Talbot - Introduction to Physiology

Question 1

what is physiology

Answer 1

how living organisms function and sense/adjust to changes in environment

Question 2

what is homeostasis

Answer 2

ability to maintain an internal environment within narrow limits or range

Question 3

what is steady state

Answer 3

there is a net change and has energy input (active process) *most biological systems

Question 4

what is equilibrium

Answer 4

there in no net change and NO energy input (passive process) - lowest energy state

Question 5

what are the 3 components of a feedback control system

Answer 5

sensor receptor, control center/integration center, and effector

Question 6

what is the sensory receptor

Answer 6

senses a change in a variable from a/the set point created by a stimulus

Question 7

what is the control center in a feedback control center

Answer 7

recieves information (afferent/neural pathway) and decides if there should be a response and how much- compares signal to set point

Question 8

what is an effector of a feedback control system

Answer 8

actually induces the change- brings back to set point (efferent pathway: neural or hormonal)

Question 9

what is a negative feedback system

Answer 9

(majority) can shut off feedback loop by itself or as part of the feedback loop - removes the stimulus and returns to the set point

Question 10

what is a positive feedback system

Answer 10

reinforces the stimulus/feedback loop to bring the system further from its set point and requires an OUTSIDE FACTOR to inhibit the loop

Question 11

what are the 4 canon’s postulates

Answer 11

1. nervous system works to preserve conditions that are compatible with normal organismal function
2. many systems maintain a tonic level of activity
3. systems not under tonic control are under antagonistic control (either by hormones or nervous system)
4. same chemical signals can have different effects in different tissues - depending on type of receptor