Page 328 - Color_Atlas_of_Physiology_5th_Ed._-_A._Despopoulos_2003

A. Skin sensors
Hairless skin Hairy skin
Horny layer
Epidermis 5 Hair follicle
1 Meissner’s corpuscles
(RA sensor)
2 Merkel’s cell
(SA1 sensor)
Dermis 3 Ruffini’s corpuscle
(SA2 sensor)
Nerve fibers
Hypodermis 4 Pacinian
corpuscle Sensory Functions of the Skin
B. Response of skin sensors for pressure (1), touch (2) and vibration (3)
10g 10g
10g 20g 40g
1g 1g
Stimulus: Pressure of weight Rate of weight change Rate of velocity change
Plate 12.3
Response: Action potentials (impulses)
1 2 3
100 20 400
AP/s 10 200
10 5 80
2 40
1 1 20
1 10 100 0.1 1 10 20 40 80 200 400
Stimulus weight (g) Rate of pressure change Vibration frequency (Hz)
(mm/s) (After Zimmermann & Schmidt)
C. Response of thermo- D. PD proprioception: Response to velocity
sensors and angle of joint flexion (text on next page)
1 Flexion 2 Angle
Fast Wide
Medium
Medium
Cold sensors Heat sensors Slow Narrow

12
Same flexion velocity
AP/s
30 30
8 D sensor
AP/s AP/s
20 20 P sensor
Same
4 end position Different
10 10 end position
0 0 0
25 30 35 40 0 5 10 15 0 5 10 15 315
Skin temperature (°C) (After Boyd & Roberts) Time (s) Time (s)
Despopoulos, Color Atlas of Physiology © 2003 Thieme
All rights reserved. Usage subject to terms and conditions of license.