IPHY 3430 Intro to Physiology and
Homeostasis Questions and Answers.
what is homeostasis, what are examples of physiological variables regulated by the body -
Answer homeostasis= similar condition/ state, maintain constant internal environment when
the external environment varies, keep regulated variable within setpoint
temp, pH, ion concentrations, nutrient availability
not maintained = dysfunction/ disease, death
identify regulated variable, stimulus/ input signal, sensor, integrator, output signal, effector/
target, physiological response in a homeostatically regulated system - Answer regulated
variable = pH, temp, ion concentration etc
stimulus/ input = regulated variable deviates from setpoint
sensor = constantly monitors and reports on regulated variable, central (eyes, ears, nose,
tongue) and peripheral (baro, osmo, chemo, thermo, proprio, mechano) sensory receptors,
increased activity with more deviance from setpoint
integrator = evaluates inputs from sensors and sends instructions, neuron or endocrine cell
output signal
effector/ target = brings about physiological response
physiological response = get back to setpoint
feedforward control - Answer occurs in anticipation of change, prepare body for possible
disturbances
positive feedback - Answer enhances the change further from setpoint, need outside factor to
stop the process
ex: childbirth- more and more activation of stretch receptors = stronger contractions and
oxytocin secretion, shut off with birth
Homeostasis Questions and Answers.
what is homeostasis, what are examples of physiological variables regulated by the body -
Answer homeostasis= similar condition/ state, maintain constant internal environment when
the external environment varies, keep regulated variable within setpoint
temp, pH, ion concentrations, nutrient availability
not maintained = dysfunction/ disease, death
identify regulated variable, stimulus/ input signal, sensor, integrator, output signal, effector/
target, physiological response in a homeostatically regulated system - Answer regulated
variable = pH, temp, ion concentration etc
stimulus/ input = regulated variable deviates from setpoint
sensor = constantly monitors and reports on regulated variable, central (eyes, ears, nose,
tongue) and peripheral (baro, osmo, chemo, thermo, proprio, mechano) sensory receptors,
increased activity with more deviance from setpoint
integrator = evaluates inputs from sensors and sends instructions, neuron or endocrine cell
output signal
effector/ target = brings about physiological response
physiological response = get back to setpoint
feedforward control - Answer occurs in anticipation of change, prepare body for possible
disturbances
positive feedback - Answer enhances the change further from setpoint, need outside factor to
stop the process
ex: childbirth- more and more activation of stretch receptors = stronger contractions and
oxytocin secretion, shut off with birth
