Medicine Notes > Oxford Medicine Notes > Neuroscience 1 Notes

Receptors And Transduction Notes

This is a sample of our (approximately) 7 page long Receptors And Transduction notes, which we sell as part of the Neuroscience 1 Notes collection, a First package written at Oxford in 2015 that contains (approximately) 266 pages of notes across 23 different documents.

Learn more about our Neuroscience 1 Notes

The original file is a 'Word (Docx)' whilst this sample is a 'PDF' representation of said file. This means that the formatting here may have errors. The original document you'll receive on purchase should have more polished formatting.

Receptors And Transduction Revision

The following is a plain text extract of the PDF sample above, taken from our Neuroscience 1 Notes. This text version has had its formatting removed so pay attention to its contents alone rather than its presentation. The version you download will have its original formatting intact and so will be much prettier to look at.

Receptors and transduction

-The ability to receive and process information about surroundings, and to respond to this, is essential for survival and reproduction.
-Sensory receptors are responsible for detecting various stimuli, with this information then potentially leading to either subconscious or conscious adjustments.
-The receptors convey four basic types of information about a stimulus: modality (type of energy), location, intensity and timing.
-A single stimulus usually activates many receptors.
-Information that is processed by the cerebral cortex leads to conscious perception of the stimuli and a conscious 'decision' about the appropriate response.
-Only a very small proportion of the total receptor stimulation leads to conscious perception of the stimulatory factor.

-Receptors can be defined as rapidly or slowly adapting. Rapidly adapting receptors respond to changes in stimulus intensity but there is very little firing if that stimulus is maintained.
-Slowly adapting receptors do not respond as rapidly when the stimulus strength changes but they continue to fire, indicating that the stimulus is still present.
-The main classes of receptor are: mechanoreceptors, thermoreceptors, chemoreceptors and nociceptors. a) Mechanoreceptors: Touch, proprioception
-Receptors for touch and proprioception terminate in a nonneural capsule- sense mechanical stimuli that indent/physical deform the receptive surface
-These may be responsive to one or several of a very broad range of stimuli including vibrations or pressure on the skin, sound (vibrations), gravity, muscle stretch, vascular pressure, and speed of movement of a joint.
-Sense physical deformation of tissue- Mechanical distension such as pressure on skin/ stretch of muscles-transduced into electrical signal by deforming and opening stretch sensitive ion channels- increase Na+ , Ca2+  depolarise the membrane
-Mechanical stimuli: forces conveyed through lipid tension in cell membrane (osmotic swelling), forces conveyed through structural proteins linked to ion channels, indirectly activated by forces conveyed to a force sensor: use a second messenger pathway, slow to activate and inactivate-outlasts the stimulus, but sensory signal amplified


Meissner corpuscles
-Located superficially in dermal ridges of glabrous (hairless) skin such as fingertips- about 1/16th the size of Pacinian corpuscles
-Detect stroking/fluttering- rapidly adaptive with small receptive fields- nerve ending is surrounded by Schwann cells which can modify the sensory input
-Can detect light touch Merkel cells- innervated by slowly adapting type 1 fibres (fire in response to steady pressure on the skin). Detect initial contact of hand with objects, slippage of objects, motion of hand over textured surface, low frequency vibration
-Located superficially with attachments to basemement membrane underlying epidermis and are dense in fignertips
-Nerve terminal surrounded by an epitheial cell- derived from neural crest cells and contains many neuroactive substances. Slow receptive fields and are slowly adapting touch receptors Pancinian corpuscles
-Largest and best studied of the mechanoreceptors in the skin- measure up to 2mm long an 1mm in diameter

****************************End Of Sample*****************************

Buy the full version of these notes or essay plans and more in our Neuroscience 1 Notes.