hs251 unit 2

major minerals

sodium, chloride, potassium, calcium, phosphorous, magnesium, sulfate

cellular fluid, signal conduction, nutrient transport

roles of sodium (3)

renin → angiotensinogen → angiotensin I → angiotensin II → aldosterone → increased sodium resorption

low sodium pathway

hyponatremia

too low sodium levels

low angiotensin II and aldosterone → increased urinary sodium excretion

high sodium pathway

1500mg

sodium AI

canned soups, deli meat, seaweed

sources of sodium

anion, component of HCl

roles of chloride

table salt, tomatoes, lettuce

sources of chloride

hypocholerema

too low chloride levels; shallow breathing, muscle weakness and spasms

intracellular fluid, electrical conduction, muscle contraction

role of potassium

hyperkalemia

heart damage from too high potassium

hypokalemia

weakness and irregular heartbeat from too low potassium

bones, muscle contractions, cell signaling

roles of calcium

parathyroid hormone

regulates calcium and phosphorous levels

low calcium → PTH stimulates kidneys to convert vitamin D to calcitrol

low calcium pathway

high calcium → thyroid releases calcitonin, PTH decreases

high calcium pathway

1000mg, 1300mg in children

calcium AI

sources of calcium

dairy, canned fish, fortified foods

dairy, avocado, bananas

sources of potassium

hypercalcemia

too high calcium levels; GI upset and bone pain

hypocalcemia

too low calcium levels; muscle spasms and tingling

bone, ATP and creatine phosphate

roles of phosphorous

dairy, meat, soft drinks

sources of phosphorous

cofactor in enzymes, bone maintenance, muscle and nerve function

roles of magnesium

leafy greens, whole grains, nuts

sources of magnesium

component of proteins and B vitamins

roles of sulfate

meat, eggs, dairy

sources of sulfate

bioavailability

proportion of mineral that is absorbed and enters circulation

2300mg

sodium UL

oxalates

acids in fruits, vegetables, coffee, and chocolate that decrease mineral absorption

phytates

acids in nuts, whole grains, and legumes that decrease mineral absorption

trace minerals

iron, zinc, copper, selenium, fluoride, iodine, chromium, molybdenum, manganese

heme iron

Fe2+; component of hemoglobin and myoglobin found in animal-based foods

non-heme iron

Fe3+; found in plant-based foods, used as fortification

15%

bioavailability of iron

component of proteins

role of copper

organ meats, nuts and seeds, bran

sources of copper

component of selenoprotein antioxidants and thyroid-regulating enzymes

roles of selenium (highest bioavailability of trace minerals)

nuts, seafood, cereals

sources of selenium

thyroid function, thyroid hormone synthesis

roles of iodine

seafood, seaweed, iodized salt

sources of iodine

goiter

enlarged thyroid gland as a result of iodine deficiency

oral and bone health

roles of fluoride

tea, coffee, potatoes

sources of fluoride

iron poisoning

large accidental ingestion of iron

iron overload

undetected excessive storage of iron

selenosis

selenium toxicity leading to brittle nails and hair

fluorosis

fluoride toxicity causing pitted teeth

improves insulin effectiveness

role of chromium

component of metalloenzymes

role of molybdenum and manganese

broccoli, poultry, nuts

sources of chromium

legumes, grains, nuts

sources of molybdenum

plant foods

sources of manganese

positive energy balance

calorie intake > calories expended

negative energy balance

calories expended > calorie intake

thermogenesis

production of heat by the body

adaptive thermogenesis

body regulation of heat production

basal metabolic rate

energy required to meet basic physiological needs; largest contributor to energy needs

resting metabolic rate

estimation of basal metabolic rate

thermic effect of exercise

increase in muscle contraction during physical activity

non-exercise activity thermogenesis

energy expended from non-exercise activities

thermic effect of food

energy used for digestion and absorption

direct calorimetry

measures energy expenditure by assessing body heat loss within a metabolic chamber

indirect calorimetry

estimates energy expenditure by measuring oxygen consumed and carbon dioxide produced

Mifflin-St. Joer equation

estimates resting metabolic rate based on gender, height, weight, age, and activity level

glucagon

promotes energy usage

insulin

promotes energy storage

satiety

sensation of fullness

leptin

hormone stimulating satiety produced by adipocytes

ghrelin

hormone stimulating hunger produced by stomach

cardiorespiratory endurance, muscular strength, muscular endurance, flexibility, body composition

five components of physical fitness

frequency, intensity, time, and type

FITT principle for improving fitness

progressive overload

gradual adaptation to increased exercise demands

carbohydrates

primary energy source during high-intensity exercise

fat

source of energy for low-to-moderate intensity activity after 20 minutes

protein

primary source for muscle repair, small amount for energy if carb intake is insufficient

simple carbs after 1 hour

fuel during exercise

carbs and protein for glycogen stores and muscle protein synthesis

fuel after exercise

body composition

proportion of fat tissue to lean mass

subcutaneous fat

fat underneath skin

visceral fat

fat stored around abdominal organs

brown fat

fat that generates heat

central obesity

more visceral fat in abdomen; increased risk for cardiovascular diseases

gynoid obesity

more fat in thighs and buttocks; more common in women

dual-energy x-ray absorptiometry

x-ray measure of bone density and body mass; most accurate measure of body composition

waist circumference and BMI

indirect measures of body composition

<18.5

underweight BMI

18.5-24.9

normal BMI

25-29.9

overweight BMI

>30

obese BMI

hypertrophy

fat cells grow in size (can decrease)

hyperplasia

cell division increasing number of fat cells

energy balance theory

theory that weight is affected by calories consumed versus expended and thermic effects of food and exercise

set-point theory

theory that physiological mechanisms maintain “set” weight or range

carbohydrate-insulin model

theory that higher carb intake drives glucose storage which contributes to weight gain