general senses Flashcards
Senses:
Maintain homeostasis, by providing information about the outside world and the internal environment
Two types of senses
general and specialized
general senses
Receptors that are widely distributed throughout the body
Skin, various organs, and joints
specialized senses
Specialized receptors confined to structures in the head
Eyes, ears, nose, and mouth
sensor receptors
Collect information from the environment, and relay it to the CNS on sensory neurons
Link nervous system to internal and external changes or events
Can be specialized cells or multicellular structures
5 types of receptors
chemoreceptors,Pain receptors (nociceptors), thermoreceptors, Mechanoreceptors: Photoreceptors:
chemoreceptors
Respond to changes in chemical concentrations
Smell, taste, oxygen concentration
pain receptors (nociceptors
Respond to tissue damage
Mechanical, electrical, thermal energy
Thermoreceptors
Respond to moderate changes in temperature
mechanoreceptors
Respond to mechanical forces that distort receptor
Touch, tension, blood pressure, stretch
photoreceptors
Respond to light
Eyes
sensation
Occurs when action potentials make the brain aware of a sensory event
Example: Awareness of pain
perception
Occurs when brain interprets sensory impulses
Example: Realizing that pain is a result of stepping on a tack
projection
Process in which cerebral cortex interprets sensation as being derived from certain receptors
Brain projects the sensation back to the apparent source
It allows a person to locate the region of stimulation
sensory adaptation
Ability to ignore unimportant (or continuous) stimuli
Best accomplished by thermoreceptors and olfactory receptors
general senses
Senses with small, widespread sensory receptors, associated with skin, muscles, joints, and viscera
General Senses are divided into 3 groups
general senses are divides into 3 groups
Exteroceptive, Interoceptive (visceroceptive), Proprioceptive senses
exteroceptive
Senses associated with body surface
Examples: Touch, pressure, temperature, and pain
interoceptive
Senses associated with changes in the viscera
Examples: Blood pressure stretching blood vessels
proprioceptive
Senses associated with changes in muscles, tendons, and joints, body position
Examples: Stimulated when changing position or exercising
3 types of mechanoreceptors respond to touch and pressure
free nerve endings, Tactile (Meissner’s) corpuscles, Lamellated (Pacinian) corpuscles
free nerve endings
Common in epithelial tissues
Simplest receptors
Sense itching and other sensations
Tactile (Meissner’s) corpuscles
Abundant in hairless portions of skin and lips
Detect fine touch and texture
Distinguish between 2 points
Lamellated (Pacinian) corpuscles
Nerve endings encased in large ellipsoidal structures
Common in deeper subcutaneous tissues, tendons, and ligaments
Detect heavy pressure and vibrations
