Ch 26 acid fluid balance Flashcards
How much % of body weight is total body water?
40 L = 60%
How much % of body weight is extracellular body fluid (plasma and intersitial fluid) ?
15L = 20%
How much % of extracellular fluid is total plasma??
3L = 20 %
How much % of extracellular fluid is interstitial fluid?
12L = 80%
What is the intersistal fluid? (where is it found?)
fluid inside tissue (between cells)
What % of body weight is intracellular fluid?
25L = 40 %
Nutrients leave blood plasma to interstitial fluid to tissue cells via _____. H20 and H20 ions are exchanged
GI tract
Nitrogenous wastes feel interstitial fluid tissue cells to blood plasma to _____.
kidneys
Avg intake of bevagrages?
1500 ML 60%
avg intake of food
750 ml 30%
avg intake of metabolism
250 Ml 10%
What is the normal amount of water that is necessary ?
2.5 L
Avg output of sweat (sensible perspiration)
200 Ml 8%
Avg output of urine
1500 mL 60 %
avg output Insensible loss via skin and lungs
700 ml 28%
What happens when ECF osmolarity goes up? (reduction in H20)
osmoreceptors in hypothalamus detect decrease and triggers the hypothalmic thirst center (sensation of thirst, water absorbed from GI tract)
What happens when plasma vol goes down?
Blood pressure goes down, renin released, angiotesin goes up, triggers hypothalmic thirst center
ESF omolarity and Na concentration in plasma goes up and triggers the osmoreceptors to stimulate the posterior pituary to release _____.
Antidiretic hormone (ADH)
What does ADH target in kidney?
collecting ducts, to reabsorb water
When we are hot and excerising (dehyrdration) this causes: (3 steps)
- Loss of H20 in ECF
- ECF osmotic pressure rises
- Cells lose H20 to ECF by osmosis (cells shrink)
When hydrated this causes: (3 steps)
- Excessive H20 enters ECF
- ECF pressure falls
- H2o moves into cells via osmosis and swell
electrolyte balance refers to ___, ____, ____, and ____ balance
salt , acid, bases and proteins
What do salts do?
control fluid movements, provide minerals for excitability, secretory activity, and membrane permeability
How do salts enter body and how do they leave?
enter via ingestion and metabolism and lost via persipation, feces, urine and vomit
What is a major cation (+) in ECF?
Na
What is a major anion (-) in ICF?
Hydrogen phosphate
potassium
What is the importance of Potassium
controls the kidney
Concentration of Na+ determines
osmolarity of ECF and influences excitablity of neurons and muscles
The total body content of Na+ determines..
ECF volume (Blood pressure)
Percent of Na+ reabsorbed in PCT
65%
percent of Na+ that is reabsorbed in ascending loop of Henele
25%
Low Na+ levels and High K+ levels causes _____ (hormone) to be released
aldesterone (renin) via adrenal cortex
High blood pressure causes ANP to target
granular cells of kidney
hypothalmus (posterior pituatery)
Adrenal cortex
What is the importance of K+ in neurons and muscle cells? (and cardiac muscle)
affects resting membrane potential
low Ca+ levels causes the PTH release to stimulate…
osteoclast activity (ca+ and PO4 release)
Ca+ absorption
Activation of Vit D by kidney
What does excess of sodium cause? (hypernatremia)
dehydration, thirst
What does deficit of sodium cause? (hyponatremia)
solute loss, water rentention, mental confusion
What does excess of Potassium do? (hyperkalemia)
renal failure, no aldosterone, vomitting, cardiac arrest, muscle weakness
What does deficit of Potassium do ? (Hypokalemia)
GI tract disturbances, starvation, Cushing’s Syndrome
What does excess Ca+ do? (hypercalemia)
hyperparathyroidism, excessive vit D, kidney stones, cardiac arrest, vomitting, muscle weakness
What does deficit of Ca do? (hypocalcemia)
hypoparathyrodism, vit D deficiency, renal failure, tingling fingers, tremors, fractures
3 mechanisms that regulate the concentration of hydrogen ions
1st Line = chemical buffer systems (Rapid)
2nd Line= brain stem respiratory centers (1-3 min)
3rd Line= renal mechanisms (potent, days-weeks)
3 chemical buffer systems
Biocarbonate, Phosphate, Protein
Biocarbonate buffer system
mixture of H2Co3 (weak acid) and salts of Hco3- (weak base)
main ecf buffer operates in ICF in cell
Phosphate buffer system
salts of H2PO4- (weak acid) and HPO4 2- (weak base)
important buffer in in urine and ICF
Protein buffer system
some amino acids (-COOH weak acids) and (-NH2 weak bases)
important buffer in ICF and blood plasma
With the protein buffer system if PH rises, then organic acid or carboxyl groups can _______
release H+
With the protein buffer system if PH falls then NH2 groups _____.
can bind H+
During CO2 unloading the reaction shifts to the ____. (left or right) and then H+ in ______ into H20
Left, incorporated
During Co2 loading the reaction shifts to the _____ (left or right) and then the H+ is ____
right, buffered by proteins
If Pco2 rises (hypercapnia) what does it activate? and causes increased____.
medullary chemoreceptors
respiratory rate and depth
Rising plasma H+ (acidosis) activates ____ and increases ___
peripheral chemoreceptors
respiratory rate and depth
Normal ph of atrial blood
ph 7.4
normal ph of venous blood
7.34
normal ph of ICF
7.0
alkalosis / alkalemia atrial ph level?
over 7.45
acidosis /acidemia ph level
under 7.35
respiratory acidosis/alkalosis cause
by failure or respiratory system to perform Ph balancing role
An important indicator of respiratory acidosis and alkalosis
blood Pco2
metabolic acidosis and alkalosis causes
all abnormalities other than those caused by rising Pco2 levels in blood
indication of metabolic acidosis and alkalosis
abnormal HCO3- levels
