1. Memmler’s The Human Body in Health and Disease 11th edition
Chapter 20
Metabolism, Nutrition and Body Temperature
Memmler’s The Human Body in Health and Disease 11th edition

2. Metabolism
*Remember: All of the life-sustaining reaction that occur within the body systems (energy is generated and used)
Two categories
Catabolism
Breakdown complex compounds into simpler compounds (digestion)
Anabolism
Building simple compounds into needed substances (building of bones)

3. Cellular Respiration
Energy released from nutrients in a series of reactions
Occurs in mitochondria
Anaerobic and aerobic phases

4. The Anaerobic Phase The Aerobic Phase Occurs in mitochondria
Occurs in cytoplasm
Yields 2 ATP molecules per glucose molecule
Product is pyruvic acid
The Aerobic Phase
Occurs in mitochondria
Yields ATP molecules per glucose molecule
Product is carbon dioxide and water

5. Metabolic Rate
Rate at which energy is released from nutrients in cells
Decreases with age
Measured in kilocalories (kcal)
We need to maintain this to continue
the basic life functions (homeostasis)

6. The Use of Nutrients for Energy
Glucose is main source of energy
Reserves stored in liver and muscle cells as glycogen
We get this mainly from carbohydrates
Other energy sources
Glycerol and Fatty acids (from fat digestion)
Amino Acids (from protein digestion)
* Before proteins can be used for energy, they must have nitrogen removed from them. The removal is done in the liver and the kidneys excrete them.

7. Anabolism (nutrients built this way)
Reactions catalyzed by enzymes!
There are 20 amino acids (Building blocks of protein)
Nonessential amino acids
- 11 can be synthesized in body
Essential amino acids
Nine of 20 must be eaten
Essential fatty acids
Linoleic acid and linolenic acid (obtained in diet)

8. Minerals and Vitamins
Minerals are chemical elements (some are parts of vitamins)
Body structure pg – Table 20-3
Fluid balance and Table 20-4
Muscle contraction
Nerve impulse conduction
Blood clotting
Vitamins are complex substances (parts of enzymes)
Water soluble – must be taken in
Fat soluble – kept in reserve in fatty tissue
Antioxidants
Stabilize free radicals (unstable molecules that lead to aging and disease)

9. Nutritional Guidelines
Percentage of calories in daily diet
Carbohydrate: 55 – 50%
Fat: 30% or less
Protein: 15 – 20%

10. Carbohydrates - Diet should be mainly complex, naturally occurring
(- grains, legumes, potatoes)
Normal blood glucose range 85 to 125 mg/dL
Glycemic effect measures how rapidly food raises blood glucose level, stimulates release of insulin (very important in teaching diabetics)
- grains, legumes, potatoes, fruit

11. Fats Saturated Most are from animal sources Solid at room temperature
Associated with heart disease and cancer)
(should make up less than 10% of fat intake)
Unsaturated
Derived from plants
Liquid at room temperature

12. Proteins Not stored in body (should be taken in all the time)
Most animal proteins supply all essential amino acids
Most vegetable proteins lack one or more essential amino acids (so, vegans need to combine foods)

13. Vitamin and Mineral Supplements
Supplements are controversial
Some populations may benefit
Some vitamins cause toxic effects when taken in excess
(- This is important for your patient teaching)

14. Alcohol
Not a nutrient
Interferes with metabolism and contributes to a variety of disorders
Should be consumed in moderation
Advise pregnant women against alcohol consumption

15. Nutritional Disorders
- Diet related disorders result from:
Excess of nutrients
Shortage of nutrients
- Issues now that are important to know:
Weight control
Food allergies (teach patients about common allergens)

16. Food Allergies Allergens can be food or food additives
Allergic reactions involve
Skin
Respiratory tract
Gastrointestinal tract
Reactions can develop anytime and can be fatal

17. Malnutrition - Can occur from missing nutrients or too much of wrong
Foods
If any vital nutrient is missing from the diet, malnutrition will occur
Watch for in elderly population (important for healing process)

18. Overweight and Obesity
Causes are complex
Incidence is increasing
Shortens life span
Measured by body mass index (BMI)
Overweight is BMI of 25 – 30
Obese is BMI greater than 30

19. Underweight Low reserves of energy Reproductive disturbances
Nutritional deficiencies
BMI less than 18.5

20. Nutrition and Aging Nutritional deficiencies may develop
Medications may interfere with appetite and absorption

21. Body Temperature
Heat is byproduct of chemical activities in body tissues
Regulatory devices keep body temperature constant within narrow limits
Homeostasis !!

22. Heat Production Amount of heat produced by organs affected by Exercise
Hormone production
Food intake
Age

23. Heat Loss More than 80% of heat loss occurs through skin Conduction
Radiation
Convection
Evaporation
15-20% heat loss through respiration and elimination
Heat loss prevention
Clothing
Fat layer under skin
*** children lose heat more rapidly

24. Temperature Regulation
Body has internal mechanisms for regulating temperature - hypothalamus

25. The Role of the Hypothalamus
Regulation of
Heat loss (protective mechanism)
Constrict skin blood vessels
Shiver
Increase cell metabolism
Overheating
Stimulate sweat glands
Dilate skin blood vessels
Muscle relaxation

26. Age Factors Newborns and elderly Reduced ability to produce heat
Reduced ability to regulate overheating

27. Normal Body Temperature
Normal range is 36.3ºC to 37.6ºC (97.8ºF to 100.8ºF)
Varies with time of day
Varies by body part :
- axilla is lower than oral & rectal is higher than oral

28. Fever Higher than normal body temperature (febrile – with fever)
Causes
Infection
Malignancies
Brain injuries
Toxic reactions
Vaccine reactions
Central nervous system diseases
Drugs that reduce fever are antipyretics
Febrile seizures – most occur due to a sudden spike in temperature;
can be CNS related

29. Responses to Excessive Heat
Heat cramps
Localized muscle cramping
Heat exhaustion
Heat retention and fluid loss
Heat stroke
Medical emergency that can be fatal

30. Responses to Excessive Cold
Hypothermia
Excessively low body temperature
Used in some types of surgery
Frostbite
Can cause permanent local tissue damage
Likely areas are face, ears, extremities

31. End of Presentation