Chapter 1: Homeostasis & Feedback

what is homeostasis?

body systems working together to maintain a stable internal environment

how does homeostasis work?

systems respond to external and interior changes to keep variables within normal ranges, like body temperature and fluid balance

what are the types of homeostatic regulation?

autoregulation and extrinsic regulation

what is autoregulation?

automatic response in cells, tissues, or organs to an environmental changes

can release chemicals to get enough nutrients

what is extrinsic regulation?

more complex regulation that involves responses controlled by nervous and endocrine systems

what are the three homeostatic regulatory mechanisms?

1) receptor : receives stimulus

2) control center : processes signal and sends instructions

3) effector : carries out instructions

why is homeostasis important?

limits fluctuations of internal conditions to keep it close to a set point / desired value

what is negative feedback?

corrective; undoes changes

response of effector negates the stimulus

brings body back into homeostasis

what is positive feedback?

more rare feedback where body exaggerates change; needs powerful / quick change

stimulus produces response that amplifies original change in condition

body is moved away from homeostasis 9normal range is not maintained)

what is a positive feedback loop?

completes a dangerous process quickly to reestablish homeostasis

what are systems integration?

systems working together to maintain homeostasis

why does homeostasis have a dynamic equilibrium?

it is a continual adaptation where the body is close to equal

perfect equilibrium means death

what happens if the physiological systems fail?

results in disease