Ap Bio: Homeostasis and Feedback

homeostasis

maintenance of a relatively stable internal environment

how does the nervous system help homeostasis

1. controls and coordinates bodily activities

2. detects + initiates rxns to changes in external + internal environments

how does the endocrine system help homeostasis

secrets glands of endocrine regulate by release of hormones

examples of disruptive external stimuli

heat, cold, lack of oxygen, pathogens, toxins

examples of disruptive internal stimuli

body temp, blood pressure, water, glucose, salts, oxygen, stress

what are the three main components of homeostasis

receptors, control center, and the effector

receptors

organ / sensor that receives the chemical signal and communicates the next component

what must the control center be able to do for homeostasis

1. receive signal and sense deviations from the norm

2. integrate info with other relevant info

3. send signals to appropriate organ / gland to make an adjustment

effector

the component that causes the change

how does the effector deal with the stimulus

it sends out chemicals

negative feedback loop

original stimulus is reversed (shut off)

positive feedback loop

original stimulus is intensified