Fluid, electrolyte, and acid-base balance Flashcards
balance =
state of equilibrium
is water and electrolyte independent or dependent of each other?
independent!
average % of water weight in female
52%
average % of water weight in male
63%
______ L of water in adult body, _____ is intracellular fluid, and ______ is extracellular fluid.
40L
2/3 intracellular fluid
1/3 extracellular fluid
what are 2 major factors of fluid movement between compartments?
- hydrostatic pressure
- colloid osmotic pressure
hydrostatic pressure
generated by fluid on the walls of the capillary, usually forcing water out of the circulatory system
colloid osmotic pressure
exerted by proteins, notably albumin, in a blood vessel’s plasma tends to pull water into the circulatory system
regulation of water intake steps
- The body loss little as 1% of its water
- Increase in the osmotic pressure of extracellular fluid due to water loss stimulates osmoreceptors in the thirst center
- Activity in the hypothalamus causes the person to feel thirsty and to seek water
- Drinking and resulting distension of the stomach by water stimulate nerve impulses that inhibit the thirst center
- Water is absorbed through the walls of the stomach and small intestine
- Osmotic pressure of extracellular fluid returns to normal
regulation of water output: dehydration
- Extracellular fluid becomes osmotically concentrated
- Osmoreceptors in the hypothalamus are stimulated by the increase in the osmotic pressure of body fluids
- Hypothalamus signals the posterior gland to release ADH into the blood
- Blood carries ADH to the kidneys
- ADH causes the distal convoluted tubules and collecting ducts to increase water absorption
- Urine output decreases and water loss is minimized
regulation of water output: excess water intake
- Extracellular fluid becomes osmotically less concentrated
- This change stimulates osmoreceptors in the hypothalamus
- Posterior pituitary gland decreases ADH release
- Renal tubules decreases water reabsorption
- Urine output increases and excess water is excreted
what positive charged ions are important? what are they vital for?
Ca+, Na+, K+
nerve impulse conduction, muscle fiber contraction, and maintenance of cell membrane permeability
Electrolytes that ionize in water and release hydrogen ions =
acids
Substances that combine with hydrogen ions =
bases
Acids
- Strong acids ionize more completely and release more H+
- Weak acids ionize less completely and release fewer H+
bases
- Strong bases ionize more completely and release more OH-
- Weak bases ionize less completely and release fewer OH-
Maintenance of acid-base balance usually eliminates acids in one of three ways:
- Acid-base buffer systems
- Respiratory excretion of carbon dioxide
- Renal excretion of hydrogen ions
Normal metabolic reactions generally produce more acid than base, reactions include:
- Cellular metabolism of glucose
- Fatty acids
- Amino acids
Respiratory secretion of CO2 steps
- Cells increase production of CO2
- CO2 reacts with H2O to produce H2CO3
- H2CO3 release H+
- Respiratory center is stimulated
- Rate and depth of breathing increase
- More CO2 is eliminated through lungs
what does the respiratory system of the brainstem help?
helps regulate H ion conc. In the body fluids by controlling the rate and depth of breathing
Renal secretion of H ions
Nephrons help regulate the H ion concentration of body fluids by excreting H ions in the urine
Acid-base (chemical) buffers function______.
rapidly
Respiratory and renal (physiological buffers) functions ________.
more slowly
Acidosis =
accumulation of acids and loss of bases
- Respiratory acidosis
- Metabolic acidosis
Alkalosis
- Develops as a result of hyperventilation
- Metabolic alkalosis = great loss of H ions from a gain bases, both accompanied by a rise in the pH of blood
Large organic molecules such as proteins are not usually found in the _____.
Interstitial fluid
Intracellular fluid
Plasma
interstitial fluid
The most abundant (-) charge ion in the extracellular fluid is_____.
Sulfate
Bicarbonate
Chloride
chloride
If the solute concentration in the extracellular fluid decreases, water ______.
Water moves into the cell
Moves out of the cell
Moves out of the blood
water moves into the cell
what is the 3 acid-base buffer system?
- bicarbonate buffer system
- phosphate buffer system
- protein buffer system
Alkalosis:
Occurs when the pH of the body fluids is less than 7.35
Can be caused by hyperventilation
Can occur as a result of anaerobic respiration
Can be caused by hyperventilation
The major effect of acidosis is the ______ of the nervous system whereas a major effect of alkalosis is ______ of the nervous system.
Depression; hyperexcitability
Hyperexcitability; depression
Depression; hyperexcitability
Respiratory regulations of pH depends upon the______.
Carbonic acid/bicarbonate buffer system
Phosphate buffer system
Protein buffer system
Carbonic acid/bicarbonate buffer system
