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
According to NERNST -
How would these imbalances impact cell behavior?
Hyponatremia (Na+)
Depressed
If you have:
1. single charges electrolytes that have + charges you will see DEPRESSION in the system
2. the system will not respond normally
According to NERNST -
How would these imbalances impact cell behavior?
Hypokalemia (K+)
Overexcitability
If you have:
1. single charged electrolytes that have + charges and you have too much potassium in the plasma it will cause overexcitability
- cells are freaking out
- firing action potentials all the time
Increased Mg2+ & Ca2+ =
depression of voltage-gated ion channel opening (rusty gate)
Increased serum - Cations (+charged ion)
(Na, K)
Stimulates cell
depolarization
Overactivity
Decreased serum anions (- charged ions)
(Cl-, PO4-)
Stimulates cell
depolarization
Overactivity
Decreased serum - Cations (+charged ion)
(Na, K)
Stimulates cell
Hyperpolarization
depression
Increased serum anions (- charged ions)
(Cl-, PO4-)
Stimulates cell
Hyperpolarization
depression
Releases H+ in a solution
Acids
Picks up H+ out of solution
Bases
Protein metabolism impacts pH due to
phosphoric acid
Anaerobic respiration of glucose makes
lactic acid
Fat metabolism (ketosis) impact pH by
ketone bodies & fatty acids
Respiratory equation impacts pH =
CO2 ➡➡ H+
Chemical buffers regulation =
fastest & present in fluids
Respiratory buffer regulation =
medium, 1-3 minutes
Renal buffer regulation =
most potent, slow (hours ➡ days)
Maintaining pH at 7.4 is a ratio of
20:1
20 HCO3- to balance 1 H+
Ratio < 20:1 is basic or acidic?
EX: 17:1
acidic
lower than 20
Ratio >20:1 is basic or acidic?
EX: 25:1
Basic
higher than 20
What is a buffer system?
Two or more chemicals that prevent extreme pH change when acid or bases are added
- Bicarbonate-carbonic acid
- Phosphate
- Hemoglobin (can bind to H+)
- Plasma proteins. (albumin binds to either Ca2+ or H+) not both
Sodium bicarbonate-carbonic acid buffer
A strong acid =
A strong base =
A strong acid =HCl
A strong base =NaOH
H2CO3 = carbonic acid
HCO3- = bicarbonate (a weak base)
Phosphate Buffer:
H2PO4- = weak acid
HPOv2- = weak base
HCl (strong acid) + NaH2PO4 (weak base) ➡NaH2PO4 (p/u free H+) + NaCl
Buffer changed strong acid to weak acid
NaOH (strong base) + NaH2PO4 ➡ Na2HPO4 + H2)
Buffer changed strong base to weak base
Hemoglobin-Oxyhemoglobin System
Acts as a second buffer in red blood cell along with bicarbonate system
HHb + O2 ⬅lungs/tissues➡ HbO2 + H+
H+ bind to Hb and do it in reverse.
Release H+ = acid
P/U H+ = base
Protein buffer System:
Protein are amphoteric =
amphoteric = can function as both a weak acid and a weak base
releasing a hydrogen - base
(Albumin binds to Ca2+) + (H+)
↔
(albumin binds to H+) + (Ca2+)
picking up a hydrogen - acid
Which of the following buffers are acting as acids?
(HbO2) + (H+ ) ➡ (HHb) + (O2)
(HbO2) + (H+ ) ➡ (HHb) + (O2)
(HHb) = acid
Which of the following buffers are acting as acids?
(H2PO4) + (OH-) ➡ (HPO42-) + (H2O)
(H2PO4) + (OH-) ➡ (HPO42-) + (H2O)
(H2PO4) = acid
Which of the following buffers are acting as acids?
(H+) + (HCO3-) ➡ (H2CO3)
(H+) + (HCO3-) ➡ (H2CO3)
(H2CO3) = base
Which of the following buffers are acting as acids?
(NH2-protein-COO-) + (2H+) ➡ (NH3+-protein-COOH)
(NH2-protein-COO-) + (2H+) ➡ (NH3+-protein-COOH)
NH3+ = acid
