Lecture 1 Flashcards
Define physiology?
Physical and chemical factors responsible for vital human functions.
How is physiology different than anatomy?
Anatomy focuses on internal and external structures in the body.
Physiology goes into the how and the why those structures work together.
Define homeostasis?
The maintenance of the body’s internal constancy, providing a framework for the study for physiology. It identifies the significance of body processes and functions and overall works to maintain a dynamic constancy. It results in the body’s maintenance of an optimal environment using negative feedback mechanisms.
Why is homeostasis so important and integral to understanding the study of Physiology?
It represents the core principle that living organisms must maintain a stable, optimal environment despite external changes in order to prevent disease and maintain health.
What are the three primary components required to maintain homeostasis?
Sensors, integrators, and effectors
What is the role of each [component required to maintain homeostasis] in regulating homeostasis?
Sensors: detect changes in the body parameters (disturbance)
Integrators: Tissues evaluating parameter deviations
Effectors: Corrects deviation
Why is it important for the body to maintain a constant internal environment?
To maintain an optimal running environment
What happens when homeostasis is not maintained?
Disease
With respect to homeostasis, how are health and disease defined?
Disease is an inability to compensate for deviation. The body is incapable of maintaining homeostasis and functions in a non-optimal running environment.
Health: the body’s ability to sense and integrate deviations and initiate correct effector responses to re-establish dynamic constancy
Is it unhealthy for body parameters to deviate?
No, it is normal. In fact, it is a healthy sign if the body is able to have deviations and then correct back to set point.
Why are the mechanisms which function to maintain homeostasis correctly termed Negative Feedback
mechanisms?
The mechanisms function to oppose the disruptor that is causing the internal environment changes.
Using temperature regulation as an example, describe the components necessary to maintain homeostasis.
The body’s temperature increases. A sensor gages that change from the body’s set point [average measured value]. It then sends the message to the integrator which reads the signal and measures the degree and direction of deviation. The integrator sends that information to the effector which puts into place changes to bring the body back to its set point temperature.
If negative feedback mechanisms function to counteract the changes which stimulated them, what do you think Positive Feedback mechanisms do?
Positive feedback mechanisms enhance the changes which stimulated them.
What function do positive feedback mechanisms have in the body (why are they advantageous in certain circumstances)?
Positive feedback mechanisms amplify a deviation. In some circumstances (like childbirth) the body must be brought even further from its set point in order to return back to set point.
Would [positive feedback mechanisms] function to help maintain homeostasis? Explain.
No, positive feedback pushes a body process to completion and amplifies a deviation, moving it away from its set point.
What is a mole?
Gram molecular weight
Why is a mole useful in physiology?
It is the standardized unit of molecular quantity and
Define solution
Homogenous mixture of 2 (or more) substances in one state. Solvent or solute. Can be solid, liquid, or gas.
Define solvent
Molecule present in the greatest amount that causes another substance to dissolve via distribution or dissociation.
Why is water such a great solvent?
It has the greatest concentration (70-95% water) and is a polar molecule (separation of charge within a neutral molecule).
What is the difference between dissolving by distribution or by dissociation?
Distribute - spread out molecules
Dissociate - ionic compound breaks into ions and disperses
What kind of molecules do you think
would likely be dissolved through distribution?
Small, nonpolar molecules
What kinds of molecules do you think would likely be dissolved through dissociation?
Ionic or polar molecules
What is the difference between molal and molar?
Molal: moles of solute per 1 liter of solvent. Solute added to 1L H2o.
Molarity: moles solute per liter of solution.
Which unit of measurement is more useful in physiology? Molal or molar? Explain.
Molar because it is more practical in clinical applications
Which is always greater than 1 L, molal or molar?
Molal
