Homeostasis relies on precise communication pathways involving receptors, coordinators, and effectors. Which statement correctly describes a homeostatic mechanism and its communication pathway in mammals?
During thermoregulation, the hypothalamus acts as an effector that directly detects core temperature changes and initiates sweating to decrease skin temperature.
In response to low blood pressure, baroreceptors in the aorta act as effectors, transmitting signals via sensory neurones to decrease heart rate.
During blood glucose regulation, β\betaβ cells in the pancreas act as both receptors detecting elevated glucose and coordinators releasing insulin, which targets liver effectors to promote glycogenesis via negative feedback.
Positive feedback loops are the primary mechanism used to maintain a stable dynamic equilibrium, as they amplify any deviations from a physiological set point to return conditions to normal.
19 exam-style questions on OCR A A Level Biology Communication and homeostasis. Each one has a worked solution and a mark scheme showing where the marks go.