fluid and osmotic pressure stuff Flashcards
What is osmotic pressure?
Movement of fluid from an area of lower solute concentration to an area of higher solute concentration.
What is the function of hydrostatic pressure in filtration?
Hydrostatic pressure is the force exerted by the blood pushing water and solutes out of the capillaries.
What is the function of oncotic pressure in filtration?
Oncotic pressure is the force exerted by plasma proteins, mainly albumin, pulling water back into the capillaries.
What is capillary hydrostatic pressure and its clinical example?
Capillary hydrostatic pressure pushes water and solutes out from the capillary to the interstitial space. Example: High blood pressure/hypertension pushes water and solutes out.
What is capillary oncotic pressure and its clinical example?
Capillary oncotic pressure pulls water and solutes from the interstitial space into the capillary and prevents it from leaving. Example: If oncotic pressure drops, it can lead to low BP, shock, or edema.
What is interstitial hydrostatic pressure and its function?
Interstitial hydrostatic pressure pushes water and solutes from the interstitial space back into the capillary, with some being drained into the lymphatic system.
What is interstitial oncotic pressure and its function?
Interstitial oncotic pressure pulls water and solutes from the capillary into the interstitial space, largely due to albumin’s role.
What are the four places water/solutes can go once in the interstitial space?
- Absorbed into cells 2. Reabsorbed into bloodstream 3. Stay in interstitial space 4. Move into lymphatic system.
What is hydrostatic pressure?
Hydrostatic pressure is the force exerted by fluid against the walls of its container, pushing water out of the capillaries.
What is oncotic pressure?
Oncotic pressure, also known as colloid osmotic pressure, is the force exerted by plasma proteins (such as albumin) that pulls water back into the capillaries from the interstitial space and it stays there.
Name the three main body spaces where fluid is stored.
The three main body spaces are: 1. Intracellular fluid (inside cells) 2. Extracellular fluid (outside cells) - Intravascular (plasma) - Interstitial (between cells) 3. Specialized fluids (e.g., lymph, CSF, synovial fluid).
What is the proportion of total body water in different fluid compartments?
Intracellular fluid accounts for ⅔ of total body water (TBW), while extracellular fluid accounts for ⅓ of TBW.
What happens to fluid distribution in the body during medical conditions like heart failure or sepsis?
Conditions like heart failure and sepsis can alter the distribution of fluids, leading to imbalances such as edema.
How does body fat affect total body water?
Adipose tissue is hydrophobic, so individuals with higher body fat have lower total body water.
How does total body water change with age?
Total body water decreases with age: - Newborns: 70-80% - Children: 65% - Adults: 60%.
What are some common ways the body loses water?
Water is lost through urination, stooling, and insensible losses (e.g., sweating, breathing).
What is the consequence of a drastic loss of water in the body?
Drastic loss of water can lead to dehydration.
What is the relationship between fluids and solutes in the body?
Fluids follow solutes; wherever solutes like sodium go, water follows, affecting fluid balance.
What is the function of Antidiuretic Hormone (ADH) aka vasopressin?
ADH acts on the kidneys and tells them to hold onto water, thus increasing water reabsorption and maintaining blood volume and pressure.
What is the function of aldosterone in the kidneys?
Aldosterone acts on the kidneys to hold onto/reabsorb salt. Water follows salt, which helps maintain blood volume and pressure.
What is the role of BNP (Brain Natriuretic Peptide) in the body?
BNP promotes diuresis by inhibiting sodium reabsorption, reduces blood volume, promotes natriuresis, and causes vasodilation, reducing heart workload and blood pressure.
How does BNP help the heart function more effectively in cases of heart failure?
In heart failure, BNP is released due to heart expansion caused by excess fluid. It acts on kidneys to excrete more water and sodium, reducing fluid overload and improving heart function.
What is tonicity in relation to solutes and water?
Tonicity refers to the concentration of solutes in relation to water in the blood.
What is the difference between isotonic, hypertonic, and hypotonic blood concentration of solutes?
Isotonic means normal solute concentration. Hypertonic means high solute concentration (too much salt), and hypotonic means low solute concentration (diluted blood).
