Homeostasis Flashcards
Define “Homeostasis”
the maintenance of an optimal set of internal conditions
Define “Tolerance limits”
the limit of factors such as body temperature and fluid balance beyond which the body malfunctions
List + identify the fluid compartments in the body
- Intracellular fluids
- extracellular fluids
Explain the concept of a feedback system
It is the bodies response to a stimulus, with the response altering the original stimulus and thus providing feedback.
Describe the stimulus-response model of homeostatic control, including defining each part; stimulus, receptor, modulator, effector, response.
The stimulus is the change in the environment that causes the system to operate. The receptor detects the change (osmoreceptors and chemoreceptors). The modulator is a control centre responsible for processing information received from the receptor and sends information to the effector. The effector carries out a response counteracting (negative) or enhancing (positive) the effect of the stimulus. The feedback is achieved because the original stimulus has been changed by the response.
Explain the meaning of the term “negative feedback”
Negative feedback is when the response has the effect of reducing or eliminating the stimulus that caused it.
Describe how negative feedback can achieve the maintenance of a steady internal state.
It maintains homeostasis, responds to a stimulus by either inhibiting or restricting hormones regulation.
describe, using an example, what happens with positive feedback
oxytocin is released during birth, this is a positive response and increases the stimulus of the uterus contractions
Outline the role of the nervous and endocrine systems in maintaining homeostasis.
The nervous system sends quick, shorter lasting impulses to maintain homeostasis whereas the endocrine system secretes slower, longer lasting hormones.
