Nurs210 Chapter 17 Key Words

Front 1

Define Homeostasis

Back 1

the state of equilibrium in the internal environment of the body, naturally maintaned by adaptive responses that promote healthy survival.

Front 2

What fluid makes up about 60% of the human body weight?

Back 2

Water

Front 3

What is ICF?

Back 3

Intracellular fluid- approximately 2/3 of the body water is located within cells

Front 4

What is ECF?

Back 4

Extracellular fluid- consists of interstitial fluid and lymph, fluid in blood, and a very small amount of fluid contained within specialized cavities of the body

Front 5

One Liter of water is equivalent to how many pounds?

Back 5

2.2 lbs (1kg)

Front 6

Electrolytes

Back 6

substances whose molecules dissociate, or split into ions, when placed in water

Front 7

Ions

Back 7

electrically charged particles

Front 8

Cations

Back 8

positively charged ions (sodium, potassium, calcium, magnesium)

Front 9

Anions

Back 9

negatively charged ions (bicarbonate, chloride, and phosphate); also, most proteins

Front 10

Valence

Back 10

the electrical charge of an ion; cations and anions combine according to their valences

Front 11

In the ICF, what is the most prevalent cation? What is the most prevalent anion?

Back 11

Cation- potassium with small amounts of magnesium and sodium.

Anion- phosphate with some protein and a small amount of bicarbonate.

Front 12

In the ECF, what is the most prevalent cation? What is the most prevalent anion?

Back 12

Cation- sodium with small amounts of potassium, calcium, and magnesium.

Anion- chloride with small amounts of bicarbonate, sulfate, and phosphate

Front 13

Define diffusion

Back 13

the movement of molecules from an area of high concentration to one of low concentration.

Net movement of molecules stops when the concentrations are equal in both areas.

Front 14

Facilitated Diffusion

Back 14

Passive diffusion where there is a carrier molecule on most cells that increase or facilitate the rate of diffusion of glucose into theese cells.

Front 15

Active Diffusion

Back 15

A process in which molecules move against the concentration gradient. External energy is required for this process.

eg. Sodium moves out of the cell and potassium moves into the cell to maintain this concentration difference. Referred to the sodium-potassium pump. The energy source for this mechanism is adenosine triphosphate (ATP), which is produced in the cell's mitochondria

Front 16

What is osmosis?

Back 16

The movement of water between two compartments separated by a semipermeable membrane (a membrane permeable to water but not to a solute).

Front 17

Define osmotic pressure?

Back 17

The amount of pressure required to stop the osmotic flow of water.

Water will move from the less concentrated side to teh more concentrated side of a chamber.

Measured in mlliosmoles (mOsm)

Front 18

Define osmolality

Back 18

Measures the osmotic force of solute per unit of weight of solvent (mOsm/kg or mmol/kg).

Pertains to fluids inside the body

Front 19

Define osmolarity.

Back 19

Measures the total milliosmoles of solute perunit of total volume of solution (mOsm/L).

Pertains to fluids outside the body.

Front 20

What is the normal range for plasma osmolality?

Back 20

275-295 mOsm/kg

Front 21

Define water deficit.

Back 21

A plasma osmolality value greater than 295 mOsm/kg; the concentration of the particles is too great or that the water content is too little

Front 22

Define water excess.

Back 22

A lab value less than 275 mOsm/kg; too little solute for the amount of water or too much water for the amount of solute

Front 23

Define isotonic fluids.

Back 23

Fluids with the same osmolality as the cell interior.

Front 24

Define hypotonic fluids.

Back 24

Solutions in which the solutes are less concentrated than teh cells (hypoosmolar)

Front 25

Define hypertonic fluids.

Back 25

Fluids with solutes more concentrated than cells (hyperosmolar)

Front 26

Define Hydrostatic Pressure.

Back 26

The force within a fluid compartment; it is the major force that pushes water out of the vascular system at the capillary level.

Front 27

Define Oncotic Pressure.

Back 27

(Colloidal osmotic pressure)- osmotic pressure exerted by colloids in solution; The major colloid in the vascular system contributing to the total osmotic pressure is protein.

Front 28

Name some causes of increased venous hydrostatic pressure.

Back 28

fluid overload, heart failure, liver failure, obstruction of venous return to the heart (e.g., tourniquets, restrictive clothing, venous thrombosis), and venous insufficiency (e.g., varicose veins)

Front 29

Name some reasons for decreased plasma oncotic pressure.

Back 29

excessive protein loss (renal disorders), deficient protein synthesis (liver disease), and deficient protein intake (malnutrition).

Front 30

Define fluid spacing.

Back 30

A term sometimes used to describe the distribution of body water.

Front 31

Define first spacing.

(r/t fluid spacing)

Back 31

Describes the normal distribution of fluid in the ICF and ECF compartments.

Front 32

Define second spacing.

(r/t fluid spacing)

Back 32

Refers to an abnormal accumulation of interstitial fluid (i.e., edema).

Front 33

Define third spacing.

(r/t fluid spacing)

Back 33

Occurs when fluid accumulates in a portion of the body from which it is not easily exchanged with the rest of the ECF.

i.e., ascites, sequestration of fluid in the abdominal cavitiy with peritonitis, and edema associated with burns.

Front 34

What mechanism is the primary protection against the development of hyperosmolality?

Back 34

Thirst mechanism; decreases in older adults

Front 35

Define dehydration.

Back 35

Refers to loss of pure water alone without corresponding loss of sodium.

Should not be confused with fluid volume deficit.