Fluid, Electrolyte, and Acid-Base Balance Flashcards
a delicate balance of fluids, electrolytes, and acids and bases maintained in the body.
Homeostasis
is the primary body fluid
Water
Water - approximately ______ of average healthy adult’s
weight
60%
Water - approximately 60% of average healthy adult’s
weight (_______________ in infants and ____ to people older
than ___)
70% to 80%; 50%; 50
TWO COMPARTMENTS OF BODY’S FLUID
INTRACELLULAR FLUID (ICF)
EXTRACELLULAR FLUID (ECF)
The two main compartments of ECF are
INTRAVASCULAR FLUID (PLASMA)
INTERSTITIAL FLUID
found within the cells of the body
INTRACELLULAR FLUID (ICF)
INTRACELLULAR FLUID (ICF) is _______ of the total body fluid in adults
2/3
found outside the cells
EXTRACELLULAR FLUID (ECF)
1/3 of the total body fluid
EXTRACELLULAR FLUID (ECF)
EXTRACELLULAR FLUID (ECF) is _____ of the total body fluid
1/3
20% of the ECF
INTRAVASCULAR FLUID (PLASMA)
found within the vascular system
INTRAVASCULAR FLUID (PLASMA)
INTRAVASCULAR FLUID (PLASMA) is ____ of the ECF
20%
75% of the ECF
INTERSTITIAL FLUID
surrounds the cells
INTERSTITIAL FLUID
INTERSTITIAL FLUID is ___ of the ECF
75%
COMPOSITION OF BODY FLUIDS
Ions
Cations
Anions
Electrolytes
charged particles
Ions
ions that carry a positive charge
Cations
ions that carry a negative charge
Anions
minerals in the body that have electrical charge
Electrolytes
chemicals from which ions are made
Electrolytes
Ex. of Cations:
- Sodium (Na+)
- Potassium (K+)
- Calcium (Ca++)
- Magnesium (Mg++
Ex. of Anions:
- Chloride (Cl-)
- Bicarbonate (HCO3-)
- Phosphate (HPO4–)
- Sulfate (SO4–)
Electrolytes are generally measured in
milliequivalents per Liter of water (mEq/L) or milligrams per 100 milliliters (mg/100mL)
MOVEMENT OF BODY FLUIDS AND ELECTROLYTES
◎ Osmosis
◎ Diffusion
◎ Filtration
◎ Active Transport
________________ are selectively permeable/semi-permeable to solutes.
Membranes
Membranes are ________________________ to solutes.
selectively permeable/semi-permeable
Movement of water across cell membranes, from the less concentrated solution to the more concentrated solution
Osmosis
substances dissolved in a liquid
Solute
component that can dissolve a solute
Solvent
the concentration of solutes in body fluids
Osmolality
power of a solution to draw water across a semipermeable membrane
Osmotic Pressure
Osmolality is reported as
solute per kilogram of water
pulls water from the interstitial space into the vascular
compartment
Colloid Osmotic Pressure (Oncotic Pressure)
solute and solvent are equal
Isotonic solution
higher osmolality than body fluids
Hypertonic solution
cells shrink
Hypertonic solution
lower osmolality than body fluids
Hypotonic solution
cells swell
Hypotonic solution
Movement of molecules through a semipermeable membrane from an area of higher concentration to an area of lower concentration
Diffusion
Fluid and solutes move together across a membranes from an area of higher pressure to one of lower pressure
Filtration
pressure in the compartment that results in the movement
Filtration pressure
pressure exerted by a fluid within a closed system on the walls of the container in which it is contained.
Hydrostatic pressure
Substances can move across cell membranes from a less concentrated solution to a more concentrated one
Active Transport
It differs from diffusion and osmosis in that metabolic energy is expended
Active Transport
Active Transport differs from diffusion and osmosis in that ___________________________
metabolic energy is expended
A substance combines with a carrier on the outside surface of the cell membrane.
Active Transport
Fluid Intake
◎ An average adult needs ______________ per day.
2,500 mL
Average Daily Fluid Intake for an Adult
Oral fluids - 1200–1500
Water in foods - 1000
Water as by-product of food metabolism- 200
primary regulator of fluid intake
Thirst mechanism
thirst center is located in the
hypothalamus of the brain
it takes __________________________ for the fluid to be absorbed and distributed throughout the body
30 minutes to 1 hour
Fluid losses that counterbalance the adult’s 2,500-mL average fluid intake
Fluid Output
Average Daily Fluid Output for an Adult
Urine - 1,400 to 1,500 mL
Insensible Losses
- Lungs (water vapor in the expired air) - 350 mL to 400 mL
- Skin - 350 mL to 400 mL
Sweat - 100 mL
Feces - 100 mL to 200 mL
Total of Average Daily Fluid Output for an Adult
2,300-2,600 mL
Homeostatic regulators/mechanisms:
- Kidneys
- Antidiuretic Hormone
- Renin-Angiotensin-Aldosterone System
- Atrial Natriuretic Factor
Primary regulator of body fluids and electrolyte balance
Kidneys
Regulates water and electrolyte secretion
Kidneys
Plays a significant role in acid-base regulation, excreting hydrogen ion (H+) and retaining bicarbonate
Kidneys
Kidneys plays a significant role in
acid-base regulation, excreting hydrogen ion (H+) and retaining bicarbonate
Regulates water excretion from the kidney
Antidiuretic Hormone (ADH)
Antidiuretic Hormone (ADH) is synthesized in the
anterior portion of the hypothalamus
is synthesized in the anterior portion of the hypothalamus
Antidiuretic Hormone (ADH)
Produced when serum osmolality rises
Antidiuretic Hormone (ADH)
Antidiuretic Hormone (ADH) is preduced when
serum osmolality rises
is suppressed when serum osmolality decreases
Antidiuretic Hormone (ADH)
Restore blood volume (and renal perfusion) through sodium and water retention
Renin-Angiotensin-Aldosterone System
When blood flow or pressure to kidneys decreases, __________ is released
renin
causes the conversion of angiotensin to angiotensin I, which is
converted to angiotensin II by angiotensin-converting enzyme
Renin
Renin causes the conversion of angiotensin to ___________________ which is converted to ______________________ by ________________________
angiotensin I; angiotensin II; angiotensin-converting enzyme
acts directly on the nephrons to promote Sodium and
water retention
Angiotensin II
Stimulates the release of Aldosterone from the adrenal cortex
Renin-Angiotensin-Aldosterone System
It promotes sodium retention
Renin-Angiotensin-Aldosterone System
Renin-Angiotensin-Aldosterone System
- When blood flow or pressure to kidneys decreases, renin is released.
- Renin causes the conversion of angiotensin to angiotensin I, which is converted to angiotensin II by angiotensin-converting enzyme.
- Angiotensin II acts directly on the nephrons to promote Sodium and water retention.
- Stimulates the release of Aldosterone from the adrenal cortex. It promotes sodium retention.
Released from cells in the atrium of the heart in response to excess blood volume and stretching the atrial walls
Atrial Natriuretic Factor (ANF)
Atrial Natriuretic Factor (ANF) is released from _________________________ in response to excess blood volume and stretching the atrial walls
cells in the atrium of the heart
Promotes sodium wasting and acts as a potent diuretic, thus reducing vascular volume
Atrial Natriuretic Factor (ANF)
Reduces thirst, reducing fluid intake
Atrial Natriuretic Factor (ANF)
Importance of electrolytes:
- Maintaining fluid balance
- Contributing to acid-base regulation
- Facilitating enzyme reactions
- Transmitting neuromuscular reactions
Ex. of Electrolytes
Sodium (Na+)
Potassium (K+)
Calcium (Ca++)
Magnesium (Mg++)
Chloride (Cl-)
Phosphate (PO4-)
Bicarbonate (HCO3-)
Most abundant cation in the ECF and a major contribution to serum osmolality
Sodium (Na+)
Normal Value of Sodium (Na+)
135-145 mEq/L
Aids in transmitting nerve impulses and contracting muscles
Sodium (Na+)
Major cation in ICF, with only small amount found in ECF
Potassium (K+)
Normal serum levels of Potassium (K+)
3.5 to 5.0 mEq/L
Vital electrolyte for skeletal, cardiac, and smooth muscle activity
Potassium (K+)
Must be consumed everyday because the body cannot conserve it
Potassium (K+)
Sources of Potassium (K+)
avocado, raw carrot, spinach, dried fruits, banana, apricot, orange, beef, pork, milk
__________ of Calcium is found in the skeletal system, with a
relatively small amount in the ECF
99%
99% of ____________ is found in the skeletal system, with a
relatively small amount in the ECF
Calcium
99% of Calcium is found in the_____________, with a
relatively small amount in the ECF
skeletal system
Vital in regulating muscle contraction and relaxation, neuromuscular function, and cardiac function
Calcium
Normal total serum levels of Calcium
8.5-10.5 mg/dL
Normal ionized serum levels of Calcium
4-5 mg/dL
increase serum Ca++ levels
Parathyroid hormone and calcitriol
decreases serum levels
calcitonin
Daily intake should be ______________ of Calcium
1,000-1,500 mg
Primarily found in the skeleton and in ICF
Magnesium (Mg++)
Magnesium (Mg++) is primarily found in the
skeleton and in ICF
Second most abundant ICF cation
Magnesium (Mg++)
Normal serum levels of Magnesium (Mg++)
1.5 to 2.5 mEq/L
Aids in relaxing muscle contractions, transmitting nerve impulses, regulating cardiac function, and intracellular metabolism.
Magnesium (Mg++)
Sources of Magnesium
cereal grains, nuts, dried fruits, legumes, green, leafy vegetables, dairy products, meat, fish
Major anion of the ECF
Chloride (Cl-)
Normal serum levels of Chloride
95 to 108 mg/dL
When sodium is reabsorbed in the kidney, ______________ usually follows
chloride
Major component of gastric juice (HCl), and is involved
in regulating acid-base balance
chloride
Found in the same foods as Sodium
chloride
Major anion of ICF
Phosphate (PO4-)
Also found in the ECF, bone, skeletal muscle, and nerve tissue.
Phosphate (PO4-)
Normal serum levels of Phosphate
2.5 to 4.5 mg/dL
Aids in metabolizing Carbohydrate, Protein, and Fat; it is absorbed in the intestines
Phosphate (PO4-)
Sources of Phosphate
meat, fish, poultry, milk products, legumes
Present in both ICF and ECF
Bicarbonate (HCO3-)
Primary function is to regulate acid-base balance
(major body buffer)
Bicarbonate (HCO3-)
major body buffer
Bicarbonate (HCO3-)
Regenerated by the kidneys
Bicarbonate (HCO3-)
Bicarbonate (HCO3-) is regenerated by the
kidneys
ECF bicarbonate levels are regulated by the
kidneys
Produced through metabolic processes
Bicarbonate (HCO3-)