Sensory Receptors Flashcards
What are sensory receptors?
Specialised cells or cell processes that provide the CNS with information (stimuli) about conditions inside or outside the body
Activation of a sensory receptor by an adequate stimulus results in
Depolarisation or graded potentials that trigger nerve impulses along the afferent fibres coursing to the CNS
The arriving information is called
Sensation
The conscious awareness of a sensation is called
Perception
What are special sense?
Localised, complex structures
What are general sensor receptors?
Widely distributed, simple structure
Special senses provided by receptors that are localised and more complex in structure
This information is distributed to specific areas of cerebral cortex and to centres throughout the brain stem
Examples of special senses are
- Hearing and balance (ear)- cochlea and labyrinth
- Olfaction/smell (nose)- olfactory receptors
- Gustation/taste (tongue)- gustatory receptors
- Sight/vision (eye)- photoreceptors (rods and cones)
- Somatic senses (I.e. Touch, temperature, pain, itch, proprioception)
General sensory receptors are widely distributed, simple structure
Some of the information they send to the CNS reaches the primary sensory cortex and our conscious awareness
Examples of general sensory receptors are
Nociceptors (pain)
Thermorecpetors (temperature)
Mechanoreceptors (physical distortion)
Chemoreceptors (chemical concentration)
What are the three broad functional categories of the general senses
Exteroceptors
Proprioceptors
Interoceptors
Exteroceptors provide information about external environment
Touch Pressure Vibration Pain Temperature Special sense receptors
Proprioceptors provide information about
Body position and movement by monitoring the degree of stretch
Interoceptors provide information about
Internal systems
Sensitive to chemical changes, tissue stretch and temperature changes
