Autonomic Nervous System Flashcards
What does autonomous mean?
Self governing - so under subconscious control
What does the autonomic nervous system control?
- Heart rate
- Blood vessel contractility
- Hormonal secretions
- Pupil diameter
- Gastrointestinal motility
What is the difference between somatic and autonomic nervous system?
Somatic - conscious control of the skeletal muscles
Autonomic - unconscious control of cardiac, smooth muscle and glands
What are the divisions of the autonomic nervous system?
Parasympathetic
Sympathetic
Enteric
What is a ganglion? (pl ganglia)
Where cell bodies of many peripheral autonomic neurones occur and form swellings on nerve trunks
What do axons of the autonomic nervous system have?
Two neuron chain
- Preganglionic neuron
- Postganglionic neuron
What occurs on the branches on postganglionic neurons?
Varicosities are present from which neurotransmitter is released
What is the neurotransmitter at preganglionic nerve?
Acetylcholine (ACh)
What are the transmitters in the postganglionic nerves?
Acetylcholine (ACh)
Noradrenaline (NA)
What are the additional transmitters called and how are they used?
Non-adrenergic non-cholinergic neurotransmission (NANC)
They are Co-transmitters that can Neurotransmit or Neuromodulate
What is another name for the parasympathetic nervous system? Why this name?
- Cranialsacral outflow
- Preganglionic axons emerge from the cranial and sacral regions of the CNS
Where are the synapses for the preganglionic axons located?
Near to/within effector tissues
This makes the preganglionic fibres long and the postganglionic fibres short
What is another name for the sympathetic nervous system? Why this name?
Thorecolumbar outflow
The preganglionic neurones only come from the thoracic or lumbar sections of the CNS
Where can the preganglionic axons terminate?
- Paravertebral sympathetic chains (chains run a long way along the chain before forming a synapse
- Prevertebral ganglia
- Adrenal Medulla (contains chromaffin cells that are similar to sympathetic ganglis cells)
What are the sizes of each neurone in the sympathetic nervous system?
Preganglionic fibres are short and postganglionic fibres are relatively long
