Homeostasis and Feedback Loops

These flashcards cover key concepts related to homeostasis, feedback loops, and their mechanisms in biological systems.

What is homeostasis?

The maintenance of static or constant conditions in the internal environment.

What happens to physiological variables when they are not homeostatically regulated?

They can fluctuate significantly, negatively impacting cell function and enzyme activity.

What are the two major systems for coordinating responses to stimuli?

The endocrine system (hormones) and the nervous system (action potentials).

What is a feedback loop?

A system that allows organisms to maintain their internal variable values within the homeostatic range.

What is negative feedback?

A process that reverses a change in a variable to maintain homeostasis.

What is positive feedback?

A process that amplifies a change in a variable, often leading to pathological conditions.

How do feedback loops maintain homeostasis?

By detecting fluctuations and triggering responses to return variables to their set points.

What is the role of the control center in a feedback loop?

It generates output that triggers a response to restore a variable to its set point.

What is the function of effectors in a feedback loop?

They carry out the responses that help return the variable to the set point.

Give an example of a negative feedback loop in the human body.

The regulation of blood pressure by baroreceptors and the heart.

What is the significance of maintaining homeostasis in organisms?

It ensures proper cellular functions, preventing denaturation of proteins and membrane stability.

What does an odd number of negative signs in a feedback loop indicate?

The direction of change that a variable is undergoing.

How do organisms regulate their internal environment?

Through feedback loops that involve sensors, control centers, and effectors.

What occurs during a positive feedback loop in childbirth?

The release of oxytocin enhances contractions until the baby is delivered.

Why can positive feedback loops be pathological?

They can lead to uncontrolled changes that are harmful, such as in cases of significant blood loss.

What is an example of how fever acts as a negative feedback mechanism?

It creates a hostile environment for pathogens by stimulating heat production in the body.