Sensory Receptors

 

Sensory Receptors Based on Type of Stimulus
উদ্দীপনার ধরনে গ্রাহক কোষের শ্রেণিবিন্যাস

গুরুত্বপূর্ণ Sensory Receptors এবং তাদের উদাহরণ

Stimulus Type উদ্দীপনার ধরন	Receptor Type গ্রাহক	উদাহরণ Example	অবস্থান Location	কার্য Function
1️⃣ Mechanical যান্ত্রিক	Mechanoreceptors	✅ Meissner's corpuscle	Dermis of skin (especially fingertips, lips)	Light touch
		✅ Pacinian corpuscle	Deep dermis, joints	Pressure, vibration
		✅ Merkel's disc	Epidermis	Sustained touch, texture
		✅ Ruffini endings	Skin, ligaments	Stretch of skin
		✅ Muscle spindle	Skeletal muscles	Muscle stretch
		✅ Golgi tendon organ	Tendons	Muscle tension
2️⃣ Thermal তাপমাত্রা	Thermoreceptors	✅ Krause end bulb	Skin (cold-sensitive areas)	Cold
		✅ Ruffini endings	Skin	Heat
3️⃣ Light আলো	Photoreceptors	✅ Rods	Retina of eye	Vision in dim light (black & white)
		✅ Cones	Retina of eye	Color vision, sharp vision
4️⃣ Chemical রাসায়নিক	Chemoreceptors	✅ Olfactory receptors	Nasal epithelium	Smell
		✅ Taste buds	Tongue	Taste
		✅ Carotid body receptors	Near carotid artery	Detects CO₂, O₂, pH in blood
5️⃣ Pain ব্যথা	Nociceptors	✅ Free nerve endings	All over body, especially skin	Pain detection (thermal, mechanical, chemical injury)

🔍 সংক্ষেপে মনে রাখার কৌশল:

• Mechanoreceptors → Touch, pressure, vibration, stretch
• Thermoreceptors → Heat/cold detection
• Photoreceptors → Light detection (eye)
• Chemoreceptors → Chemical signals: smell, taste, blood gases
• Nociceptors → Pain sensation (injury or harmful stimulus)

💡 NEET/Medical গুরুত্বপূর্ণ তথ্য:

Remember:

• Meissner's and Pacinian corpuscles are both mechanoreceptors but detect different stimuli
• Rods outnumber cones in the retina (120 million rods vs 6 million cones)
• Nociceptors can detect multiple types of harmful stimuli (polymodal)