BIOLOGY 2C03 Lecture Notes - Golgi Tendon Organ, Nociception, Proprioception
Document Summary
Somatosensory i: basic terms used in somatosensory systems. Specificity: to specific forms of energy and to specific modalities. Afferent nerve fiber types (see also table on p. Afferent peripheral nerves can be divided into 4 groups: i-iv (or a-a decreasing axon diameter/conduction velocity (see chart on p. 3 for function: mechanoreceptors afferents: all a-b except for low threshold c. Sai (aka merkel): bottom of sweat duct ridges, form and texture perception. Saii (aka ruffini): skin stretch (e. g. hand shape, lip/mouth position) Raii (aka pacinian): extremely sensitive to vibrations. Also there are hair-related (like rai) and field and low threshold c (unknown functions) afferents: proprioception afferents, small afferents. Joint: ii and iii, varying morphology and response properties. Primary spindle: ia, sensitive to muscle length and contraction speed. Secondary spindle: ii, sensitive to muscle length. Golgi tendon organ: ib, sensitive to muscle force nociceptive: myelinated but unmyelinated endings, heterogeneous. Warm: unmyelinated c, sensitive to warmth (basic thermometer)