ANAPHY: U13.3 Digestive System (Nutrition, Metabolism, Body Temperature Regulation)

Nutrition

Process by which food is taken into and used by the body

Includes ingestion, digestion, absorption, transport and metabolism

Ingestion, digestion, absorption, transport, metabolism

What 5 methods are included in nutrition?

Nutrients

Chemicals used by the body; consist of CHO, CHON, lipids, vitamins, minerals and water

Carbohydrates, Proteins, Lipids, Vitamins, Minerals, Water

What are 6 chemicals nutrients consist of?

Vitamins, Minerals, H2O

What nutrients are taken into the body as they are?

Trace Elements

Nutrients needed in small amounts

Essential Nutrients

Nutrients needed by body and cannot be produced by body

MyPlate

Serves as visual reminder for making choices at mealtime, half the meal should be fruits and vegetables

Kilocalorie

Energy required to raise the temperature of 1,000 grams of water 1 degree centigrade

Calorie

Unit of measurement used to express the energy content of food

Large Polysaccharides, Starch, Glycogen, Cellulose

4 Types of Complex Carbohydrates

Starch

Energy-storage molecules in plants

Glycogen

Energy-storage molecules in animals, located mainly in muscle and liver

Cellulose

Forms plant cell walls; served as fiber and give bulk to feces

Glucose

Energy source used to produce ATP

Excess of this leads to glycogen or lipid

Sugar forms part of DNA, RNA & ATP

Combine with protein form glycoproteins

ATP, DNA, RNA

What is glucose used to produce?

Glycogen or Lipids

What does excess glucose lead to?

Glycoproteins

When glucose combines with protein, what is formed?

Acceptable Macronutrient Distribution Range (AMDR)

(From Google)

Recommended percentage range of calories that should come from each macronutrient (carbohydrates, protein, and fat) in a healthy diet

45-65%

What is the AMDR for Carbohydrates?

Triglycerides, steroids, phospholipids & fat-soluble vitamins

What are 4 types of lipids?

Triglyceride

What is the most common type of lipid in the diet?

Monounsaturated Fat & Polyunsaturated Fat

2 Types of Unsaturated Fats

Monounsaturated Fat

One type of unsaturated fat

From olive and peanut oils

Polyunsaturated Fat

One type of unsaturated fat

From fish, sunflower and corn oils

Hydrogenated Oil

Liquid fat processed to solid form; becomes harder in room temperature

Trans Fat

What type of fat is hydrogenated oil?

Increase LDL & decrease HDL, risking cardiovascular disease

What is the effect of trans fatty acids, increasing risk of what?

Cholesterol

Steroid found in high concentrations in the brain, liver and egg yolks, whole milk, cheese, butter and meats; not found in plants

Phospholipids

Major components of cell membrane; found in variety of food like egg yolk

Lecithin

Example of a phospholipid

20-35% in adults

25-35% for children & adolescents

30-35% 2-3 y o children

What is the AMDR for Lipids based on age?

Triglycerides

Lipid that acts as a source of energy for ATP production

Pads organs, skin insulator that prevents heat loss

What is the main function of adipose tissue?

Cholesterol

What lipid is part of cell membrane; can become bile salts and steroid hormones (estrogen, progesterone and testosterone) regulating reproductive system?

Bile Salts & Steroid Hormones (Estrogen, Progesterone, Testosterone)

What can cholesterol become?

Phospholipids

What lipid is part of cell membrane and form myelin sheath?

Lecithin

Present in bile to emulsify fats

Eicosanoids

From fatty acids, involved in inflammation, tissue repair, and smooth muscle contractions

Linoleic acid and alpha-linolenic acid

2 essential fatty acids, found in plant oils like canola & soybean oil

Linoleic Acid

One of the essential fatty acids, found in plant oils like canola & soybean oil

Converted to arachidonic acid that produce prostaglandins & increase blood clotting.

Arachidonic Acid

What does linoleic acid get converted into?

Produces prostaglandins, increasing blood clotting

What does arachidonic acid produce, causing what?

Alpha-Linolenic Acid

One of the essential fatty acids, found in plant oils like canola & soybean oil

Converted to eicosapentaenoic acid (ePa) that produce prostaglandins that decrease blood clotting. Food rich with EPA: salmon, tuna, sardines increase synthesis of prostaglandins that < blood clotting. Fish oil supplements are alternatives.

Eicosapentaenoic Acid (ePa)

What is Alpha-Linolenic Acid converted into?

Produces prostaglandins that decrease blood clotting

What does Eicosapentaenoic Acid (ePa) produce, causing what?

Salmon, Tuna, Sardines, Fish Oil Supplements

Examples of food rich in ePa

Animal Proteins (like red meat, fish, poultry, egg, cheese)

What tend to be complete in protein?

Plant Proteins (like leafy green veg, grains and legumes)

What tend to be incomplete in protein?

1. Structural Strength

2. Muscle Contraction

3. Regulation

4. Buffering

5. Clotting

6. Transport

7. Ion Channels

8. Receptors

9. Immune System

9 Functions/Uses of Proteins

10-35%

What is the AMDR for proteins?

CHON

What elements compose proteins?

Vitamins

Organic molecules found in minute quantities in food & essential to normal metabolism

Provitamin

Refer to part of vitamin that can be modified into a functional vitamin ( Beta carotene to vit A)

Fat-Soluble & Water-Soluble

2 Categories of Vitamins

Vitamins ADEK

Fat Soluble Vitamins

Vitamins B & C

Water Soluble Vitamins

Recommended Dietary Allowance (RDA)

Guide for estimating nutritional needs based on age, gender & other factors

Minerals

Inorganic nutrients, essential for normal metabolic functions

1. Establishing resting membrane potential

2. Generating action potential

3. Strength of bones & teeth

4. Acting as coenzymes

5. Buffers or regulators of osmotic pressures

What are 5 processes minerals are involved in?

Daily Values

Dietary references that can be used to plan a healthful diet; Appear on food labels.

Metabolism

Total of all chemical reactions that occur in the body

Catabolism & Anabolism

2 Types of Metabolism

Catabolism

Type of metabolism

Energy-releasing process by which large molecules are broken down to smaller ones

Anabolism

Type of metabolism

Energy-requiring process by which small molecules are joined to form larger ones.

Cellular Metabolism

Chemical reactions within cells

Carbohydrates (CHO), Protein (CHON), Lipids

What macronutrients can be a source of ATP?

Active transport, muscle contraction and molecular synthesis

What are 3 ways energy from ATP is used for?

Absorptive State & Postabsorptive State

2 Types of Metabolic States

Absorptive State

Type of metabolic state

After a meal, nutrients are used as energy, with some being stored.

Last about 4hrs after each meal.

4 hours

How long does the Absorptive State typically last after a meal?

Postabsorptive State

Type of metabolic state

Occurs late in the morning, late in the afternoon or during the night after each absorptive state is concluded.

Stored nutrients (glycogen, glycerol, amino acids) are converted and used for energy.

Glycogen, Glycerol, Amino Acids

During the Postabsorptive State, what are converted and used for energy?

Metabolic Rate

Total energy expenditure per unit of time

Body Temperature

Maintained by balancing heat input with heat loss

Heat

What does metabolism produce?

Radiation, Conduction, Convection, Evaporation

4 Ways Heat is Exchanged

Radiation

One way heat is exchanged

Heat gain or loss without physical contact

Conduction

One way heat is exchanged

Exchange of heat by direct contact

Convection

One way heat is exchanged

Transfer of heat between body & air/H20

Evaporation

One way heat is exchanged

Conversion of water into gaseous form

Greater the temp difference, the greater the rate of heat exchange

Relationship between temperature difference and heat exchange

Neural Circuits in the Hypothalamus

What keeps body temperature at a set point?

Vasodilation & Sweating

Increases heat loss from the body

Vasoconstriction & Shivering

Promotes heat gain by the body

Negative-Feedback Mechanism

What type of mechanism does body temperature follow?