The Nervous System Definitions Flashcards
CNS
Brain and spinal cord
What is the peripheral nervous system?
The nerves and ganglia outside of the CNS
What is the somatic nervous system?
Associated with skeletal muscle to provide voluntary control of body movements (part of PNS)
what is the autonomic nervous system?
Provides unconscious control of functions of internal organs, e.g. heartbeat, digestion (part of PNS)
what is the reflex arc?
An inborn response to a stimulus and is rapid, automatic and beneficial
what is resting potential?
the potential difference across the membrane when no nervous impulse is being conducted
What is an excitable cell?
A cell which can change its resting potential
What is the all or nothing law?
Law stating that “An action potential is either initiated or it is not, and it is always the same size”
what is saltatory conduction?
Jumping of action potentials from one Node of Ranvier to the next due to the electrical insulation of myelin
what is a nerve net?
The most simple type of nervous system found in simple organisms such as hydras, jellyfish and sea anemones.
What is a synapse?
Tiny gap between neurones. An impulse can be transmitted across electrically or chemically
What is an Excitatory drug?
A substance which increases the likelihood of depolarisation at a post-synaptic membrane
What is an inhibitory drug?
A substance which decreases the likelihood of depolarisation at a post-synaptic membrane
