Chapter 16 Flashcards
Sensation definition
Conscious or subconscious awareness of changes in the internal or external environment
Perception definition
Conscious interpretation of sensations and primarily functions from the cerebral cortex
Sensory modality definition
The unique type of sensation examples: touch, pain, vision, or hearing
What are the two classes of sensory modalities?
- General senses
- Special senses
What are the two general senses and what they do?
- Somatic senses: include tactile sensations, thermal sensation, pain sensations, and proprioceptive sensations
- Visceral senses: conditions within internal organs example: pressure, stretch, chemicals, nausea, hunger, and temperature
What is proprioceptive Sensation’s?
Allow perception of both the static (nonmoving) positions of limbs and body parts (joint and muscle position sense) and movements of the limbs and head
What are the special senses?
Sensory modalities of smell, taste, vision, hearing, and equilibrium or balance
Sensory receptor in terms of sensation?
- Either a specialized cell or dendrites of a sensory neuron
- Responds well to one particular stimulus
- Response weekly or not at all to other stimuli
Selectivity in sensory receptors?
When a receptor responds well to one particular stimuli and only weakly or not at all to other stimuli
What are the four events that need to occur for sensation to arise?
- Stimulation of the sensory receptor
- Transduction of the stimulus
- Generation of nerve impulses
- Integration of sensory input
What is transduction in a sensory receptor?
When a sensory receptor converts the energy in the stimulus into a graded potential
What are the three classes sensory receptors can be grouped into?
- Microscopic structures
- Location of the receptors and the origin of stimuli that activate them
- Type of stimulus detected
What are the three labels of microscopic structures in sensory receptors?
- Free nerve endings of first order sensory neurons
- Encapsulated nerve endings of first order sensory neurons
- Separate cells that synapse with first order sensory neurons
What are free nerve endings?
Bare (not encapsulated) dendrites that lack any structural specialization that can be seen under a light microscope
these are receptors for pain, temperature, tickle, itch, and some touch sensations
What are encapsulated nerve endings?
Dendrites are enclosed in a connective tissue capsule that has a distinctive microscopic structure these capsules enhance sensitivity or specificity of the receptor
examples: pressure, vibration, and some touch sensations
Separate cells?
Sensory receptors for special senses can be specialized separate cells that synapse with sensory neurons
including hair cells for hearing and equilibrium in the inner ear, gustatory receptors in taste buds, and photo receptors in the retina of the eye for vision
What is a receptor potential?
A graded potential generated by the sensory receptor responding to a stimulus
What are the three groups of sensory receptors based on location of the receptors and the origin of the stimuli that activate them?
- Exteroceptors: Located at or near the external surface sensitive to stimuli originating outside the body: hearing, vision, smell, taste, touch, pressure, vibration, temperature and pain
- Interoceptors or visceroceptors: Located in blood vessels, visceral organs, muscles, and nervous system. monitoring internal environment conditions not consciously perceived
- Proprioceptors: Located in muscles, tendons, joints, and the inner ear. provide information about body position, muscle length and tension, and the position and movement of your joints
What are the six groups of sensory receptors distinguished by the type of stimulus they detect?
- Mechanoceptors
- Thermoreceptors
- Nociceptors
- Photoreceptors
- Chemoreceptors
- Osmoreceptors
What is a characteristic of most sensory receptors?
Adaptation - where the receptor potential decreases in amplitude during a maintained constant stimulus
Somatic sensations?
Arise from stimulation of sensory receptors embedded in the skin or subcutaneous layer; in mucous membranes of the mouth, vagina, and anus; and skeletal muscles tendons and joints
The most somatic sensory receptors are found at the tip of the tongue, the lips, and the fingertips
What’s it called when somatic sensations arise from stimulating the skin surface?
Cutaneous sensations
What are the four modalities of somatic sensation?
- Tactile
- Thermal
- Pain
- Proprioceptive
What are the tactile sensation’s?
Touch, pressure, vibration, itch, and tickle