A and P 3 Week 7
Which one is most significant in the extracellular fluid?
Bicarbonate
If water gained exceeds water loss, how does fluid shift between the ECF & the ICF?
ECF moves into ICF because of loss in osmotic pressure and then cells swell
Do receptors monitor ECF or ICF levels?
ECF only, osmoreceptors and baroreceptors
If water loss exceeds water gained, how does fluid shift between the ECF & the ICF?
Less water leaves the ICF so less water enters the ECF
Do we ever expend energy to move water (pumping water molecules)?
No
Which one is most significant in the intracellular fluid?
Phosphate
Why must blood pH be maintained?
To help enzymes and brain function
What triggers their release?
When the atria are stretched because of high blood pressure
Does blood pH affect electrolyte balance?
Yes
Does gravity alone allow for its movement through the ureters? If not, what aides its passage?
...
What is lost in urine (generally)?
95% water and 5% solutes (nitrogenous wastes and ions (nat, K, phoshates, sulfates))
What are buffers?
A buffer is a system of one of more compounds that act to resist changes in pH when a strong acid or base is added
What hormones have decreased release (are inhibited)?
ADH and aldosterone
What hormones have decreased release (are inhibited)?
ANP
What hormones are released?
ANP and BNP
How would you define blood acidosis or alkalosis?
Acidosis is when arterial pH drops below 7.35 and alkalosis is when arterial blood pH goes over 7.45
Once the hormones have acted, what effect does this have on blood osmolarity, volume and pressure?
Can decrease BV and BP and increase osmolarity
Once the hormones have acted, what effect does this have on blood osmolarity, volume and pressure?
Can increase BV and BP and can help you retain water
Of the chemical, respiratory & urinary buffer systems, which one is the first responder?
Chemical
Urine passes through the following structures in which order on its way to the bladder: renal pelvis, ureter, collecting duct.
Collecting duct, renal pelvis, ureter
What is the major cation & anion of the ICF & ECF?
ECF is sodium and ICF is potassium
What is the effect on ECF osmolarity, volume and pressure?
Low osmolarity, high BV and BP
What is osmosis?
Movement of water from higher to lower
Can you pump water?
No
Does the micturition reflex send a signal to the brain (i.e. do you have conscious control over this reflex?)?
Not over reflex but a sphincter that you have control over
How is water moved in the body?
Osmosis
What type is hemoglobin?
Protein
Trace the path of urine from where it is formed in the collecting duct to its exit from the body. What structures does it pass through?
Renal pelvis, Ureter, bladder, urinary bladder, urethra
What hormones are released?
Rennin, ADH and sometimes aldosterone
Besides the 3 chemical buffers discussed above, what are the other 2 main physiological buffer mechanisms?
Respiratory and urinary system
Of the chemical, respiratory & urinary buffer systems, which one buffers the greatest quantity of acid or base?
Urinary
What is micturition?
Urination
What are the 3 first responder buffers that immediately affect blood pH?
bicarbonate, phosphate and protein buffer systems
Which division of the nervous system dominates in this reflex?
parasympathetic
What hormone(s) action(s) have the opposite affect of the natriuretic peptides?
Aldosterone, ADH
What is the hormone that controls potassium balance in the body?
Aldosterone
What are the hormones that control sodium balance in the body?
Aldosterone and ADH
Generally speaking (few sentences max), why is it important for the body fluids, electrolytes & pH to remain balanced?
Body fluid important to maintain blood pressure and the other two are for cellular processes
What happens if dietary gains are less than losses from the body?
Body's content of water will decrease
How does the respiratory system regulate pH?
By monitoring CO2
How does the urinary system regulate pH (in terms of H+ secretion)?
By reabsorbing/generating new HCO3 and excreting HCO3
Generally, what maintains homeostasis of ECF ions and water?
Hormones
What are natriuretic peptides (ANP & BNP)?
Hormones
What is the effect on ECF osmolarity, volume and pressure?
Increased osmolarity, decreased BV and BP
What are likely sources of excessive H+ ions that create blood acidosis?
Ingesting it, metabolic by-products and transport of co2 in blood as hco3 which produces h+
How do they function to create a high volume, low concentration urine?
Inhibiting the collecting ducts to reabsorb NA and suppressing the release of ADH, rennin and aldosterone
What ion largely determines the osmotic potential of the ECF?
Sodium
Which ion must be more tightly regulated in the ECF, Na+ or K+?
Sodium
How do natriuretic peptides affect BP?
They affect BP by causing vasodilation, inhibit aldosterone and ADH
