Nutrition processes refer to the series of actions and reactions involved in the intake, absorption, transportation, assimilation, biosynthesis, and excretion of nutrients by our body. These processes are essential for growth, repair, maintenance, energy production, and overall health and well-being.

The nutrition process begins with the ingestion of food, which is then broken down into simpler molecules during digestion. These molecules are absorbed into the bloodstream and transported to various cells and tissues throughout the body. Once inside the cells, they undergo further chemical reactions to produce energy, synthesize new proteins and DNA, and maintain cellular function.

The waste products generated from these processes are then excreted from the body through various routes such as urine, feces, sweat, and breath. Proper nutrition processes are critical for optimal health, and any disruptions or imbalances in these processes can lead to diseases and other health complications.

Parenteral nutrition (PN) is a medical term used to describe the delivery of nutrients directly into a patient's bloodstream through a vein, bypassing the gastrointestinal tract. It is a specialized medical treatment that is typically used when a patient cannot receive adequate nutrition through enteral feeding, which involves the ingestion and digestion of food through the mouth or a feeding tube.

PN can be used to provide essential nutrients such as carbohydrates, proteins, fats, vitamins, minerals, and electrolytes to patients who have conditions that prevent them from absorbing nutrients through their gut, such as severe gastrointestinal tract disorders, malabsorption syndromes, or short bowel syndrome.

PN is administered through a catheter that is inserted into a vein, typically in the chest or arm. The nutrient solution is prepared under sterile conditions and delivered through an infusion pump to ensure accurate and controlled delivery of the solution.

While PN can be a life-saving intervention for some patients, it also carries risks such as infection, inflammation, and organ damage. Therefore, it should only be prescribed and administered by healthcare professionals with specialized training in this area.

Total Parenteral Nutrition (TPN) is a medical term used to describe a specialized nutritional support system that is delivered through a vein (intravenously). It provides all the necessary nutrients that a patient needs, such as carbohydrates, proteins, fats, vitamins, and minerals. TPN is typically used when a patient cannot eat or digest food through their gastrointestinal tract for various reasons, such as severe malabsorption, intestinal obstruction, or inflammatory bowel disease. The term "total" indicates that the nutritional support is complete and meets all of the patient's nutritional needs.

Enteral nutrition refers to the delivery of nutrients to a person through a tube that is placed into the gastrointestinal tract, specifically into the stomach or small intestine. This type of nutrition is used when a person is unable to consume food or liquids by mouth due to various medical conditions such as swallowing difficulties, malabsorption, or gastrointestinal disorders.

Enteral nutrition can be provided through different types of feeding tubes, including nasogastric tubes, which are inserted through the nose and down into the stomach, and gastrostomy or jejunostomy tubes, which are placed directly into the stomach or small intestine through a surgical incision.

The nutrients provided through enteral nutrition may include commercially prepared formulas that contain a balance of carbohydrates, proteins, fats, vitamins, and minerals, or blenderized whole foods that are pureed and delivered through the feeding tube. The choice of formula or type of feed depends on the individual's nutritional needs, gastrointestinal function, and medical condition.

Enteral nutrition is a safe and effective way to provide nutrition support to people who are unable to meet their nutritional needs through oral intake alone. It can help prevent malnutrition, promote wound healing, improve immune function, and enhance overall health and quality of life.

A nutrition survey is not a medical term per se, but it is a research method used in the field of nutrition and public health. Here's a definition:

A nutrition survey is a study design that systematically collects and analyzes data on dietary intake, nutritional status, and related factors from a defined population or sample. It aims to describe the nutritional situation, identify nutritional problems, and monitor trends in a population over time. Nutrition surveys can be cross-sectional, longitudinal, or community-based and may involve various data collection methods such as interviews, questionnaires, observations, physical measurements, and biological samples. The results of nutrition surveys are used to inform nutrition policies, programs, and interventions aimed at improving the nutritional status and health outcomes of populations.

Nutritional Sciences is a field of study that deals with the scientific examination and understanding of nutrients in food, how the body uses them, and the relationship between diet, health, and disease. It encompasses various disciplines including biochemistry, physiology, molecular biology, epidemiology, and clinical nutrition.

The field covers several key areas such as:

1. Nutrient metabolism: This involves studying how nutrients are digested, absorbed, transported, stored, and utilized in the body for energy production, growth, maintenance, and reproduction.
2. Diet and disease prevention: Nutritional sciences investigate the role of diet in preventing or managing various health conditions like obesity, diabetes, cardiovascular diseases, and cancer.
3. Functional foods and nutraceuticals: This area focuses on studying the potential health benefits of specific foods or food components beyond their basic nutritional value, including functional foods (foods that have demonstrated health benefits) and nutraceuticals (nutrient-rich supplements derived from food sources).
4. Public health nutrition: Nutritional sciences also address population-wide nutrition issues, such as malnutrition, food insecurity, and the development of public policies related to food and health.
5. Clinical nutrition: This subfield applies nutritional principles and research findings to patient care, focusing on developing individualized dietary plans for patients with various medical conditions.

Overall, Nutritional Sciences aims to provide a solid scientific foundation for making informed dietary choices and promoting optimal health outcomes across populations and individuals.