Case 2 summary
General ILOs:
- To demonstrate knowledge of how the development of the vertebral column and
spinal cord affects their anatomical relationship with each other and with the
spinal nerves (dermatomes)
The anterolateral system has two major components:
Mechanical stimulation
Painful and temperature stimulation
Somatic sensation originates from sensor organs in the skin or muscles and travel to their
corresponding dorsal root ganglia or cranial nerve ganglia before passing on to the spinal
cord.
Afferent fibres are often surrounded by mechanoreceptor to help differentiate stimuli. If they
lack mechanoreceptors, they are referred to as free nerve endings.
Different sensory afferent fibre types exist:
A-alpha: supply sensory receptors in muscles
A-beta: provide sensation of touch
A-sigma/C-fibres: provide information about pain and temperature
1
MBChB Y2 – Guillaume Antem
, The receptive field refers to an area of skin which results in stimulation of an action potential.
Two-point discrimination is the minimal interstimulus distance needed to perceive two
distinct stimuli.
Afferent fibre can be considered in two types:
Rapidly adapting afferent: convey rapidly changing/urgent stimuli (ie: movement)
Slowly adapting afferent: provide information about ongoing stimulation (ie: shape,
size)
Dermatomes determine the territory innervated by each nerve. These vary for each individual.
Dermatomes overlap more for touch, pressure and vibration than they do for pain and
temperature. Hence, testing for pain/temperature provides more localised information about
segmental nerve injury.
- To demonstrate knowledge of pain pathways, receptors and the
neurotransmitters involved in differentiating between chronic pain and acute
pain
The anterolateral system
Nociceptors detect noxious stimuli. The cell bodies of nociceptors are located in the spinal
ganglia for the body and trigeminal ganglia for the face.
Continuous stimulation of nociceptors can result in sensitisation (reduced threshold for
stimulation). Nociceptors never show adaption (increased threshold for stimulation).
The principal neurotransmitter for nociceptors is glutamate. Perception of moderate to intense
pain is mediated by release of substance P due to high-frequency action potential generation
in the nociceptor.
The anterolateral system consists of three tracts:
2
MBChB Y2 – Guillaume Antem
General ILOs:
- To demonstrate knowledge of how the development of the vertebral column and
spinal cord affects their anatomical relationship with each other and with the
spinal nerves (dermatomes)
The anterolateral system has two major components:
Mechanical stimulation
Painful and temperature stimulation
Somatic sensation originates from sensor organs in the skin or muscles and travel to their
corresponding dorsal root ganglia or cranial nerve ganglia before passing on to the spinal
cord.
Afferent fibres are often surrounded by mechanoreceptor to help differentiate stimuli. If they
lack mechanoreceptors, they are referred to as free nerve endings.
Different sensory afferent fibre types exist:
A-alpha: supply sensory receptors in muscles
A-beta: provide sensation of touch
A-sigma/C-fibres: provide information about pain and temperature
1
MBChB Y2 – Guillaume Antem
, The receptive field refers to an area of skin which results in stimulation of an action potential.
Two-point discrimination is the minimal interstimulus distance needed to perceive two
distinct stimuli.
Afferent fibre can be considered in two types:
Rapidly adapting afferent: convey rapidly changing/urgent stimuli (ie: movement)
Slowly adapting afferent: provide information about ongoing stimulation (ie: shape,
size)
Dermatomes determine the territory innervated by each nerve. These vary for each individual.
Dermatomes overlap more for touch, pressure and vibration than they do for pain and
temperature. Hence, testing for pain/temperature provides more localised information about
segmental nerve injury.
- To demonstrate knowledge of pain pathways, receptors and the
neurotransmitters involved in differentiating between chronic pain and acute
pain
The anterolateral system
Nociceptors detect noxious stimuli. The cell bodies of nociceptors are located in the spinal
ganglia for the body and trigeminal ganglia for the face.
Continuous stimulation of nociceptors can result in sensitisation (reduced threshold for
stimulation). Nociceptors never show adaption (increased threshold for stimulation).
The principal neurotransmitter for nociceptors is glutamate. Perception of moderate to intense
pain is mediated by release of substance P due to high-frequency action potential generation
in the nociceptor.
The anterolateral system consists of three tracts:
2
MBChB Y2 – Guillaume Antem
