Osmolality and Acid Base

• concentration of a solution in terms of number of particles. 
• 1 osmole=1 gram molecular weight of osmotically active substance (IONIZES IN WATER INTO 1 SUBSTANCE--NaCl dissociates into 2 osmoles.

• concentration of a solution in terms of osmoles of solute per kilogram of water
• Increased osmolality causes increased osmotic pressure
• Hypertonic solutions raise osmolality, which raises osmotic pressure, which draws water out of cells into the ECF

• part of osmotic pressure produced by colloids (proteins and large molecules) in blood vascular system
• important in kidneys
• High will draw fluids in (and cause hydrostatic pressure)

proteins and large molecules in body fluids (blood)

• force exerted by a fluid against capillary wall. 
• Helps move fluids between capillaries and interstitial fluids
• tends to push out
• Highest is at arteriolar end (pushing out) and lowest is at veinous end (pushing in)

maintains homeostasis.   Influences most enzymes.  Too many lowers pH (decreases sodium potassium pump). 

• release an H+ in water.  HCl, H₂CO₃, sulfuric produced in protein metabolism
• Most arise from transporting CO₂ from tissue to lungs.  More CO₂ = more acidic
• CO₂ + H₂O <--> C₂CO₃ <--> H⁺ + HCO₃^-
• Can also be due to tissue breakdown/catabolism or when kidneys don't eliminate H+, diarrhea rich in bicarbonate

Most arise from transporting CO2 from tissue to lungs.  More CO2 = more acidicCO2 + H2O <--> C2CO3 <--> H+ + HCO3-Can also be due to tissue breakdown/catabolism or when kidneys don't eliminate H+, diarrhea rich in bicarbonate

• ion or molecule that can accept H+
• HCO3-, hemoglobin
• many proteins
• bicarbonate is made from metabolism of plants.  Uses H+=net loss
• hyperventilation (increased expiration of CO2)

• bicarbonate is made from metabolism of plants.  Uses H+=net loss
• hyperventilation (increased expiration of CO2)
• vomiting (loses many H+ ions)
• urine can contain H+

excess H+ in blood.  pH below 7.4

excess removal (less) of H+ in blood.  pH above 7.4

• arterial: 7.4
• venous: 7.35.  More CO₂ = more acidic

• breakdown of fatty acids and proteins creates sulfuric acid.  This increases H+ in the blood, pH down, creating a metabolic acidosis.  
• Treat: stimulates ventilation (hyperventilation) to get rid of CO2, kidneys excrete H+

• less breathing means a buildup of CO2, leading to a buildup of H+, pH down.  Respiratory acidosis
• Treat: restore breathing or kidneys add bicarb to blood and excrete more H+ and less bicarb

• too little CO2, less H+, buildup of bicarbonate, PH up, respiratory alkylosis
• Treat: stop hyperventilating (overuse of ventilator in anesthitized), Kidneys eliminate bicarb, hold on to H+

• Chemical acid-base buffer system (combine acid and base to tie up excessive before excretion)
• respiratory system (removal of CO₂)
• kidney (excretes H⁺ or H₂CO₃)

• chemical system regulating H+. 
• Doesn't eliminate H+ from or add to the body, just keeps it tied up until balance can be restored

• chemical system regulating H+.  
• Can act within a few minutes to expel CO2 (or not) to raise or lower H+

• system that regulates H+
• slower-acting system that actually changes the concentration (the other two just balance).  Eliminate excess acid or base from the body in urine.

• any substance that can reversibly bind H+ 
• bicarbonate and hemoglobin are most common.

CO₂ + H₂0 <--> H₂CO₃ <--> H⁺ and HCO₃^-

• respiratory acidosis
• respiratory alkylosis
• metabolic acidosis
• metabolic alkylosis

• most common acid-base abnormality.  
• Diabetes or starving (breaking down proteins, producing ketones)

Caused by potassium deficiency, obvious stuff, in ruminant, torsion and dilation of the abomasum