4- Toothache Flashcards
General sensory pathways carry information from what?
From different modalities:
Skin, mucus membranes, joints and muscles to the brain
Give an example of pain pathways from toothache and the body?
- The Spinothalamic pathway
2. The Dorsal column pathway
What can we call general sensory pathways?
Somatoesthetic pathways
What are the modalities of the spinothalmic pathway?
- Pain
- Temperature
- Simple touch and some light pressure
Describe what carries the nerve impulses in the spinothalmic pathway
Carried via thin, poorly myelinated or unmyelinated fibres
Conduction relatively slow
What are the modalities of the Dorsal column pathway?
- Discriminative touch
- Pressure
- Vibration
Describe what carries the nerve impulses in the Dorsal column pathway
Carried via large diameter, heavily myelinated fibres
Fast conduction
What is grey matter?
A collection of nerve cell bodies
What is white matter?
Axons with myelin sheaths
What 2 parts make up a Neurone?
Cell body
Axon
What is the grey matter described as in the brain?
As the cortex of the brain
Where is the grey matter found in the spinal cord?
In the inside
Where is the white matter found in the spinal cord?
On the outside
What is a collection of grey matter called inside the central nervous system?
A nuclei or nucleus
What is a collection of grey matter called inside the peripheral nervous system?
A gangli or ganglion
What is the white matter described as in the brain?
A pathway or tract
How many pairs of spinal nerves do we have?
31
How many pairs of cranial nerves do we have?
12
What type of nerves are the spinal nerves?
They are mixed fibre nerves (have both motor and sensory fibres)
What type of nerves are the cranial nerves?
They are mixed fibre nerves (have both motor and sensory fibres)
What are dermatomes?
A specific region of skin of the body innervated by a single spinal nerve
What to dermatomes allow us to do?
Create a sensory map of the body so that if a patient is not feeling sensation is a specific area we know exactly which spinal nerve has been affected
Where is the primary somatosensory cortex located?
In the post central gyrus
What information is received by the primary somatosensory cortex ?
- Pain and temperature sensation
2. Touch sensation
How many neurones make up a sensory pathway
3
Where is the primary motor cortex located?
In the pre central gyrus
Describe the 1st order neurone that makes up the sensory pathway
Travels From the PNS to CNS.
Cell bodies in peripheral ganglia. It is Pseudounipolar.
What is a Pseudounipolar neurone?
This neurone has one projection from the cell body that has split into two branches
One branch runs to the periphery and the other to the spinal cord
What is a unipolar neurone?
A neurone that has only one projection from the cell body
Describe the 2nd order neurone that makes up the sensory pathway
Axons cross midline.
It Runs to thalamus (part of diencephalon).
Describe the 3rd order neurone that makes up the sensory pathway
It Run from the thalamus to the cerebral cortex (primary somatosensory area)