Physiology Practical (2) PDF

Physiology Physiological Solutions PRACTICAL (2) DR. El-Sawy 0  Physiology Physiologic...

Physiology Physiological Solutions PRACTICAL (2) DR. El-Sawy 0  Physiology Physiological Solutions Mole Molarity  Molecular weight (MW) of  Amount of moles of compound Definition the substance in grams dissolved in 1 liter of water.  If MW of sodium is 23 gm and chloride is 35 gm and glucose 180 gm so: Example 1 molarity Na+  23 gm/L 1 molarity NaCl  23 +35 = 58 gm/L 1 molarity Glucose  180 gm/L  The molecular weight of a solute in grams, divided by number Definition of ions or particles into which it dissociates in solution.  Osmoles = No. of particles of dissociation. × no. of moles  For non-ionizing molecules as glucose, urea and inulin  1mole = 1 osmol/L1  For a substance that dissolve into 2 particles as Nacl Example  1mole = 2 osmol/L  For a substance that dissolve into 3 particles as CaCl2  1mole = 3 osmol/L Osmolarity Osmolality Number of osmoles per liter of solution. Number of osmoles per Osmolarity of ECF & ICF = 280 to 300 kilogram of solvent. mosm/L. DR. El-Sawy 1  Physiology Physiological Solutions Definition  The osmolality of a solution relative to plasma. Hypertonic Isotonic Hypotonic Solutions have Solutions have Solutions have higher osmolality same osmolality less osmolality than plasma as plasma than plasma Types Shrinks stay the same swells & bursts DR. El-Sawy 2  Physiology Physiological Solutions  The artificially prepared solutions that are used to keep animal tissues alive outside the body by : Providing a homeostatic environment outside the body under controlled conditions while performing a pharmacological experiment on isolated tissues. Role of these solutions : 1. Keep the isolated tissues alive. 2. Provide nutrients to the tissues. 3. Act as a buffer. 4. Mimic the body tissue fluid (in ionic composition). Why not use Pure Water? Perfusion of tissues with pure water destroys the cells. It draws important crystalloids from cells It also leads to rupture of the cell membrane due to accumulation of water inside the cells. DR. El-Sawy 3  Physiology Physiological Solutions  Physiological solutions are given intravenously for patients as fluid replacement therapy in cases of: Indications 1. Dehydration. 2. Diarrhea. 3. Blood or plasma loss.  NaCl 0.9% Examples  Glucose 5%  Ringer. Note  Most important criteria of physiological solutions is Isotonicity  The prepared solution should be isotonic to tissue fluid.  Alterations in this principle may lead to loss of function due to : Shrinkage  If hypertonic. Swelling  If hypotonic. Balance of cations and anions + Distilled water Isotonicity DR. El-Sawy 4  Physiology Physiological Solutions Components of Physiological Solutions Na (Sodium) Ca (Calcium) K (Potassium) Cl (Chloride) Mg (Magnesium) Distilled water Glucose Role of some Ion : Ion Role Sodium bicarbonate  Used to adjust the pH of the solution (alkaline)  Supplies energy for the isolated tissue, Acts as a Glucose nutrient, and helps with the contractility of the tissue Air, pure O2, or  Required for the proper functioning of the tissues. carbogen (95%  Helps with the stirring of the solution and O2with 5% Co2)  Facilities the diffusion of drugs in the solution. Physiological solutions Frogs' ringer Mammalian ringer Tyrode solution Krebs solution solution solution DR. El-Sawy 5  Physiology Physiological Solutions Physiological saline Ringer’s solution Glucose 5% solution Tyrode’s solution isotonic IV fluid.  0.6% sodium chloride  Contains :  Administered to :  as lactated Ringer's solution for frog’s tissues. 1. NaCl Supply water solution, but contains :  0.9% for mammalian 2. KCl Correct increase in 1. Magnesium tissues. 3. CaCl2 serum osmolality. 2. Sugar (usually glucose)  0.9% NaCl is an Isotonic 4. NaHCO3 as an energy source IV fluid  Sometimes with other 3. Bicarbonate and minerals as MgCl2 phosphate as a buffer  The precise proportions of instead of lactate. these vary from species to species  Must be gassed with O2 & Co2 when used for cell culture applications and physiology. DR. El-Sawy 6  Physiology Physiological Solutions Physiological saline Ringer’s solution Glucose 5% solution Tyrode’s solution DR. El-Sawy 7  Physiology Physiological Solutions Precautions during Preparation :  Should be prepared on the same day of the experiment: No stock NaHCO₃ when stored with calcium precipitates Ca(HCO₃)₂ solution Glucose can encourage the growth of microorganisms Ph  Should be between 7.3 and 7.8 depending on the organ  Should be constant Temperature  Mammalian tissue solution at 37°C (isolated rabbit intestine).  Heart tissue → Pure O2 Aeration  Intestine → Normal air How to prepare NaCl 0.9% Glucose 5% 0.9 gm of NaCl in 100 ml of 50 gm of glucose in 1000 ml of distilled water then mix distilled water then mix DR. El-Sawy 8