Homeostasis Flashcards
Cons trash homeostasis for single cell and multi-cellular organisms
Single cell- controlled by their environment
Multicellular generate their own environment where the cells live, that environment must be controlled and maintained by that organisms
What is homeostasis ?
Ability of the body to maintain a relatively stable internal environment despite external variances
What is physiology?
The study of the various mechanisms that maintain homeostasis
What are the cell requirements?
Maintain its functional integrity; act with other cells to perform required organ function; contribute to organism survival
How can ICF affect other cells?
The ICF within the cells communicates within the extracellular fluid that bathes and surrounds the cells; to function normally
Describe the water distribution of the body
Intracellular water 40% body weight; 28L)
Extracellular water (20% body weight, 14L)
Interstitial fluid and lymph water (15% body weight; 10.5L)
Plasma water (5% body weight; 3.5L)
Total body water (60% body weight; 42L)
How much body weight is water in either genders?
60% water for boys
50% water for girls
How much of the body water is is extracellular fluid?
1/3
Fluid that bathed the cells. Plasma; interstitial fluid and specialized transcellular fluid compartments- cerebrospinal , synovial, and pleural fluids
How much of the body is intracellular fluid?
Fluid within cells. Substances in plasma must pass through the interstitial fluid before entering the cells. Water distributes between compartments depending on the solute concentration present in each compartment
What is steady state?
Maintenance of a state that doesn’t change with time, and energy expenditure may be necessary
e.g., ECF Na+ > ICF Na+ and concentrations are maintained at a set level balanced over time —> requiring energy
What is equilibrium?
Implies that two compartments have the same amount of free energy so there is not net energy transfer between two compartments
Contrast steady state and equilibrium
Equilibrium and steady state are NOT the same thing
-when a system is in balance or harmony, it is in a steady state
In our body: ECF and ICF solutes are in a steady state (body expends effort and energy to maintain uneven solute concentrations to allow optimal function( but water is in equilibrium between the compartments (due to solute concentration difference)
Summarize equilibrium
There is no net flux of energy from one compartment to another
Rate of forward reaction = rate of reverse reaction
What is dynamic equilibrium?
When products are being converted to reactants and vice versa
