Water Balance Flashcards
Our body weight is how much % water
60%
Water weight is mostly found?
Intracellular
What is a flickering cluster
Water molecules joined together transiently in a H bond lattice
At 37 degrees Celsius what happens to water molecules
15% of the water molecules are joined together to four others
Because of the polarization of water what can two molecules of water form
A linkage known as H bond
T or F
Covalent bonds are equally strong as H bonds
False
H bonds are not as strong
What is a solution
Substance dissolved in liquid
What is a solute
Dissolved substance
What is a solvent
The liquid
Hydrophilic molecules (3)
Dissolve readily
NaCl
Urea
Why cant hydrocarbons be surrounded by water
Because of the h-c bonds
What is molar concentration (2)
The number of osmotic active particles
Determines osmotic pressure
The osmotic pressure exerted by particles in a solution is determined by
Number of particles
T or F
The osmotic pressure exerted by particles in a solution is determined by mass of particle
False
By number of particles
What is osmosis
Movement of water from one part to another
What is molarity
Amount of substances per unit volume (mol/L)
What is molality
Amount of substance per unit mass of solvent
In living organisms, what is used to describe the concentration of solutes in a solution?
Why?
Molality over molarity
Because volume is temperature dependent
What is a molar
Concentration of a substance in a liquid
The extracellular compartment is
4% plasma
16% interstitial fluid
The intracellular compartment is
40% water
Water in the interstitium can be found in the form of (3)
A gel, virulets of free fluid, and as free fluid vesicles
About 1% of interstitial fluid is called what
Transcellular water
Where is the transcellular water located (8)
Lymph in lymphatic nodes Cerebrospinal fluid in brain Synovial fluid in joints Aq. Humour and vitreous body in eyes Endolymph in ears Pleural Pericardial and peritoneal fluids between serous membranes Glomerular filter in kidneys
Water intake (3)
Ingest liquid
Ingest food
Produce water in respiration
Water loss is by (4)
Kidneys
Skin
Lungs
GIT or feces
An animal is in fluid balance when
The amount of water gained each day is equal to the amount loss to environment
What is the main way of water regulation in the body
By adjusting the volume of water performed of water intake
Either by drinking more or less fluid
How can you loss water(4)
Sweat
Urine
Feces
Insensitive prespiration
How can you gain water (3)
Eating
Drinking
Metabolic generation
What is insensitive prespiration
Gradual movement of water across the skin and respiratory tract
What is metabolic generation
Production of water within cells as a result of oxidative phosphorylation within mitochondria
What separates the intracellular fluid from the interstitial fluid
The plasma membrane
What divides the interstitial fluid from blood plasma
Blood vessel walls
How can the body fluid move around (4)
Blood
Nutrients
Oxygen
Interstitial fluid
Blood
Vehicle for transport and exchange of materials between body cells and outside
Nutrients
Enter blood for distribution to tissues throughout the body
Oxygen from blood
Wastes can be excreted through urine, exhaled by lungs or follow some other route
The exchange between plasma and interstitial fluid occurs across
The capillary walls
The exchange between plasma and interstitial fluid happens in three ways
Vesicular transport
Diffusion
Bulk flow
Substances in blood plasma cross the capillary wall 1st by _____ into a _______ cell and then by _______ into IF
Endocytosis
Endothelial cell
Exocytosis
Vesicular transport accounts for
Only a small fraction of the exchange
What uses the vesicular transport
Exchangeable proteins
T or F
Most substances are exchanged through vesicular transport
False
By difussion
Examples of diffusion (2)
Exchange of O2 and CO2 between blood and lungs
Solutes like glucose down their concentration gradients
Bulk flow consists
Of filtration and reabsorption
What is filtration
Net movement of material from blood to IF
Reabsorption is
From IF to blood
Filtration predominates where
At arteolar en of capillaries
Reabsorption predominates where
Venule end of capillaries
What happens to the fluid that is not reabsorbed by venous system
Passes into lymphatic capillaries
Movement of water in body is mainly controlled by
Hydrostatic and osmotic pressure
What is edema
Movement of abnormal amount of water from plasma onto IF
Osmotic pressure does what
Stops the water movement to more concentrated area
Physiological adjustments are regulated primarily by
Hormones
What are electrolytes
Compounds that dissociate into ions when in solution and are able to conduct electricity
Functions of electrolytes (3)
Facilitates the osmotic movement of water between body compartments
Help maintain the H ion concentration
Crucial to the production and maintenance of membrane potential and action potentials
Major cations of EC
Sodium
Major anion of EC
Cl
Major cation IC
K potassium
Major anion IC
Phosphate
EC compounds
Sodium
Chloride
Bicarbonate
IC compounds
Potassium
Magnesium
Phosphate
Chloride is involved with (2)
Formation of HCl in stomach
Transmission of nerve impulses
Magnesium is involved in (2)
Enzyme activation
Neuromuscular transmission
Potassium is involved with (3)
Regulation of water and electrolytes content ICF
Transmission nerve impulses
Acid base balance
Sodium is involved with (5)
Regulation of fluid volume within ECF Increases plasma membrane permeability Controls body water distribution Acid base balance Nerve impulse transmission
T or F
The IC and EC osmolality are independently different
False
Same
Transcellular fluid is important for
Function but represents an insignificant fraction of the total body water
What is afluid shift
Water movement between ECF and ICF
Shifts occur in response to changes in osmolality of ECF
If osmolality EC increases what would happen
Becomes HYPERTONIC
water will then move from cells into ECF until osmotic equilibrium is restored
If osmolality EC decreases
Becomes HYPOTONIC
water will move from EC into cells and volume of ICC will increase
What is tonicity
Refers to the effective osmotic pressure, whether moveme t of water will cause cell to change in size
What is isotonic
Solution which causes a cell to neither shrink or swell
Hypotonic
Causes cell to swell
Hypertonic
Causes cell shrinkage
What mechanosensors stimulate the ion flow OUTFLOW causing expansion
K
Cl
What mechanosensors stimulate the ion flow INFLOW AND CAUSES SHRINKAGE
Na
Cl
K
Net water losses or ______
Will
Hypovolemia
Increase ecf osmolality
What is sensible water loss
Vol that can be measured
Non sensed water loss
Cannot be regulated nor measured
Dehydration is
Reduced fluid volume less than normal
Hypertonic dehydration (4)
Most common
Water loss exceeds electrolytes loss
Increase ECF osmolality
Increase ICF osmolality
Isotonic dehydration
Water loss equals electrolytes loss
Hypotonic dehydration
Loss of electrolytes exceeds water loss
Osmolality of ECF decreases
Overhydration is
Fluis volume is greater than normal
Hypervolemia
Hypertonic overhydration
Gain of electrolytes is greater than gain of water
Isotonic overhydration (3)
Gain isotonic fluid
Increased ECF
Error in fluid administration
Hypotonic overhydration
Gain of water
Electrolytes unchanged
Decreased ECF and ICC osmolality
What are the main causes for water loss (4)
Vomiting
Diarrhea
Hemorrhage
Hyperventilation
What happens when fluid is being lost in regards to salt
Salt will get more concentrated in the ECF
What are the hormones that regulate water loss (3)
ADH
Aldosterone
Atrial natriuretic peptide (ANP)
Osmoreceptors in hypothalamus include neurons that secrete
ADH
Where is ADH
In the anterior hypothalamus but is released from the post pituitary gland
T or F
The greater the osmolality the less release of ADH will occur
False
What are the effects of ADH (2)
Stimulate water conservation in the kidneys reducing urinary water loos and urine
Stimulate thirst center to promote drinking of fluid
Aldosterone is secreted by
Adrenal cortex
What is a role of aldosterone
Role in determining the rate of sodium absorption in kidneys
Secretion and release of aldosterone occurs in response to what
To activating of the renin angiotensin system
Fall in plasma volume or blood pressure increases the secretion of
Aldosterone
Rise in ECF osmolarity accompanied by water deprivation will do what in regards to aldosterone
Will reduce its release which will decrease renal Na reabsorption and increase in urinary excretion of Na
Increase K leves will stimulate the secretion of what
And cause
Aldosterone
Causing the kidneys to eliminate excess K
ANP is released by
Cardiac muscle cells in response to abnormal stretching of the atrial walls
Abnormal stretching of the atrial walls can be caused by
Elevated blood pressure or increase in blood volume
How can ANP reduce blood volume and pressure (4)
Increase water loss in kidney
Reduce thirst
Blocking the release of ADH
Stimulating peripheral vasodilation
The compartment volume is calculated as
Amount of tracer/ concentration of tracer
A tracer should (7)
Be non toxic
Be rapidly and evenly distributed throughout the nominated compartment
Not enter any other compartment
Not be metabolized
Not be excreted during equilibration period
Easy to measure
Not interfere with fluid distribution
What are the ionics (3) used for a tracer
82 Br
35 SO4
Chloride isotopes
What are the crystalloids used by a tracer (2)
Mannitol
Inulin
T or F
Crystalloids are larger and less diffusable throughout the EC so do not enter cells
True
