Diabetes Glossary Terms: L-P

the breakdown of lipids into fatty acids via the action of the enzyme lipase.

a protein that has a fatty acid molecule attached to it. They are important in certain processes, e.g. transporting cholesterol.

a thin composite layer of lipoprotein surrounding an individual cell.

the sum of all the physical and chemical changes within cells and tissues that maintain life and growth. The breakdown processes that occur are known as catabolic (catabolism), and those that build materials up are called anabolic (anabolism). The term may also be applied to describe one particular set of changes, e.g. protein metabolism. Basal metabolism is the minimum amount of energy required to maintain the body's vital processes, e.g. heartbeat and respiration, and is usually assessed by means of various measurements taken while a person is at rest.

a group of genes located on chromosome 6, which code for the HLA antigens.

a neurotransmitter of the sympathetic nervous system secreted by nerve endings and also the adrenal glands. It is similar to adrenaline in structure and function. It increases blood pressure by constricting the vessel, slowing heartbeat and increasing breathing in both rate and depth.

a gland with both endocrine and exocrine functions. It is located between the duodenum and spleen, behind the stomach, and is about 15 cm long. There are two types of cells producing secretions. The acini produce pancreatic juice that goes to the intestine via a system of ducts. This contains an alkaline mixture of salt and enzymes - trypsin and chymotrypsin to digest proteins, amylase to break down starch and lipase to aid digestion of fats. The second cell types are in the islets of Langerhans, and these produce two hormones, insulin and glucagon, secreted directly into the blood for control of sugar levels.

inflammation of the pancreas, occurring in several forms but often associated with gallstones or alcoholism. Any bout of the condition that interferes with the function of the pancreas may lead to diabetes and malabsorption.

a small, but very important endocrine gland at the base of the hypothalamus. It has two lobes, the anterior adenohypophysis and the posterior neurohypophysis. The pituitary secretes hormones that control many functions and is itself controlled by hormonal secretions from the hypothalamus. The neurohypophysis stores and releases peptide hormones produced in the hypothalamus, namely oxytocin and vasopressin. The adenohypophysis secretes growth hormone, gonadotrophin, prolactin (involved in stimulating lactation), ACTH and thyroid-stimulating hormones.

a light-coloured fluid component of blood in which the various cells are suspended. It contains inorganic salts with protein and some trace substances. One protein present is fibrinogen.

the passing of a larger than normal quantity of urine, which is also usually pale in colour. It may be the result merely of a large fluid intake or of a condition such as diabetes or a kidney disorder.