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. It’s 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
Meissner’s corpuscles	Detect changes in texture
Merkel’s 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 ‘headband’