Sensory Receptors
SENSORY RECEPTORS
- Act as transducers.
- Transforming different stimuli (Mechanical/Thermal) into electrical signals for conduction through nervous system.
TYPES OF SENSORY RECEPTORS:
- Exteroreceptors.
- Proprioceptor.
- Interoceptors/Visceroreceptors.
EXTERORECEPTORS:
- Provide information about external environment.
- Examples touch, pressure, temperature, light, sound, taste, & smell.
TYPES OF EXTERORECEPTORS:
1. General exteroreceptors –
- Subtypes – Cutaneous mechanoreceptors, Thermoreceptors & Nociceptors.
2. Special exteroreceptors –
- Subtypes – Mechanoreceptors, Chemoreceptors & Photoreceptors.
DESCRIPTION OF EXTERORECEPTORS:
1. General exteroreceptors:
1a) Cutaneous mechanoreceptors –
Superficial
- Detect touch.
- Slowly adapting → Merkel’s disk.
- Rapidly adapting → Meissner’s corpuscle.
Deep
- Detect deep touch, pressure, & Vibration.
- Slowly adapting → Ruffini’s end organ.
- Rapidly adapting → Pacinian corpuscle.
1b) Thermoreceptors:
- Warmth receptors & Cold receptors.
1c) Nociceptor / Pain receptors:
- Thermal nociceptors.
- Mechanical nociceptors.
- Polymodal nociceptors.
- Silent nociceptors.
2. Special extroreceptors –
- Mechanoreceptors: Hair cells in cochlea.
- Chemoreceptors: Gustatory receptors (taste buds) & olfactory receptors.
- Photoreceptors: Rods & cones in Retina
PROPRIOCEPTORS:
- Provide information about position of body or limbs in space.
- Present in muscle, tendons & joints & vestibular apparatus
TYPES OF PROPRIOCEPTORS:
- General & special mechanoreceptors.
DESCRIPTION OF PROPRIOCEPTORS:
1. General mechanoreceptors:
- Golgi tendon organ, muscle spindle & joint capsule.
2. Special mechanoreceptors:
- Hair cells in otolith organs (utricle & saccules) & semicircular canals.
INTEROCEPTORS / VISCERORECEPTORS: interoceptors
- Sense visceral state or internal environment.
- E.g.
- Receptors sensing BP (Baroreceptors)
- Chemoreceptors.
- Osmoreceptors.
TYPES:
- General interoceptors:
- Mechanoreceptors – Baroreceptors.
- Chemoreceptors – Osmoreceptors.
- Glucoreceptors.
Exam Question
SENSORY RECEPTORS
TYPES OF SENSORY RECEPTORS:
- Exteroreceptors.
- Proprioceptor
- Interoceptors/Visceroreceptors.
EXTERORECEPTORS:
1. General exteroreceptors:
1a) Cutaneous mechanoreceptors –
Superficial
- Detect touch.
- Slowly adapting→ Merkel’s disk.
- Rapidly adapting → Meissner’s corpuscle.
Deep
- Detect deep touch, pressure, & Vibration.
- Slowly adapting → Ruffini’s end organ.
- Rapidly adapting → Pacinian corpuscle.
1b) Thermoreceptors:
- Warmth receptors & Cold receptors.
1c) Nociceptor / Pain receptors:
- Thermal nociceptors.
2. Special Exteroreceptors:
- Chemoreceptors: Gustatory receptors (taste buds) & olfactory receptors.
INTEROCEPTORS / VISCERORECEPTORS:
TYPES:
- General interoceptors:
- Chemoreceptors – Osmoreceptors.
- Glucoreceptors.
Don’t Forget to Solve all the previous Year Question asked on Sensory Receptors
