Neuroanatomy Flashcards
(102 cards)
What are the two areas of the nervous system and what is included in each of these categories?
PNS
- Cranial nerves (come off brain stem)
- Spinal nerves (come off spinal cord)
- Ganglia (dorsal root ganglia and autonomic ganglia)
CNS
- Brain and spinal cord

What are ganglia?
They are cell bodies of neurones that exist outside of the nervous system
Whats the purpose of the CNS?
Its the control centre for information processing, responding to sensory information, some are voluntary and some are involuntary
Whats included in the CNS and PNS when organising the nervous system in higher order organisms ?
PNS
- Nerve
- ganglia (aggregations of neurones)
- sensory receptors
CNS
- Brain
- spinal cord
Label this neuron…


Why are there several dendrites in neurons?
They are multi-polar so there are several denrites
What is around the axon in a neuron?
myelin which is white in colour and provides insulation to help speed up conduction in the neuron
Tell me 3 functions of a neuron?
Recieve stimuli
Transmit nerve impulses or action potentials
Activate muscles
What the role of a dendrite?
They collect electrical signals and carry input to cell body. They do this with chemical signals as well
Whats the role of the cell body/ Soma (these mean the same thing)?
It integrates signals and generates action potentials
Whats the role of an axon?
Transmits signals over long distances from the cell body to the axon terminals in order to communicate to the next neuron or organ its transmitting information to
Neurons in all species are the functional units of the nervous system, they are organised into a functional network which is capable of what?
- resonse to stimuli
- information processing
- communication

Differences in the nervous system amongst species are due to what?
Not the neurones but how they are organised
What are the ways in which neurons can be organised in different species give an example of a species which possess this type of organisation?
Nerve nets (simple organisms have nerve nets): hydras, jellyfish etc.
Cephalisation: starfish (echinoderms)
CNS: humans, cats, dolphins
PNS: humans, cats, dolphins
Name a multicellular organism without a nervous system?
sea sponges
Invertebrate nervous systems are specialised for what?
- stimulus/ response
- receptor/ effector
- reflexes, conditioned responses e.g. escape from predators
What are nerve nets?
What organisms is it found in?
The simplest form of the nervous system found in some invertebrates such as hydras and jellyfish
Individual nerve cells exist in a net-like formation scattered in layers of body wall.

Why do neurones in a nerve net exist in a ‘loose network’?
In order to allow for contraction and expansion of the body cavity
What do nerve nets lack?
distinct central or peripheral regions, and anything that resembles a brain
Nerve nets have no associative activity they only have what?
Reflexes (with action potentials)
Can nerve signals travel in both directions?
In an electrical synapse the signals can travel in both directions
In a chemical synapse the signals can only travel in one direction
What type of information can neurons carry?
What does the neuron do with the information that it recieves?
Information from sensory organs that detect touch, light or other changes in the environment
These neurons in turn contact neurons that control movement of the organism e.g. swimming
Species like star fish (echinoderms) display some centralisation of the nervous system explain the organisation of the nervous system in star fish and what this allows in terms of movement ?
They have a ring of neurons located in the centre with somple bundles of neurons (radial nerves) extending from the right to the tip of each arm
Radial nerve nets form nerve nets permitting coordinated movement of each arm and the tube feet located on the surface of the arm

When species show cephalisation, how is this known from their structure?
Cephalisation is an evolutionary trend over mant generations where the mouth, sense organs and nerve ganglia become concentrated at the front end of the animal producing a head region
The animals tend to show bilateral symmetry (right and left half and a head end)


































