Somatic NS Flashcards
What is exteroception and what are the two examples?
Sensory information from the environment
Nociception (pain)
Proprioception (joint and movement, where the limbs are in space)
What is exteroception and the two examples?
Sensory information from the environment
Nociception (pain)
Proprioceprion (joint movement in space)
What is interoception?
Sensory information about the state of organs
Blood pressure
PO2
Where are sensory neurons found
Cell body is always in the dorsal root
What is found in the ventral root of the spinal cord
Motor neuron cell bodies
What are the 4 types of sensory nerve fibres
A alpha
A beta
A delta
C
What are A alpha nerve fibres like and their function
Myelinated
Sense muscle tension and change in muscle length- 1b
Sense rate of change in muscle length- 1a
80-120 m/s
What are A beta nerve fibres like
Myelinated
Senses muscle spindles and skin sensation
33-75m/s
What are a delta nerve fibres like
Thinly myelinated
Free endings
Detect pain and the cold
What are C nerve fibres like
Non myelinated
Detects pain and warmth
What detects pain
Free nerve endings
What are where are primary afferent neurones
It’s the nerve fibre that goes from the sensory organ to the first synapse
Cell body is always outside the CNS in the sensory ganglion
What does the secondary afferent neurone do?
Transmits the information from the dorsal horn of the spinal cord to the thalamus or the cerebrum
Cell body is inside the CNS
What does the third afferent neurone do?
Transmits information to the somatosensory cortex in the telencepholon (usually from the thalamus)
Cell body is in the thalamus
What is decussation
When the fibre tracts change from one side to the other
