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| This glossary contains: 19186 medical terms |
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Accessory optic system (AOS)
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Accessory optic system (AOS) Region of the vertebrate midbrain to which some optic nerve fibers project. Cells respond to large slowly moving textured patterns and are selective for both direction and speed of motion suggesting they are involved in the computation of global motion. Possibly used for the detection of retinal slip and used in image stabilization. Consists of two sets of retina ganglion cell fibers and three target nuclei in the anterior portion of the midbrain, the dorsal, medial and lateral nuclei.
RELATED TERMS--------------------------------------
Nerve
Tissue that conveys sensation, temperature, position information to the brain.
Retinal
Light-absorbing portion of rhodopsin. The absorption of light causes retinal to change from 11-cis to 11-trans configuration
Retina
A membrane lining the inside of the back of the eye that contains light-sensitive nerve cells that convert focused light into nerve impulses, making vision possible.
Ganglion
A cluster of nerve cells.
Cell
Fundamental structural unit of all life. The cell consists primarily of an outer plasma membrane, which separates it from the environment; the genetic material (DNA), which encodes heritable information for the maintainance of life; and the cytoplasm, a heterogeneous assemblage of ions, molecules, and fluid.
Nuclei
See nucleus.
Anterior
The front, as opposed to the posterior. The anterior surface of the heart is toward the breast bone (the sternum).
Dorsal
Toward the back.
Medial
Anatomical term meaning on the inside (as opposed to lateral). Not to be confused with median (nerve) that is compressed in carpal tunnel syndrome.
Lateral
Toward the side, sideways.
SIMILAR TERMS--------------------------------------
Accelerated phase of leukemia
Refers to chronic myelogenous leukemia (CML) that is progressing. The number of immature, abnormal white blood cells in the bone marrow and blood is higher than in the chronic phase but not as high as in the blast phase.
Acceptable daily intake
Estimate of the amount of a substance in food or drinking water, expressed on a body mass basis (usually mg/kg body weight), which can be ingested daily over a lifetime by humans without appreciable health risk. For calculation of the daily intake per person, a standard body mass of 60 kg is used. The acceptable daily intake is normally used for food additives (tolerable daily intake is used for contaminants). Abbreviated ADI.
Access
1. In general, a means of approaching something. 2. In health care, the opportunity or right to receive health care. 3. In dialysis, the point on the body where a needle or catheter is inserted to gain entry to the bloodstream.
Accessibility of services
The ability to get medical care and services when needed.
Accessible
Refers to tumors that can be approached by a surgical procedure; tumors that are not deep in the brain or beneath vital structures. Inaccessible tumors cannot be approached by standard surgical techniques.
Accessory
Additional, extra, supplementary, subsidiary to the main thing. An accessory digestive organ is an organ that helps with digestion but is not part of the digestive tract. The accessory nerve is so-called because it receives an additional (accessory) root from the upper part of the spinal cord. An accessory placenta is an extra placenta separate from the main placenta.
Accessory cell
Cell required for, but not actually mediating, a specific immune response. Often used to describe antigen-presenting cells (APC; see below).
Accessory digestive organ
An organ that helps with digestion but is not part of the digestive tract. The accessory digestive organs are the tongue, salivary glands, pancreas, liver, and gallbladder.
Accessory digestive organs
Organs that help with digestion but are not part of the digestive tract. These organs are the tongue, glands in the mouth that make saliva, pancreas, liver, and gallbladder.
Accessory dwelling unit
(ADU) A separate housing arrangement within a single-family home. The ADU is defined by Medicare as a complete living unit and includes a private kitchen and bath.
Accessory nerve
The eleventh cranial nerve, which emerges from the skull and receives an additional (accessory) root from the upper part of the spinal cord. It supplies the sternocleidomastoid and trapezius muscles. The sternocleidomastoid muscle is in the front of the neck and turns the head. The trapezius muscle moves the scapula (the wingbone), turns the face to the opposite side, and helps pull the head back. The accessory nerve is so-called because, although it arises in the brain, it receives an additional (accessory) root from the upper part of the spinal cord. Damage to the accessory nerve can be isolated (confined to the accessory nerve) or it may also involve the ninth and tenth cranial nerves which exit through the same opening (foramen) from the skull . Accessory neuropathy (nerve disease) can sometimes occur and recur for unknown reasons. Most patients recover. Paralysis of the accessory nerve prevents rotation of the head away from that side and causes drooping of the shoulder.
Accessory neuropathy
Disease of the accessory nerve which is the eleventh cranial nerve. The accessory nerve supplies the sternocleidomastoid and trapezius muscles. The sternocleidomastoid muscle is in the front of the neck and turns the head. The trapezius muscle moves the scapula (the wingbone), turns the face to the opposite side, and helps pull the head back. Damage to the accessory nerve can be confined to the accessory nerve or it may also involve the ninth and tenth cranial nerves which exit through the same opening (foramen) from the skull . Accessory neuropathy can sometimes occur and recur for unknown reasons. Most patients recover. Paralysis of the accessory nerve prevents rotation of the head away from that side and causes drooping of the shoulder.
Accessory oculomotor nucleus
Receives input from the pretectal area, innervates the ciliary ganglion. Mediates pupillary light reflexes.
Accessory placenta
"An extra placenta separate from the main placenta. Also called a succenturiate or supernumerary placenta. The placenta is the organ joining the mother and fetus, the organ that permits the provision of oxygen and nutrients to the fetus and the release of carbon dioxide and waste products from the fetus to the mother. The word ""placenta"" means a flat cake. The main placenta is disk-shaped and at full term measures about 7 inches (18 cm) in diameter and a bit less than 2 inches (4 cm) thick. The upper surface of the placenta is smooth while the under surface is rough. The placenta and the fetal membranes are the afterbirth."
PREVIOUS AND NEXT TERMS--------------------------------------
Anterior position
When the baby faces the back of the mother's pelvis in utero and/or during labor.
Apgar score
The first test most babies are given (at one and five minutes after birth). Assesses five basic indicators of health: respiration, pulse, activity level, response to stimulation, and appearance.
Au pair
A foreign national who lives with an American family for up to a year, and in exchange for room, board, and a small stipend, helps with childcare and housework. She may or may not have any previous experience caring for children, unlike nannies, who usually do.
Absorption spectrum
The relationship between the wavelength of light striking a pigment and how strongly the light is absorbed.
Accessory oculomotor nucleus
Receives input from the pretectal area, innervates the ciliary ganglion. Mediates pupillary light reflexes.
Accessory optic system (AOS)
Accidental view
A special view of an object in which small perturbations in lighting or viewing direction drastically change its appearance. For example, imagine looking at a pencil straight on from the tip. (As opposed to Generic View).
Acuity
The highest spatial frequency rsolvable with a grating of unity contrast (i.e. the maximum possibly contrast).
Action potential
A photoreceptor's relative spectral sensitivity.
Action spectra
A photoreceptor's relative spectral sensitivity.
Adaptation
A change in the sensitivity to light of a photoreceptor or the visual system as a whole to match the average light intensity present.
RELATED TERMS--------------------------------------
Nerve
Tissue that conveys sensation, temperature, position information to the brain.
Retinal
Light-absorbing portion of rhodopsin. The absorption of light causes retinal to change from 11-cis to 11-trans configuration
Retina
A membrane lining the inside of the back of the eye that contains light-sensitive nerve cells that convert focused light into nerve impulses, making vision possible.
Ganglion
A cluster of nerve cells.
Cell
Fundamental structural unit of all life. The cell consists primarily of an outer plasma membrane, which separates it from the environment; the genetic material (DNA), which encodes heritable information for the maintainance of life; and the cytoplasm, a heterogeneous assemblage of ions, molecules, and fluid.
Nuclei
See nucleus.
Anterior
The front, as opposed to the posterior. The anterior surface of the heart is toward the breast bone (the sternum).
Dorsal
Toward the back.
Medial
Anatomical term meaning on the inside (as opposed to lateral). Not to be confused with median (nerve) that is compressed in carpal tunnel syndrome.
Lateral
Toward the side, sideways.
SIMILAR TERMS--------------------------------------
Accelerated phase of leukemia
Refers to chronic myelogenous leukemia (CML) that is progressing. The number of immature, abnormal white blood cells in the bone marrow and blood is higher than in the chronic phase but not as high as in the blast phase.
Acceptable daily intake
Estimate of the amount of a substance in food or drinking water, expressed on a body mass basis (usually mg/kg body weight), which can be ingested daily over a lifetime by humans without appreciable health risk. For calculation of the daily intake per person, a standard body mass of 60 kg is used. The acceptable daily intake is normally used for food additives (tolerable daily intake is used for contaminants). Abbreviated ADI.
Access
1. In general, a means of approaching something. 2. In health care, the opportunity or right to receive health care. 3. In dialysis, the point on the body where a needle or catheter is inserted to gain entry to the bloodstream.
Accessibility of services
The ability to get medical care and services when needed.
Accessible
Refers to tumors that can be approached by a surgical procedure; tumors that are not deep in the brain or beneath vital structures. Inaccessible tumors cannot be approached by standard surgical techniques.
Accessory
Additional, extra, supplementary, subsidiary to the main thing. An accessory digestive organ is an organ that helps with digestion but is not part of the digestive tract. The accessory nerve is so-called because it receives an additional (accessory) root from the upper part of the spinal cord. An accessory placenta is an extra placenta separate from the main placenta.
Accessory cell
Cell required for, but not actually mediating, a specific immune response. Often used to describe antigen-presenting cells (APC; see below).
Accessory digestive organ
An organ that helps with digestion but is not part of the digestive tract. The accessory digestive organs are the tongue, salivary glands, pancreas, liver, and gallbladder.
Accessory digestive organs
Organs that help with digestion but are not part of the digestive tract. These organs are the tongue, glands in the mouth that make saliva, pancreas, liver, and gallbladder.
Accessory dwelling unit
(ADU) A separate housing arrangement within a single-family home. The ADU is defined by Medicare as a complete living unit and includes a private kitchen and bath.
Accessory nerve
The eleventh cranial nerve, which emerges from the skull and receives an additional (accessory) root from the upper part of the spinal cord. It supplies the sternocleidomastoid and trapezius muscles. The sternocleidomastoid muscle is in the front of the neck and turns the head. The trapezius muscle moves the scapula (the wingbone), turns the face to the opposite side, and helps pull the head back. The accessory nerve is so-called because, although it arises in the brain, it receives an additional (accessory) root from the upper part of the spinal cord. Damage to the accessory nerve can be isolated (confined to the accessory nerve) or it may also involve the ninth and tenth cranial nerves which exit through the same opening (foramen) from the skull . Accessory neuropathy (nerve disease) can sometimes occur and recur for unknown reasons. Most patients recover. Paralysis of the accessory nerve prevents rotation of the head away from that side and causes drooping of the shoulder.
Accessory neuropathy
Disease of the accessory nerve which is the eleventh cranial nerve. The accessory nerve supplies the sternocleidomastoid and trapezius muscles. The sternocleidomastoid muscle is in the front of the neck and turns the head. The trapezius muscle moves the scapula (the wingbone), turns the face to the opposite side, and helps pull the head back. Damage to the accessory nerve can be confined to the accessory nerve or it may also involve the ninth and tenth cranial nerves which exit through the same opening (foramen) from the skull . Accessory neuropathy can sometimes occur and recur for unknown reasons. Most patients recover. Paralysis of the accessory nerve prevents rotation of the head away from that side and causes drooping of the shoulder.
Accessory oculomotor nucleus
Receives input from the pretectal area, innervates the ciliary ganglion. Mediates pupillary light reflexes.
Accessory placenta
"An extra placenta separate from the main placenta. Also called a succenturiate or supernumerary placenta. The placenta is the organ joining the mother and fetus, the organ that permits the provision of oxygen and nutrients to the fetus and the release of carbon dioxide and waste products from the fetus to the mother. The word ""placenta"" means a flat cake. The main placenta is disk-shaped and at full term measures about 7 inches (18 cm) in diameter and a bit less than 2 inches (4 cm) thick. The upper surface of the placenta is smooth while the under surface is rough. The placenta and the fetal membranes are the afterbirth."
PREVIOUS AND NEXT TERMS--------------------------------------
Anterior position
When the baby faces the back of the mother's pelvis in utero and/or during labor.
Apgar score
The first test most babies are given (at one and five minutes after birth). Assesses five basic indicators of health: respiration, pulse, activity level, response to stimulation, and appearance.
Au pair
A foreign national who lives with an American family for up to a year, and in exchange for room, board, and a small stipend, helps with childcare and housework. She may or may not have any previous experience caring for children, unlike nannies, who usually do.
Absorption spectrum
The relationship between the wavelength of light striking a pigment and how strongly the light is absorbed.
Accessory oculomotor nucleus
Receives input from the pretectal area, innervates the ciliary ganglion. Mediates pupillary light reflexes.
Accessory optic system (AOS)
Accidental view
A special view of an object in which small perturbations in lighting or viewing direction drastically change its appearance. For example, imagine looking at a pencil straight on from the tip. (As opposed to Generic View).
Acuity
The highest spatial frequency rsolvable with a grating of unity contrast (i.e. the maximum possibly contrast).
Action potential
A photoreceptor's relative spectral sensitivity.
Action spectra
A photoreceptor's relative spectral sensitivity.
Adaptation
A change in the sensitivity to light of a photoreceptor or the visual system as a whole to match the average light intensity present.
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This dictionary contains 19186 terms.
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