FSN 210 chapter 14 - Water
Briefly explain how the sodium potassium pump works.
A transmembrane transport protein located in the cell membrane can pump potassium ions into and sodium ions out of a cell. Energy is used by this sodium-potassium pump to move each ion against its concentration gradient (low to high). This maintains a high concentration of Na+ outside the cell and a high concentration of K+ inside the cell
Be able to describe functions of water in the body.
Because of its unique chemical and physical characteristics, water plays several key roles in the body. The maintenance of blood volume and the transport of nutrients and oxygen throughout the body depend on water. Water is the basis for the fluids synthesized throughout the body, such as saliva, bile, and amniotic fluid. Water helps form lubricants in the knees and other joints. Water also serves as a solvent in many metabolic processes and actively participates as a reactant in numerous chemical reactions. Temperature Regulation: water has a high heat capacity, or specific heat. This means water resists temperature changes. Also, sweat. Waste Product Removal: urea, the nitrogen-containing by-product of protein metabolism. Must be excreted in urine if excessive.
How is water distributed throughout the body?
Body water is found in 2 body components - the intercellular compartment (inside cells) and the extracellular component (outside cells). Almost two-thirds of body water is found in the intracellular fluid. The rest is found in extracellular fluid, where it is divided into two additional compartments: interstitial fluid, the fluid between cells, and intravascular, the fluid in the blood and the lymph
What is hyponatremia and how what is the cause of it?
Drinking too much water rapidly water can cause a condition called water intoxication. Water intoxication develops when the kidneys cannot remove water fast enough to keep pace with water intake. As a result, water accumulates in the blood and dilutes the sodium in the serum. To balance intercellular and extracellular electrolyte concentrations, water from the diluted blood is pulled by osmosis into the cells, causing them to swell.
What are common signs of dehydration?
Dry mouth and skin, fatigue and muscle weakness, decreased urine output, deep yellow (concentrated) urine, headaches, and dizziness. As dehydration progresses, solute concentrations in the blood rise, blood pressure decreases, and heart rate increases due to low blood volume. If fluid losses continue, kidney failure, seizures, delirium, and coma can occur.
About how much water does a person need in a day?
The Adequate Intake for water has been set at 15 cups (3.7 liters) per day for men and 11 cups (2.7 liters) for women. Water needs vary with factors such as body size, physical activity environmental conditions, and dietary intake. This water can come from plain water, other beverages, and foods. Water needs are met when inputs and outputs are balanced.
How does the body maintain intracellular and extracellular fluid balance?
The body controls the amount of water in each compartment mainly by controlling the electrolyte concentrations.
About how much does water make up of the human body?
Water is the largest component of the human body, making up 50 to 75% of body weight, depending on age and body fat content. Highest in infants and children, and declines as we age. About 55% of adult's body weight is water. Lean individuals have greater percentage because lean tissue contains about 73% water whereas adipose tissue contains only 20%
What is osmotic pressure and how does it work?
osmosis: the passive diffusion of water across a semipermeable membrane - in the body, these are cell membranes. With the concentration of solutes (mainly electrolytes) differs on the 2 sides of the membrane, water will move low to high solute concentration. Osmotic pressure is the amount of force needed to prevent dilution of the compartment containing the higher particle concentration
