Summary
Summary Neurons and synaptic transmission AQA A level psychology Cornell style notes
- Course
- Institution
Detailed Cornell notes on neurons and synaptic transmission
[Show more]
Seller
Follow
meganhughes
Content preview
NEURONS AND SYNAPTIC TRANSMISSIONThe structure and function of neurons
Neuron Neuron: the basic building blocks of the nervous system, neurons are
nerve cells that process and transmit messages through electrical and
chemical signals
The structure and function of neurons
• There are 100 billion neurons(nerve cells) in the human nervous
system
• 80% of which are located in the brain
• By transmitting signals electrically and chemically, these neurons
provide the nervous system with its primary means of
communication
Types of neurons
There are 3 types of neurons:
Sensory
neurons
• Sensory neurons: these carry messages from the PNS to the CNS
• Long dendrites
• Short axons
• Sensory neurons are located outside of the CNS, in the PNS in
Relay neurons clusters known as ganglia
• Relay neurons: these connect the sensory neurons to the moto or
other relay neurons
• Short dendrites
• Short axons
• Relay neurons make up 97% of all neurons and most are found
Motor neurons within the brain and the visual system
, • Motor neurons: these connect the CNs to effectors such as
muscles and glands
• Short dendrites
• Long axons
• The cell bodies of motor neurons may be in the central nervous
system(CNS) but they have long axons which form part of the
peripheral nervous system(PNS)
Cell body The structure of a neuron
• Neurons vary in size from >1mm to up to a metre long, but all
Dendrites share the same basic structure
Axon Cell body: (or soma) includes a nucleus, which contains the genetic
Myelin sheath material of the cell.
Dendrites: branchlike structures which protrude from the cell body.
These carry nerve impulses from neighbouring neurons towards the cell
body
Axon: carries the impulses away from the cell body down the length of
the neuron.
Nodes of Myelin sheath: this is a fatty layer that protects the axon and speeds up
Ranvier electrical transmission of the impulse.
• If the myelin sheath was continuous this would have the reverse
effect and slow down the electrical impulse, thus the myelin
Terminal sheath is segmented by gaps called nodes of Ranvier.
buttons
Nodes of Ranvier: these speed up the transmission of the impulse by
forcing it to 'jump' across the gaps along the axon
Terminal buttons: at the end of the axon terminal buttons communicate
with the next the next neuron in the chain across a gap known as the
Action potential synapse
Electrical transmission- the firing of a neuron
• When a neuron is in a resting state the inside of the cell is
Synaptic negatively charged compared to the outside
transmission • When a neuron is activated by a stimulus, the inside of the cell
becomes positively charged for a split second causing an action
potential to occur
• This creates and electrical impulse that travels down he axon
towards the end of the neuron
Neural Synaptic transmission
networks Synaptic transmission: the process by which neighbouring neurons
communicate with each other by sending chemical messages across the
gap(the synapses) that separates them
Chemical- transmission
Presynaptic • Neurons communicate with each other within groups known as
terminal neural networks
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller meganhughes. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $4.53. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
79223 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now
Recently viewed by you
