Communication and Homeostasis

Good communication system will:
⦁    cover the whole body
⦁    enable specific communication
⦁    enable rapid communication
⦁    enable short term and long term responses
⦁    enable cells to communicate with each other

Stimulus -->A change in the environment that causes a response.
Response --> A change in behaviour or physiology due to a change in the environment.
Homeostasis --> Maintenance of the internal environment at a constant state despite external changes.
E.g. Bloob pressure, blood sugar levels, body temperature
Negative feedback --> Process that brings about a reversal in any change in conditions. (essential for homestasis).
Positive feedback--> A process that increases any change detected by receptors (Usually harmful & does not lead to homeostasis.)
Exceptions labour
Cell signalling--> A process in which one cell releases a chemical that is detected by another cell. This 2nd cell then responds to this signal.

Ectotherms--> An organism that relies on external sources of heat to regulate its body temperature.

Advantages
⦁    Less food is used in respiration
⦁    May be able to survive for long periods without eating
⦁    Greater proportion of energy obtained from food, used for growth

Disadvantages
⦁    Less active in cooler temperatures (more risk of predation)
⦁    May not be capable of activity during winter as they never warm up sufficiently.

Temperature Regulation
Change behaviour or physiology to increase or decrease…