Definitions

Human Physiology

Lesson 43 : Autonomic Nervous System, Reflex Action & Sensory Receptors

Definitions

Mechanoreceptors: receptors that transduce mechanical stimuli (touch, pressure etc.) into nerve impulse e.g. pacinian corpuscle.
Thermo receptors:
receptors that transduce temperature sensation into a nerve impulse e.g. Ruffini corpuscle.
Nociceptors
: receptors that transduce pain sensation into nerve impulse.
Photoreceptors
: receptors that respond to light stimulatios. E.g. Rods & Cones of retina.
Interesting features are:

  • The retina contains more than 127 million light-detecting cells called rods and cones. Rods work well in dim light, but see only shades of grey. Cones see colours but work only in bright light.
  • When we blink, the eyelid spreads moisture from the tear glands over the surface of the eye, cleaning it. We blink every 3-7 seconds, without even realizing it.
  • The cochlea of the ear has more than 20,000 hair cells to detect the vibrations from sounds.
  • The semicircular canals next to the ear detect head movements to help the body keep its balance.
Index
Previous
Home
Next
Last modified: Wednesday, 11 April 2012, 5:33 AM