Transcript Water

Water
Composition of the Human Body
Water
• Makes up about 70% of total body weight.
• This varies and males and females differ.
• We need water –
can survive for only a
few days without it.
• It is found in:
• Intracellular fluid
• Extracellular fluid
Composition of the Body
Where is Water in the Body?
Intracellular
and
Extracellular
Fluid
Compartments
Functions of Water in the Body
• Water is a polar molecule
• Slight sidedness in charge (+ and -)
• Hydrogen Bonds Important feature
Functions of Water in the Body
• THE Liquid in which substances are dissolved
List substances in Plasma:
Proteins (albumins), ions,
minerals, hormones, vitamins,
fatty acids, triglycerides,
lipoproteins, glucose, amino
acids, O2, CO2, antibodies,
enzymes, eicosanoids and
metabolic waste products
urea and uric acid
Blood Sample
after Centrifugation
Functions of Water in the Body
• Transport Nutrients throughout the body
• Transports O2 and hormones to cells
• Removes Waste products for Excretion in
Urine and Feces
• Important to Digestion – required for the
breakdown (Hydrolysis) of the 3 organic
macronutrients that are energy yielding.
plasma
Functions of Water in the Body
• Maintains Tb (Body Temperature)
• Especially Regulation of Cooling!
• Important Lubricant for:
• Joints
• Eyes
• Mouth and Gastrointestinal Tract
• Lungs
• Urogenital Tract
Tears and saliva are ~ 95% water, but also contain oils, proteins and
antimicrobial agents (like lysozymes). Also in human milk and mucus.
Functions of Water
• Protective Cushion
In Pregnancy, fetus is surrounded by watery
amniotic fluid.
• Provides Structure to Cells
• Participates in Chemical Reactions (see later)
• Bicarbonate Buffer Role in Acid-Base Balance
• Water is used to reduce or increase pH levels.
H2O + CO2
H2CO3 +
H+ + HCO3-
Acid-Base Balance
Water is used to reduce or increase pH levels
H2O
H+ + OH-
Acid = H+
Base = OH-
Proton
Donator
Proton
Acceptor
To Maintain Good Health a Diet many Recommend is:
~ 60% Alkaline Forming Foods
~ 40% Acid Forming Foods
Strongly Acidic
pH 4.0
Mildly Acidic
pH 4.5 to 6.5
Neutral
pH 7.0
White Bread,
Processed
Cheese
Alcohol, Beers
Sodas,
Tea, Coffee
Sugar,
French Fries
Peanuts, Walnuts
Meat and Fish,
Canned Fruits
De-ionized
Water
Many Fruits,
Coconut
Legumes
Most Nuts
Egg Yolks
Raw Milk
Brown Rice
Basmati Rice
Artificial
Sweeteners
Dairy, Cocoa
Raw Cream,
Whey
Most Vegetables Asparagus, Garlic
Almonds
Cayenne Pepper
Cucumber
Avocados
Raw Spinach
Kale
Quinoa,
Kelp, Celery,
Buckwheat
Broccoli
Falx Seed
Raw Swiss Chard
Olive oil
Cooked Spinach Raw Honey
Mildly Alkaline
pH 7.5 to 9.5
Strongly
Alkaline
pH 10.0
Melon, Raisins,
Vegetable Juices
What are the 4
Properties of Water?
1) Solvency
2) Cohesion
3) Thermostability
4) Reactivity
1. Universal Solvent
All substances in the body are either dissolved in
water or carried by another substances in water
2. Cohesion
The Answer is…
H Bonds
Adhesion and Cohesion
3. Thermostability
Water Helps
Regulate
Body
Temperature
Water absorbs and releases
heat generated by the body
Water has a High Heat Capacity: This means it takes a
lot of heat energy to change the temperature of water.
Water has a High Heat of Vaporization: This means when
water goes from a liquid to a gas, it takes a lot of heat
energy with it.
4. Reactivity
Water participates in chemical reactions
a) Dehydration
Synthesis
b) Hydrolysis
How to Maintained
Balance?
How do we Maintained Water Balance?
Fluid Balance is a crucial part of Homeostasis
“Constantly changing to stay the same”
Water Balance
Water Consumed = Water Excreted
Our Bodies must Adapt Quickly and Effectively
to Changes in Water Intake and Water Losses
Key Factors:
Water Intake = Diet
Water Loss = Kidneys
Sources of Body Water in Diet!
• Beverages are the largest source of Water.
• All foods contain some water.
• Fruits and Vegetables contain the most.
• Grains contain the least.
• Metabolic H2O (~300 ml/day)
• Water generated during metabolism
C6H12O6 + 6O2
6CO2 + 6H2O + E
• These sources contribute to an average daily
intake of 2,550 ml (about 2 quarts).
Sources of Water and Routes of Excretion
Water Excreted via kidneys,
Large Intestine, Lungs, and Skin
• Majority of fluid is excreted via Kidneys as Urine
• Urine production depends water intake. (1.5 L)
• Water is lost through Large Intestine in the stool.
• Level of Fibers can effect excretion. (100 ml)
• Diarrhea and vomiting can increase excretion.
• Insensible Water Loss
• Evaporated from Lungs via Exhalation (350 ml)
• From Perspiration of the Skin (600 ml)
Sweat
The degree of Water Loss through Sweat Varies:
Environmental factors
– Temperature
– Humidity
– Wind
– Sun's intensity
– Clothing worn
– Amount of physical activity
Sweat also Contains:
Lactate, lysozyme, urea, minerals (sodium, chloride, potassium,
calcium, magnesium + trace elements) exogenous organic
compounds; pH ranges from 4.5 and 7.0.
Solute + Solvent = Solution
By definition, the solvent is whatever is in abundance.
In the human body solvent = Water
Everything else in the water are solutes
Osmolarity is a way to express the
concentration of a solution
= the total number of solutes
(particles) in solution (1 liter).
Tonicity = ‘Strength’ of a Solution
Osmosis - the net movement of water across a
semipermeable membrane from region of high
to low water concentration.
Electrolytes Participate in Fluid Balance
• Electrolytes maintain Water balance between
compartments.
• Na+ and K+ have the greatest effect on fluid balance.
• Osmosis
• Affects the movement of water across cell’s
semipermeable membrane
• Water moves from Low concentration to a High
concentration of electrolytes.
• Osmotic Pressure controls directional of water flow.
• Movement based on Osmolarity of Solutions.
(# of solutes)
Water moves across cell membranes by osmosis
Osmosis generates a force called
Osmotic Pressure
The Effect of Water and Osmosis
on Animal and Plant Cells
Water potential
same on both sides
Water Balanced between Fluid Compartments
• Body Fluid is Located:
• In Intracellular Fluid (ICF): Within the cells
• Largest fluid compartment in the body
• Contains potassium, proteins, various acids
• In Extracellular Fluid (ECF): Outside the cells
• Contains NaCl and NaHCO2 (bicarbonate)
• 2 Types of Extracellular Fluid (ECF)
• Interstitial fluids: Bathe the outside of cells
• Intravascular (plasma) fluids: blood & lymph
• Water moves between ECF and ICF easily.
Intracellular and Extracellular
Fluid Compartments
Electrolytes Participate in Fluid Balance
• Electrolytes
• Charged (+/-) minerals, conduct electrical current
• Potassium K+
• Phosphate PO43• Magnesium Mg2+
• Cations: Positive charge:
• Anions: Negative charge:
• Calcium Ca2+
• Chloride Cl• Sodium Na+
Electrolytes Participate in Fluid Balance
• The Na+/K+ Pump
Maintains normal electrolyte concentrations
• Two Na+ ions are exchanged for three K+ ions.
• Keeps the cell from swelling and bursting
Vital in creating and maintaining the RMP
(Resting Membrane Potential) – to assist in electrical
conduction in nerve and muscle cells
Creates gradients for co- transport of ions and nutrient
absorption
Plasma Proteins Regulate Fluid Balance
The Na+-K+ Pump
Water and all Solutes
affect Blood Pressure
• If the body retains too much fluid, blood volume
increases and blood pressure will likely rise.
• Kidneys regulate blood volume & electrolyte balance. If
you have too much, it’s easy –you get rid of excess!
• If you need to SAVE water: These 4 Hormones Help:
• Renin (enzyme) - triggers cascade of to save water
• Angiotensin – triggers thirst, ADH and Aldosterone.
• Antidiuretic Hormone (ADH) = Vasopressin
• Aldosterone – triggers Na+ retention
Renin Helps Conserve Water and Salts
• Blood Pressure falls or Na+ concentration is reduced.
• Renin is secreted by the kidneys.
• Enzyme activates angiotensin I from the inert
protein angiotensinogen in the blood.
• In the lungs, angiotensin I is converted to
Angiotensin II – this then does the following:
 Triggers Thirst (in hypothalamus)
 Stimulates release of Antidiuretic Hormone (ADH)
 Stimulates adrenal glands to release Aldosterone
 Is a powerful vasoconstrictor
ADH Helps Stimulate Fluid Intake and
Reduce Urine Output
• Blood Volume Drops:
• Hypothalamus detects decrease in blood
pressure and increase in concentration of salts.
• Thirst mechanism and fluid intake stimulated.
• Hypothalamus stimulates Pituitary gland to
release ADH.
• ADH stimulates the kidneys to reabsorb water
and decrease urine output.
• Blood volume increases & osmolarity returns to
normal.
Aldosterone and Sodium Reabsorption
• Renin-Angiotensin system adapts to Hydration.
• Too little sodium
• Osmolarity drops in extracellular fluid (ECF).
• Fluid shifts from blood to interstitial fluid.
• Blood volume and blood pressure decrease.
• Angiotensin II triggers the adrenal glands to
release aldosterone.
• Aldosterone
• Signals kidneys to retain more Na+
• Indirectly leads to water retention
Blood Volume Regulates Blood Pressure
How Much Water Do You Need?
• Water Needs Depend on:
• Physical Activity
• Environmental Factors
• Diet
Note: About 80% intake from beverages and
20% from food (small % metabolic).
Keep Hydrated! Use your observational skills
to determine if you are over or de-hydrated.
Daily Beverage Recommendations
Water Sources
• Drink bottled or tap water, milk, and juices
throughout the day. Let’s talks about this…
• Most foods can also contribute to meeting daily
water needs.
• Fruits and vegetables can be 70% or more
water by weight.
• Dry grain products provide some water.
• Cooking actually often adds water to food.
Drugs in Your Drinking Water
Prescription Drugs (Prozac, Zoloft, Statins…).
Antibiotics (for people and animals).
Birth Control (Synthetic Female Sex Hormones).
Rocket Fuel – Perchlorate Interrupt thyroid hormones,
needed for pre- and postnatal development. Hypothyroidism.
Heavy Metals - mercury, arsenic, chromium, cadmium, nickel
and lead. These are all toxic to the human body.
Chlorine – toxic cell killer! (trihalomethanes + Cl- = carcinogen).
Fluoride - toxic to living organisms, leads to fluorosis.
Diuretics – increase urine output
• Caffeine:
• Mild diuretic that constricts blood vessels in
the kidneys.
• Some people are more sensitive to caffeine
than others.
• Tolerance to it’s diuretic effects.
Alcohol Will Dehydrate
• Inhibits ADH (interfering with water balance)
• Can induce urination as quickly as 20 minutes
after consumption
• Causes Dehydration
• Affects electrolyte concentration, especially K+
Alcohol is also a CNS Depressant
Cerebral Cortex: Uninhibited or Impaired judgment
Hippocampus: Prevents short-term memories from becoming longterm; may experience exaggerated emotions and may black out
Cerebellum: Individual loses hand-eye (leg) coordination
Brain Stem: Impaired breathing and heart rate
Diuretic Medications Can Help Treat
Hypertension
• First line of treatment for hypertension
• Often pharmaceutical diuretics
• Promote diuresis by inhibiting the reabsorption of
sodium
– Increased sodium excretion increases fluid excretion.
– Reduces blood volume and lowers blood pressure
• Some diuretics increase potassium loss and the
risk of hypokalemia.
Consuming Too Much Water
Can Cause Hyponatremia
Water Intoxication
•
Drinking fluid too fast without adequate Na+
replacement depletes Na+ and increases the
rate of urine production.
• Results in Hyponatremia = not enough Na+
•
Can cause swelling in the brain and death!
• Symptoms include fatigue, confusion, and
disorientation, unconsciousness...
Consuming Too Little Water
• Dehydration can be caused by:
• Inadequate Water Intake
• Strenuous Exercise in the Heat
• Losing Excessive amounts of water from:
diarrhea, vomiting, high fever, use of diuretics
• As little as a 2% loss of body water can trigger:
• Loss of short- and long-term memory
• Lower attention span and cognition (lethargy)
• Reduced ability to maintain core temperature
• Increased risk of fatigue
Signs of Dehydration
The Thirst Mechanism
•
•
Thirst often first sign of dehydration.
Water lost from the body causes:
• Reduced Blood Volume
• Reduced Blood Pressure
•
•
–
–
–
•
As a Consequence…
if severe enough leads to Hypotension
Reduced Cardiac Output
Impaired Digestion
Fainting or blackout
Water depleted from ECF and ICF
Monitor Water Intake to Avoid
Overhydration and Dehydration (cont'd)
• Evaluate urine color to assess hydration.
Structure of Three Alcohols
From Sugar to Alcohol
• Fermentation of sugars by yeasts make Alcohol
• The Sugar can be from:
•Grains (e.g. glucose and maltose) or
•Fruits (glucose and fructose)
From Sugar to Alcohol
Yeast Metabolizes glucose into:
Ethanol + Carbon dioxide
C6H12O6
2 C2H35OH + 2 CO2
CO2 bubbles off & alcohol beverage is left.
– Wine: From grapes
– Beer: From malted cereal grains (barley)
• Fermentation stops when alcohol content
reaches 11 to 14 %
Anatomy of a Grain
In a typical Grain
Bran = 14%
Germ = 3%
Endosperm
(Starch) = 83%
Anatomy of a Grain
Wine from fermentation of natural sugars in grapes.
Cider is from apples; Perry from pears; Mead from honey.
Brandy from distillation of fruit-fermented drinks
(involves Evaporation and Concentration of alcohol content)
Beer, Whiskey, and Vodka are produced by fermentation of Grain
Starches converted to sugar by amylase – naturally present in the
kernels of the grain that have malted (i.e., germinated).
Potatoes and un-malted grain are also starches amylase will
ferment; this can be added to the mixture.
Whiskey and Vodka are also distilled.
flavoring during distillation.
Gin made by adding
Sake is rice wine involves fermentation mold Aspergillus oryzae.
Rum by fermentation then distillation of sugarcane (molasses).