algogenic:
Something which sensitizes nociceptors (pain receptors). Things such as histamine, potassium and substance P are algogenic, and are typically released locally at sites of injury.
Definitions: Anatomy & Physiology
central nervous system:
The portion of the nervous system that consists of the brain and spinal cord.
central pain:
Pain that is caused/ sustained by a process in the central nervous system (CNS). This means an injury that has healed, but produced changes in the CNS may still be felt as painful.
cerebrospinal fluid:
The fluid that surrounds and flows through the brain and spinal cord. It has numerous functions, including support.
deafferentation:
Loss of normal sensory input, perhaps due to nerve injury. This can make the nerves normally receiving the missing sensory input sensitized to remaining input.
dura:
The leathery membrane surrounding the spinal cord. This forms a 'sac' containing the cerbrospinal fluid (CSF) which bathes the spinal cord. It is actually a collection of several layers of tissue (dura mater, pia mater and arachnoid).
dural puncture headache:
A headache caused by a leak of cerebrospinal fluid (CSF) through a hole in the dura. The lack of CSF is believed to cause tension on the vascular and nervous structures. It typically resolves spontaneously.
epidural space:
The space within the bony structure of the spinal column that surrounds the spinal cord itself. This space is filled with fat , which acts as padding, and blood vessels.
gate control theory:
A model for pain mechanisms. It describes how nerve fibers that don't cary pain signals can block the passage of pain signals to the brain. It 'explains' why rubbing a sore spot can help it feel better.
intrathecal:
Being within the layers of the dura. This is the space filled by the cerebrospinal fluid.
mononeuropathy:
A neuropathy involving a single nerve.
neuritis:
An inflammation of the nerve(s). Without inflamation, you can't have neuritis.
neurogenic pain:
Caused or maintained by dysfunction or injury in a nerve or nerves. If the dysfunction is short lived, this term may be used rather than neuropathic pain.
neuropathy:
A dysfunction in the nerve(s). This does not have to be painful. It may cause tingling or other sensations.
nociception:
Detection of something which is potentially damaging to the body. It may not actually produce damage, but it it the 'sensory' aspect of pain.
nociceptor:
A receptor that is normally sensitive to stimuli that is causing or may cause tissue injury.
noxious stimulus:
A stimulus that may cause damage to tissue (like the heat from a fire). This is the normal stimulus for nociceptors.
pain threshold:
The smallest amount of pain that is able to be percieved. This may vary by factors in the environment, as well as the individual.
pain tolerance:
The most pain a subject is willing to tolerate.
peripheral nervous system:
The portions of the nervous system that are outside of the brain and spinal cord. For example, the nerves bringing sensation to your toes.
polyneuropathy:
A neuropathy involving multiple nerves. An example is diabetic neuropathy, where all the nerves to a foot (for example) may be effected.
sensitization:
A nerve or receptor can be made to respond more intensely to a stimulus, or respond to a stimulation it would normally ignore, in certain circumstances. This is being 'sensitized'.
threshold stimulus:
The lowest stimulus measured that produces a sensation.
