{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

readerL14 - Somatosensory System Page 14-1 Unlike other...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Somatosensory System Unlike other sensory systems we will study in this course, the somatosensory system does not have a single receptor sheet where somatosensory information is transduced. Instead, somatosensory receptors are found throughout our bodies , located on our skin surfaces , in our muscles and joints , and in our internal organs. There are several different types of somatosensory receptors which transduce different modalities of somatosensory sensation. The different receptor types have different mechanisms of transduction, different types of axons, and carry information to the brain by different pathways. Mechanoreceptors in skin Somatosensory receptors (1) Free nerve endings Free nerve endings all look the same anatomically (no specializations) but have four different functions. Two types of free nerve endings are thermoreceptors (transducing changes in temperature ) and two other types are nociceptors (transducing pain ). (A) “Cold” receptors (i) Respond to sudden decreases of temperature, adapt over the course of a few seconds. Transduction mechanism unknown. (ii) Have small diameter myelinated axons. @ How fast will action potentials travel in these axons? (iii) Send information to the brain via the spinothalamic pathway. Page 14-1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
(B) “Hot” receptors (i) Respond to sudden increases in temperature, adapt over the course of a few seconds. Transduction mechanism unknown. (ii) Have very small diameter unmyelinated axons. @ How fast will action potentials travel in these axons? (iii) Send information to the brain via the spinothalamic pathway An experiment : We put our right hand in cold water for 10 seconds and at the same time put our left hand in hot water for 10 seconds. Then we put both hands in the same bucket of lukewarm water. @ What do we feel on our left hand? @ What do we feel on our right hand? @ Which sensation do we feel fi rst? (C) “Sharp pain” receptors (i) Respond to stimuli causing a shearing force on the skin such as cuts or bruises. Transduction probably chemical.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}