
Gene: The basic biological unit of heredity . A segment of deoxyribonucleic acid (DNA) needed to contribute to a function. See the entire definition of Gene
Genes: The basic biological units of heredity . Segments of deoxyribonucleic acid (DNA) needed to contribute to a function. See the entire definition of Genes
Genetic: Having to do with genes and genetic information.
Genetics: The scientific study of heredity . Genetics pertains to humans and all other organisms. So, for example, there is human genetics, mouse genetics, fruitfly genetics, etc. See the entire definition of Genetics
Jaw: The bones below the mouth (the mandible) and the bone above the mouth just above the mouth (the maxilla). The word jaw comes from the Anglo-Saxon ceowan meaning to chew. See the entire definition of Jaw
Motor: In medicine, having to do with the movement of a part of the body. Something that produces motion or refers to motion. For example, a motor neuron is a nerve cell that conveys an impulse to a muscle causing it to contract. The term "motor" today is also applied to a nerve that signals a gland to secrete. Motor is as opposed to sensory.
Mutation: A permanent change, a structural alteration, in the DNA or RNA . In humans and many other organisms, mutations occur in DNA. However, in retroviruses like HIV , mutations occur in RNA which is the genetic material of retroviruses. See the entire definition of Mutation
Nose: The external midline projection from the face. See the entire definition of Nose
Osteopenia: Mild thinning of the bone mass, but not as severe as osteoporosis . Osteopenia results when the formation of bone (osteoid synthesis) is not enough to offset normal bone loss (bone lysis). Osteopenia is generally considered the first step along the road to osteoporosis, a serious condition in which bone density is extremely low and bones are porous and prone to shatter. Diminished bone calcification, as seen on plain X-ray film, is referred to as osteopenia, whether or not osteoporosis is present. The diagnosis of osteopenia may also be made by a special X-ray machine for bone density testing. See the entire definition of Osteopenia
Osteoporosis: Thinning of the bones with reduction in bone mass due to depletion of calcium and bone protein . Osteoporosis predisposes a person to fractures, which are often slow to heal and heal poorly. It is more common in older adults, particularly post-menopausal women; in patients on steroids; and in those who take steroidal drugs. Unchecked osteoporosis can lead to changes in posture , physical abnormality (particularly the form of hunched back known colloquially as " dowager's hump "), and decreased mobility. See the entire definition of Osteoporosis
Pelvis: The lower part of the abdomen located between the hip bones.
Protein: A large molecule composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein. See the entire definition of Protein
Scoliosis: Sideways ( lateral ) curving of the spine (the backbone ). See the entire definition of Scoliosis
Sinus: 1. An air-filled cavity in a dense portion of a skull bone. The sinuses decrease the weight of the skull. The sinuses are formed in four right-left pairs. The frontal sinuses are positioned behind the forehead, while the maxillary sinuses are behind the cheeks. The sphenoid and ethmoid sinuses are deeper in the skull behind the eyes and maxillary sinuses. The sinuses are lined by mucous-secreting cells. Air enters the sinuses through small opening in bone called ostia. If an ostium is blocked, air cannot pass into the sinus and likewise mucous cannot drain out. See also: Sinusitis . See the entire definition of Sinus
Skeletal: Pertaining to the skeleton, the bones of the body which collectively provide the framework for the body.
Skull: The skull is a collection of bones which encase the brain and give form to the head and face. The bones of the skull include the following: the frontal, parietal, occipital, temporal, sphenoid, ethmoid, zygomatic, maxilla, nasal, vomer, palatine, inferior concha, and mandible. See the entire definition of Skull
Spine: 1) The column of bone known as the vertebral column, which surrounds and protects the spinal cord. The spine can be categorized according to level of the body: i.e., cervical spine (neck), thoracic spine (upper and middle back), and lumbar spine (lower back). See also vertebral column. 2) Any short prominence of bone. The spines of the vertebrae protrude at the base of the back of the neck and in the middle of the back. These spines protect the spinal cord from injury from behind.
Syndrome: A set of signs and symptoms that tend to occur together and which reflect the presence of a particular disease or an increased chance of developing a particular disease. See the entire definition of Syndrome
Transcription: Making an RNA copy from a sequence of DNA (a gene). Transcription is the first step in gene expression.
- Sinus Infection - Learn about sinus infections and inflammation of the sinuses (also known as sinusitis) with information written by doctors for patients. Includes causes, symptoms, diagnosis, and complications of sinus infection.
- Scoliosis - Scoliosis causes abnormal curvature of the spine. Get the facts on scoliosis types and symptoms. Treatment may involve exercises, surgery, physical therapy, yoga and massage.
- Otitis Media - Learn more about otitis media and how this acute or chronic middle ear infection, that mostly affects children, is caused, diagnosed and treated on MedicineNet.com
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