SENSES Flashcards
Sensory modality
-each unique type of sensation
-form of stimulus
-chemicals, temperature, light
Location:
-location of stimulus and receptor
General senses
-Somatic senses
-Visceral senses
Somatic senses
-conscious
-tactile: touch, pressure, vibration itch and tickle
-thermal sensations
-pain
-proprioception: awareness of limb and joint position in space
Visceral senses
-unconscious
-conditions within internal organs
Special senses
-smell
-taste
-vision
-hearing
-equilibrium and balance
Categorized by location (sensory receptors)
-Exteroceptors
-Interceptors
-Proprioceptors
Exteroceptors
-near the external surface of the body
-respond to external stimulus
Interceptors
-in blood vessels, organs and muscles
-not consciously perceived
Proprioceptors
-in muscles, tendons and joints, and the inner ear
-information about body position and movement of joints
Categorized by mode of activation (sensory receptors)
-Mechanoreceptors
-Baroreceptors
-Thermoreceptors
-Nociceptors
-Photoreceptors
-Chemoreceptors
Mechanoreceptors
-deformation
Baroreceptors
-detect stretch/pressure
Thermoreceptors
-temperature
Nociceptors
-painful stimuli
-chemoreceptive free nerve endings activated by tissue damage from intense thermal, mechanical or chemical stimuli
Photoreceptors
-photons of light
Chemoreceptors
-chemicals in the mouth (taste), nose (smell) and body fluids
Slow pain
-gradually increase in intensity over a period of seconds to minutes
-conducted along unmyelinated axons
-often has a burning, aching or throbbing quality
Fast pain
-occurs rapidly
-acute well localized
-perception occurs rapidly
-nerve impulses propagate along myelinated axons
Superficial somatic pain
-stimulations of receptors in the skin
Deep somatic pain
-stimulations of receptors in the skeletal muscle, joints, tendons and fascia
Visceral – referred pain
-stimulations of receptors in visceral organs
-pain is felt on or just deep to the skin that overlies stimulated organ or in a surface area far from the stimulated organ (referred pain)
Referred pain
-feel visceral pain in another area then where pain originated
-sensory nerve signals from certain viscera are perceived as originating not from the organ but instead from the skin and skeletal muscle
Free nerve endings
Structure:
-dendritic endings of sensory neurons
Location:
-closest to skin surface (papillary layer of the dermis and some dendritic endings extend into the deepest layers of the epidermal strata); mucous membrane
Function:
-detects temperature, pain, light touch and pressure
Encapsulated endings
-sensory nerve endings that are surrounded by a connective tissue capsule
-mechanoreceptors that can sense pressure, vibration, tension, and length
Tractile receptors
-thermoreceptors, mechanoreceptors or nociceptors located in the skin
-Unencapsulated
-Encapsulated
Unencapsulated
-bare dendritic endings
Encapsulated
-eclosed by tissue or cells
