Chapter 1 Flashcards
Exam 1
Define physiology.
the study of the normal functioning of a living organism and its component parts
List the levels of organization from atoms through organism.
Atoms, molecules, cells, tissues, organs, organ systems, organisms
What is the teleological explanation?
function explains the “why”
what is the mechanistic explanations?
process describes the the “how”
What are the 4 major themes in physiology?
1) structure + function are closely related
2) living organisms need energy
3) information flow coordinates body functions
4) homeostasis maintains internal stability
Define homeostasis.
maintenance of a relatively stable internal environment despite changes in the internal and/or external environment
What happens when homeostasis fails?
disease, infection, or death
What are the 2 major compartments of the human body?
extracellular fluid (ECF) and intracellular fluid (ICF)
What major compartment is higher in Na+?
ECF
what major compartment of the human body is higher in K+?
ICF
Describe ECF
the watery internal environment that surrounds (and serves as a buffer zone) the cells
Describe ICF
fluid within cells
Explain the law of mass balance.
(in an open system) requires input to equal output
Explain how the law of mass balance applies to the body’s load of a substance.
mass balance = (existing body load) + (intake or metabolic production) - (excretion or metabolic removal)
Distinguish between equilibrium and steady state.
- Dynamic steady state: materials are constantly moving between 2 compartments
- equilibrium: implies composition of compartments are identical
List the 3 components of a control system.
1) input signal
2) integrating center
3) output signal
Compare local control, long-distance control + reflex control.
- local control: restricted to a tissue or cell
- reflex/long-distance control: always uses nervous and/or endocrine systems to control long distance signaling
Explain the relationship between a regulated variable and its set-point.
A variable is regulated by the response loop which controls the function + activates when the function moves outside the set-point (normal value)
Compare negative feedback, positive feedback, and feedforward control.
- negative: tries to return to homeostasis; tries to reduce/eliminate original stimulus
- positive: does not try to return to homeostasis
- feedforward: allows the body to anticipate change
Explain what happens to set-points in biological rhythms.
regulated variables create repeating patterns/cycles
What is an example of biological rhythms?
- daily circadian rhythm
List the 7 steps of a reflex.
1) stimulus
2) sensor
3) input signal
4) integrating center
5) output signal
6) target
7) response
