How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is...
-
Upload
emil-walters -
Category
Documents
-
view
232 -
download
0
Transcript of How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is...
![Page 1: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/1.jpg)
How does water move in the body?
• The cell membrane is semi-permeable
• Water can move freely
• Water is in equilibrium between cells and extracellular fluids (osmotic equilibrium)
• Ions and solutes are disequilibrium
• Osmosis water moves along its concentration gradient across a semi-permeable membrane
![Page 2: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/2.jpg)
Distribution of solutes in the body fluid compartments
plasma
Intracellular fluid
Interstitial fluid
![Page 3: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/3.jpg)
Distribution of solutes in the body fluid compartments
Ions and solutes are in disequilibrium
![Page 4: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/4.jpg)
Ions and solutes are in disequilibrium
• Water can cross the cell membrane
Na+
K+
Na+
K+
proteins
![Page 5: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/5.jpg)
Osmosis
• water moves along its concentration gradient across a semi-permeable membrane
• Water moves to dilute a solute
![Page 6: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/6.jpg)
Osmosis
![Page 7: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/7.jpg)
Osmotic pressure is pressure exerted to counter the movement of water to dilute something
![Page 8: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/8.jpg)
Osmolarity
• Describes the number of particles in solution• Know this and the direction of water movement
can be predicted
• # of particles in 1 liter of solution
• Is expressed as osmoles/L, or OsM
• If very dilute: milliosmoles/L, or mOsM
• Human body, approx 300 mOsM
![Page 9: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/9.jpg)
Osmolarity: number of particles in 1L
• 1 M glucose = 1 OsM glucose
• 1M NaCl = 2 OsM NaCl, because NaCl disassociates to 2 ions in solution.
Na+ Cl-
![Page 10: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/10.jpg)
Compare the osmolarity of 2 solutions:
• Solution A
• 1 OsM glucose
• A is hyposmotic to B
• (A has fewer particles than B)
• Solution B
• 2 OsM glucose
• B is hyperosmotic to A
• (B has more particles than A)
![Page 11: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/11.jpg)
• Solution C
• 1 OsM NaCl
• C is hypotonic to B
• (C has fewer particles/L than B)
Compare the osmolarity of 2 solutions:
• Solution B
• 2 OsM glucose
• B is hyperosmotic to C
• (B has more particles/L than A)
![Page 12: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/12.jpg)
Compare the osmolarity of 2 solutions:
• Solution A
• 1 OsM glucose
• A is isosmotic to C
• Solution C
• 1 OsM NaCl
• C is isosmotic to A
![Page 13: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/13.jpg)
Osmosis, the diffusion of water across the cell membrane, has consequences on cells
• After water leaves a cell, the volume changes (it can shrink)
![Page 14: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/14.jpg)
Tonicity
• Describes how the cell volume will change in a solution
![Page 15: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/15.jpg)
P is penetrating solute
N is nonpenetrating solute
![Page 16: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/16.jpg)
![Page 17: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/17.jpg)
![Page 18: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/18.jpg)
Water moved into the cell to dilute the solutes.
![Page 19: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/19.jpg)
• Cell gains volume in a hypotonic solution
• Cell looses volume in a hypertonic solution
• Cell keeps the same volume in an isotonic solution.
![Page 20: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/20.jpg)
Tonicity indicates how the cell volume will change in a solution
• In a hypotonic solution, the cell has a higher concentration of a nonpenetrating solute than the solution, water moves in.
• In a hypertonic solution, the cell has a lower concentration of nonpenetrating solute than the solution, water leaves the cell
![Page 21: How does water move in the body? The cell membrane is semi-permeable Water can move freely Water is in equilibrium between cells and extracellular fluids.](https://reader035.fdocuments.us/reader035/viewer/2022062315/56649f065503460f94c1c030/html5/thumbnails/21.jpg)
During intavenous injection:
• 0.9% (normal) saline isotonic
• D5--.9% saline (5% dextrose) isotonic
• D5W hypotonic
• 0.45% saline hypotonic
• Vs dehydration hypotonic
• Vs blood loss isotonic