Water H notes

Importance of Water Comprise 50-70% of the body Comprise 50-70% of the body Blood, muscles, lungs, and your brain all contain large amounts of water. Blood, muscles, lungs, and your brain all contain large amounts of water. Required in large amounts BUT does not give us energy Required in large amounts BUT does not give us energy Intracellular fluid Intracellular fluid –Fluid within the cell Extracellular fluid Extracellular fluid –Interstitial –Intravascular

Functions of Water (1 of 3) Transports nutrients in the body. Transports nutrients in the body. Protects your joints and organs. Protects your joints and organs.

Functions of Water (2 of 3) Transports oxygen to your cells Transports oxygen to your cells Amniotic fluid, joint lubricants, saliva, bile Amniotic fluid, joint lubricants, saliva, bile Metabolic processes Metabolic processes

Functions of Water (3 of 3) Body temperature regulation Body temperature regulation –Water absorb any excess heat –Body secretes fluids via perspiration –Skin is cool as perspiration evaporates Removal of body waste Removal of body waste –Via urine –Urea excretion –Avoid concentrated urine

Fluid Balance Controlled by the electrolyte concentration Controlled by the electrolyte concentration “Where ions go, water is sure to follow” “Where ions go, water is sure to follow” Osmosis Osmosis –Movement of water from a more concentrated to a less concentrated solution

Toxicity of Water? Too much water without sufficient electrolytes intake Too much water without sufficient electrolytes intake More water than the kidneys can handle More water than the kidneys can handle Usually not a problem (people won’t drink that much) Usually not a problem (people won’t drink that much) Overwhelms the kidneys Overwhelms the kidneys Headaches, blurred vision, cramps, convulsions Headaches, blurred vision, cramps, convulsions

Are You Drinking Enough? Recommend 1ml per 1kcal Recommend 1ml per 1kcal (Fig. 11-3) (Fig. 11-3) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

How Much Water do You Need to Drink? We have all heard that we should drink 6, 8 ounce glasses of water a day. We have all heard that we should drink 6, 8 ounce glasses of water a day. A good estimate is to take your body weight in pounds and divide that number in half. A good estimate is to take your body weight in pounds and divide that number in half. That gives you the number of ounces of water per day that you need to drink. That gives you the number of ounces of water per day that you need to drink. For example, if you weigh 160 pounds, you should drink at least 80 ounces of water per day. For example, if you weigh 160 pounds, you should drink at least 80 ounces of water per day.

Dehydration Water is lost through urination, respiration, and by perspiration. Water is lost through urination, respiration, and by perspiration. Active people lose more water than sedentary people. Active people lose more water than sedentary people. Diuretics such as caffeine pills and alcohol result in the need to drink more water because they trick your body into thinking you have more water than we need. Diuretics such as caffeine pills and alcohol result in the need to drink more water because they trick your body into thinking you have more water than we need.

Signs of Dehydration Symptoms of mild dehydration include chronic pains in joints and muscles, lower back pain, headaches and constipation. Symptoms of mild dehydration include chronic pains in joints and muscles, lower back pain, headaches and constipation. A strong odor to your urine, along with a yellow or amber color indicates that you may not be getting enough water. A strong odor to your urine, along with a yellow or amber color indicates that you may not be getting enough water. Note that riboflavin, a B Vitamin, will make your urine bright yellow. Note that riboflavin, a B Vitamin, will make your urine bright yellow. Thirst is an obvious sign of dehydration and in fact, you need water long before you feel thirsty. Thirst is an obvious sign of dehydration and in fact, you need water long before you feel thirsty.

The Thirst Mechanism Not reliable Not reliable (Fig. 11-4) (Fig. 11-4) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

FYI If you exercise you should drink another eight ounce glass of water for every 20 minutes you are active. If you exercise you should drink another eight ounce glass of water for every 20 minutes you are active. If you drink alcohol, you should drink at least an equal amount of water. If you drink alcohol, you should drink at least an equal amount of water. When you are traveling on an airplane, it is good to drink eight ounces of water for every hour you are on board the plane. When you are traveling on an airplane, it is good to drink eight ounces of water for every hour you are on board the plane. If you live in an arid climate, you should add another two servings per day. If you live in an arid climate, you should add another two servings per day.

Water Safety Most drinking water is safe Most drinking water is safe The Environmental Protection Agency regulates water safety The Environmental Protection Agency regulates water safety Power to local and state authorities to advise public Power to local and state authorities to advise public Rural areas may need to have their water tested Rural areas may need to have their water tested Chlorine and ammonia are added to kill most microbes—I.e. Cryptosporidium Chlorine and ammonia are added to kill most microbes—I.e. Cryptosporidium Chlorine can be evaporated via boiling or standing Chlorine can be evaporated via boiling or standing