AP BIOLOGY

Detailed explanation-1: -Thermoreceptors-They respond to changes in temperature such as heat and cold. External thermoreceptors are present in the skin, tongue, etc. They detect any changes in the external temperature. Internal thermoreceptors are present in the hypothalamus, which respond to internal changes and maintain homeostasis.

Detailed explanation-2: -Chemoreceptors detect the presence of chemicals. Thermoreceptors detect changes in temperature. Mechanoreceptors detect mechanical forces.

Detailed explanation-3: -A thermoreceptor is a non-specialised sense receptor, or more accurately the receptive portion of a sensory neuron, that codes absolute and relative changes in temperature, primarily within the innocuous range.

Detailed explanation-4: -A classical model of the sensory system states that thermoreceptors (e.g., thermoTRPs) in skin nerve endings are sensors that transform temperature into the firing rate codes that are sent to the brain, where the codes are decoded as “cold” by a labeled line theory.

Detailed explanation-5: -Thermoreceptors are of two types, warmth and cold. Warmth fibres are excited by rising temperature and inhibited by falling temperature, and cold fibres respond in the opposite manner.