CH.9: WATER AND MINERALS Flashcards
Characteristics of Water
Makes up 50 to 75% of body weight
needs no digestion and is easily absorbed
serves as a major solvent
essential without water death can occur within 2-3 days
Water inside the cells 2/3 of body water
Intracellular water
Water surrounding the cells or in the fluid portion of blood
Extracellular water
Balance between intra and extracellular fluid is maintained by concentration of_____, particularly sodium potassium, chloride and phosphate ions
ions
Total water intake includes
Water in beverages and foods.
_______ water formed by cells as a metabolic byproduct
metabolic water
Body water is loss through
urine perspiration exhaled air feces insensible perspiration
The small amounts of water we are losing via our skin but we dont notice
insensible perspiration
How much water is needed?
women-11 cups (2.7L)
men-15.5 cups(3.7L)
_______: are the major regulator of body’s water content and ion concentration.
KIDNEYS
Function of kidneys:
maintains proper hydration by filtering excess ions from the blood
remove excess sodium
remove drugs and metabolic wastes
____ & ____ ___ waste products of protein metabolism
urea and uric acid
Water conservation occurs when
person is hot and perspire heavily
Hormones that participate in sodium and water conservation include
Antidiuretic Hormone (ADH) Aldosterone
Substances that increase urine output INHIBIT ADH resulting in urinary water losses
diuretics
Two common dietary diuretics
Caffeine and alcohol
When the body’s fluid losses are greater than its fluid input
Dehydration
Every 16 oz of water lost by the body represents ___ __ of body weight
1 Ib
People at risked for dehydration
older adults
sick people
athletes and laborers
Too much water consumed at a time or conditions in which kidneys have difficulty filtering water from blood
Water intoxication
Elements in Earth’s rocks, soil, and natural water sources 15-22 mineral elements are essential nutrients
minerals
Minerals ______ be destroyed but they can be lost from foods
CANNOT
Roles of Minerals
Structural component of tissue ions blood clottin fluid balance acid base balance cofactors in chemical reactions part of certain enzymes
True or false animal foods generally contain higher amounts of mineral than plant foods
true
__________ of minerals varies. In general, minerals in animal foods are more easily absorbed than minerals in plant foods
Bioavailability
“hard water” contains a variety of minerals including calcium sulfur copper iron and zinc.
tap water
Many minerals have a ______ ____ ___ _____ ______. As a results it is relatively easy to consume a toxic amount, especially by taking supplements that only contain a particular mineral
Narrow Range of Safe Intake
The most plentiful mineral in the human body> 99% in bones and teeth 1% in extracellular fluid. Healthy adults absorb 25% of calcium.
Calcium
Function of Calcium
Bone formation and maintenance Teeth muscle contraction blood clot formation nerve impulse transmission cell metabolism
Secretes calcitonin when blood calcium is too high. Stimulates OSTEOBLAST which builds bone
Thyroid gland
Secretes parathryroid hormone when blood calcium is too low. Stimulates OSTEOCLAST which break down bone.
Parathyroid glands
A chronic disease characterized by low bone mass and reduced bone structure
osteoporosis
Need for Sodium
major postively charged ion in extracellular fluid
conduct nerve impulses
involved in transporting glucose and amino acids into cells
Condition characterized by persistently elevated blood pressure.
Hypertension
Need for potassium
major positively charged ion in intracellular fluid
nerve impulses
contracting muscles
kidney function
Role of Magnesium
participates in 300 chemical reactions
regulation of muscle and nerve function
maintenance of strong bones
strengthening the immune system
Need for Iron
component of hemoglobin and myglobin. involved in energy generation and immune function
Iron containing protein in RBC that transports oxygen to tissues and some CO2 away from tissues
hemoglobin
Iron containing protein in muscle cells that controls oxygen uptake from RBC
myoglobin
Most iron stored as _______ in the liver.
ferritin
Need for Zinc
wound healing
normal of taste and smell
dna synthesis
immune function
Need for Iodide
normal thyroid function
thyroid hormone
Characterized by enlarged thyroid gland. common before advent of iodized salt in areas where iodine content of soil was poor
Goiter
irreversible condition affecting infants born to women who were iodide deficient during pregnancy
cretinism
Need for Selenium
selenoproteins (antioxidants)
Need for Chromium
enhance insulin’s action on cell membranes. Open for glucose
