ADLs #2 - Midterm Flashcards
Define nutrition.
Processes involved in the ingestion, digestion, absorption, and use of foods and fluids by the body.
What are factors greatly affected by what we eat?
- life expectancy
- personality
- behaviour
- energy level
- sense of well-being
Since early in childhood, food becomes associated with:
- celebration
- consolation
- reward
- punishment
- symbol of love
- part of social gatherings
Briefly describe the function of the digestive system.
- for the body to get energy from the food we eat, the food must first be changed into a form that can be absorbed into the bloodstream and carried to the cells
- where digestion occurs
- starts in the mouth and is completed in the intestines
- has a chemical and mechanical component
Digestion
Process of changing food into a useable form for the body that takes place in the digestive system.
Digestive system: Mouth
- food enters digestive system through mouth
- food is chewed and mixed with saliva
- the tongue and automatic muscle movements in the pharynx moves food out of the mouth and into the esophagus = swallowing
- larynx automatically closes off the passage to the lungs at the time that swallowing occurs
Digestive system: Esophagus
- connects to the stomach
- a muscular tube that helps move food particles into the stomach
- peristalsis moves nutrients down the esophagus into the stomach (involuntary muscle contractions)
Digestive system: Stomach
- a temporary storage place for food
- churns and mixes (mechanical action) at the same time that food is being broken down by acids (chemical action)
- lined with a mucous membranes which protects the stomach that contains glands that secrete gastric juices (contains strong acids)
- digestive juices mix with the food particles to form a semi-liquid substance called chyme
- can take 3-5 hours
Digestive system: Small intestine
- 6 metres long
- most important area of digestion
- most of the job of breaking food down into usable parts takes place here
- important chemical changes take place here
- proteins and fats are changed into forms that can be absorbed
- made up of the duodenum, jejunum and ileum
- has tiny projections called villi that line the small intestine and absorb the digested nutrients into capillaries
Digestive system: Duodenum
- where more digestive juices are added to the chyme
- the juices chemically break down the nutrients so that they can absorbed
Digestive system: Jejunum and ileum
-most of the absorption of nutrients takes place in these two places
Digestive system: Liver
- helps the small intestine with its activities
- metabolizes fats, proteins and carbohydrates
- detoxifies substances from blood
- stores fat-soluble vitamins
- produces bile, cholesterol and bilirubin
Digestive system: Gall bladder
- the digestive juices is bile (greenish liquid) produced by the liver and is then stored in the gall bladder
- bile aids in digestion of fat and absorption of fat-soluble vitamins
- gives stool its brownish colour
Digestive system: Pancreas
- secretes enzymes for digestion
- juices from pancreas and small intestine are added to chyme
Digestive system: Large intestine
- final phase of digestion
- what is left of the chyme after it has passed through the small intestine enters this area where water is absorbed
- any leftover material that cannot be used by the body is called feces and is expelled from the body through the anus
Define nutrients.
Substances that are ingested, digested, absorbed and used by the body.
Nutrients: Protein
- for growth and repair of tissues, blood clotting and fight against infection and disease
- can be complete (contains all the amino acids needed by the body) or incomplete proteins
- complete proteins found in eggs, meat, fish and milk
- incomplete proteins found in vegetables, legumes and grains (but can be combined to be receive complete proteins
- foods high in proteins are usually expensive and lack in diet of people with low income
Nutrients: Carbohydrates
- found in sugar, breads, cereals, fruits and vegetables
- seldom lacking in diet of people around the world
- supply energy for heat and activity, provide fibre for bowel elimination (fibre not digested so provides bulk that helps pass wastes from the body)
Nutrients: Fats
- provide energy but not as easily used by the body as carbohydrates so are saved for emergencies when carbohydrates are not available
- adipose tissue (body fat) that helps conserve body heat and forms a protective cushion around internal organs
- fat makes food taste good
- found in butter, margarine, oils, cheese, milk, eggs, chocolate, salad dressing, cream and ice cream
Nutrients: Vitamins
- essential for body functioning
- help to promote growth, increase resistance to disease, build strong teeth and bones
- vitamin A,D,E,K are fat-soluble and can be stored by the body
- vitamin B,C are water-soluble and must be ingested daily
Nutrients: Minerals
- help build body tissues (bones and teeth) and help with nerve function
- calcium, phosphorous, iron, iodine, sodium and potassium
Nutrients: Water
- 3/4 of body weight is water
- aids in digestion and elimination, controls body temperature, lubricates moving parts
- water enters body in beverages like milk, juice, soup and fruit
- water is not in sugar, pure fats, oils
- people can live a few weeks without food but only a few days without water
- drink at least 200 mL of water every day
Which are the best sources of energy and why?
- complex carbohydrates (grains, cereal, fruit, vegetables) are the best because they take longer to digest
- simple carbohydrates (donuts, potato chips) are broken down very quickly and easily stored as fat by the body
- 1 gram of protein or carbohydrate produces 28 kJ
- 1 gram of fat supplies 63 kJ
If you eat 3 grams of carbohydrate, 4 grams of protein and 2 grams of fat, which will give you the most calories in kJ?
3 grams of carbohydrate = 328kJ = 84kJ
4 grams of protein = 428kJ = 112kJ
2 grams of fat = 2*63kJ = 126kJ