The role of the neuron, and the role of glial cells in
supporting neuronal function
Neuron is an individual nerve cell. Specialised to
receive, process and/or transmit messages.
Sensory neurons located in the
PNS and send sensory
information to the CNS. They are
specialized to respond to a
stimulation
Motor neurons carry
messages from CNS to cells
in skeletal
muscles/organs/glands
Interneurons are
connecting neurons and
are in the CNS only.
Parts of the Neuron
Dendrite receives information from a
nearby neuron.
Soma is the cell body which combines
information from the dendrites and sends
it to the axon.
Axon transmits information from the
soma towards axon terminal.
Axon terminal hold and release
neurotransmitters substance.
Axon terminal hold and release
neurotransmitters substance.
Myelin is the white and fatty substance that
insulates an axon increasing speed of
neural transmissions
Myelin sheath protects against
interference from nearby neurons. It is
not continuous and is separated by
small gaps called nodes of Ranvier.
Glial cells are specialised cells that
are involved in insulation,
nutrients, repair and eliminate
waste in the nervous system.
Synaptic transmissions
Structure and function of
the brain
Forebrain higher order thinking such as
thinking, learning, memory, perception,
Hypothalamus: maintains homeostasis
and regulates pituitary gland (hormones)
Thalamus: filters information from sense
receptor sites (except the nose), and
directs it to the appropriate lobes
Cerebrum: made up of the four lobes
Midbrain controls functions such as
movement; processing of: visual, auditory
information, sleep and arousal (‘alertness’)
Reticular formation is a network of
neurons that runs through the centre
of the midbrain, hindbrain and brain
stem towards the forebrain.
Reticular activating system (RAS)
screens incoming sensory
information and regulates arousal
Hindbrain controls motor function and
vital and automatic responses such as
breathing + heart rate + sleep + arousal
Pons is involved with
sleep, dreaming and
arousal
Medulla controls vital
body functions
Cerebrum coordinates
movement, balance and precision
The role of the cerebral cortex
Cerebral cortex is
divided into 4 lobes
Frontal Lobe function is to initiate
and execute voluntary motor
activity, planning and speech
Primary motor cortex responsible for
the planning, initiation and
performance of specific movements
Broca’s area responsible
for articulate speech
Parietal Lobe receives and
processes sensory information
Primary somatosensory cortex receives and
process sensory information from the skin
and body parts.
Temporal Lobe processes auditory perception
and has a role in memory, visual perception
including facial recognition and emotional
responses to sensory information.
Primary auditory
cortex receives and
processes sound from
both ears
Wernicke’s area is responsible
for speech comprehension
and interpreting the sounds
of human speech
Occipital Lobe receives and
processes visual information
Primary visual cortex is the largest area
of the occipital lobe and responsible for
processing visual information
Brain plasticity and brain
damage
Development and changes in brain
structure and function
Development
Myelination is the growth
and development of
myelin
Synaptogenesis is the formation of new
synapses between the brain’s neurons.
Synaptic pruning is a process where synaptic
connections are eliminated which is designed
to fine tune the neural connections
Neural pathways and connections
Frontal Lobe development
Brain Plasticity = the ability
for the brain to change in
response to experience
Adaptive plasticity is the ability of brain to
compensate for loss of function or maximize
the remaining functions
Rerouting = undamaged neuron
that has lost a connection will
seek a new active neuron
Sprouting = growth to form
new connections. This
process involves rerouting
Developmental plasticity is the
development and consolidation of neural
pathways in the foetal stage as well as in
babies, children and adolescents
1. Proliferation = A foetus’s cells develop
into neurons. Approx. 250,000/min
2. Migration = newly formed neurons move
outward to their destination. The neuron’s
role is determined by its location.
3. Circuit formation = axons of new
neurons grow out to target cells and form
synapses with them.
4. Circuit pruning = elimination of excess
synapses and neurons
5. Myelination
Sensitive period is a time when an
organism is more responsive to certain
stimulation
Critical period is a narrow period
where in development an animal is
preprogrammed for learning to occur
Brain injury is any brain damage that impairs/interferes with the
normal functioning of the brain, either temporarily or permanently.
Biopsychosocial
changes
Biological changes are primarily
physical. E.g. prefrontal cortex
injury would affect motor
activities
Psychological changes are primarily emotional,
personality and cognition which in turn can
impact on behaviour. Persistent apathy,
inability to plan (severe cases)
Social changes are a breakdown in relationships,
difficult to establish new relationships. Due to the
combined biological and psychological changes.
Neurological disorders
Spatial neglect is a neurological
disorder where individuals are unable
to notice anything on either their left or
right side. Patients believe there is
nothing wrong with them
Parkinson’s disease is a progressive
neurological disorder that has both motor
and non-motor symptoms
Motor Symptoms: Tremors,
Muscle rigidity, Slowness of
movement, Postural inability
Non-motor symptoms: Speech,
Anosmia, Slow cognitive processing,
Mental Health problems
Treatments - Two types of dopamine-based
medication to help people manage:
Medication that is converted to dopamine by
the brain called L-dopa. Based on levodopa
which is a chemical converted to dopamine
by neurons (a pre-cursor). Effectively
stimulate the reception site of dopamine