Sensory ModalitiesA sensory modality is a way of sensing, like vision or hearing. Modality in someone’s voice gives a sense of the person’s mood. In logic, modality has to do with whether a proposition is necessary, possible, or impossible. In general, amodality is a particular way in which something exists.Stimulus modality, also called sensory modality, is one aspect of a stimulus or what we perceive after a stimulus. For example, the temperature modality is registered after heat or cold stimulate a receptor. Some sensory modalities include: light, sound, temperature, taste, pressure, and smell.• General Senses:1. Somatic (Exteroceptors)a. Touchb. Pressure c. Temperature d. Proprioceptione. Pain2. Visceral (Interoceptors) a. Painb. Pressure• Special Sensesa. Smell or Olfactionb. Taste or Gustationc. Sight or Vision d. Sound or Auditorye. Balance or EquilibriumStimulation of a sensory receptorTransduction of the stimulus Conversion of the stimulus into a graded potential3. Generation of an impulse Conversion of a graded potential into an action potential at a trigger zone and propagation to CNS.Integration of sensory inputAUDITORY Auditory learners learn best through hearing, using their ears and their voices as the primary way to learn. They learn best through verbal lectures, discussions, talking things through and listening to what others have to say. Auditory learners interpret the underlying meanings of speech through listening to tone of voice, pitch, speed and other nuances. Written information may have little meaning until it is heard. These learners often benefit from reading text aloud and using a tape recorder.VISUAL Visual learners need to see the material to learn most effectively. They need to see the teacher’s body language and facial expression to fully understand the content of a lesson. They may think in pictures and learn best from visual displays including: diagrams, illustrated text books, overhead transparencies, videos, flipcharts and hand-outs. During a lecture or classroom discussion, visual learners often prefer to take detailed notes to absorb the information.KINESTHETIC Kinesthetic learners are those who learn best by doing. Kinesthetic persons learn best through a hands-on approach, actively exploring the physical world around them. They may find it hard to sit still for long periods and may become distracted by their need for activity and exploration.Chemoreceptions A sensory nerve cell or sense organ, as of smell, or taste, that are able to detect and respond to chemical stimuli. ORA sensory receptor that detects chemical stimuli in the environment and relay that information to the central nervous system. ExplainationA chemoreceptor, also known as chemosensor, is a specialized sensory receptor cell which transduces (responds to) a chemical substance (endogenous or induced) and generates a biological signal. This signal may be in the form of an action potential if the chemoreceptor is a neuron (nerve cells or in form of neurotransmitter that activate nearby a nerve fibers ifchemosensor is a specialized sensory receptor cell, such as taste receptor in taste budor in internal peripheral chemoreceptor such as carotid body. In more general terms, a chemosensor detects toxic or hazardous chemicals in the internal or external environment of the human body and transmits that information to the central nervous system, and rarely the peripheral nervous system, in order to expel the biologically active toxins from the blood, and prevent further consumption of alcohol and/or other acutely toxic recreational intoxicants.ExamplesExamples of distance chemoreceptorsExample 1 Olfactory receptor neurons in the olfactory system.Olfaction involves the ability to detect chemicals in the gaseous state. In vertebrates, the olfactory system detects odors and pheromones in the nasal cavity.Within the olfactory system there are two anatomically distinct organs: the main olfactory epithelium (MOE) and the vomeronasal organ(VNO). It was initially thought that the MOE is responsible for the detection of odorants, while the VNO detects pheromones. The current view, however, is that both systems can detect odorants and pheromones.1 Olfaction in invertebrates differs from olfaction in vertebrates. For example, in insects, olfactory sensilla are present on their antennae.Example 2Taste buds 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. These chemical compounds can either trigger an appetitive response for nutrients, or a defensive response against toxins depending on which receptors fire. Fish and crustaceans, who are constantly in an aqueous environment, use their gustatory system to identify certain chemicals in the mixture for the purpose of localization and ingestion of food.Example 3Insects use contact chemoreception to recognize certain chemicals such as cuticular hydrocarbons and chemicals specific to host plants. Contact chemoreception is more commonly seen in insects but is also involved in the mating behavior of some vertebrates. The contact chemoreceptor is specific to one type of chemical.