6: Autonomic nervous system Flashcards
Define and explain dual innovation
organ that uses both sympathetic and parasympathetic divisions
- generally have opposing effects
- they counter balance to control organ function
- on will predominantly work and the other follows
Sympathetic control is
- prepares body for heightened activity
- exercise, excitement, emergency, embarrassment
- fight or flight
examples of sympathetic control in the body
Heart= increased rate and strength of contraction
lungs= bronchiole dialation
sweat glands= increase sweat
eyes= isis dilates, lense flatterns= adjust vision
Parasympathetic control is
- stimulates abdomnal viceral activity.
- conserve energy- rest and digest
- not all organs have parasympathetic function
examples of parasympathetic control in the body
heart= decreases heart rate= blood pressure decreases
lungs= bronchiole constriction
eyes= iris constricts lense thickens/concaves to adjust vision
Are somatic and autonomic afferent or efferent?
efferent meaning the pass on motor control
How do autonomic and somatic differ?
1- neural pathway (how effector gets to target)
2- effects (target organs)
3- Organ responses
4- neurotransmitters (NT)
Describe somatic nervous system pathway
control centre= primary motor cortex (input from cerebellum and basal nuclei) CNS=upper motor neuron PNS= lower motor neuron Target= skeletal muscles Function= voluntary movement and somatic reflexes
Describe the autonomic nervous system pathway
control centre= hypothalamus (input from limbic system and cerebrum) CNS= interneurons PNS= pre and post ganglionic neurons Target= glands, smooth and cardiac muscles Function= involuntary control - viceral organ function - glandular activity
- viceral reflexes
Where are somatic cell bodies located?
- spinal cord motor nucleus (anterior grey horns) exit via spinal nerves
- brainstem nucleus that exit via cranial nerves
Where are autonomic cell bodies located?
- spinal cord motor nucleus and exit via ventral root spinal nerves
- brain stem nucleus exit via cranial nerves
Define a Neurotransmitter
transfer signal either from on neuron to another (preganglionic) or from myeline to myeline.
Role of ACh
released by preganglionic neurons and travels to post ganglionic neuron which it bind to receptors on the surface and releases which creates an action potential in postganglionic neuron which is how the signal is passed on.
Similarities between sympathetic and parasympathetic
- Serve many of the same organs
- Involve pre and post ganglionic neurons
- Preganglionic neurons release Ach
- Presence of Ganglia
Differences between sympathetic and parasympathetic
- Both divisions do not innervate all organs
- Location of preganglionic cell bodies and axon points from CNS
- Length of axons
- Location of the ganglia.