The Human sensory system consists of the following sub-systems: • Visual system • Auditory system • Somatosensory system • Gustatory system • Olfactory system • Vestibular system In a sensory system, a sensory receptor is a sensory nerve ending that responds to a stimulus in the internal or external environment of an organism. In response to stimuli, the sensory receptor initiates sensory transduction by creating graded potentials or action potentials in the same cell or in an adjacent one. Structures that are specialized to respond to the changes in the environment These are called stimuli Sensory receptors in periphery detects the stimuli Sensation and interpretation takes place in the brain

1. Sense receptors
Sana Afreen
Msc I Food and Nutrition
N-1631
Subject:Human Physiology

2. Human sensory system
The Human sensory system consists of the
following sub-systems:
Visual system
Auditory system
Somatosensory system
Gustatory system
Olfactory system
Vestibular system

3. Sensory receptor
A sensory receptor is a sensory nerve ending that
responds to a stimulus in the internal or external
environment of an organism. In response to
stimuli, the sensory receptor initiates sensory
transduction by creating graded
potentials or action potentials in the same cell or
in an adjacent one.
• Structures that are specialized to respond to the
changes in the environment
• These are called stimuli
• Sensory receptors in periphery detects the stimuli
• Sensation and interpretation takes place in the
brain

4. Classification by location

5. Classification by type of stimulus
detected

6. Classification by type of stimulus
detected

9. AdaptationSignalsSensationTypeReceptor
Rapid
Frequency/Velocity &
Direction
Touch: Flutter &
Movement
Encapsulated
& layered
Meissner
corpuscle
RapidFrequency: 30-800 HzTouch: Vibration
Encapsulated
& layered
Pacinian
corpuscle
SlowDirection & ForceTouch: Skin Stretch
Encapsulated
collagen
Ruffini
corpuscle
Rapid
Direction &
Velocity
Touch: MovementUnencapsulatedHair follicle
SlowLocation & MagnitudeTouch, Pressure, Form
Specialized
epithelial cell
Merkel
complex
Depends
on information
carried
Tissue damage,
Contact, or
Temperature change
Pain, Touch, or
Temperature
Unencapsulated
Free Nerve
Ending

10. On the basis of Modality
Touch
Touch receptors are found all over the body. The
most common are free nerve endings, which
sense pain, pressure, and temperature in
addition to touch. Touch receptors include
Merkel’s discs , Meissner’s corpuscles, which
detect light touch, and Pacinian corpuscles,
which sense deep pressure and vibration

12. Olfaction
When odour molecules enter the nose, they stimulate the cilia (tiny
hairs) attached to receptor cells, causing nerve impulses to pass to the
olfactory bulb and then to the brain.

13. Taste
Each bud contains about 25 sensory receptor cells, on which tiny taste
hairs are exposed to drink and food dissolved in saliva. Buds sense the
five basic tastes: bitter, sour, salty, sweet, and umami (a savoury, meaty
taste).

14. Audition
• The Organ of Corti is inside the cochlea which
holds the hair cells, the nerve receptors for
hearing.
• Signals from hair cells are changed into nerve
impulses. The nerve impulses are sent out to the
brain by the cochlear portion of the auditory
nerve. The auditory nerve carries impulses from
the cochlea to a relay station in the mid-brain, the
cochlear nucleus. These nerve impulses are then
carried on to other brain pathways that end in the
auditory cortex (hearing part) of the brain.

15. In ear- Organ of Corti

16. Vision
Rods are located near the edges of the retina and are
responsible for peripheral and night vision. Cones are
responsible for seeing in the day, in color and in detail.

17. Thank you