Digestive System: Functions, Structures, and Nutritional Care

Digestive Process and Key Terms

Digestion converts carbohydrates, fats, and proteins into simpler units for absorption. Insulin, secreted by the pancreas, regulates blood glucose. Heartburn is a burning sensation in the chest. Dysphagia is difficulty swallowing. A sphincter is a ring of circular muscle fibers. Sensory properties involve color, texture, etc. Metabolism encompasses chemical and physical processes in cells. Enteral nutrition is provided through the intestinal tract. Parenteral nutrition is administered by puncturing. Basal metabolism is the minimum energy expenditure for life processes. Bromatology studies food, its storage, and processing.

Role of Nutrition and Diet Concepts

Nutrition provides energy (carbohydrates, fats, proteins), regulates metabolic processes (vitamins, minerals), and supports tissue growth/repair (proteins). Power involves obtaining and preparing food for ingestion (oral, enteral, parenteral). Diet is the food consumed over time, considering health or disease. Nutrition encompasses ingestion, digestion, absorption, distribution, metabolism, and waste elimination. A basal diet has no restrictions, while preventive or therapeutic diets address specific health conditions.

Enteral Nutrition and Nutrients

Enteral Nutrition: Indications and Complications

Enteral nutrition serves as the main diet, dietary supplement, or complementary diet via sonda. Objectives include meeting caloric needs and maintaining intestinal function in malnourished patients or those with swallowing difficulties. Administration routes include nasogastric, oroduodenal, and jejunostomy. Complications can be mechanical, metabolic, infectious, or gastrointestinal.

Basic Nutrients

Essential nutrients include carbohydrates, lipids, proteins, vitamins, and minerals. Macronutrients (carbohydrates, proteins, lipids) provide energy, while micronutrients (vitamins, minerals, trace elements) support various bodily functions.

Carbohydrates

Carbohydrates include simple sugars (glucose, fructose, lactose) and complex carbohydrates (starch, cellulose, pectin).

Lipids

Lipids (fats) are composed of carbon, hydrogen, and oxygen. They include saturated, unsaturated, and trans fatty acids, phospholipids, and cholesterol.

Balanced Diet and Energy Intake

A balanced diet provides the necessary energy and nutrients for optimal health, considering individual activity levels and energy needs.

Digestive System Structures

Mouth to Esophagus

The mouth (oral cavity) includes lips, cheeks, teeth, gums, tongue, and palate. The pharynx is involved in both respiration and digestion. The esophagus transports food to the stomach via peristalsis.

Stomach and Intestines

The stomach secretes hydrochloric acid and mucin. The small intestine (duodenum, jejunum, ileum) absorbs nutrients. The large intestine (cecum, colon, rectum) absorbs water and eliminates waste.

Accessory Organs

Salivary glands produce saliva. The liver produces bile, stores glucose and minerals, and participates in metabolism. The gallbladder stores bile. The pancreas produces insulin, glucagon, and digestive enzymes.

Digestion, Absorption, and Disorders

Saliva contains enzymes like amylase. Digestive enzymes break down carbohydrates (disaccharidases), fats (lipases), and proteins (peptidases, enterokinase). Absorption is the process of nutrients entering the bloodstream. Disorders include esophageal, gastric, and intestinal issues (celiac disease, lactose intolerance), liver and gallbladder diseases (cirrhosis, gallstones), and pancreatic conditions (pancreatitis, diabetes).

Ostomy Care and Nutritional Support

Ostomized Patients

An ostomy is a surgically created opening connecting an internal organ to the outside. Types include ileostomy and colostomy (ascending, transverse, descending, sigmoid), which can be temporary or permanent.

Stoma and Skin Care

Stoma care involves proper appliance fit, peristomal skin protection, and secure fixation. Skin care includes gentle cleansing, drying, measuring the stoma, and using appropriate devices. Complications can be early (necrosis, collapse, hemorrhage, infection, edema) or late (hernia, prolapse, skin irritation).

Nasogastric Tubes and Rectal Catheters

Nasogastric tubes are used for feeding, aspiration, or decompression. Rectal catheters are inserted through the anus for administering medications or draining fluids.