Homeostasis & Feedback Loops

removing heat through evaporation

Sweat helps cool the body by

Why is it important for living things to maintain a stable internal environment?

To prevent disease and possibly death

Examples of physiological mechanisms that help maintain body temperature

Goosebumps, shivering, vasoconstriction

What are 3 ways the body's internal environment might become unstable?

exposure to extreme heat/cold, injury, infection, medications

What happens to our bodies when we are exposed to temperature extremes?

heat: sweat, blood vessels dilate, remove clothing

cold: shiver, blood vessels constrict, add clothing

Homeostasis

the body's ability to maintain a stable internal environment

How does insulin help regulate blood glucose?

it allows the cells to take in glucose from the blood which causes the blood glucose levels to go down

positive feedback loop

feedback loop which a change in a given direction causes additional change in the same direction

negative feedback loop

feedback loop which a change in a given direction causes change in the opposite direction (response cancels out the stimulus)

Receptors/Sensors

detect changes on the variable (set point)

Effectors

execute the necessary changes to adjust the variable

What two components of a feedback loop initiate a direct transfer of information?

receptor & control center

What two components of a feedback loop directly cause change to the variable?

effector & stimulus

Control Center

compares the variable in relation to a set point and signals the effectors to generate a response

What two main systems are involved in maintaining homeostasis?

endocrine & nervous

Hyperthermia

extreme temperature elevation that is a medical emergency

Hypothermia

dangerously low body temperature

Two examples of positive feedback loops

childbirth and lactation

Two examples of negative feedback loops

temperature and blood sugar control

3 parts of a homeostatic mechanism

receptor, control center, effector

Normal body temperature

98.6 F, 37C

Correct order of the elements of a control system

stimulus, receptor, control center, effector, response