Digestive system hormones

The administration of drugs to ease disease and chronic, severe pain or to provide benefits such as hormone replacement therapy is difficult because drugs taken orally may lose much of their potency in the harsh conditions of the digestive system. In addition, they are distributed throughout the entire body, not just where they are needed, and side effects can be significant. Recently, however, techniques have been developed to deliver drugs gradually over time, to the exact location in the body where they are needed, and even at the time when they are needed. 

Explain how the following mechanisms regulate activity of the digestive system intrinsic nerve plexuses, extrinsic autonomic nerves, and gastrointestinal hormones... 

The more classical Itinehoii of parathyroid hormone is concerned with its control of the maintenance of constant circulating calcium levels. Its action is on 11) Ihe kidney, where it increases the phosphate in the urine. (2) the skeletal system, where it causes calcium resorplion from bone, and t3l the digestive system, where it accelerates (stimulates) calcium absorption into the hitskI The hormone and gland exhibit characteristics of feedback control when the concentration of calcium tons in the blood falls, the secretion of the hormone increases, and when their concentration rises, the secretion of hormone decreases... 

PANCREATITIS Inflammation of the pancreas, an essential part of both the endocrine and the digestive systems. The pancreas secretes juices that aid in digestion, and a number of hormones (including insulin). 

In addition to growth factors, it has been shown that countless other molecules have multiple functions. Cholecystokinin, for example, is a peptide that acts as a hormone in the intestine, where it increases the bile flow during digestion, whereas in the nervous system it behaves as a neurotransmitter. Encephalins are sedatives in the brain, but in the digestive system are hormones that control the mechanical movements of food. Insulin is universally known for lowering the sugar levels in the blood, but it also controls fat metabolism and in other less known ways it affects almost every cell of the body. 

Proteins are needed in the body for amino acids. Proteins are broken down in the digestive system to form amino acids which are then absorbed by the rest of the body to form new proteins in the form of vital body tissues such as muscle, connective tissue, and skin. There are two types of protein, fibrous and globular proteins. Fibrous protein is insoluble and goes into making the structural tissues of the body. Globular protein forms amino acids that become enzymes and hormones and other vital parts of cellular functioning within the body. 

Dietary triglycerides, 226, 319-320, 366-367 Digestion, see also AbsorpOon Digestive hormones Digestive molecules Digestive system carbohydrates, 10(3-116 control, 58,88 Cephalic phase, 66-68 chemical phase, 69 innerv ation, 58,66-69 dietary bbers. 143 lipids, 93-103... 

The human immune system is complex and involves the digestive tract, the blood and lymph systems, hormones, and many other specialized cells that enable the human body to respond to exogenous substances that may come in contact with the body. This ranges from fighting off an E. coli infection to healing a small cut. 

Control mechanisms for the food intake of farm animals can be envisaged as operating at three levels. At the metabolic level, concentrations of nutrients, metabolites or hormones may stimulate the nervous system to cause the animal to start or stop feeding. At the level of the digestive system, the quantities of digesta may determine whether or not the animal ingests more food. Finally, external influences such as climatic variables and the ease with which food can be ingested will also influence food intake. In... 

Niacin is vital for energy release in tissues and cells. Working with riboflavin and thiamin, it helps to maintain healthy nervous and digestive systems. It is essential for growth and is involved in the synthesis of hormones. 

CCK is found in the digestive tract and the central and peripheral nervous systems. In the brain, CCK coexists with DA. In the peripheral nervous system, the two principal physiological actions of CCK are stimulation of gaU. bladder contraction and pancreatic enzyme secretion. CCK also stimulates glucose and amino acid transport, protein and DNA synthesis, and pancreatic hormone secretion. In the CNS, CCK induces hypothermia, analgesia, hyperglycemia, stimulation of pituitary hormone release, and a decrease in exploratory behavior. The CCK family of neuropeptides has been impHcated in anxiety and panic disorders, psychoses, satiety, and gastric acid and pancreatic enzyme secretions. 

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