Glossary of Terms used in The Medical Biochemistry Page

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acanthosis nigricans brown to black, poorly defined, velvety hyperpigmentation of the skin
afferent neurons neurons that project into the cortex of the brain; sensory neurons are afferents
amenorrhea lack of menses
angiokeratoma benign cutaneous injury of capillaries resulting in small lesions on the skin; typically having a red to blue color
angiokeratoma corporus diffusum hyperkeratinized deep-red to blue-black skin lesions
anion gap defined as difference in concentration of cations other than Na+ and anions other than Cl and HCO3: value deteremined by equation as follows [Na+ – (Cl + HCO3)]
apoptosis term defining the process of programmed cell death
arachnodactyly abnormally long and slender fingers and toes
arcus cornea whitish ring on the peripheral cornea
argonaute proteins that are components of the RISC
articular cartilage cartilage covering the bony ends of the articulating joints
ataxia inability to coordinate voluntary muscle movements; unsteady movements and staggering gait
atheromas fat deposits in the arteries
atherosclerosis condition in which an artery wall thickens as the result of a build up of fatty materials such as cholesterol
atlantoaxial subluxation a mis-alignment between the 1st and 2nd cervical vertebrae
axial hypotonia a floppiness associated with the inability to sit

B    top

Babinski reflex the great toe flexes toward the top of the foot and the other toes fan out after the sole of the foot has been firmly stroked; also known as the extensor plantar reflex
bilirubin encephalopathy characterized by yellow discoloration of the basal ganglia in babies with intense jaundice; commonly referred to as kernicterus
bradykinesia slowed ability to start or stop movements
bromodomain domain in proteins that binds to acetylated lysines in histones
bronze diabetes bronze skin pigmentation seen in hemochromatosis, coupled with the resultant diabetes

C    top

calculi stones, such as those found in kidney or gall bladder
cherry-red spot a red circular area surrounded by gray-white retina as seen during an eye examination typical in lysosoaml storage diseases such as Tay-Sachs disease
choanal atresia blockage in the back of the nasal passage
chordae tendineae tendons that connect the papillary muscles to the tricuspid and mitral valves
choreoathetosis occurrence of involuntary movements in combination with chorea which itself refers to irregular, rapid, uncontrolled, and excessive movements
chromodomain domain in proteins that binds to methylated histones
Cooley anemia is thalassemia major which refers to thalassemias associated with total loss of β-globin (referred to as β0-thalassemia) or partial loss (referred to as β+-thalassemia)
coxa valga deformity of the hip where the angle formed between the head and neck of the femur and its shaft is increased
craniosynostosis premature fusion of the cranial sutures

D    top

decerebrate posturing an abnormal body posture that involves the arms and legs being held straight out, the toes being pointed downward, and the head and neck being arched backwards
dentigerous cysts an odontogenic cyst associated with the crown of an unerupted, or partially erupted, tooth
diaphyses the main or mid section (shaft) of the long bones
direct bilirubin when bilirubin is conjugated to glucuronate the measurement of this form of bilirubin does not require addition of alcohol to promote the azotization reaction used for determining bilirubin concentration
dolichocephaly elongated skull
dolichostenomelia condition of unusually long and thin extremities
dysarthria difficulty in articulating words caused by impairment of the muscles used in speech
dysmetria lack of coordination of movements characterized by under- or over-shooting intended position
dysmorphic relating to a body characteristic that is abnormally formed
dysphagia disordered eating
dysplasia abnormal development or growth of tissues, organs, or cells
dystonia abnormal tonicity of muscle characterized by prolonged, repetitive muscle contractions that may cause twisting or jerking movements
dysostosis multiplex characterized by an enlarged skull, thickened calvarium, premature closure of lamboid and sagittal sutures, shallow orbits, enlarged J-shaped sella and abnormal spacing of the teeth with dentigerous cysts

E    top

ectopia lentis displacement of the crystalline lens of the eye
efferent neurons neurons that project out of the cortex of the brain; motor neurons are efferents
epigenetics refers to phenotype differences manifesting in the absence of genotype differences; acting on the gene as opposed to by the gene
epiphyseal relating to the growth area near the end of a bone
epistaxis relating to the nose
esophageal varices extremely dilated sub-mucosal veins in the esophagus
exomphalos an umbilical hernia at birth in which some abdominal organs push into the umbilical cord
extensor plantar response extension of the big toe and fanning of the other toes in response to stimulation of the bottom of the foot; more commonly known as the Babinski reflex

F    top

favism a condition characterized by hemolytic anemia (breakup of red blood cells) after eating fava beans (Vicia fava)

G    top

gingival relating to the gums
glucosuria excess urinary glucose output
guggulsterone also called guggul (or guggal) or guggul lipid; is an extract from the Commiphora mukul tree of India

H    top

hamartin protein encoded by the tuberous sclerosis 1 (TSC1) gene
hemarthroses bleeding in the joints
hemochromatosis a disorder in iron metabolism that is characterized by excess iron absorption, saturation of iron-binding proteins and deposition of hemosiderin (amorphous iron deposits) in the tissues
hemodialysis a method for removing waste products such as potassium and urea, as well as free water from the blood when the kidneys are in renal failure
hydrops fetalis a condition in the fetus characterized by an accumulation of fluid, or edema, in at least two fetal compartments, including the subcutaneous tissue, pleura, pericardium, or in the abdomen
hyperlordosis exaggerated lumbar curvature of the spine
hypermetric saccades fast movement of the eyes
hyperphagia excessive hunger and abnormally large intake of solid foods
hyperreflexia defined as overactive or over responsive reflexes
hypertelorism an abnormally increased distance between two organs or bodily parts, usually referring to an increased distance between the eyes
hypertrichosis excessive growth of hair in locations where it is not normally found
hypogonadism a defect of the reproductive system that results in lack of function of the gonads (ovaries or testes).
hypoplasia underdevelopment or incomplete development of a tissue or organ
hypotonia a disorder that causes low muscle tone (the amount of tension or resistance to movement in a muscle), often involving reduced muscle strength
hypsarrhythmia abnormal EKG patterns observed in infants suffering spasms

I    top

icteric yellowish
immunophilin intracellular proteins that binds to immunosuppressive drugs such as FK506 and rapamycin
imprinting process whereby expression of a given gene is determined by the parental origin; involves differential DNA methylation
incretin any substance/hormone that induces insulin release from the pancreas in response to food intake
indirect bilirubin when bilirubin is not conjugated to glucuronate the measurement of this form of bilirubin requires the addition of alcohol to promote the azotization reaction used for determining bilirubin concentration

K    top

kernicterus this is ilirubin encephalopathy which is characterized by yellow discoloration of the basal ganglia in babies with intense jaundice
kwashiorkor a form of malnutrition that occurs when there is not enough protein in the diet
kyphoscoliosis an abnormal curvature of the spine in both the coronal and sagittal planes, a term combined from kyphosis and scoliosis

L    top

leukopenia decreased white blood cell count
lipoxin anti-inflammatory eicosanoids synthesized through lipoxygenase interactions, hence the derivation of the name
lumbar lordosis excessive inward curvature of the lower spine

M    top

macrocephaly refers to a head circumference greater than two standard deviations above the mean for age, sex, race and gestation
macroglossia enlarged tongue
macroorchidism large testicles
menorrhagia an abnormally heavy and prolonged menstrual period at regular intervals
metabolic acidosis a disturbance in the body's acid-base balance that results in excessive acidity of the blood; due to increased production of H+ by the body or the inability of the body to form bicarbonate; usually causes rapid breathing, confusion or lethargy may also occur
metabolic alkalosis a disturbance in the body's acid-base balance that results in excessive alkalinity of the blood caused by an elevation in plasma bicarbonate (HCO3) concentration; in most cases, metabolic alkalosis is caused by loss of hydrochloric acid (HCl) through the kidney or GI tract, especially due to vomiting
metaphyses the wider portion of a long bone adjacent to the epiphyseal plate; the part of the bone that grows during childhood
microcephaly head circumference that is at least 2 standard deviations smaller than normal
micrognathia abnormally small lower jaw
myoclonic epilepsy a form of epilepsy associated with involuntary muscle twitching
myoclonus involuntary muscle twitching

N    top

neuropathy disease or abnormality in the nervous system
nystagmus involuntary eye movements

O    top

ocular proptosis abnormal protrusion of the eyeball
oculomotor apraxia difficulty in moving the eyes from side to side
odontoid hypoplasia decreased ossification of the odontoid bone which is the anterior process of the second vertebra
ophthalmoplegia paralysis or weakness of one or more of the muscles that control eye movement

P    top

paraparesis weakness in the lower extremities
parathesis  an abnormal sensation of the skin, such as numbness, tingling due to poor circulation in the limbs
pectus carinatum also called pigeon chest, is a deformity of the chest characterized by a protrusion of the sternum and ribs
pectus excavatum also called funnel chest, a condition in which the ribs and sternum grow inward producing a concave appearance of the anterior chest wall
peroxin name for any of several proteins/enzymes functioning in the peroxisomes; usually the proteins are identified as PEX followed by a number, e.g. PEX1
platyspodylia flatness of the bodies of the vertebrae
pneumothorax abnormal presence of air in the pleural cavity resulting in the collapse of the lung
polydactyly refers to extra fingers and/or toes
polydypsia increased thirst
polyphagia increased appetite
polysomes also called polyribosomes, are a cluster of ribosomes, bound to a mRNA
polyuria excess urinary water and electrolyte output
primary amenorrhea failure of menses to occur by age 16
prosaposin precursor protein for the saposins; designated as SAP-A, -B, C, and -D
proteosome machinery in the cell for targeted destruction of proteins
ptosis drooping eyelids
purpura fulminans hemorrhagic condition usually associated with infection or sepsis
purpuric skin bleeding bleeding from purplish patches on the skin

R    top

resolvin: Rv eicosanoid derivatives that have anti-inflammatory actions that lead to the resolution of the inflammatory cycle, hence the derivation of their names as resolvins
respiratory acidosis abnormal decrease in the pH of the blood (acidosis) due to decreased ventilation of the pulmonary alveoli, leading to elevated arterial carbon dioxide concentration; primarily caused by alveolar hypoventilation
respiratory alkalosis results from increased alveolar respiration (hyperventilation) leading to decreased plasma carbon dioxide concentration which leads to decreased hydrogen ion and freely ionized blood calcium concentrations
ristocetin an antibiotic isolated from Amycolatopsis lurida that used to be used to treat staphylococcal infections. Ristocetin induces binding of von Willebrand factor to platelet glycoprotein Ib (GPIb)

S    top

saposin any member of a small glycoprotein family required for the hydrolysis of sphingolipids by specific lysosomal hydrolases; identifed as SAP-A, -B, -C, and -D
scoliosis a medical condition in which a person's spine is curved from side to side, shaped like an "S"
sirtuin human homolog of yeast silent information regulator 2, Sir2
spastic paraparesis characterized by spasms associated with weakness in the lower extremities
steatosis describing the abnormal retention of lipids within a cell. It reflects an impairment of the normal processes of synthesis and elimination of triglyceride fat
strabismus a disorder in which the eyes do not line up in the same direction when focusing
syndactyly fusion of the fingers and/or toes, results in webbing of the digits, occurs with a frequency of 1 in 2,000 to 1 in 3,000 live births making it the most common congenital malformation of the limbs

T    top

telangiectasias small dilated vessels near the surface of the ski
tenase complex clotting cascade protein complex
thalassemia a term relating to any genetic defect that results in reduced rate of synthesis of one of the globin chains that make up hemoglobin
thrombocytopenia low platelet count
tophaceous deposits sandy, gritty, nodular masses of urate crystals typical in patients with gout
tuberin protein encoded by the tuberous sclerosis 2 (TSC2) gene


urolithiasis urate kidney stones


visceromegaly enlargement of the internal organs in the abdomen, such as liver, spleen, stomach, kidneys, or pancreas


xanthomas fat deposits in the skin and tendons

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Michael W King, PhD | © 1996–2016, LLC | info @

Last modified: February 19, 2015