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level: 16.2 Feedback mechanisms

Questions and Answers List

level questions: 16.2 Feedback mechanisms

QuestionAnswer
Negative feedback (1)- Homeostatic system involve receptors, communication system + effectors
Negative feedback (2)- Receptors detect when a level is too high or low, info is communicated via the nervous system or hormonal system
Negative feedback (3)- The effectors respond to counteract the change, bringing the level back to normal
Negative feedback (4)- The mechanism restores the level back to normal
Negative feedback (5)- Negative feedback keeps things around the normal level e.g. body temp is usually kept within 0.5 c above or below 37 c
Negative feedback (6)- Negative feedback only works within certain limits - If the change is too big then the effectors may not be able to counteract it - E.g. a huge drop in temp cause by prolonged exposure to cold weather may be too large to counteract
Positive feedback (1)- Some changes trigger a positive feedback mechanism, which amplifies the change
Positive feedback (2)- The effectors respond to further increase the level away from the normal level
Positive feedback (3)- Positive feedback is useful to rapidly activate something e.g. a blood clot - Platelets become activated and releases a chemical, this triggers more platelets to be activated - Platelets quickly form a blood clot at the injury site - The process ends with - feedback, when the body detects the blood clot has been formed
Positive feedback (4)- Positive feedback can also happen when a homeostatic system breaks down e.g. if ur too co,d or too hot for too long
Hypothermia involves posotive feedback- It is low bod temp (below 35 c) - It happens when the heats lost from the body quicker than it can be produced - As the bod temp falls the brain doesn't work properly + shivering stops - This makes the bod temp fall even more - + feedback takes bod temperature away from normal level, it continues to decreases unless action is taken
How multiple negative feedback mechanisms gives more control (1)- Homeostasis involves multiple - feedback mechanisms for each thing being controlled - This is coz having more than 1 mechanism gives more control over changes in ur internal enviro. than just having 1 - feedback mechanism
How multiple negative feedback mechanisms gives more control (2)- Having multiple - feedback mechanisms means u can actively increase or decrease a level so it returns to normal
How multiple negative feedback mechanisms gives more control (3)- If u only had 1, all u could do would be turn it on or turn it off - You'd only be able to actively change a level in 1 direction so it returns to normal
How multiple negative feedback mechanisms gives more control (4)- Only 1 - feedback mechanism means a slower response and less control