Fluids, Electrolytes and Acid-Base Balancing Flashcards
What constitutes extracellular fluid? (6)
Plasma Interstitial fluid Lymph CSF Synovial fluid Humors of the eye
What is intracellular fluid?
Water inside the cell
What must exist for homeostasis to happen?
A constant balance between the fluids and electrolytes
What are the three things required to maintain the constant balance in homeostasis?
Water
Electrolytes
Non-electrolytes
What are three positively charged electrolytes (cations) found in the intracellular space?
Potassium K+
Calcium Ca++
Magnesium Mg++
What is one positively charged electrolyte (cation) found in the extracellular space?
Sodium Na+
What is one negatively charged electrolyte (anion) in the intracellular space?
Phosphate PO4 3-
What are two negatively charged electrolytes (anion) in the extracellular space?
Chloride Cl-
Bicarbonate HCO3-
What are two ways that water enters the body?
Digestive system
Cellular metabolism
What are the four ways water exits the body?
Kidney’s
Lung’s
Sweat
Feces
What is net filtration?
Pressure-driven movement of fluid and solutes from blood capillaries into the interstitial fluid
Fluid is moved from blood to interstitial fluid within the capillary bed (filtration) and then reabsorbed as necessary
What are the six forces that affect net filtration?
Tonicity
Blood hydrostatic pressure (BHP)
Blood colloid osmotic pressure (BCOP)
Interstitial fluid colloid osmotic pressure (IFCOP)
Interstitial fluid hydrostatic pressure (IFHP)
Membrane permeability
What is the equation for net filtration pressure?
NFP=(BHP+IFOP) - (IFHP+BCOP)
What are the three types of fluid in tonicity?
Isotonic
Hypotonic
Hypertonic
What is the definition of an isotonic fluid?
It has an equal solute concentration
It is the same pressure
What is the definition of a hypotonic fluid?
It has a lesser solute concentration
It has less pressure
What is the definition of a hypertonic fluid?
It has a higher solute concentration
It has more pressure
What is blood hydrostatic pressure (BHP)?
It is the mechanical force of water against cellular membranes
What does the blood hydrostatic pressure represent in the capillary network?
The blood pressure of the capillary network
What is the mmHg within the capillary network, caused by blood hydrostatic pressure?
25-30 mmHg
Where is the pressure for blood hydrostatic pressure created?
The contraction of the left ventricle
What is the blood colloid osmotic pressure?
It is the overall osmotic effect of colloids (plasma proteins) in the vasculature
What does the blood colloid osmotic pressure oppose?
The filtration of larger solutes
What does the blood colloid osmotic pressure maintain?
It maintains levels of intravascular fluids
What is the interstitial fluid colloid osmotic pressure? (IFOP)
IFOP pulls fluid out of the capillaries into the interstitial fluid
Why is interstitial fluid colloid osmotic pressure present?
It is present due to the solute concentration in the interstitium
What is interstitial fluid hydrostatic pressure?
IFHP pushes fluid from interstitial spaces back into the capillaries
What is the membrane permeability?
It allows only a small portion of plasma proteins to cross the capillary membranes
What are three factors that change the amount of total body water?
Age
Sex
Fat content
What is ADH?
Anti-diuretic hormone
What is water balance and the perception of thirst regulated by?
ADH
What are the three reasons ADH is released?
Increased plasma osmolality
Decreased circulating blood volume
Lowered venous and arterial pressure
What happens after the release of ADH?
Water is reabsorbed from the renal tubules and collecting ducts of the kidneys