11 Sensory Systems
Learning Objectives
- Apply the rules of medical language to build, analyze, spell, pronounce, abbreviate, and define terms as they relate to the sensory system
- Identify meanings of key word components of the sensory system
- Use terms related to the sensory system
Sensory System Word Parts
Click on prefixes, combining forms, and suffixes to reveal a list of word parts to memorize for the Sensory System.
Introduction to the Sensory Systems
Ask anyone what the senses are, and they are likely to list the five major senses as taste, smell, touch, hearing, and sight. However, these are not all of the senses. The most obvious omission from this list is balance. Touch can be further subdivided into pressure, vibration, stretch, and hair-follicle position, on the basis of the type of mechanoreceptors that perceive these touch sensations. Other overlooked senses include temperature perception by thermoreceptors and pain perception by nociceptors.
Within the realm of physiology, senses can be classified as either general or special. A general sense is one that is distributed throughout the body and has receptor cells within the structures of other organs. Mechanoreceptors in the skin, muscles, or the walls of blood vessels are examples of this type. General senses often contribute to the sense of touch, as described above, or to proprioception and kinesthesia , or to a visceral sense, which is most important to autonomic functions. A special sense is one that has a specific organ devoted to it, namely the eye, inner ear, tongue, or nose. The figure below shows the series of events that lead to stimulation of a sense organ.
Gustation (Taste) and Olfaction (Smell)
Watch Taste & Smell: Crash Course Anatomy & Physiology #16 (10 minutes)
Sensory System Medical Terms
Gustation (Taste)
Gustation is the special sense associated with the tongue. The surface of the tongue, along with the rest of the oral cavity, is lined by a stratified squamous epithelium. Raised bumps called papillae contain the structures for gustatory transduction. There are four types of papillae, based on their appearance:
- circumvallate
- foliate
- filiform
- fungiform
Within the structure of the papillae are taste buds that contain specialized gustatory receptor cells for the transduction of taste stimuli. These receptor cells are sensitive to the chemicals contained within foods that are ingested, and they release neurotransmitters based on the amount of the chemical in the food. Neurotransmitters from the gustatory cells can activate sensory neurons in the facial, glossopharyngeal, and vagus cranial nerves.
Only a few recognized submodalities exist within the sense of taste, or gustation. Until recently, only four tastes were recognized: sweet, salty, sour, and bitter. Research at the turn of the 20th century led to recognition of the fifth taste, umami, during the mid-1980s. Very recent research has suggested that there may also be a sixth taste for fats, or lipids.