BIO 105-03

Bio 105 Lecture 7 Notes

I. Water

A. Basic Info
B. Functions
C. Water balance

1. How balance
2. Out of balance

  • Thirst mechanism signals dehydration: blood volume decreases, sodium concentration increases in blood
  • Brain triggers thirst mechanism and secretion of antidiuretic hormone (ADH) to reduce urine output
  • fluid inside cells moves into blood by osmosis
  • dry mouth due to increased electrolyte concetration in blood
  • other ways to tell if you are dehydrated:
  • cornerstone method, measure body weight before and after high physical activity or labor
  • urine color: urine is more concentrated when dehydrated and darker in color
  • too much water can cause hyponatremia (sodium blood level too low)
  • during endurance athletic events or strenuous military training

a. Too much
b. Too little

D. Needs

  • daily water needs vary depending on physical activity, environmental factors, diet
  • recommendations based on reported total water intake of healthy Americans
  • men 16 C/day (13 C of beverage)
  • women 12 C/day, (9 C bev)

II. Macrominerals

  • inorganic elements found on the periodic table and needed in relatively small amounts
  • minerals have varying bioavailability
  • some minerals compete for absorption: too much of one can decrease absorption of another (ex: excess zinc can reduce copper absorption)
  • some substances bind materials, making them unavailable for absorption (ex: oxalates in spinach bind calcium)

A. Sodium

1. Basic info
2. Functions

  • sodium is an electrolyte (charged ion) in blood and in the fluid surrounding cells
  • 90% of sodium consumed is in form of NaCl
  • functions: chieff role is regulation of fluid balance
  • also transports substances such as amino acids across cell membranes
  • sodium level is maintained by kidnets reducing or increasing sodium excretion as needed
  • smaller amounts lost in stool and sweat
  • food sources: about 77% of sodium consumed by Americans is from processed foods (only 5% added during cooking, 6% added at table, 12% natural food content

3. Too much
4. Too little

  • upper limit is set for adults to reduce the risk of hypertension (high blood pressure)
  • cut back on processed foods and salt added to foods to lower sodium intake
  • sodium deficiency is rare

5. Hypertension

a. Basic info

  • blood pressure is a measure of force that blood exerts on the walls of the arteries
  • expressed as systolic (when heart beats) over diastolic (at rest)
  • 120/80mm Hg = normal
  • systolic > 129 or diastolic >80 = prehypertension

b. Cause and effects

  • increase in blood volume or a narrowing of the blood vessels
  • some of the risk of developing hypertension is inherited
  • constant high pressure of blood throu arteries causes damage over time
  • contributes to atherosclerosis; heart enlarges, weakens
  • damages arteries leading to brain, kidneys, legs, increasing risk of stroke, kidney failure, partial amputation of leg

c. Control

  • is a silent killer – no symptoms, have BP checcked regularly
  • mineral intake can affect the risk of hypertension
  • diets high in salt may increase blood pressure
  • diets high in potassium calcium and magnesium

B. Potassium

1. Functions

  • fluid balance of electrolyte between cells
  • blood buffer, helps keep blood pH and acid-base balance correct
  • muscle contraction and nerve impulse conduction
  • can help lower HBP
  • aids in bone health, increase bone density
  • reduces kidney stones by helping to excrete citrate

2. Too much
3. Too little

  • too much from supplements or salt substitutes can cause hyperkalemia in some individuals
  • can cause irregular heartbeat, damage to heart,
  • too little causes hypokalemia
  • muscle weakness, cramps, irrregular heartbeat & paralysis
  • can occur in excessive vomiting and or diarrhea, in anorexia and/or bulimia eating disorders

C. Calcium

1. Basic info

  • most abundant mineral in the body (99% in bones & teeth)

2. Functions

  • helps build strong bones & teeth
  • plays a role in muscles contraction and nerve signaling
  • may help lower HBP
  • may fight colon cancer
  • may reduce risk of kidney stone
  • may reduce obesity risk

3. Too much or too little

  • too much calcium leads to hypercalcemia (impaired kidneys, calcium deposits in body
  • too little can lead to less dense, weakened, brittle bones and increased risk for osteoporosis

4. Osteoporosis

  • bones are living tissue, constantly changing
  • peak bone mass occurs in early adulthood (20’s)
  • slowly more bone is lost than added
  • as bones lose mass, become more porous and prone to fractures, leading to osteoporosis

D. Phosphorous

1. Basic info

  • second most abundant mineral in body
  • 85% in bones, rest in cells and fluids outside cells, including blood

2. Functions

  • needed for bones & teeth
  • important component of cell membranes
  • needed for energy metabolism and stores
  • acts as a blood buffer
  • part of DNA/RNA

3. Too much
4. Too little

  • upper limit to prevent hyperphosophatemia, which can lead to calcification/hardening of tissues
  • too little can result in muscle weakness, bone pain, rickets, confusion, death
  • would need to be in state of near starvation to experience deficiency

E. Magnesium

1. Basic info

  • 4th most abundant mineral in body
  • about half in bones, most of rest in cells

2. Functions

  • helps >300 enzymes, including energy metacolism
  • used in synthesis of protein
  • helps muscles and nerves function properly
  • maintains healthy bones and regular heartbeat
  • may help lower high blood pressure and reduce risk of type 2 diabetes

3. Too much
4. Too little

  • many Americans fall short of daily needs (70-80% met)
  • UL from supplements (not foods) is set to avoid diarrhea
  • deficiencies are rare but diuretics and some antibiotics con inhibit absorption

F. Chloride

1. Basic info

  • part of HCl in the stomach

2. Functions

  • Na & Cl are major electrolytes outside of cells and in blood to help maintain fluid balance
  • acts as buffer to keep blood at normal pH
  • salt is main source

3.. Too much/too little

  • upper limit matches Na UL
  • deficiencies rare

G. Sulfur

1. Basic info

  • component of other compounds in body, including some B vitamins

2. Functions

  • helps give some proteins 3D shape
  • as part of amino acids methionine and cysteine
  • sulfites used as food preservative to prevent spoilage and discoloration

3.. Too much/too little

  • no known toxicity or deficiency symptoms

III. Trace Minerals

  • trace minerals (microminerals) are needed in small amounts μg/day

A. Iron

1. Basic info

  • heme iron
  • animal sources
  • part of hemoglobin and myoglobin
  • easily absorbed
  • non-heme iron
  • in plant foods
  • not as easily absorbed, due to phytates and other substances
  • body only absorbs 10-15% or iron consumed
  • absorption increases if body stores are low
  • iron not excreted in urine or stool, and once absorbed, very little leaves body (95% recycled and reused)

2. Functions

  • hemoglobin in red blood cells uses iron to transport oxygen and carbon dioxide waste
  • myoglobin transports and stores oxygen in muscle cells
  • helps enzymes that make neurotransmitters

3. Too much
4. Too little

  • too much iron can cause contipation, nausea, vomiting, diarrhea
  • iron overload can damage heart, kidneys, liver, nervous system
  • leading cause of accidental poisoning in shildren
  • hemochromatosis, genetic disorder, can cause iron overload
  • deficiency is most common nutritional disorder in world
  • iron-deficiency anemia occurs when iron stores depleted and hemoglobin levels decrease

B. Zinc

1. Basic info
2. Functions
3. Too much
4. Too little

C. Chronium

1. Functions
2. Too much/too little

D. Flouride

1. Basic info
2. Functions
3. Too much/too little

E. Iodine

1. Basic info
2. Functions
3. Too much
4. Too little

Clicker Questions

Approximately, how many days can you live without water?

Is It possible to die from drinking too much water?

How many minerals are found in your body?

What vitamin regulates calcium and phosphorous?

What part of the cell membrane contains phosphorous?
Two of the above
All of the above

If you are suffering from anemia, your doctor may prescribe supplements of this trace mineral…

Which trace mineral is important for your dental health?

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