Part 3 Topic B Flashcards Preview

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Flashcards in Part 3 Topic B Deck (15)

what plays a key role in the ability to maintain homeostasis in the face of changing environmental conditions?

the autonomic nervous system


maintaining homeostasis requires:

work, the organism has to "actively" maintain a steady state


negative feedback

describes the effect in which the final product of a biochemical pathway inhibits the first step; the process in which a stimulus acts on a sensor that communicates with an effector, producing a response that opposes the initial stimulus. Negative feedback is used to maintain steady conditions, or homeostasis


homeostatic regulation relies on:

negative feedback


what is thermoregulation?

the ability to maintain a constant body temperature



the active regulation and maintenance, in animals, organs, or cells, of a stable internal physiological state in the face of a changing external environment


how does the endocrine system maintain homeostasis?

depends on feedback from the target organ to the endocrine gland that secretes the hormone which increases/decreases its subsequent production of hormone


hormones are transmitted through the:

bloodstream - feedback can occur over varying distances


positive feedback

in the nervous system, the type of feedback in which a stimulus causes a response that leads to an ENHANCEMENT of the original stimulus that leads to a larger response. In the endocrine system, the type of feedback in which a stimulus cases a response, and that responses causes a further response in the same direction. In both cases, the process reinforces itself until interrupted


what are four things always involved in a system of feedback?



constant feedback between the response and sensor maintains a set point, meaning...

homeostasis is an active process


the sensor and effector may be...

a single cell, an endocrine organ, or a series or endocrine organs


diabetes mellitus

a disease that results when the control of blood-glucose levels by insulin fails


positive feedback provides enhancement that allows for:

accelerated responses of target cells for a period of time


a positive feedback loop reinforces itself until:

it is interrupted or broken by some sort of external signal outside the feedback loop but from within the body ex. giving birth