Week 6 - Study Guide Flashcards
Most abundant solutes =
electrolytes
Feces, sweat, and insensible
Meaning we cannot regulate it
Obligatory losses
Evaporation through skin and lungs
Cannot sense it
Insensible losses
We can alter through influence of hormones. Minimum 500 ml/day
urine
Hormones = ADH & Aldosterone
Only influences the reabsorption of water.
Produced when solute concentration is too high - meaning dehydrated
ADH
causes thirst
kidneys retains water
causes vasoconstriction in the periphery
Water reabsorption to reduce osmotic pressure
Produced to change in osmotic pressure
All about retaining the right balance of solutes.
By holding on to Na+ and water.
It will assist the solute balance in the body.
Also maintains BP
Aldosterone - mineral corticoid
Reabsorption of Na, Cl, H2O
Increase BV - but does not alter osmotic pressure
Produced due to change in BP
HPc
OPif
Moves water into or out of vasculature?
move water OUT OF vasculature
HPif
OPc
Moves water into or out of vasculature?
move water INTO vasculature
Is balance the same at the arterial and venous end?
No - always tend to push more fluid out then return.
But - lymphatic system soaks up any excess
Mid-capillary pressure gradient is 0.5 mmHg, which way does fluid go?
Beginning to push fluid back in
On the arterial end, fluid moves_____
fluid moves out
NFP = 10 mmHg
On the venous end, fluid moves ____
fluid moves in
NFP = -8mmHg
Edema is created by
Change in pressure gradients influencing ECF movement
capillary filtration & osmotic uptake
Interference in lymphatic drainage
Edema may result if:
-
High BP
= push more fluid out at the arteriole end than what can be sucked up by the lymphatics or return to circulation at the venule end -
Increase [plasma protein] interstitial fluid
= liver - site of plasma protein production (albumin). disability to to build plasma proteins - meaning there will not be the osmotic pressure in plasma to pull fluid back which causes edema -
Decrease [plasma protein]
= excessive plasma proteins leaking out
remember - if you have inflammation - capillaries can become leaky - fluids and smaller solutes leave, problem - plasma proteins start to leave. Not only do you have fluid leaking out - you have more because osmotic pressure in the interstitial fluid has increased -
Lymphatic Obstruction
= lymph system is not able to pick up the.
slack
= cause could be infection or damage to lymphatic system
= microbial infection blocking lymphatic system
Dehydration due to
- hemorrhage
- burn
- diarrhea
- vomiting
- sweating
AND
6. water deprivation
7. diuretic abuse
8. endocrine disorders
DEHYDRATION
Fluid loss > intake
- excessive ECF osmolarity (water will go towards the osmotic pressure)
- fluid moves down its gradient from ICF➡ECF
- ⬇cell volume = dysfunction
meaning:
- Excessive loss of water from ECF
- ECF osmotic pressure rises
- Cells lose H2O to ECF by ososis; cells shrink
OVERHYDRATION
Hypotonic Hydration
Water intoxication
- excessive water enters the ECF
- ECF osmotic pressure falls
- Water moves into the cells by osmosis; cells swell - lyse - cellular edema
Impacts the brain it could be fatal
Electrolyte Functions:
Na+
Extracellular
- Nerves & muscles
- Regulates ECF
Electrolyte Functions:
Ca2+
Extracellular
- Nerves & muscles
- enzyme activation
- blood clotting
- PTH regulates. (MOST IMPORTANT)
- Ionized and protein bond form
Electrolyte Functions:
K+
Intracellular
- Nerves & muscles
- Regulates cell volume
- pH control (K+/H+ shift)
Electrolyte Functions:
Mg2+
Intracellular
- Nerve & muscles & junctions
- enzyme activation
- ionized and protein bond form
Electrolyte Functions:
HPO4-
Intracellular
- Energy, RBCs, and Nervous system function
Excess NaCl intake =
redistribution of body water toward solutes
affects plasma first than interstitial fluid
According to NERNST -
How would these imbalances impact cell behavior?
Hypermagnesemia (Mg2+)
Depressed
- Positive 2 charges
- and they impact the way voltage-sensitive channels react
- They will have opposite pattern
Remember ➡Hyperkalemia - single positive charge causes overexcitability
Hypermagnesemia 2+ will depress the system
