Nervous system Flashcards
What do Afferent and Efferent mean?
Afferent - signal sent into CNS
Efferent - signal sent out of CNS
Describe the PNS (2)
- Detects internal/external stimuli
- Controls conscious (somatic) movement and autonomic function
Describe the CNS (3)
- Consists of brain and spinal cord
- Processes internal/ external information relayed
- Communicates with PNS to act on effectors
Describe Neurons and how they communicate (2)
- Fundamental cell units of nervous system
- Use electrical/chemical signalling to communicate
What are the 3 types of communication neurons perform?
- Input
- Computation
- Output
What are the 3 main classes of neuron?
- Sensory neurons
- Interneurons (process/relay)
- Motor neuron (effectors)
Describe how neurons communicate (3)
- Neurons sends electrical impulse (action potential) along axon to terminals
- Action potential release chemical neurotransmitter into synapse (acetylcholine)
- Neurotransmitter can initiate action potential in subsequent neuron
What are the 2 types of nerve fibres exiting the CNS to the PNS?
- Spinal nerves
- Cranial nerves
Describe nerve fibres, and what they contain (3)
Axons bundled together (contains axons, connective tissue and blood vessels etc)
Describe spinal nerves
nerve fibres exiting spinal cord
how many pairs of spinal nerves exit the spinal cord to innervate regions of the body?
31
Describe a dermatome and what it provides
- Regions of body innervated by given spinal nerve
- Provides motor control + sensation
Name the 5 dermatomes (Can The Lorax Say Cheese)
- Cervical
- Thoracic
- Lumbar
- Sacral
- Coccygeal
How many cranial nerve pairs are there?
12
Where do the cranial nerves send signals from?
brain/brainstem