Fluid, Electrolyte, Acid-Base Balance Flashcards
Percentage of water in body for males and females?
60% for males
50% for females
Differences due to intercellular fluid
Composition of the human body mostly made up of:
Proteins
What is extracellular fluid made out of?
Interstitial (25%) and Plasma (8%)
How is fluid balance maintained in the body?
through the digestive system: water in
and through the urinary system: water out
2 major subdivisions of extracellular fluid:
1) interstitial fluid of peripheral tissue
2) plasma of circulating blood
How does the body maintain specific fluid compartments?
through selectively permeable membranes, specific membrane channels
What is the most abundant cation in Extracellular fluid?
Sodium
What is the most abundant cation in Intracellular fluid?
Potassium
What is the most abundant anion in Extracellular fluid?
Chlorine
What are the most abundant anions in Intracellular fluid?
Protein and (HPO42-)
How does osmosis eliminate minor differences in concentration?
Plasma membranes are permeable to water
4 rules of regulating fluids and electrolytes:
1) ECF Rules
2) Concentration matters
3) Water is so passive
4) its all a matter of balance
All homeostatic mechanisms that monitor and adjust body fluid composition respond to?
Changes in ECF
What do receptors monitor?
They Monitor concentrations and plasma volume
Is water passive or active in regards to regulation of fluid?
ALWAYS PASSIVE
What 3 hormones affect fluid and electrolyte balance?
ADH, aldosterone, and natriuretic peptides
What 2 thing does ADH stimulate?
Thirst and water conservation at kidneys
The osmoreceptors in “____” monitor osmotic concentration of “____”?
Hypothalamus, ECF
Will a higher or a lower osmotic concentration increase ADH release?
Higher concentration because ADH lowers osmotic concentration
Where is ADH release?
Posterior lobe of the pituitary gland
What system is aldosterone activated by?
renin-angiotensin system
What gland secretes aldosterone?
The cortex of the adrenal gland
When aldosterone causes kidney to conserve salt….
…stimulates water retention because water follows salt
What is the function of ANP and BNP?
Blocks release of ADH and aldosterone, reducing thirst, to ultimately lower blood pressure and plasma volume.
Is the circulation between the ECF and ICF compartments large or small-scale?
Small scale
What are the percentages of the normal volume of ECF split up in interstitial fluid and plasma?
80% interstitial fluid, 20% plasma
Which volume is greater, ICF or ECF?
ICF; it acts as a water reserve and prevents large osmotic changes in ECF
What is the pH of ECF?
7.35-.7.45
3 types of acids in the body:
1) Volatile Acids
2) Fixed Acids
3) Organic Acids
What is an important volatile acid in body fluids?
Carbonic acid
What is the most important factor affecting pH in body tissues?
Pressure of CO 2
2 ways organic acids are made:
Anaerobic (Lactic acid): builds up rapidly
Aerobic: Metabolizes rapidly, and does not accumulate
3 major buffer systems:
1) protein (regulates protein in ECF and ICF)
2) carbonic acid - bicarbonate (ECF)
3) phosphate (pH of ICF)
What is the only intracellular buffer system with an immediate effect on ECF pH?
Hemoglobin Buffering System
Why is acidosis more common?
Because normal cellular activites generate acids
