Nevrous System- Neurons Flashcards
Nervous and Endocrine work together to achieve?
- communication
- integration
- co-ordination
Nervous System
made up of specialised cells called neurons.
divided into central and peripheral nervous systems
Define CNS
consists of the brain and spinal cord. Carries impulses to and from CNS.
Define PNS
all nerves attached to the central nervous system (cranial and spinal nerves). Carries impulses to and from the PNS
Afferent
afferent (sensory) neurons carry messages towards the central nervous system
Efferent
efferent (motor) neurons carry messages away from the central nervous system
Neurons
basic structural unit of the nervous system. They are specialised cells that carry impulses to and from CNS or connect nerve impulses.
Anatomy of a neuron
- afferent (sensory)
- efferent (motor)
- connector (interneurons, association neurons)
Nerve Impulses
only travel in one direction along a neuron
travel from dendrites –> cell body –> axon
What is the structure and function of the axon?
single long extension of the cytoplasm which carries impulses from the cell body to the axon terminal
What is the structure and function of the dendrites?
short extensions of the cytoplasm which carry impulses to the cell body
Describe difference between myelinated and unmyelinated neurons.
Myelinated neurons contain a myelin sheath which allows neurons to travel faster and Unmyelinated neurons do not contain a myelin sheath around the axon.
What is the structure and function of the cell body?
part of the neuron that contains the nucleus and passes impulse from dendrites to axon
What is the structure and function of the schwann cell?
a special cell that wraps around the axon and creates myelin
What is the structure and function of myelin?
is a layer of fatty material that covers the axon to speed up nerve impulse transmission
