Chapter 14 Highlights Flashcards
What tissues doe motor neurons of autonomic nervous system innervate?
- Smooth muscle
- Cardiac muscle
- Glands
Function of motor neurons of ANS?
Make adjustments to ensure optimal support for body activities
Differences in somatic and autonomic nervous systems
- Effectors
- Efferent pathways and their neurotransmitters
- Target organ responses to neurotransmitters
Effectors of somatic nervous system
Skeletal muscles
Effectors of autonomic nervous system
- Cardiac muscle
- Smooth muscle
- Glands
Efferent pathways of somatic nervous system
Thick, heavily myelinated somatic motor fiber makes up each pathway from the CNS to the muscle
Efferent pathways of autonomic nervous system
- 2-neuron chain
- Preganglionic neuron in CNS has a thin, lightly myelinated preganglionic axon
- Ganglionic neuron in autonomic ganglion has an unmyelinated postganglionic axon extending to the effector organ
Neurotransmitter effects of somatic nervous system
- All somatic motor neurons release acetylcholine (ACh)
- Effects are always stimulatory
Neurotransmitter effects of ANS
- Preganglionic fibers release ACh
- Postganglionic fibers release norepinephrine or ACh at effectors
- Effect is either stimulatory or inhibitory, depending on type of receptors
Origin of fibers of sympathetic NS
Thoracolumbar region of the spinal cord
Length of fibers of sympathetic NS
- Short preganglionic
- Long postganglionic
Location of ganglia in sympathetic NS
Close to spinal cord
Origin of fibers of parasympathetic NS
Brain and sacral spinal cord (craniosacral)
Length of fibers of parasympathetic NS
- Long preganglionic
- Short postganglionic
Location of ganglia in parasympathetic NS
In visceral effector organs
What is an example of using one preganglionic nerve by the sympathetic nervous system?
- Adrenal gland
- Everything else uses two nerves (one pre- and one postganglionic nerve)
What neurotransmitter do cholinergic receptors release?
ACh
What neurotransmitter do adrenergic receptors release?
NE
What happens through the sympathetic NS?
- Increases heart and respiratory rate
- Inhibits digestion and elimination
What happens through the parasympathetic NS?
- Decreases heart and respiratory rates
- Allows for digestion and the discarding of wastes
What part of the brain controls ANS functions?
- Hypothalamus
- Subconscious cerebral input via limbic lobe
- Other controls come from the cerebral cortex, reticular formation, and spinal cord
