Chapter 7 Nutrients Involved in Fluid and.docx

17 Pages
Unlock Document

Simon Fraser University
Biomedical Physio & Kines
BPK 110
Leah Esplen

Chapter 7 Nutrients Involved in Fluid and Electrolyte Balance and In Depth Fluids • its ability to move freely • adapting to the shape of the container that holds it • there are different types of fluids in our bodies • 50-70% of a healthy adult's body is composed of fluids • about 2/3 of this fluid is held within body cells and is called intracellular fluid • remaining 1/3 of this fluid is outside the body's cell (either in body's tissue or plasma) and called extracellular fluid • There are two types of extracellular fluid: o Tissue fluid:  found between the cells within tissues and organs of the body such as liver o Intravascular fluid  found within blood and lymphatic vessels  plasma is the fluid portion of blood that carries the blood cells and also contains protein The body fluid levels of tissues varies by • tissue type: lean tissues such as muscle are more than 70% fluid by weight, whereas fat tissues are 10-20% ; lean tissues have higher fluid content • gender: makes have more lean tissue than women, therefore more body fluid • age: lean tissue is lost with age and body fluid is lost with it Electrolytes • body fluid is composed of water • we would die if our cell and tissues only contained pure water, therefore within the body fluids are variety of dissolved substances that are critical to life • electrolytes: o mineral salts dissolved in water including: sodium, potassium, chloride, phosphorus o when dissolved in water, the two component minerals separate and form ions (electrically charger particle either positively or negatively charged) • Fluids have an overall neutral charge due to the balances between electrolytes o In intracellular fluid, K and HPO 2–are the predominant electrolytes 4 (potassium and phosphate) o In extracellular fluid, Na and Cl predominate (sodium and chloride) o There is a slight electrical charge difference on either side of the cell membrane Functions of Fluids 1. Fluids dissolve and transport substances • water is an excellent solvent because it can dissolve many different substances and transport them to their cells • the dissolved materials, or solutes, include amino acids, glucose, water- soluble vitamins, minerals, and medications • fats don't dissolve in water, therefore they are either attached to or surrounded by water soluble proteins 2. Fluids account for blood volume • Blood volume is the amount of fluid in blood • increased blood volume can cause blood pressure to rise (hypertension) and may cause stroke or heart disease • decreased blood volume can cause low blood pressure (tiredness, confusion, dizziness) 3. Fluids help maintain body temperature • because water has a high heat capacity, the temperature of our body fluids remains quite stable because it would take a lot of energy to raise its temperature • sweating releases heat as the evaporation of water from teh skin cools the skin and blood Evaporative cooling occurs when heat is transported from the body core through the bloodstream to the surface of the skin. 4. Fluids protect and lubricate our tissues • Cerebrospinal fluid protects the brain and spinal column • Amniotic fluid protects the fetus • Synovial fluid is a coating around joints • Digestive secretions allow for easy passage of material like saliva • Pleural fluid covering lungs allows for expansion and contraction in chest cavity Functions of electrolytes 1. Electrolytes help regulate fluid balance • water follows the movement of electrolytes, moving by osmosis to areas where the concentration of electrolytes is high • this allows for the controlled movement of fluids into and out of cells • some illnesses that lead to protracted (extended) vomiting and diarrhea can alter this balance 2. electrolytes enable our nerves to respond to stimuli + + • Movement of Na and K across the membranes of nerve cells changes the electrical charge across the membrane • This change in electrical charge carries the nerve impulse along the nerve cell 3. electrolytes signal our muscles to contract • The movement of calcium (Ca ) into a muscle cell stimulates the muscle to contract • The Ca is pumped back out of the cell after the muscle contraction Maintaining Fluid Balance • fluid balance is maintained by different mechanisms that tells us to drink fluid when dehydrated and excrete fluid as urine when we consume more than we need • Thirst mechanism: 1. a group of hypothalamic cells that causes you to desire to drink 2. the thirst mechanism makes us fell thirsty whenever:  an increased concentration of sodium and other dissolved substances. ex: ham and potato chips  reduction in blood volume and blood pressure. this is can happen when fluids are lost because of sweating, blood loss, vomiting, or diarrhea, or not enough of water intake  dryness in the tissues of the mouth and throat which causes a reduced production of saliva • To prevent hydration, the hypothalamus release a hormone that signals the kidney to reduce urine flow and return more water to the bloodstream.Also, water is drawn out of the salivary glands • We gain fluids from 3 primary sources 1. beverages 2. foods; ex: iceberg lettuce contains 96% water 3. body's production of metabolic water (water formed from the body's metabolic reactions, 10-14%) • We sense water lost through urine output and sweating so we refer to this as sensible water loss; we notice it • The kidneys control how much water is reabsorbed; excess water is processed by the kidneys and excreted as urine • Insensible water loss is the loss of water not noticeable by a person such as through evaporation ( water is continuously evaporated from the skin even when person is not sweating) and exhalation from the lungs during breathing. • other 7 ways of fluid loss: o illness that involves fever, coughing, vomiting, diarrhea, and a runny nose o traumatic injury, internal bleeding, blood donation, surgery ( all blood loss) o exercise; lost through sweat and lungs o environmental conditions like humid and dry areas o pregnancy because water is continually given to fetus o breastfeeding o consumption of diuretics (increase fluid loss via urine ) like alcohol Water • essential for life • required for fluid and electrolyte balance and many metabolic reactions • recommended intake varies and depends on age, body size, health status, physical activity level and environmental conditions • DRI: adult men (19-50 yrs): 3.7 L Amount and sources of water •
More Less

Related notes for BPK 110

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.