Physiology Lec3 PDF

# Two Type of transport ## Passive Transport - With Concentration gradients - Molecules move from high concentration area to low concentration area. - Downward hadd... ### Passive transport - It's a free Movement of the Particles from High Concentration to area of low Concentration. - By Kin...

# Two Type of transport ## Passive Transport - With Concentration gradients - Molecules move from high concentration area to low concentration area. - Downward hadd... ### Passive transport - It's a free Movement of the Particles from High Concentration to area of low Concentration. - By Kinetic energy ### What affects diffusion? - Directly Proportional - Concentration - Temperature - Surface area of the membrane - Inversely Proportional - Thickness of the membrane - Square root of Molecular weight #### What affects diffusion? - Water soluble - The greater the Dipid solubility of substances, the greater the rate of diffusion. - Lipid soluble - "The greater the Dipid solubility of subs. the greater the rate of diffusion." - "Due to it's highest solubility Coefficient (ny( سوان بتاع", ## Water-Soluble Molecules - **Small** - Can pass by simple diffusion on the transmembrane protein. - **You need three conditions to pass:** - Very small, Kinetic energy very high. - "The electric charge of the Channel is opposite [to the molecule's charge]." - "The greater hydration energy, the thicker is water jacket the slower of diffision." - "Molecules smaller than the channel pass from high to low by carrier." - **Large** - Need carrier protein. - **Carrier proteins** are essential in transport, and specific for each molecule. - No ATP - **Facilitated diffusion** - Increases up to a limit when concentration increases to a transport maximum (Saturation). - **Examples of facilitated diffusion:** - **Competitive inhibition** - "when something else binds to the carrier protein and prevents the molecule from binding" - **Diabetes mellitus** occurs when there is a decrease in blood glucose carrier. - The reason is "due to decrease of glucose carrier." - Treatment "insulin supplementation - improve the condition." - "Maximum level of facilitated diffusion is reached when concentration increases." - This is "due to Saturation of Carrier Protein." ## Filtration - It's apassive transport to (solveds) dissolvent molecules from high Pressure to the low Pressure. - **Pressure for filtration occurs in three areas:** - **Artery**: Arterial blood pressure - **Venous**: Venous blood pressure - **Capillary**: Capillary hydrostatic pressure ("the pressure inside the capillary"). - **Fluid**: Plasma isomatic Presure - **Filtration** has two types: - **Filtration** of blood through blood capillaries. - Is essential for tissue fluid formation. - Tissue fluid has a hydrostatic pressure ("the pressure inside the tissues"). - "Normally Capillary hydrostatic is... higher than... the tissue fluid hydrostsatic." - **Filtration** of blood through kidney glomeruli. - Is the first step of urine formation. - "The kidney capillaries have the highest hydrostatic pressure of all the body." - "Low hydrostatic pressure can cause edema - prevents edema." - **Factors affecting filtration**: - Difference of hydrostatic pressure ("the pressure inside the capillaries compared to the pressure inside the tissues"). - Surface area of the cell membrane. - Permeability of the cell membrane. ## Osmosis - Passive diffusion of solvent "water" through semi-permeable membrane from the side of low solute Concentration (low Nac) to side of high solute Concentration. - **Examples of osmosis:** - **Cell edema** - "The extracelluar fluid has a lower osmolarity than the intracellular fluid, so water rushes into the cell." - **Cell dehydration** - "The extracelluar fluid has a higher osmolarity than the cell, so water rushes out of the cell." - "It is depend on Kinetic energy of the solvent molecule." - **Kinetic energy depends on two factors:** - **Particles' size** - **Number of solute particles** - **Net water** - "the difference in the amount of water moving from one side of the membrane to the other." - **Examples of situations with osmosis:** - When you drink a lot of salty water, "the Na (sodium) particles will rush out of the cell, and the cell will dehydrate." - "Active particles increase the osmolarity (number of active particles). Water moves from intra to extra." - "If the concentration of Particles in the cell is lower than the concentration of Particles in the blood (hypotonic), water will enter the cell causing the cell to swell and cause Cell edema." - "If the concentration of Particles in the cell is higher than the concentration of Particles in the blood (hypertonic), the water will leave the cell, causing the cell to shrink and cause Cell dehydration." ## Cell edema - **Hypertonic**: Give hypertonic water to the cell, causing the water to move from the cell to the blood and making the cell return to normal. - **Hypotonic**: Give hypotonic water to the cell, causing the water to move from the blood to the cell and making the cell return to normal. ## Osmosis definitions - **Osmotic pressure**: "The pressure that is required to stop osmosis." - **Osmolality**: "The measure of active particles of solute per kg of water" - **Osmolarity**: "The measure of the concentration of particles per liter of water." - **Plasma Osmolality**: "The measure of active particles per kg of plasma. - **Calculation of Plasma Osmolality**: 2Na (mea, 055 glucose (mg%) + 0, 36 urea (mg%) - **Examples of Plasma Osmolality**: "When the concentration of urea increases in the blood (due to renal failure), it causes water to be drawn from the cells to the blood, causing cell dehydration and a decrease in the amount of water in the tissues." - **Renal Failure**: a condition where the kidneys cannot filter waste products from the blood (urea), causing water to be drawn from the cells to the blood and causing cell dehydration and a decrease in the amount of water in the tissues. ## Why are solutions used to treat cell edema and dehydration? - **Hypertonic solution**: Used to treat cell edema by "increasing the osmolarity of the extracelluar fluid, drawing water out of the cells and into the blood." - **Hypotonic solution**: Used to treat cell dehydration by "decreasing the osmolarity of the extracelluar fluid, drawing water into the cell and increasing the volume of the cell." ## Donnan’s equilibrium - **The protein inside the cell is negative**: "It needs something positive to neutralize it." - **Sodium ions will rush in to neutralize the protein**: "The Sodium ions entering the cell will increase the osmolarity of the cell.  - **Water will rush in to equalize the osmolarity**: "The water moving into the cell will cause cell edema.  - **Why doesn't cell edema happen all the time?**: Because "the sodium-potassium pump (Na+/K+ pump) removes the excess sodium from the cell, preventing cell edema." - **What would happen if the Na+/K+ pump is not functioning correctly?**: The cell would be unable to remove the excess sodium from the cell, "so cell edema would occur." - **What would happen if there is a decrease in ATP?**: "The sodium-potassium pump (Na+/K+ pump)" wouldn't be able to function properly. - **Why would there be a decrease in ATP?**: "There might be a problem with the mitochondria." ## Active transport - **Primary Active Transport**: The transport of substances across a cell membrane against its concentration gradient using energy from ATP molecules. - The primary active transport needs a carrier molecule to help the substance move across the membrane. - Examples of primary active transport: - Sodium-potassium pump (Na+/K+ pump) - Hydrogen ion pump - Calcium ion pump - **Secondary Active Transport**: The transport of substances across a cell membrane against its concentration gradient using energy from a pre-existing concentration gradient of another substance. - The secondary active transport often requires a carrier molecule to facilitate the movement of both substances across the membrane. - There are two types of secondary active transport: - **Symport**: Both substances move in the same direction. - **Antiport**: Both substances move in opposite directions. - **Co-transport**: "The transport of two substances in the same direction by the same carrier protein." - **Counter-transport**: "The transport of two substances in opposite directions by the same carrier protein."