Lecture 3 - Different classes of neruones Flashcards
What are sensory neurons?
afferent neurones that carry information about the internal and external world to the CNS
What are interneurons?
neurones that can be afferent or efferent and convey signals from one neurone to another
What are motor neurone?
efferent neurones that carry signals out of the CNS to target effector organs (muscles, glands)
name three structural neurones?
Pyramidal cells
Granule cells
Stellate cells
Where are pyramidal cells found?
Found in various brain regions such as cortex and hippocampus
Where are stellate cells found?
Found in cerebellum and cortex
Where are granule cells found?
Found in cerebellum, cortex, olfactory bulb and cochlear nucleus
what kind of components are found in pathways in the brain?
They can include peripheral and central components
They can have ascending (afferent) and descending (efferent) components.
What do sensory neurones do?
Sensory neurones gather information from sensory receptors
What do motor neurones do?
They exhibit specific characteristics and transit between central and peripheral nervous system (efferent)
They are multipolar
What are reflex arcs give an example?
Reflex arcs are rapid, simple circuits composed of three types of neurone
An example is the knee jerk reflex
What are cytoarchitectonic maps?
maps based on the classification of different neurones
Which four cell types work together to learn skilled motor tasks?
Molecular layer
Purkinje cell layer
Granule cell layer
White matter layer
what are pyramidal neurones?
these are large cells which have cone/pyramid shaped cell bodies
what are granule cells?
grain shaped cells (e.g. like grains of sand)
what are stellate cells?
star shaped cells
what stem structure of pyramidal cells?
they have apical and basal dendrites and long axons
Large projection neurones
what type of neurone are stellate cells?
Small interneurones
what’s the structure an shape of stellate neurones?
star shaped dendritic field and generally relatively short axons
what are stellate neurones in the cortex like?
In cortex some have spines and are excitatory and some are aspinous and are inhibitory
what type of neurone are granule cells?
Small interneurones
granule cells have small _____ ______.
cell bodies
what are Functional activities in the nervous system organised into?
pathways which contain different neurones working together
pathways in the brain are _______.
unidirectional
can there be cross talk between two sides of the brain?
yes
pathways in the brain have the ability to do what?
They can loop back on themselves (feedback)
where can sensory receptors be found?
eye, inner ear, skin, joints, nose, tongue
what do the sensory neurones of the spine contribute to?
somatosensory system
what type of sensory neurones are found in the peripheral nervous system?
pseudo-unipolar
are sensory neurones afferent or efferent?
afferent
where do motor neurones start and end?
Motor neurones project from the brain and spinal cord, the latter ending in muscles and glands
where do upper motor neurones in cortex descend too?
descend to projections to lower motor neurones in the spine.
A fact about lower motor neurones …
Lower motorneurones leave the spinal cord along spinal nerves, joining the incoming sensory neurones after the ventral and dorsal roots
why do reflex arcs use only one or two synapses?
to decrease time from sensation to response
what are the two subclasses of anaotmist?
Lumpers – like to put cells into fewer groupings
Splitters – like to make more groupings by looking at ever finer details
