AP BIOLOGY

Detailed explanation-1: -Chemoreception, an ability to perceive specific chemical stimuli, is one of the most evolutionarily ancient forms of interaction between living organisms and their environment. Chemoreception systems are found in organisms belonging to all biological kingdoms.

Detailed explanation-2: -Chemoreceptors are found in the peripheral and central nervous systems. They have their most dramatic effects on the regulation of respiration but are also important in control of the circulation.

Detailed explanation-3: -Examples of direct chemoreceptors include: Taste receptors in the gustatory system: The primary use of gustation as a type of chemoreception is for the detection of tasteants. Aqueous chemical compounds come into contact with chemoreceptors in the mouth, such as taste buds on the tongue, and trigger responses.

Detailed explanation-4: -Stimulation of carotid chemoreceptors consistently increases ventilatory rate and depth (seeChapter 24), but ordinarily it changes the heart rate only slightly. The magnitude of the ventilatory response determines whether the heart rate increases or decreases as a result of carotid chemoreceptor stimulation.