The Nervous System Flashcards
What are the two divisions of the nervous system and their components ?
- The central nervous system- brain & spinal cord
- The peripheral nervous system- all other nerves
What are the divisions of the peripheral nervous system?
Autonomic nervous system: parasympathetic and sympathetic
Somatic nervous system: Sensory (afferent) and Motor (efferent) division
What are the cells of the nervous system?
Neurones
Schwann Cells
Neuroglial/Glial Cells
What are the two properties of neurones?
Irritability
conductivity
What are the key features of neurones?
Cell body
Axon
Schwann Cells
Nodes of Ranvier
Dendrites
Synaptic end bulb
What do Schwann cells do?
Layers form the myelin sheath
Acts an insulator
What are the nodes of Ranvier and what do they do?
Gaps in myelin sheath
Assist rapid transmission of action potentials in myelinated neurones
What is the function of a dendrite?
Form synapses with other dendrites
Provide a large surface area to receive information to pass to the cell body
Name the neuroglial cells.
Microglia
Astrocytes
Oligodendrocytes
What is the main function of Astrocytes?
Main supporting tissue of the CNS
Forms part of the blood brain barrier.
What do sign synaptic end bulbs contain?
Synaptic vesicles containing neurotransmitters.
A nerve impulse running TO the brain and CNS is known as?
A nerve impulse running FROM the brain and CNS is known as?
Afferent (sensory)
Efferent (motor)
Give 3 characteristics of nerve impulses?
Travels in one direction
Can only send one message at one speed
The frequency or number of pulses can vary
What is the characteristic of the ion channels in the Axon?
Voltage gated
What are the stages in a neural impulse?
• Resting neuron
• Excitatory stimulus
• Sodium channels open
• Sodium irons enter the neuron
• Potassium channels open
• Potassium ions leave the neuron
• Recharging phase