# Body Fluids
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**Body fluids** are the various fluids inside your body. About 50-70% of an adults weight is made up of various fluids. Maintaining a proper amount and [[fluid volume balance|balance]] of these fluids is very important to our overall health and highly controlled. Additionally, various fluids have various [[electrolytes]] associated with them and their [[osmosis|osmolarity]] is vital to maintaining cell health.
The functions of the body fluids are necessary for life.
- [[blood volume]], which determines [[blood pressure]]
- [[homeostasis]]
- [[thermoregulation]]
- facilitating [[membrane transport]]
- ions/[[electrolytes]]
- [[osmosis|osmolarity]]
- maintains neuromuscular function in particular
- cell [[metabolism]]
![[body fluids.png]]
Body fluids can be typically broken down into two broad categories, Intercellular, and extracellular. Extracellular fluid can be broken down into interstitial fluid, plasma and transcellular fluid.
- **Intracellular fluid** is fluid that is inside the cells themselves, which is also called the [[cytoplasm]].
- **Extracellular fluid** is all the fluid that that is not inside the cell itself, but in the surrounding area. It comes in two categories:
- **Interstitial fluid** is the fluid that flows in the surrounding tissue, that is outside by the circulatory and lymphatic systems and the actual cell walls. About 2/3s of extracellular fluid is interstitial fluid.
- **Intravascular fluid**, often just referred to as [[plasma]] is the fluid in the [[blood|bloodstream]] and the [[lymphatic system|lymph]]. About 1/3 of extracellular fluid is intravascular fluid.
- **Transcellular fluid** is fluid that is outside of a cell, but contained within something else. For example:
- [[cerebrospinal fluid]]
- [[synovial joint|synovial fluid]]
- [[eyes|aqueous humor]]
- [[serous membrane|serous fluid]]
- [[gastric gland|gastric juices]]
- [[urine]]
- perilymph and endolymph in the [[ears|inner ear]]
Example of compartmentalization of the total body fluids of an average 70 kg male.
![[body fluid percentages.png]]
## Factors that Alter Body Fluids
- [[adipose tissue]] has a low water content
- a lot of adipose tissue will be a dryer person
- [[muscle tissue]] has a high water content
- a lot of muscle tissue will be a wetter person
- sex
- AFAB typically have a lower percentage (50% vs 60%)
- age
- [[pediatrics]]
- babies have a great need and they're about 80% water and they can dry out very quickly
- higher body surface area to mass ratio is great, so insensible losses through the skin can be high, especially if they have a fever
- their [[kidneys]] are immature and cannot adjust well
- they cannot communicate thirst
- [[older adult]]
- have decreased [[hypothalamus|thirst drive]]
- may have mobility issues preventing access
- may struggle with incontinence and decide not to drink as much
- decreased muscle mass
- altered nutritional intake
- reduced [[kidneys|kidney function]]
- often on meds like [[diuretics]]
- lower [[cardiac reserve]]
- thinner skin causes more insensible loss via skin
Dehydration signs and symptoms
altered mental status
delirium
not enough water [[fluid volume deficit]]
[[dehydration]] is a particular type of FVD for water specifically
too much water
[[fluid volume excess]]
## Problems with Fluid Volume
- [[fluid volume excess]]
- [[fluid volume deficit]]
IMBALANCES
third spacing like [[ascites]]
[[anasarca]] is generalized swelling everywhere
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