Class Notes (807,396)
Canada (492,741)
Biology (2,220)
BIO271H1 (40)
Ohana (6)

Lecture 4

6 Pages
Unlock Document

University of Toronto St. George

Lecture 4 Sensory Physiology: Mechanoreception Mechanoreceptors o Can be simple undifferentiated nerve endings, or o Can be complex, like the Pacinian corpuscle o Mechanoreceptors also include stretch receptors in the skin, and the auditory and vestibular structures of the vertebrate ear o Mechanoreceptors are activated by a stretch or distortion of their plasma membrane o Transduce mechanical stimuli into electrical signals o All organisms (and most cells) sense and respond to mechanical stimuli o Why do we need mechanoreception? o Two main types of mechanoreceptor proteins: ENaC Epithelial sodium channels TRP chanels Transient receptor potential channels o Mechanosensory Protein Receptors Channels are linked to extracellular matrix and to the cytoskeleton Mechanical stimuli cause the extracellular anchors to move relative to the cytoskelton, pulling on the channel and causing a conformational change that opens and closes the channel Touch and Pressure o Proprioreceptors (monitor body position) o Baroreceptors (detect pressure changes) o Tactile receptors Receptors that detect touch, pressure, and vibration Widely dispersed in skin Receptor structure: Some are free nerve endings In some the nerve endings are enclosed in accessory structures Eg. Pacinian corpuscle Free Nerve Endings and Merkels Disks o Merkels Disks are free nerve endings associated with an enlarged epidermal cell o Used for fine tactile discrimination
More Less

Related notes for BIO271H1

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.