Question

what are the signal transductions for the five senses

Answer 1

Signal transduction is a process by which sensory information is detected by sensory receptors and is converted to electrical energy for it's transmission to the nervous system.

Signal transduction occurs in all five senses - vision, taste, smell, hearing and mechanical senses such as - touch, pain, pressure and vibration.

Vision -

Here the sensory receptors are rods and cons present in retina which converts light energy into electrical energy with the help of confirmational change in rhodopsin protein, this signal is then transmitted to the brain.

Hearing -

Here then sensory receptor is cochlea in which hair cells are present on sensory epithelium. Here , vibrations that is mechanical energy is converted to electrical energy and is transmitted to the brain via auditory nerve.

Taste -

Gustatory receptors are present on the tongue, which has ability to perceive five different types of taste sensations - bitter, sour, sweet, salt and umami. These taste receptors has G proteins which are activated when there is food in the mouth.

Smell -

Olfactory cells act as sensory receptor which as G protein receptors on it. Whenever there is any odorant molecule in environment , it enters the nose and gets impacted on mucus from where it binds to G protein receptors and activates signalling which causes neurotransmitter release in the nerve pathway and travels to olfactory bulb.

Mechanoreceptors

Here mechanical energy that is pressure, temperature - hot or cold, vibrations, touch etc is picked up by mechanoreceptors present in the skin (example - ruffini's corpuscles, pacinian corpuscle etc) and converts mechanical energy into electrical energy which is then transmitted to the brain via various nerve pathways.