Question: The region under the coat adjacent to the scratch acts as what?
About the article "Electrochemistry", section "Coating".

Candidate passages:
Metals can be coated with paint or other less conductive metals ("passivation").
This prevents the metal surface from being exposed to electrolytes.
Scratches exposing the metal substrate will result in corrosion.
The region under the coating adjacent to the scratch acts as the anode of the reaction.
See Anodizing
The muscular coat (muscular layer, muscular fibers, muscularis propria, muscularis externa) is a region of muscle in many organs in the vertebrate body, adjacent to the submucosa membrane.
It is responsible for gut movement such as peristalsis. 
  "Scratch" (Kaela Kimura album), by Kaela Kimura  "Scratch" (soundtrack), the soundtrack to the 2001 documentary "Scratch"  "Peter Gabriel" (1978 album), a self-titled album also referred to as "Scratch"  "Scratch", 1974 live album by The Crusaders  
Scratch track may refer to:  Scratch track race or Scratch race, a track cycling discipline in which all riders start together  Scratch track, a sound recording used as a temporary placeholder during the recording and editing process  Scratch Track, an American band  
Characteristics of the Scratch Reflex.
General Characteristics.
The scratch reflex is generally a rhythmic response.
Results from animal studies have indicated that spinal neural networks known as "central pattern generators" (CPGs) are responsible for thegeneration and maintenance of the scratch reflex.
One fascinating discovery about the scratch reflex is that supraspinal structures are not necessary for the generation of the reflex.
The scratch response is programmed into the spinal cord, and can beproduced in spinal animals.
Another equally fascinating feature of the scratch reflex is that the spinal CPGs which generate and maintain the reflex are capable of producing the reflex in the absence of movement-related sensoryfeedback.
This discovery was made while studying animals with silenced afferent neurons from the scratching limb,meaning no movement-related sensory feedback was available to the spinal circuits driving the scratch.
Amazingly, these animals were capable of producing a functional scratch response, albeit diminished in accuracy.
When afferent feedback is provided, the scratch responseis more accurate in terms of accessing the stimulus site.
Recordings indicate that feedback modulates the timing and intensity of scratching, in the form of phase and amplitude changes in nerve firing.
In studying the scratch reflex, researchers have named a number of regions on the surface of the body as they relate to the reflex.
A "pure form domain" is a region on the surface of the body, that when stimulated, elicits only one form of the scratch reflex.
A "form" isa movement-related strategy used by the animal to perform the scratch; for example, to scratch the upper back, humans are limited to one scratch form, involving the elbow raised above the shoulder to provide access to the upper back.
In addition to pure form domains, there alsoexist a number of "transition zones", which can be successfully targeted by more than one "form" of the reflex, and which usually lie at the boundary of two pure form domains.
Researchers have also developed terms to describe the scratch reflex movements themselves.
A "pure" movement is one in which only one form of the scratch response is utilized to respond to the stimulus.
A "switch" movement occurs in a transition zone, and is characterized by the smooth switching between two different scratch forms inresponse to the stimulus.
A "hybrid" movement is observed and occurs at transition zones as well, and is characterized by two rubs during each scratch cycle, where each rub is derived from one pure form movement.
Research on hybrid and switch movements at transition zonesindicates that the CPGs responsible for scratch generation are modular and share interneurons.
For this reason, in both the switch and hybrid movements, the path of the moving limb is smooth and uninterrupted.
Studies from EMG recordings have indicated that reciprocal inhibition between hip-related interneurons in the CPG for the scratch reflex is "not" necessary for the production and maintenance of the hip-flexor rhythm that is a key part of the scratch reflex.
This research further supports the findings on switch and hybrid movements, which suggest a modular organization of unit generator CPGs used in combination to achieve a task.
Another general aspect of the scratch response is that the response continues even after afferent input from the stimulated zone ceases.
For a few seconds after the cessation of the scratch, the neural networks involved in the generation of the scratch reflex remain in a state of heightened sensitivity.
During this period of increased excitability, stimuli normally too weak to trigger a scratch response are capable of eliciting a scratch response in a site specific manner.
That is, stimuli, too weak to elicit the scratch response when applied in a rested preparation, are capable of eliciting the scratch response during the period of increased excitability just following a scratch response.
This excitability is due, in part, to the long time constant of NMDA receptors.
Research has also shown that voltage-gated calcium channels have a role in the increased excitability of spinal neurons.