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Thyroid Agenesis
Thyroid dysgenesis is a cause of congenital hypothyroidism where the thyroid is missing, ectopic, or severely underdeveloped. It should not be confused with iodine deficiency, or with other forms of congenital hypothyroidism, such as thyroid dyshormonogenesis, where the thyroid is present but not functioning correctly. Congenital hypothyroidism caused by thyroid dysgenesis can be associated with PAX8. __TOC__ Ectopic thyroid An ''ectopic thyroid'', also called ''accessory thyroid gland'', is a form of thyroid dysgenesis in which an entire or parts of the thyroid located in another part of the body than what is the usual case. A completely ectopic thyroid gland may be located anywhere along the path of the descent of the thyroid during its embryological development, although it is most commonly located at the base of the tongue, just posterior to the foramen cecum of the tongue. In this location, an aberrant or ectopic thyroid gland is known as a ''lingual thyroid''. If the thyro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scintigraphy
Scintigraphy (from Latin ''scintilla'', "spark"), also known as a gamma scan, is a diagnostic test in nuclear medicine, where radioisotopes attached to drugs that travel to a specific organ or tissue (radiopharmaceuticals) are taken internally and the emitted gamma radiation is captured by external detectors (gamma cameras) to form two-dimensional images in a similar process to the capture of x-ray images. In contrast, SPECT and ''positron emission tomography'' (PET) form 3-dimensional images and are therefore classified as separate techniques from scintigraphy, although they also use gamma cameras to detect internal radiation. Scintigraphy is unlike a diagnostic X-ray where external radiation is passed through the body to form an image. Process Scintillography is an imaging method of nuclear events provoked by collisions or charged current interactions among nuclear particles or ionizing radiation and atoms which result in a brief, localised pulse of electromagnetic radiation, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congenital Hypothyroidism
Congenital hypothyroidism (CH) is thyroid hormone deficiency present at birth. If untreated for several months after birth, severe congenital hypothyroidism can lead to growth failure and permanent intellectual disability. Infants born with congenital hypothyroidism may show no effects, or may display mild effects that often go unrecognized as a problem. Significant deficiency may cause excessive sleeping, reduced interest in nursing, poor muscle tone, low or hoarse cry, infrequent bowel movements, significant jaundice, and low body temperature. Causes of congenital hypothyroidism include iodine deficiency and a developmental defect in the thyroid gland, either due to a genetic defect or of unknown cause. Treatment consists of a daily dose of thyroid hormone (thyroxine) by mouth. Because the treatment is simple, effective, and inexpensive, most of the developed world utilizes newborn screening with blood thyroid stimulating hormone (TSH) levels to detect congenital hypothyr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyroid
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thyroid is located at the front of the neck, below the Adam's apple. Microscopically, the functional unit of the thyroid gland is the spherical thyroid follicle, lined with follicular cells (thyrocytes), and occasional parafollicular cells that surround a lumen containing colloid. The thyroid gland secretes three hormones: the two thyroid hormones triiodothyronine (T3) and thyroxine (T4)and a peptide hormone, calcitonin. The thyroid hormones influence the metabolic rate and protein synthesis, and in children, growth and development. Calcitonin plays a role in calcium homeostasis. Secretion of the two thyroid hormones is regulated by thyroid-stimulating hormone (TSH), which is secreted from the anterior pituitary gland. TSH is regula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectopia (medicine)
An ectopia () is a displacement or malposition of an organ or other body part, which is then referred to as ectopic ({{IPAc-en, ɛ, k, ˈ, t, ɒ, p, ɪ, k). Most ectopias are congenital, but some may happen later in life. Examples *Ectopic ACTH syndrome, also known as small-cell carcinoma. *Ectopic calcification, a pathologic deposition of calcium salts in tissues or bone growth in soft tissues * Cerebellar tonsillar ectopia, aka Chiari malformation, a herniation of the brain through the foramen magnum, which may be congenital or caused by trauma. * Ectopic cilia, a hair growing where it isn't supposed to be, commonly an eyelash on an abnormal spot on the eyelid, distichia *Ectopia cordis, the displacement of the heart outside the body during fetal development * Ectopic enamel, a tooth abnormality, where enamel is found in an unusual location, such as at the root of a tooth *Ectopic expression, the expression of a gene in an abnormal place in an organism * Ectopic hormone, a horm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodine Deficiency
Iodine deficiency is a lack of the trace element iodine, an essential nutrient in the diet. It may result in metabolic problems such as goiter, sometimes as an endemic goiter as well as congenital iodine deficiency syndrome due to untreated congenital hypothyroidism, which results in developmental delays and other health problems. Iodine deficiency is an important global health issue, especially for fertile and pregnant women. It is also a preventable cause of intellectual disability. Iodine is an essential dietary mineral for neurodevelopment among children. The thyroid hormones thyroxine and triiodothyronine contain iodine. In areas where there is little iodine in the diet, typically remote inland areas where no marine foods are eaten, iodine deficiency is common. It is also common in mountainous regions of the world where food is grown in iodine-poor soil. Prevention includes adding small amounts of iodine to table salt, a product known as ''iodized salt''. Iodine compound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyroid Dyshormonogenesis
Thyroid dyshormonogenesis is a rare condition due to genetic defects in the synthesis of thyroid hormones. It is due to either deficiency of thyroid enzymes, inability to concentrate, or ineffective binding. Signs and symptoms Patients develop hypothyroidism with a goiter. Cause This is due to inability to produce thyroid hormones due to congenital absence of peroxidase or dehalogenase enzymes Diagnosis Types One particular familial form is associated with sensorineural deafness ( Pendred's syndrome). OMIM Online Mendelian Inheritance in Man (OMIM) is a continuously updated catalog of human genes and genetic disorders and traits, with a particular focus on the gene-phenotype relationship. , approximately 9,000 of the over 25,000 entries in OMIM ... includes the following: Treatment These patients respond well to levothyroxine (synthetic T4) and the goiter may decrease in size if any. They may not require surgery at any time. References External links Thyroid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PAX8
Paired box gene 8, also known as PAX8, is a protein which in humans is encoded by the ''PAX8'' gene. Function This gene is a member of the paired box (PAX) family of transcription factors. Members of this gene family typically encode proteins which contain a paired box domain, an octapeptide, and a paired-type homeodomain. The PAX gene family has an important role in the formation of tissues and organs during embryonic development and maintaining the normal function of some cells after birth. The PAX genes give instructions for making proteins that attach themselves to certain areas of DNA. This nuclear protein is involved in thyroid follicular cell development and expression of thyroid-specific genes. PAX8 releases the hormones important for regulating growth, brain development, and metabolism. Also functions in very early stages of kidney organogenesis, the müllerian system, and the thymus. Additionally, PAX8 is expressed in the renal excretory system, epithelial cells of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyroid
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thyroid is located at the front of the neck, below the Adam's apple. Microscopically, the functional unit of the thyroid gland is the spherical thyroid follicle, lined with follicular cells (thyrocytes), and occasional parafollicular cells that surround a lumen containing colloid. The thyroid gland secretes three hormones: the two thyroid hormones triiodothyronine (T3) and thyroxine (T4)and a peptide hormone, calcitonin. The thyroid hormones influence the metabolic rate and protein synthesis, and in children, growth and development. Calcitonin plays a role in calcium homeostasis. Secretion of the two thyroid hormones is regulated by thyroid-stimulating hormone (TSH), which is secreted from the anterior pituitary gland. TSH is regula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foramen Cecum (tongue)
The tongue is a muscular organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive process, and is the primary organ of taste. The tongue's upper surface (dorsum) is covered by taste buds housed in numerous lingual papillae. It is sensitive and kept moist by saliva and is richly supplied with nerves and blood vessels. The tongue also serves as a natural means of cleaning the teeth. A major function of the tongue is the enabling of speech in humans and vocalization in other animals. The human tongue is divided into two parts, an oral part at the front and a pharyngeal part at the back. The left and right sides are also separated along most of its length by a vertical section of fibrous tissue (the lingual septum) that results in a groove, the median sulcus, on the tongue's surface. There are two groups of muscles of the tongue. The four intrinsic muscles alter the shape of the tongue and are not attached to bone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyoid Bone
The hyoid bone (lingual bone or tongue-bone) () is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid cartilage. At rest, it lies between the base of the mandible and the third cervical vertebra. Unlike other bones, the hyoid is only distantly articulated to other bones by muscles or ligaments. It is the only bone in the human body that is not connected to any other bones nearby. The hyoid is anchored by muscles from the anterior, posterior and inferior directions, and aids in tongue movement and swallowing. The hyoid bone provides attachment to the muscles of the floor of the mouth and the tongue above, the larynx below, and the epiglottis and pharynx behind. Its name is derived . Structure The hyoid bone is classed as an irregular bone and consists of a central part called the body, and two pairs of horns, the greater and lesser horns. Body The body of the hyoid bone is the central part of the hyoid bone. *At the fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyroglossal Duct
The thyroglossal duct is an embryology, embryological anatomical structure forming an open connection between the initial area of development of the thyroid gland and its final position. It is located exactly mid-line, between the anterior 2/3 and posterior 1/3 of the tongue. The thyroid gland starts developing in the oropharynx in the fetus and descends to its final position taking a path through the tongue, hyoid bone and muscles of the neck, neck muscles. The connection between its original position and its final position is the thyroglossal duct. This duct normally atrophy, atrophies and closes off as the Tongue#Surface of the tongue, foramen cecum before childbirth, birth but can remain open in some people. Clinical significance A thyroglossal duct that fails to atrophy is called a persistent thyroglossal duct, a condition that may lead to the formation of a thyroglossal duct cyst. References {{Authority control Human head and neck Embryology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
