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| This glossary contains: 19186 medical terms |
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Choroid
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Choroid This is the vascular coat between the sclera and the retina, which furnishes blood and nutrition to the outer layer of the retina.
RELATED TERMS--------------------------------------
Vascular
Pertaining to blood vessels.
Sclera
The sclera is the white part of the eye. The clear cornea is the front extension of the sclera.
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.
Blood
The life-maintaining fluid which is made up of plasma, red blood cells (erythrocytes), white blood cells (leukocytes), and platelets; blood circulates through the body's heart, arteries, veins, and capillaries; it carries away waste matter and carbon dioxide, and brings nourishment, electrolytes, hormones, vitamins, antibodies, heat, and oxygen to the tissues.
SIMILAR TERMS--------------------------------------
Chorda tympani
A branch of the facial nerve (the seventh cranial nerve) that serves the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain.
Chordae Tendinae
The thin, fibrous chords that lead from the valve leaflets to the small papillary muscles within the heart muscle wall, contributes to the support of the tricuspid and mitral valves.
Chordae tendineae
Thread-like bands of fibrous tissue which attach on one end to the edges of the tricuspid and mitral valves of the heart and on the other end to the papillary muscles, small muscles within the heart that serve to anchor the valves.
Chordee
Fixed curvature or tying down of the penis or hypertrophied clitoris as in the hypospadiac birth defect characteristic of various types of hermaphroditism.
Chordoma
A form of bone cancer that usually starts in the lower spinal column.
Chorea
Rapid, jerky, dance-like movement of the body.
Chorioangioma, placental
A benign vascular (blood vessel) tumor of the placenta (afterbirth). Large chorioangiomas cause complications including polyhydramnios (excess amniotic fluid), maternal and fetal clotting problems (coagulopathies), premature delivery, toxemia, fetal heart failure, and hydrops (excess fluid) affecting the fetus.
Choriocarcinoma
A highly malignant tumor that arises from trophoblastic cells within the uterus. Choriocarcinoma tends to be invasive and to metastasize early and widely through both the venous and lymphatic systems. Choriocarcinoma is one of the two types of gestational trophoblastic tumor, the other being hydatidiform mole.
Chorion
The outermost of the two membranes surrounding the embryo/fetus, part of which forms the fetal portion of the placenta.
Chorionic gonadotropin
Human chorionic gonadotropin (hCG) is a peptide hormone produced in pregnancy, that is made by the embryo soon after conception and later by the trophoblast (part of the placenta). Its role is to prevent the demise of the corpus luteum of the ovary and thereby maintain progesterone production that is critical for a pregnancy in humans. hCG may have additional functions, for instance it is thought that it affects the immune tolerance of the pregnancy.
Chorionic villus sampling
A procedure for first-trimester prenatal diagnosis. Chorionic villus sampling may be done between the eighth and tenth weeks of pregnancy. The aim is to diagnose severe abnormalities afflicting the fetus. In the procedure, tissue is withdrawn from the villi (vascular fingers) of the chorion, a part of the placenta, and examined. Chorionic villus sampling is referred to commonly as CVS.
Chorionic Villus Sampling (CVS)
A procedure in which a small sample of cells are taken from the placenta through a small catheter placed up through the vagina and the cervix. This is done earlier in pregnancy than amniocentesis and is used to test for chromosomal and other biochemical abnormalities that may affect the health and well being of the baby.
Chorioretinitis
An inflammation of the back of the eye involving the choroid and retina. It may be due to a number of different diseases, which affect the body such as toxoplasmosis, histoplasmosis, sarcoidosis, tuberculosis and syphilis.
Choroideremia
Atrophy or decay of the choroid, choriocapillaris and Bruch’s membrane of the eye, leading to a severe loss of vision. Usually progresses to light perception by 50 years of age. Leads to night blindness tunnel vision and reduced visual acuity. No treatment available.
Choroiditis
An inflammation of the back of the eye involving the choroid and retina. It may be due to a number of different diseases, which affect the body such as toxoplasmosis, histoplasmosis, sarcoidosis, tuberculosis and syphilis.
PREVIOUS AND NEXT TERMS--------------------------------------
CAM Treatment
CAM is an abbreviation for Cambridge (England) where a new therapy for amblyopia was proposed that used rotating gratings (series of black and white bars). Patients would view the rotating gratings while they performed various drawing tasks on top of the rotating gratings. Research has shown, however, that CAM treatment is not effective at improving visual acuity in amblyopic children.
Carbidopa
Carbidopa is a peripheral decarboxylase inhibitor. Dopa decarboxylase is an enzyme that converts levodopa into dopamine - a major neurotransmitter and neuromodular of cellular function. Carbidopa is sometimes used to prevent the peripheral conversion of levodopa into dopamine in peripheral sites such as the gut, thus allowing more levodopa to reach the brain where it can have therapeutic effects.
Chalazion
In the eyelid there are a number of glands that produce lubricants for the cornea and eyelid. A Chalazion occurs when a gland become plugged, enlarged, or infected. The lid looks like it has a lump about the size of a small pea. Occasionally it occurs as a thickness within the lid. Warm compresses help some disappear; others require surgical removal by an Ophthalmologist.
Choroideremia
Atrophy or decay of the choroid, choriocapillaris and Bruch’s membrane of the eye, leading to a severe loss of vision. Usually progresses to light perception by 50 years of age. Leads to night blindness tunnel vision and reduced visual acuity. No treatment available.
Chorioretinitis
An inflammation of the back of the eye involving the choroid and retina. It may be due to a number of different diseases, which affect the body such as toxoplasmosis, histoplasmosis, sarcoidosis, tuberculosis and syphilis.
Choroid
Choroiditis
An inflammation of the back of the eye involving the choroid and retina. It may be due to a number of different diseases, which affect the body such as toxoplasmosis, histoplasmosis, sarcoidosis, tuberculosis and syphilis.
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.
Cone
One of the two light receiving retinal cells (the other is the rod) that is responsible for daylight vision (e.g., color vision, high visual acuity, bright light vision). The area of the retina that provides central or reading vision, known as the fovea, contains only cones.
Cone Dystrophy
Also sometimes referred to as cone degeneration. The cones of the eye degenerate over time leading to visual acuity between 20/50 and 20/200 – legal blindness. There may be a progressive vision loss, abnormal color vision and photophobia. No treatment is available, except for dark sunglasses for the photophobia. Patients with cone dystrophies and cone degenerations benefit for rehabilitation services.
Cone Rod Degeneration
Also called cone-rod dystrophy. Leads to a loss of visual acuity between 20/25 to 20/400 – legal blindness. First there is a loss of cone photoreceptors followed by a loss of rod photoreceptors. Visual fields may be restricted, abnormal color vision and photophobia. No treatment is available.
RELATED TERMS--------------------------------------
Vascular
Pertaining to blood vessels.
Sclera
The sclera is the white part of the eye. The clear cornea is the front extension of the sclera.
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.
Blood
The life-maintaining fluid which is made up of plasma, red blood cells (erythrocytes), white blood cells (leukocytes), and platelets; blood circulates through the body's heart, arteries, veins, and capillaries; it carries away waste matter and carbon dioxide, and brings nourishment, electrolytes, hormones, vitamins, antibodies, heat, and oxygen to the tissues.
SIMILAR TERMS--------------------------------------
Chorda tympani
A branch of the facial nerve (the seventh cranial nerve) that serves the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain.
Chordae Tendinae
The thin, fibrous chords that lead from the valve leaflets to the small papillary muscles within the heart muscle wall, contributes to the support of the tricuspid and mitral valves.
Chordae tendineae
Thread-like bands of fibrous tissue which attach on one end to the edges of the tricuspid and mitral valves of the heart and on the other end to the papillary muscles, small muscles within the heart that serve to anchor the valves.
Chordee
Fixed curvature or tying down of the penis or hypertrophied clitoris as in the hypospadiac birth defect characteristic of various types of hermaphroditism.
Chordoma
A form of bone cancer that usually starts in the lower spinal column.
Chorea
Rapid, jerky, dance-like movement of the body.
Chorioangioma, placental
A benign vascular (blood vessel) tumor of the placenta (afterbirth). Large chorioangiomas cause complications including polyhydramnios (excess amniotic fluid), maternal and fetal clotting problems (coagulopathies), premature delivery, toxemia, fetal heart failure, and hydrops (excess fluid) affecting the fetus.
Choriocarcinoma
A highly malignant tumor that arises from trophoblastic cells within the uterus. Choriocarcinoma tends to be invasive and to metastasize early and widely through both the venous and lymphatic systems. Choriocarcinoma is one of the two types of gestational trophoblastic tumor, the other being hydatidiform mole.
Chorion
The outermost of the two membranes surrounding the embryo/fetus, part of which forms the fetal portion of the placenta.
Chorionic gonadotropin
Human chorionic gonadotropin (hCG) is a peptide hormone produced in pregnancy, that is made by the embryo soon after conception and later by the trophoblast (part of the placenta). Its role is to prevent the demise of the corpus luteum of the ovary and thereby maintain progesterone production that is critical for a pregnancy in humans. hCG may have additional functions, for instance it is thought that it affects the immune tolerance of the pregnancy.
Chorionic villus sampling
A procedure for first-trimester prenatal diagnosis. Chorionic villus sampling may be done between the eighth and tenth weeks of pregnancy. The aim is to diagnose severe abnormalities afflicting the fetus. In the procedure, tissue is withdrawn from the villi (vascular fingers) of the chorion, a part of the placenta, and examined. Chorionic villus sampling is referred to commonly as CVS.
Chorionic Villus Sampling (CVS)
A procedure in which a small sample of cells are taken from the placenta through a small catheter placed up through the vagina and the cervix. This is done earlier in pregnancy than amniocentesis and is used to test for chromosomal and other biochemical abnormalities that may affect the health and well being of the baby.
Chorioretinitis
An inflammation of the back of the eye involving the choroid and retina. It may be due to a number of different diseases, which affect the body such as toxoplasmosis, histoplasmosis, sarcoidosis, tuberculosis and syphilis.
Choroideremia
Atrophy or decay of the choroid, choriocapillaris and Bruch’s membrane of the eye, leading to a severe loss of vision. Usually progresses to light perception by 50 years of age. Leads to night blindness tunnel vision and reduced visual acuity. No treatment available.
Choroiditis
An inflammation of the back of the eye involving the choroid and retina. It may be due to a number of different diseases, which affect the body such as toxoplasmosis, histoplasmosis, sarcoidosis, tuberculosis and syphilis.
PREVIOUS AND NEXT TERMS--------------------------------------
CAM Treatment
CAM is an abbreviation for Cambridge (England) where a new therapy for amblyopia was proposed that used rotating gratings (series of black and white bars). Patients would view the rotating gratings while they performed various drawing tasks on top of the rotating gratings. Research has shown, however, that CAM treatment is not effective at improving visual acuity in amblyopic children.
Carbidopa
Carbidopa is a peripheral decarboxylase inhibitor. Dopa decarboxylase is an enzyme that converts levodopa into dopamine - a major neurotransmitter and neuromodular of cellular function. Carbidopa is sometimes used to prevent the peripheral conversion of levodopa into dopamine in peripheral sites such as the gut, thus allowing more levodopa to reach the brain where it can have therapeutic effects.
Chalazion
In the eyelid there are a number of glands that produce lubricants for the cornea and eyelid. A Chalazion occurs when a gland become plugged, enlarged, or infected. The lid looks like it has a lump about the size of a small pea. Occasionally it occurs as a thickness within the lid. Warm compresses help some disappear; others require surgical removal by an Ophthalmologist.
Choroideremia
Atrophy or decay of the choroid, choriocapillaris and Bruch’s membrane of the eye, leading to a severe loss of vision. Usually progresses to light perception by 50 years of age. Leads to night blindness tunnel vision and reduced visual acuity. No treatment available.
Chorioretinitis
An inflammation of the back of the eye involving the choroid and retina. It may be due to a number of different diseases, which affect the body such as toxoplasmosis, histoplasmosis, sarcoidosis, tuberculosis and syphilis.
Choroid
Choroiditis
An inflammation of the back of the eye involving the choroid and retina. It may be due to a number of different diseases, which affect the body such as toxoplasmosis, histoplasmosis, sarcoidosis, tuberculosis and syphilis.
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.
Cone
One of the two light receiving retinal cells (the other is the rod) that is responsible for daylight vision (e.g., color vision, high visual acuity, bright light vision). The area of the retina that provides central or reading vision, known as the fovea, contains only cones.
Cone Dystrophy
Also sometimes referred to as cone degeneration. The cones of the eye degenerate over time leading to visual acuity between 20/50 and 20/200 – legal blindness. There may be a progressive vision loss, abnormal color vision and photophobia. No treatment is available, except for dark sunglasses for the photophobia. Patients with cone dystrophies and cone degenerations benefit for rehabilitation services.
Cone Rod Degeneration
Also called cone-rod dystrophy. Leads to a loss of visual acuity between 20/25 to 20/400 – legal blindness. First there is a loss of cone photoreceptors followed by a loss of rod photoreceptors. Visual fields may be restricted, abnormal color vision and photophobia. No treatment is available.
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This dictionary contains 19186 terms.
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