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| This glossary contains: 19186 medical terms |
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Color opponent channel
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Color opponent channel Pathway that begins with the midget (parvo) ganglion cells in the retina and terminates within the parvocellular layer of the LGN. Conduction slower than that of Magnocellular Pathway.
RELATED TERMS--------------------------------------
Ganglion
A cluster of nerve cells.
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.
LGN
See Lateral Geniculate Nucleus.
SIMILAR TERMS--------------------------------------
Coloboma
A congenital (born with) problem with the eye that is related to a maldevelopment or underdevelopment of a part of the eye. It may involve the eyelid, or interior part of the eye (involving the choroid and occasionally the optic nerve). No treatment is available.
Colocort
Colocort is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): hydrocortisone.
Colon
Another name for the large intestine. The section of the large intestine extending from the cecum to the rectum. An adult colon is approximately five to six feet in length and is responsible for absorbing water and forming, storing and expelling waste.
Colon cancer
A malignant (cancerous) tumor arising from the inner wall of the large intestine. Although the exact causes of colon cancer are not known, it appears that both hereditary and environmental factors, like what we eat, play a role in its development. The early stages of cancer may have no symptoms.
Colon cancer and polyps
Benign tumors of the large intestine are called polyps. Malignant tumors of the large intestine are called cancers. Benign polyps do not invade nearby tissue or spread to other parts of the body. Benign polyps can be easily removed during colonoscopy, and are not life threatening. If benign polyps are not removed from the large intestine, they can become malignant (cancerous) over time. Most of the cancers of the large intestine are believed to have developed from polyps.
Colon cancer family history
A family history of colorectal cancer (CRC). First-degree relatives of people with CRC are themselves at a 2 to 3-fold increased risk of colorectal cancer. (Parents, brothers and sisters, and children are first-degree relatives.) When the family history includes 2 or more relatives with CRC, the possibility of an inherited CRC syndrome is increased.
Colon polyp
A fleshy growth on the inside (the lining) of the colon (the large intestine). Colon polyps are extremely common. Their incidence increases as individuals get older. Half of all people over the age of 60 harbor at least one polyp.
Colon polyps
Small, fleshy, mushroom-shaped growths in the colon.
Colon syndrome, nervous
A common gastrointestinal disorder involving an abnormal condition of gut contractions (motility) characterized by abdominal pain, bloating, mucous in stools, and irregular bowel habits with alternating diarrhea and constipation, symptoms that tend to be chronic and to wax and wane over the years. Although the disorder can cause chronic recurrent discomfort, it does not lead to any serious organ problems.
Colonaid
Colonaid is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): atropine sulfate; diphenoxylate hydrochloride.
Colonial Manor Nursing Home
The Colonial Manor Nursing Home is a hospital in York, Pennsylvania, United States.
Colonic (adjective)
Relating to the colon, that part of the large intestine that runs from the cecum to the rectum.
Colonic (noun)
Colonic irrigation, the infusion of liquid into the colon through a tube in the rectum.
Colonic inertia
A condition of the colon in which colon muscles do not work properly, causing constipation.
Colonoscope
A flexible, lighted instrument used to view the inside of the colon.
Colonoscopic polypectomy
The removal of tumor-like growths (polyps) using a device inserted through a colonoscope.
Colonoscopy
A procedure that allows the physician to view the entire length of the large intestine, and can often help identify abnormal growths, inflamed tissue, ulcers, and bleeding. It involves inserting a colonoscope, a long, flexible, lighted tube, in through the rectum up into the colon. The colonoscope allows the physician to see the lining of the colon, remove tissue for further examination, and possibly treat some problems that are discovered.
Colony-stimulating factor
A laboratory-made agent similar to a substance in the body that stimulates the production of blood cells.
Coloproctectomy
An operation to remove the colon and rectum. Also called proctocolectomy.
Color hearing
"A form of chromesthesia in which hearing a musical tone elicits the perception of a color. In one case, an art teacher had a broad range of consistent linkages between tone and color. For her, high octaves tended to evoke lighter color values, while lower octaves elicited darker ones. And rapid major chord tone sequences elicited rapid flashes of colors, ""somewhat like fireworks exploding."" "
Color opponency
When a cell is excited by one part of the visible spectrum and inhibited by another. First observed in ganglion cells in the retina.
Colorado River Medical Center
The Colorado River Medical Center is a hospital in San Bernardino, California, United States.
Colorado Springs doctors
All doctors near Colorado Springs, the United States of America.
Colorado tick fever
A viral illness spread by ticks. Characterized by headache, backache and fever that begins to break and then returns midway through the course of the illness.
Colorblindness
The inability to perceive colors in a normal fashion. The most common forms of colorblindness are inherited as sex-linked (X-linked) recessive traits. Females are carriers and males are affected. As a result, approximately 1 in 8 males is colorblind as compared to less than 1 in 100 females.
Colorblindness, red-green
A form of colorblindness in which red and green are perceived as identical. This is the most common type of colorblindness. It is also known as deuteranomaly, deuteranopia, and Daltonism.
Colorectal
Related to the colon and/or rectum.
Colorectal adenoma and carcinoma 1
Abbreviated CRAC1. Also known as hereditary mixed polyposis syndrome.
Colorectal adenomatous polyposis, recessive
Autosomal recessive form of colorectal adenomatous polyposis.
Colorectal cancer
Cancer that occurs in the colon (large intestine) or the rectum (the end of the large intestine). A number of digestive diseases may increase a person's risk of colorectal cancer, including polyposis and Zollinger-Ellison syndrome.
Colorectal polyp
A polyp (a fleshy growth) on the inside lining of the colon or rectum.
Colorectal surgeon
A general surgeon who has had further training and is expert in the diagnosis and treatment of benign and malignant diseases of the colon, rectum, and anus.
Colorectal transit study
A test to see how food moves through the colon. The patient swallows capsules that contain small markers. An x-ray tracks the movement of the capsules through the colon.
Colostomy
An operation that makes it possible for stool to leave the body after the rectum has been removed. The surgeon makes an opening in the abdomen and attaches the colon to it. A temporary colostomy may be done to let the rectum heal from injury or other surgery.
Colostomy bag
A removable, disposable bag that attaches to the exterior opening of a colostomy (stoma) to permit sanitary collection and disposal of bodily wastes.
Colostomy, iliac
A colostomy in which the exterior opening (stoma) is located on the lower left side of the abdomen.
Colostomy, transverse
A colostomy in which the exterior opening (stoma) is located on the upper abdomen.
Colostrum
Thin, white, first milk produced by the breasts during late pregnancy and for a few days after childbirth. It provides a nursing infant with essential nutrients and infection-fighting antibodies.
Colour blindness
The inability to perceive differences between some or all colors that other people can distinguish. It is most often of genetic nature, but might also occur because of eye, nerve, or brain damage, or due to exposure to certain chemicals.
Colovage
Colovage is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): polyethylene glycol 3350; potassium chloride; sodium bicarbonate; sodium chloride; sodium sulfate, anhydrous.
PREVIOUS AND NEXT TERMS--------------------------------------
Center-Surround
A type of spatial receptive field structure in which the central region of the receptive field and the Surround portion influence cell activities in different ways e.g. ON-center, OFF-Surround
Chromatic adaptation technique
Used to identify receptor inputs. An adapting light is chosen such that it affects the response to one of the inputs to a cell far more than the other. The cells response is selectively desensitized so that the cell is largely driven by the other input. This way the response properties of the cell can now be studied in relative isolation.
Chromostereopsis
The optics of the eye are such that short wavelengths are refracted slightly more than long wavelengths creating a positional disparity on the retina. When viewed by two eyes a stereoscopic disparity is obtained. This is termed Chromostereopsis or Chromatic Stereopsis
Closed-Loop control
A control system in which the output is continuously modified by feedback from the environment.
Color opponency
When a cell is excited by one part of the visible spectrum and inhibited by another. First observed in ganglion cells in the retina.
Color opponent channel
Complex cells
Cells in the primary visual cortex (V1) that responding either to an edge, a bar or a slit stimulus of a particular orientation falling anywhere in its receptive field. The exact location of the stimulus within the receptive field is not as critical. Have receptive fields longer than those of simple cells. The cell behaves non-linearly, responding to a drifting cosine grating with a uniform increase in activity with no sinusiodal modulcation (i.e. insensitive to phase). For a historical perspective see Simple Cells.
Concentric field
A receptive field divided into an inner circular region and an outer ring-shaped region. Light falling in each of the two regions has opposite effects on the response of the cell.
Cone opsin
Light absorbing molecule in cone cells.
Contrast sensitivity function
The reciprocal of the threshold contrast required to obtain a criterion response from a cell or a human subject as a function of spatial frequency. Falls off in sensitivity as the spatial frequency of the test pattern increases.
Coplanar ratio hyphothesis
An hypothesis by Gilchrist in which the visual system does not use retinal contrasts to determine relative lightnesses but uses depth information to determine which regions are at the same depth (coplanar) and uses their contrasts to deteremine the lightness perceived. This hypothesis has come under recent attack.
RELATED TERMS--------------------------------------
Ganglion
A cluster of nerve cells.
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.
LGN
See Lateral Geniculate Nucleus.
SIMILAR TERMS--------------------------------------
Coloboma
A congenital (born with) problem with the eye that is related to a maldevelopment or underdevelopment of a part of the eye. It may involve the eyelid, or interior part of the eye (involving the choroid and occasionally the optic nerve). No treatment is available.
Colocort
Colocort is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): hydrocortisone.
Colon
Another name for the large intestine. The section of the large intestine extending from the cecum to the rectum. An adult colon is approximately five to six feet in length and is responsible for absorbing water and forming, storing and expelling waste.
Colon cancer
A malignant (cancerous) tumor arising from the inner wall of the large intestine. Although the exact causes of colon cancer are not known, it appears that both hereditary and environmental factors, like what we eat, play a role in its development. The early stages of cancer may have no symptoms.
Colon cancer and polyps
Benign tumors of the large intestine are called polyps. Malignant tumors of the large intestine are called cancers. Benign polyps do not invade nearby tissue or spread to other parts of the body. Benign polyps can be easily removed during colonoscopy, and are not life threatening. If benign polyps are not removed from the large intestine, they can become malignant (cancerous) over time. Most of the cancers of the large intestine are believed to have developed from polyps.
Colon cancer family history
A family history of colorectal cancer (CRC). First-degree relatives of people with CRC are themselves at a 2 to 3-fold increased risk of colorectal cancer. (Parents, brothers and sisters, and children are first-degree relatives.) When the family history includes 2 or more relatives with CRC, the possibility of an inherited CRC syndrome is increased.
Colon polyp
A fleshy growth on the inside (the lining) of the colon (the large intestine). Colon polyps are extremely common. Their incidence increases as individuals get older. Half of all people over the age of 60 harbor at least one polyp.
Colon polyps
Small, fleshy, mushroom-shaped growths in the colon.
Colon syndrome, nervous
A common gastrointestinal disorder involving an abnormal condition of gut contractions (motility) characterized by abdominal pain, bloating, mucous in stools, and irregular bowel habits with alternating diarrhea and constipation, symptoms that tend to be chronic and to wax and wane over the years. Although the disorder can cause chronic recurrent discomfort, it does not lead to any serious organ problems.
Colonaid
Colonaid is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): atropine sulfate; diphenoxylate hydrochloride.
Colonial Manor Nursing Home
The Colonial Manor Nursing Home is a hospital in York, Pennsylvania, United States.
Colonic (adjective)
Relating to the colon, that part of the large intestine that runs from the cecum to the rectum.
Colonic (noun)
Colonic irrigation, the infusion of liquid into the colon through a tube in the rectum.
Colonic inertia
A condition of the colon in which colon muscles do not work properly, causing constipation.
Colonoscope
A flexible, lighted instrument used to view the inside of the colon.
Colonoscopic polypectomy
The removal of tumor-like growths (polyps) using a device inserted through a colonoscope.
Colonoscopy
A procedure that allows the physician to view the entire length of the large intestine, and can often help identify abnormal growths, inflamed tissue, ulcers, and bleeding. It involves inserting a colonoscope, a long, flexible, lighted tube, in through the rectum up into the colon. The colonoscope allows the physician to see the lining of the colon, remove tissue for further examination, and possibly treat some problems that are discovered.
Colony-stimulating factor
A laboratory-made agent similar to a substance in the body that stimulates the production of blood cells.
Coloproctectomy
An operation to remove the colon and rectum. Also called proctocolectomy.
Color hearing
"A form of chromesthesia in which hearing a musical tone elicits the perception of a color. In one case, an art teacher had a broad range of consistent linkages between tone and color. For her, high octaves tended to evoke lighter color values, while lower octaves elicited darker ones. And rapid major chord tone sequences elicited rapid flashes of colors, ""somewhat like fireworks exploding."" "
Color opponency
When a cell is excited by one part of the visible spectrum and inhibited by another. First observed in ganglion cells in the retina.
Colorado River Medical Center
The Colorado River Medical Center is a hospital in San Bernardino, California, United States.
Colorado Springs doctors
All doctors near Colorado Springs, the United States of America.
Colorado tick fever
A viral illness spread by ticks. Characterized by headache, backache and fever that begins to break and then returns midway through the course of the illness.
Colorblindness
The inability to perceive colors in a normal fashion. The most common forms of colorblindness are inherited as sex-linked (X-linked) recessive traits. Females are carriers and males are affected. As a result, approximately 1 in 8 males is colorblind as compared to less than 1 in 100 females.
Colorblindness, red-green
A form of colorblindness in which red and green are perceived as identical. This is the most common type of colorblindness. It is also known as deuteranomaly, deuteranopia, and Daltonism.
Colorectal
Related to the colon and/or rectum.
Colorectal adenoma and carcinoma 1
Abbreviated CRAC1. Also known as hereditary mixed polyposis syndrome.
Colorectal adenomatous polyposis, recessive
Autosomal recessive form of colorectal adenomatous polyposis.
Colorectal cancer
Cancer that occurs in the colon (large intestine) or the rectum (the end of the large intestine). A number of digestive diseases may increase a person's risk of colorectal cancer, including polyposis and Zollinger-Ellison syndrome.
Colorectal polyp
A polyp (a fleshy growth) on the inside lining of the colon or rectum.
Colorectal surgeon
A general surgeon who has had further training and is expert in the diagnosis and treatment of benign and malignant diseases of the colon, rectum, and anus.
Colorectal transit study
A test to see how food moves through the colon. The patient swallows capsules that contain small markers. An x-ray tracks the movement of the capsules through the colon.
Colostomy
An operation that makes it possible for stool to leave the body after the rectum has been removed. The surgeon makes an opening in the abdomen and attaches the colon to it. A temporary colostomy may be done to let the rectum heal from injury or other surgery.
Colostomy bag
A removable, disposable bag that attaches to the exterior opening of a colostomy (stoma) to permit sanitary collection and disposal of bodily wastes.
Colostomy, iliac
A colostomy in which the exterior opening (stoma) is located on the lower left side of the abdomen.
Colostomy, transverse
A colostomy in which the exterior opening (stoma) is located on the upper abdomen.
Colostrum
Thin, white, first milk produced by the breasts during late pregnancy and for a few days after childbirth. It provides a nursing infant with essential nutrients and infection-fighting antibodies.
Colour blindness
The inability to perceive differences between some or all colors that other people can distinguish. It is most often of genetic nature, but might also occur because of eye, nerve, or brain damage, or due to exposure to certain chemicals.
Colovage
Colovage is a prescription or over-the-counter drug which is (or once was) approved in the United States and possibly in other countries. Active ingredient(s): polyethylene glycol 3350; potassium chloride; sodium bicarbonate; sodium chloride; sodium sulfate, anhydrous.
PREVIOUS AND NEXT TERMS--------------------------------------
Center-Surround
A type of spatial receptive field structure in which the central region of the receptive field and the Surround portion influence cell activities in different ways e.g. ON-center, OFF-Surround
Chromatic adaptation technique
Used to identify receptor inputs. An adapting light is chosen such that it affects the response to one of the inputs to a cell far more than the other. The cells response is selectively desensitized so that the cell is largely driven by the other input. This way the response properties of the cell can now be studied in relative isolation.
Chromostereopsis
The optics of the eye are such that short wavelengths are refracted slightly more than long wavelengths creating a positional disparity on the retina. When viewed by two eyes a stereoscopic disparity is obtained. This is termed Chromostereopsis or Chromatic Stereopsis
Closed-Loop control
A control system in which the output is continuously modified by feedback from the environment.
Color opponency
When a cell is excited by one part of the visible spectrum and inhibited by another. First observed in ganglion cells in the retina.
Color opponent channel
Complex cells
Cells in the primary visual cortex (V1) that responding either to an edge, a bar or a slit stimulus of a particular orientation falling anywhere in its receptive field. The exact location of the stimulus within the receptive field is not as critical. Have receptive fields longer than those of simple cells. The cell behaves non-linearly, responding to a drifting cosine grating with a uniform increase in activity with no sinusiodal modulcation (i.e. insensitive to phase). For a historical perspective see Simple Cells.
Concentric field
A receptive field divided into an inner circular region and an outer ring-shaped region. Light falling in each of the two regions has opposite effects on the response of the cell.
Cone opsin
Light absorbing molecule in cone cells.
Contrast sensitivity function
The reciprocal of the threshold contrast required to obtain a criterion response from a cell or a human subject as a function of spatial frequency. Falls off in sensitivity as the spatial frequency of the test pattern increases.
Coplanar ratio hyphothesis
An hypothesis by Gilchrist in which the visual system does not use retinal contrasts to determine relative lightnesses but uses depth information to determine which regions are at the same depth (coplanar) and uses their contrasts to deteremine the lightness perceived. This hypothesis has come under recent attack.
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This dictionary contains 19186 terms.
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