Lecture 3 Flashcards
Define Resting Membrane Potential?
The Resting membrane potential is the electrical potential that exists across the cell membrane due to the different concentration of ions across the cell.
How does the Resting membrane potential occur and what is the value for RMP?
The RMP occurs when a cell has a concentration gradient, and the ion diffuses, for example K+ ions, leaving a negative charge in their place and hence creating an electrical potential which balances out and has a value of -70mV at equilibrium.
Define Regulated variable.
The variable that is being monitored and the system is trying to keep stable.
Define Set point.
The target value for that variable.
Define reference (normal) range.
The acceptable value range for the regulated variable.
Define variation.
Variation of the regulated variable values within and between ‘normal’ people.
Define negative feedback.
Negative feedback is when the system reacts to oppose the change that has occurred and tries to get the regulated variable back to the set point.
What is the sensor?
Monitors the actual value of the regulated variable.
What is the integrator?
The integrator compared the actual value with the set point of the regulated variable. (determines and controls the response).
What is the effector?
The effector produces the response that restores the regulated variable back to its ‘set point’.
What is are the types of communication pathways?
- Neurona - fast (axons and neurotransmitter)
- Hormonal - targets cells with specific receptors for a particular hormone. (good for widespread).
Define Radiation.
Lossing heat to a colder external environment.
Define Conduction.
Losing heat by being in contact with something colder than you.
Define Convection.
If you lose a warm layer of air around you, it will be replaced by colder air and hence more heat will be lost.
Define Evaporation.
Lowering body temperature by using body heat to evaporate sweat.
