Chapter 14 - Water and Major Minerals Flashcards
Functions of water in body?
- solvent
- transports stuff
- lubricates and protects
- regulates body temperature
- plays in metabolic reactions (hydrolysis and dehydration)
- maintains acid-base balance
How much of us is water?
60-70%
Who (males or females) has more? Why?
males, because they have more lean muscle
Age – who has more?
elderly- less, we dry out
infants - most
Intracellular fluid (ICF)
fluid inside cells
Interstitial fluid
outside cell but not in vessel
Intravascular fluid
in vessel but not in cell
plasma
Fluid in ICF and ECF contain what?
solutes
electrolytes, salts, ions
Cations and anions of ICF?
cation - potassium, magnesium
anion - phosphate
Cations and anions of ECF?
cation - sodium
anion - chloride
Water follows ___ and moves via ___
electrolytes
osmosis
Water needs vary with what?
body size
physical activity
environmental conditions
dietary intake
AI of water?
1/2 body weight in oz
15 cups for men
11 cups for women
Water needs are met when?
when water inputs and outputs are balanced
Where else do we get water from?
food
cellular respiration
How much water does the combo of food and cellular respiration yield?
2.5 L per day
Dehydration
inadequate water levels
Why is it easy to become dehydrated?
insensible losses
Insensible losses
water loss that we are not aware of
Is urination an insensible loss?
no
What are the symptoms of dehydration?
dry mouth and skin fatigue muscle weakness decreased urine output concentrated urine headache dizziness
Who is most at risk of dehydration?
sick children
elderly
athletes
people who work outside in warm and humid conditions
What controls thirst?
mouth
hypothalamus
nerve and hormone control
What is ADH triggered by?
- high particle concentrations in blood
- hypothalamus recognizes this
- hypothalamus triggers pituitary to release ADH
What does ADH do?
causes kidneys to absorb water preventing losses
Where do we most of our sodium from?
sodium-containing food additives and food processing
What gets rid of sodium for us?
kidneys
Hypernatremia can cause what?
hypertension
Who is at risk for hypernatremia?
elderly
Hyponatremia
low blood sodium
What can cause hyponatremia?
GI tract illnesses
water intoxication
Who is at risk for hyponatremia?
athletes
infants
How does sodium relate to the small intestine?
helps absorb glucose and some amino acids here
How does sodium relate to nerves and muscles?
required for normal nerve and muscle function
Normal nerve and muscle function relies on what?
electrical charge created by the shift of sodium and potassium across cell membrane
Where is the net negative charge typically found?
inside cells
How does sodium aid in water balance?
when sodium levels are high, water is retained until levels go down
What is the UL for sodium?
2300 mg/day
% of U.S. adults that consume more than AI?
90%
Excess sodium leads to increased risk of…
hypertension
heart disease
stroke
What leads to more calcium output in urine?
greater than 2g/day of sodium
Blood volume
amount of fluid in the blood
How does high blood volume affect blood pressure?
increases blood pressure
Renin is released from what organ for what purpose?
released by kidneys
reabsorb sodium
What is the purpose of renin related to blood volume/pressure and hormones?
renin restores blood volume/pressure
starts activation of other hormones like aldosterone
Where is angiotensinogen made?
protein made in the liver
Where does the conversion to angiotensis II occur?
in blood stream
What is angiotensin II?
powerful vasoconstrictor
What does angiotensin II trigger?
triggers production of aldosterone
What does aldosterone signal?
kidneys to retain sodium in order to retain water
Where is aldosterone produced?
adrenal glands
Where is potassium found?
many unprocessed foods
Most adults need to do what to their potassium intake?
increase it
What are the functions of potassium?
- major cation in cells
- same functions as sodium
- may also reduce effects of high salt intake
How does potassium reduce the effects of high salt intake?
- suppresses renin-angiotensin system
- promotes secretion of sodium and water
- keeps blood pressure normal
What are the causes of electrolyte deficiency?
- heavy sweating
- chronic diarrhea
- vomiting
- kidney disorders
What are the symptoms of electrolyte deficiency?
- acid/base imbalance
- muscle cramps
- confusion
- constipation
- irregular heartbeat
- sudden death
What is the overall definition of a mineral?
essential, inorganic elements needed in small amounts for function, growth, and maintenance of tissues
What is a major mineral?
need 100 mg or more daily
found in larger quantities in body
What source of minerals are the richest and have the best bioavailability?
animal sources
The quality of minerals is influenced by what?
agricultural practices and food processing
the more refined, the less minerals
Other than bioavailibility, what else influences if a mineral will be absorbed?
physiological need
Bioavailibility is subject to what?
competition of absorption
Phytic acid
found in wheat grain. legume fiber, and unleavened breads
Oxalic acid
found in green leafies
Polyphenyls
tea, dark chocolate, wine
Osteons consist of
central canal
blood vessels
Two types of bone
cortical (compact) bone
trabecular (spongy) bone
Osteocytes
specialized bone cells
secrete minerals
Trabecular bone has spaces filled with what?
red bone marrow
Which type of bone is strongest?
trabecular bone
What famous structure was modeled after the structure of trabecular bone?
Eiffel Tower
Bone consists of what?
protein fibers
collagen
minerals - calcium and phosphorous
Minerals in bone form what?
hydroxyapatite
Hydroxyapatite binds to what?
collagen
Osteoblasts
build bone
Osteoclasts
dissolve bone
The building and dissolving of bone does what?
change blood calcium levels
At what age do we experience peak bone density?
30
What causes a decrease in bone density?
osteoblast acitivity decreases while osteoclast acitivty remains the same
Most recognized nutrient associated with bone health?
Calcium
What else is essential for bone/dental health?
Vitamin D
Fluoride
What is the most abundant mineral in the body?
clacium
How much of the adult body weight does calcium account for?
1-2%
What are the functions of calcium?
bone/teeth structure
-important regulatory roles
What kind of regulatory roles does calcium have?
nerve transmission
muscle contraction
blood pressure regulation
release of certain hormones
What are the two ways that calcium is absorbed?
active transport
passive diffusion
What does the absorption of calcium depend upon?
availability of active form of vitamin D
What are tannins, fiber, phytates, and oxalates?
anti-nutrients
The bioavailability of calcium is decreased in the presence of what? Why?
anti-nutrients
calcium prefers to bind to them rather than being absorbed
What hormones are related to calcium?
calcitonin
parathyroid hormone
What releases calcitonin?
thyroid gland
What does calcitonin do?
- reduces osteoclast activity to inhibit calcium release
- stimulates osteoblasts
- acts on kidney to increase calcium excretion
What does parathyroid hormone do?
- acts as osteoclasts in bone to release calcium
- triggers kidney to form calcitrol
What does calcitrol do?
- acts on SI to increase calcium absorption
- tells kidneys not to release calcium into urine, and activates vitamin D
What percentage of calcium is absorbed in adults?
25-30
What factors increase calcium absorption?
stomach acid
vitamin D
growth hormone
When bone is lost and strength declines, what is diagnosed?
osteoporosis
How does osteoporosis affect bones?
become fragile and more likely to break
What areas of the body are more likely to break with osteoporosis?
hip
wrist
vertebrae
Kyphosis
hunchback created by compression fractures in the vertebrae, usually as a result of osteoprosis
Who sees the highest rates of osteoporosis?
caucasians
asians
How is osteoporosis identified?
DEXA scan
scans bone density
How do you prevent osteoporosis?
- diet including calcium, vitamin D, magnesium, phosphorous, potassium, vitamin K, protein
- weight-bearing activity
- avoid smoking
- eat less meat, desserts, fried foods, alcohol, sweetened beverages
Vitamin C is also known as what?
ascorbic acid
ascorbate
How can vitamin C be destroyed?
oxygen
light and heat
contact with copper or iron cookware
What are the functions of vitamin C?
- antioxidant
- helps maintain immune system
- important in production of collagen
- aids in iron absorption
Can the consumption of vitamin C shorten the life of a cold? Explain
No
supplementing with vitamin C well before a cold could reduce the length and intensity of the cold
Explain how vitamin C acts as an antioxidant
neutralizes free radicals so they can no longer steal electrons
How does vitamin C aid in the production of collagen?
vitamin C hydroxalates collagen fibers, making it into a strong triple helix structure
What is the disease associated with vitamin C deficiency?
scurvy
What are the major minerals?
Sodium
Potassium
Calcium
Vitamin C
