Exam 7 Special Senses 70X Flashcards
What is the conscious or subconscious awareness of external or internal stimuli?
Sensation
Impulses that reach the thalamus provide what type of awareness of the sensation?
Crude awareness of location and type of sensation
Impulses that reach the cerebral cortex enable type of awareness of the sensation?
Precise location of the stimulus, as well as type of stimulus
What is the conscious awareness and interpretation of the meaning of sensations?
Perception
There is no perception of sensory impulses that do not reach what?
Thalamus and cerebral cortex
What is a sensory modality?
Unique type of sensation:
- Touch
- Pain
- Vision
- Hearing
An individual sensory neuron will carry information for how many modalities?
Only ONE type of Modality
What are the two classes the sensory modalities are grouped?
General Senses
Special Senses
What senses are included into the General Senses class?
Somatic Senses
Visceral Senses
What modalities are included in the General Senses class?
- Tactile Sensations: Touch, Pressure, Vibration, Itch, Tickle
- Thermal Sensations: Warm, Cold, Hot
- Pain Sensations
- Proprioceptive Sensations
- Dynamic Sensations: movements of limbs and head
What sensation provides information about conditions within internal organs?
Visceral Sensations (of the General Sense Class)
Visceral sensation is usually not appreciated at what level of awareness?
Conscious level of awareness (other than as “feeling good” or “feeling bad”)
What modalities are included in the Special senses class?
Smell Taste Vision Hearing Equilibrium
What are the two different kinds of graded potentials that are produced by sensory receptors?
Generator Potentials
Receptor Potentials
(Amplitude of both types varies directly w/intensity of stimulus)
Generator potential are produced by dendrites of what?
- Free Nerve Endings
- Encapsulated Nerve Endings
- Receptive Part of Olfactory Receptors
Most sensory receptors exhibit ADAPTATION, which refers to what?
Decrease in generator potential or receptor potential amplitude when exposed to continuous constant stimulus over a long term
What causes the perception of a sensation to fade or disappear, even though the true magnitude of the stimulus has not changed?
Adaptation (of sensory receptors)
What receptors are rapidly adapting receptors and quickly stop firing in response to a constant stimulus?
Meissner’s Corpuscles
Pacinian Corpuscles
What receptors are slowly adapting receptors and continue to fire in response to constant stimulus?
Merkel’s disks
Ruffini Endings
What type of sensation arises from stimulation of sensory receptors embedded in the skin or subcutaneous layer, mucous membranes, muscles, tendons, joint, and inner ear.
Somatic Sensations
Somatic sensations that arise from stimulating the surface of the skin are termed what?
Cutaneous Sensations
What are the four modalities of Somatic Sensation?
Tactile
Thermal
Pain
Proprioceptive
What modalities are included in (or comprise) Tactile Sensations?
Touch Pressure Vibration Itch Tickle
Tactile sensations arise to a great degree by activation of the same structural type of receptor, What type of tactile sensation stimulate Free nerve endings and Encapsulated Nerve Endings?
Free Nerve Endings: -Itch -Tickle Encapsulated Nerve Endings: -Touch -Pressure -Vibration
Touch sensations are usually due to stimulation of what?
Tactile receptors in the skin or subcutaneous layer
What kind of touch: is the ability to perceive that something has contacted the skin, but its location, shape, size, and texture can not be ascertained
Crude Touch
Define: Fine Touch
Specific information about the location touched, and shape, size, and texture of the source of stimulation
What sensation is interpreted from sustained sensation felt over a larger area than touch occurring w/ deformation of deeper tissues than does touch? What does this mean for these receptors?
Pressure
-Pressure receptors can be deeper
What receptors are free nerve endings found in every tissue of the body except the brain?
Pain Receptors
What term is used for Pain receptors? What type of adaptation do they have?
Nociceptors
-Exhibit very little adaptation
Nociceptors can be activated by what?
Intense thermal, mechanical, or chemical stimuli
What chemicals are release by irritated or injured tissue in which stimulate nociceptors?
Kinins
Prostaglandins
Potassium Ions
What are the two types of pain? What are these differentiated based on?
Types: Fast and Slow
Differentiated:
-Types of nerve fibers that propagate impulses (speed of propagation)
-Where in the body the particular type of pain can occur
What pain is propagated along medium-diameter, myelinated A fibers, not felt in deeper tissues of the body, and perception of pain occurs very rapidly?
Fast Pain
Fast Pain is also termed what?
Acute Pain
Sharp Pain
Pricking Pain
What are some examples of what would cause fast pain?
Needle Puncture
Knife Cut
What pain is propagated along small-diameter, unmyelinated C Fibers, felt in both the skin, deeper tissues of the body, and internal organs, Perception occurs a second or more after stimulus is applied?
Slow Pain
Ex: Toothache
Slow Pain is also termed what?
Chronic Pin Burning Pain Aching Pain Throbbing Pain (May be excruciating)
What is Selectivity? (Regarding a neuron)
Sensory receptors specialize and monitor one (and only one) type of stimulus to which it is sensitive
((Sensory receptors comprise either specialized cells or dendrites of a sensory neuron))
`The process of a sensory receptor converting stimulus energy into electrical energy, in which the sensory puts out a graded potential w/varying amplitude depending on the strength of the stimulus, is called what?
Transduction
What is a first-order neuron?
Sensory neurons that conduct impulses from the PNS into the CNS
The CNS has specific regions that receive and integrate sensory impulses, where are Conscious sensations or perceptions integrated into?
Cerebral Cortex
In what ways are Sensory Receptors Classified?
- Microscopic Appearance
- Origin of Stimuli and Consequent location of receptor
- Type of Stimulus detected
What are the different Classifications by Microscopic Appearance for Sensory Receptors Nerves?
- Free Nerve Ending
- Encapsulated Nerve Endings
- Separate Cells
Which nerve ending have the microscopic appearance of bare dendrites, no structural specialization microscopically?
Free Nerve Endings
Free Nerve Endings are involved in sensory of what types of stimuli?
Pain Thermal Tickle Itch Some Touch
What Nerve endings have a microscopic appearance in which the dendrites are enclosed in connective tissue capsules which enhances sensitivity or specificity of the receptor?
Encapsulated Nerve Endings
Encapsulated Nerve Endings are involved in sensory of what types of stimuli?
- Pressure & Vibration (Lamellated)
- Touch (Meisner) (Some)
What Nerve endings classification falls into the special senses and in which specialized cell synapses w/first-order sensory neuron?
Separate Cells
Separate Cells of the special senses are involved in sensory of what types of stimuli?
- Hearing and Equilibrium Hair Cells (Inner Ear)
- Photoreceptors (retina)
- Gustatory receptors (Taste Buds)
