Terms to know about touch

Cortex

The outer layer of an organ, in this case the cerebrum. The nerve cells are found here. The part of the cerebrum used to do something; e.g. the olfactory cortex. Also refers to the part of the cerebrum under a particular bone; e.g. the frontal cortex.

Nerve

A group of axons connecting the central nervous system with an effector organ

Tract

A group of axons passing through the brain to connect two groups of neurons. Itís like a nerve, but embedded in the brain tissue.

Association cortex

A part of the cerebral cortex that lets you make connections between what you sense and what you think, remember, or feel

 

 

 

 

Soma

Refers to all of the body except the internal organs

Viscera

The internal organs

 

Somatic senses

Senses felt by the soma; Touch, pressure, itch, vibration, temperature, proprioception, pain

Visceral senses

Senses felt by the viscera; mainly pressure and pain

Mechanoreceptors

Neurons that fire in response to mechanical stimuli

Chemoreceptors

Neurons that fire in response to chemical stimuli

Thermoreceptors

Neurons that fire in response to temperature

photoreceptors

Neurons that fire in response to light or dark

nociceptors

Neurons that fire in response to painful stimuli

proprioceptors

Neurons that fire in response to changes in body position

Free nerve endings

Detect pain and temperature

Meissnerís corpuscles

Detect changes in texture

Merkelís disks

Detect indentation

Ruffini end organs

Detect skin stretch

Pacinian corpuscles

Detect deep pressure and vibration

Muscle spindles

Detect whether a muscle is stretched or not

Golgi tendon organs

Detect whether tendons are stretched or not

Primary somatic sensory cortex

In the parietal lobe, right behind a Ďheadbandí