Essentials of Anatomy and Physiology

your own metabolic rate. A number of factors affect
the metabolic rate of an active person:

1. Exercise—Contraction of skeletal muscle increases
   energy expenditure and raises metabolic rate (see
   Box 17–5: Weight Loss).
   2. Age—Metabolic rate is highest in young children
   and decreases with age. The energy require-
   ments for growth and the greater heat loss by a
   smaller body contribute to the higher rate in chil-
   dren. After growth has stopped, metabolic rate
   decreases about 2% per decade. If a person

410 Body Temperature and Metabolism

Table 17–6 MINERALS

Mineral Functions Food Sources Comment

Calcium

Phosphorus

Sodium

Potassium

Chlorine

Iron

Iodine

Sulfur

Magnesium

Manganese

Copper

Cobalt

Zinc

• Formation of bones and teeth


• Neuron and muscle functioning


• Blood clotting


• Formation of bones and teeth


• Part of DNA, RNA, and ATP


• Part of phosphate buffer system


• Contributes to osmotic pressure
  of body fluids


• Nerve impulse transmission and
  muscle contraction


• Part of bicarbonate buffer system


• Contributes to osmotic pressure of
  body fluids


• Nerve impulse transmission and
  muscle contraction


• Contributes to osmotic pressure of
  body fluids


• Part of HCI in gastric juice


• Part of hemoglobin and myoglobin


• Part of some cytochromes in cell
  respiration


• Part of thyroxine and T 3


• Part of some amino acids


• Part of thiamine and biotin


• Formation of bone


• Metabolism of ATP–ADP


• Formation of urea


• Synthesis of fatty acids and choles-
  terol


• Synthesis of hemoglobin


• Part of some cytochromes in cell
  respiration


• Synthesis of melanin


• Part of vitamin B 12


• Part of carbonic anhydrase needed
  for CO 2 transport


• Part of peptidases needed for protein
  digestion


• Necessary for normal taste sensation


• Involved in wound healing
  
  
  • Milk, cheese, yogurt,
    shellfish, leafy green
    vegetables
  
  
  • Milk, cheese, fish, meat
  
  
  • Table salt, almost all
    foods
  
  
  • Virtually all foods
  
  
  • Table salt
  
  
  • Meat, shellfish, dried
    apricots, legumes, eggs
  
  
  • Iodized salt, seafood
  
  
  • Meat, eggs
  
  
  • Green vegetables,
    legumes, seafood, milk
  
  
  • Legumes, grains, nuts,
    leafy green vegetables
  
  
  • Liver, seafood, grains,
    nuts, legumes
  
  
  • Liver, meat, fish
  
  
  • Meat, seafood, grains,
    legumes
  
  
  
  

Vitamin D required for

absorption; stored in

bones

Vitamin D required for

absorption; stored in

bones

Most abundant cation ()

in extracellular fluid

Most abundant cation ()

in intracellular fluid

Most abundant anion ()

in extracellular fluid

Stored in liver

Insulin and keratin require

sulfur

Part of chlorophyll in green

plants

Some stored in liver

Stored in liver

Vitamin B 12 stored in liver