Exam II Water Balance Flashcards
Substances that dissolve readily in water
Hydrophilic
Molecules that contains a preponderance of non polar bonds and are insoluble in water
Hydrophobic
about % of the total body weight is water
60
Where in our body is most of the water found?
a. extracellularly located
b. intracellularly located
b. intracellular
3 ways of water intake
- ingested liq.
- ingested food
- metabolic water
4 ways of water loss
- Kidneys
- Skin excretes water as sweat
- lungs, as exhaled water vapor
- GI tract, in poo
An animal is in fluid balance when _____.
The amt. of water gained each day is equal to the amount lost to the environment
about 80% of the ECF is ______.
Interstitial fluid
About 20% of the ECF is ____
blood plasma
Where can transcellular water be found?
Lymph vessels CFS Synovial joints Eyes Ears glomerular filtrate
What are the 3 types of ECF?
- IF
- Plasma
- Transcellular water
The movement of water through a semipermeable memb.
osmosis
Mechanisms that monitor and adjust the composition of body fluids
Homeostatic mechanisms
T/F. Homeostatic mechanisms respond to changes in ICF.
F. ECF
Compounds that dissociate into ions when dissolved in a solution and are able to conduct electricity?
Electrolytes
What area the functions of electrolytes in the body
- Cell metabolism
- Facilitate osmotic movement of H2O
- Maintain H+ conc.
- Production and maintenance of membrane potentials and action potentials
What is the use of Ca+ in the body
- bone and teeth
- blood coagulation
- neural transmission
- muscle contraction
- PM and cell junctions
- Enzyme activation
- Messenger molecules
What is the use of chloride in the body?
- HCl
2. Transmission of nerve impulses
What is the use of Mg in the body
- enzyme activation
2. Neuromuscular transmission
What is the use of K+ in the body?
- Water and electrolytes in ICF
- Nerve impulses
- Acid base balance
What is the use of Na in the body?
- ECF
- . inc PM permeability
- body water distribution
- A-B balance
- Nerve transmission
Which cations are located in the ECF?
Na and Ca
What cations are located in the ICF
K and Mg
What Anions are located in the ECF?
Cl- HCO-
What Anions are located in the ICF?
Phosphate and Protein
Alterations in H2O balance are normally analyzed as changes in either ___ or ___
ECF or ICF
If osmolality of ECF increases it becomes _____ with respect to the ICF and water will move from _____ to ____
Hypertonic, From the cells to ECF
If osmolality of the ECF dec. it becomes ____ with respect to ICF and water will move from ____ to ____
Hypotonic, from ECF into cells
Which of the following hormones are involved in water balance?
a. ADH
b. Aldosterone
c. ANP
d. A and B
e. All of above
e. All of above
What 3 hormones regulate fluid loss
- ADH
- Aldosterone
- ANP
Which hormone has osmoreceptors in the hypothalamus that monitors the osmotic conc. of ECF
ADH
The rate of ADH release varies directly with ____
osmolarity
The higher the osmolarity the more/less ADH released
More
Inc. release of ADH has 2 effects:
- Stimulates H2O conservation at kidneys, reducing urinary water loss and concentrating urine
- stimulates thirst
Which hormone plays a major role in determining the rate of Na absorption in the kidneys?
Aldosterone
Where is Aldosterone secreted from?
Adrenal cortex
The higher the plasma aldosterone conc. the more/less the kidneys will conserve Na
More
T/F Aldosterone stimulates kidneys to retain water?
T
T/F Secretion of Aldosterone is directly influenced by Na ion concentration in the plasma
F
What are the 3 ways Aldosterone is stimmulated?
- RAAS
- Rise in ECF Osmolality
- ECF K+ levels
What stimulates RAAS?
dec. in plasma volume or BP
T/F. RAAS will cause an inc. in urination and inc. in fluid retention
F. Dec. in urinationa and inc. in fluid retention
T/F. the goal of RAAS is to inc. blood volume
T
Where is ANP released from?
Cardiac muscles
ANP is released when there is an inc. or dec. in BP?
Inc.
What are the 4 ways ANP dec. blood pressure
- inc. H2O loss in kidneys
- dec. thirst
- block the release of ADH
- Stimulate peripheral vasodilation
The actions of angiotensin II are opposed by which hormone?
ANP
What two forces control water movement?
- hydrostatic pressure
2. Colloid osmotic pressure
Presence of excess fluid in the tissues
Edema
What are the 4 common causes of intracellular edema
- hyponatremia
- Depression of metabolic systems of cells
- ischemia
- inflammation
What are the 3 common causes of extracellular edema
- leakage of fluid from plasma
- lymphatic vessel failure
- inc. capillary pressure
How do loop diuretics work?
inhibit the NKCC receptors in the TAL
Do loop diuretics inc. or decrease GFR
inc.
Kidneys cant concentrate urine and a large amt. of dilute urine is excreted
Diabetes insipidus
Type of diabetes Caused by a lack of ADH synthesis
D. insipidus centralis
Type of Diabetes when ADH is produced, but cant act on kidney
D. insipidus renalis
solution causes cell to neither shrink or swell
isotonic
Solution causes cell to swell
Hypotonic
Solution causes cell to shrink
hypertonic
Water loss that cannot be measured
insensible
Water loss that can be measured
sensible
type of dehydration where water loss exceeds electrolyte loss
hypertonic
Type of dehydration were electrolyte loss exceeds water loss
hypotonic
Type of dehydration where water loss and electrolyte loss are the same
isotonic
Type of overhydration where there is a gain of water without a gain of electrolytes
hypotonic
Type of over hydration where there is a gain of electrolytes without a gain of water
hypertonic
type of diuretics that inhibit NaCl reabsorption in the DT
Thiazide
Which diuretic leads to hypokalemia
thiazide
type of diuretics that block Na channels in the CD leading to reduction of K excretion
K-sparing diuretics
block the aldosterone receptor and the ENaC
Aldosterone antagonists