EXAM 4: Fluid and Electrolytes

NURS207: Foundations

body fluid is primarily made up of…

water

what percent of the body is water?

70%

obese people have ____ water percentage

less

water is ___ free

fat

____ tend to have a higher percentage of body fat than men

women

purpose of water in the body

solvent for electrolytes, maintains normal body temp, transportation of nutrients, wastes, hormones, RBC & WBC, platelets

intracellular fluid

65% of liquid, fluid found within the cells of the body

extracellular fluids

36% of fluid, fluid outside the cells

intracellular fluid contains solutes such as…

oxygen, electrolytes, glucose

intracellular fluid is vital to normal cell functioning because..

it provides a medium for pmetabolic processes to take place

extracellular fluid is the transport system that…

carries nutrients to the cells and waste products from the cellse

extracellular fluid consists of…(3 kinds of fluids)

interstitial, intravascular, transcellular

transcellular fluid is within…

the cerebrospinal column, joints, eyes, lymph, pleural cavity

electrolytes

contain electrically charged particles called ions

cations

ions with a positive charge

anions

ions with a negative charge

examples of cations

sodium, potassium, calcium, magnesium

examples of anions

chloride, bicarbonate, phosphate, sulfate

cations of the intracellular fluid

potassium (K+) and Mg (magnesium)

anions of intracellular fluid

phosphate (PO4-) and sulfate (SO4)

ions of extracellular fluid

calcium (Ca++) and sodium (Na++)

albumin

protein in the plasma, carries ions, has an osmotic effect, draws water to it

osmolality

the concentration of solutes to water

when body water decreases…

the concentration of solutes increases, serum osmolality increases

urine osmolality measures..

renal function and hydration status

acid

a substance containing hydrogen ions that can be released

base

a substance that accepts hydrogen ions

pH

the hydrogen ion concentration

normal pH

7.35-7.45

acidosis range

6.8-7.35

alkalosis

7.45-7.8

chemical buffers

prevent body fluids from becoming too acidic or alkaline

what is the most common body acid?

carbonic-acid (H2CO3)

what is the most common body base?

bicarbonate (HCO3-)

what should the ratio of bicarbonate to carbonic-acid be?

20:1

when serum CO2 is increased, in causes…

respirations to increase in rate and depth

when serum CO2 is decreased, it causes respirations to ___ in rate and depth

decrease

if there is acidosis the kidneys…

excrete hydrogen ions and form bicarbonate ions

if there is alkalosis the kidneys…

retain hydrogen and excrete bicarbonate (HCO3-) ions

what electrolytes need to be taken daily because they are not in the body?

sodium and chloride

what electrolytes are stored in the cells and bones?

potassium and calcium

osmotic pressure…

holds fluid in the vessels

hydrostatic pressure…

forces fluid into the tissue spaces

solute

the substance that dissolves in a solution

solvent

the liquid/solution

osmosis (passive)

the movement of a pure solvent through a semipermeable membrane from an area of less concentration to higher concentration until equilibrium is reached

osmotic pressure

the drawing power for water

a high solute concentration means…

a high osmotic pressure and it draws water into itself until equilibrium is reached

osmolarity of a solution is the…

concentration of particles in a solution (solute), pulling power of the solution

diffusion

the movement of a solute in a solvent across a semipermeable membrane from an area of high concentration to an area of low concentration

osmosis refers to ____ movement

solvent

diffusion of solutes refers to ____ solute movement

solute

net movement

movement that occurs between diffusion and osmosis until equilibrium is reached

capillary filtration

process by which water and diffusible substances move together in response to pressure of blood against the walls of the capillaries

what is the movement during capillary filtration? (high to low or low to high)

high to low pressure, this is how nutrients and oxygen are delivered to tissues and it is driven by hydrostatic pressure

hydrostatic pressure

the pressure of fluid on the walls of the container it is contained

reabsorption

prevents too much fluid from leaving capillaries no matter how much hydrostatic pressure exits

osmotic pressure is affected by ____ especially ____

plasma proteins such as albumin

colloid osmotic pressure

tends to keep fluid in the intravascular which opposes hydrostatic pressure

at the _____ end of the capillaries, hydrostatic pressure is greater than colloid pressure which causes fluid and solute to move out of the capillary and into the interstitial space

arterial

at the _____ end of the capillaries, colloid pressure is greater than hydrostatic pressure so the colloid pressure draws water back into capillaries to be filtered through the kidneys

venous

active transport

goes against the concentration gradient, requires metabolic activity and energy

how do sodium and potassium move in and out of the cell? (by what kind of transport)

active transport

fluid in the body can regulated by…

fluid intake, output, hormonal controls

fluid intake daily

oral is 1500 mL but with foods it will equal 2500 mL

thirst is stimulated by…

receptors in the hypothalamus, eating salty food or excessive fluid loss

thirst is dimisnihed by…

illness, LOC, aging

decreased thirst may be due to…

hypovolemia

fluid output daily

1500 mL through urine

sensible water loss

can be measured through urination, defecation, wounds

insensible water loss

cannot be measured, evaporation through skin and lungs

the kidneys must produce a minimum of ____ mL of urine every 24 hrs

500-600

the kidneys must produce at least ____ mL/hr

30

urine production is influenced by what two hormones?

ADH/vasopressin and aldosterone

Which of the following is true?

• Hydrostatic pressure is greatest at the venous end of the vessels.

• Osmosis refers to the movement of solvent (water) in the direction of the greatest concentration of solutes.

• Ideally, intake and output should be equal.

• ADH causes diuresis.

• Osmosis refers to the movement of solvent (water) in the direction of the greatest concentration of solutes.

  • Ideally, intake and output should be equal.

relative changes of fluid and electrolyte imbalance

when fluids or electrolytes shift from one body space to another

absolute changes of fluid and electrolyte imbalance

when fluids and electrolytes are lost outside the body

hypovolemia occurs when…

the body loses both water and electrolytes from the ECF

dehydration

results from loss of water from circulation, fluid shifts from inside the cell to the outside

hemoconcentration

where there is an increased concentration of cells and solids in the blood due to fluid loss

causes of dehydration or hypovolemia

diabetes, renal failure, fever, exercise, sweating, vomiting, diarrhea

assessments of hypovolemia or dehydration

dry mucous membranes, decreased tissue turgor, tachycardia, tachypnea, low BP, flat neck veins, thirst

interventions for hypovolemia and dehydration

give oral fluids and IVs, mouth care, stop bleeding and replace blood

hypervolemia

the body retains water and sodium

edema

excess interstitial fluid

what is edema caused by?

increased capillary permeability, increased capillary hydrostatic pressure, decreased plasma oncrotic pressure

third space syndrome

fluid shifts from the vascular space into an area that is not readily accessible

water intoxication

overhydration, body takes in more water than it excretes

water intoxication symptoms

mental changes, blurred vision, muscle cramps and twitching, paralysis, N/V