CH 15 Flashcards
what does the ANS regulate the activity of?
- smooth muscle
- cardiac muscle
- glands
what can the ANS receive signals from?
- somatic senses
- special senses
- visceral organs
what are the components of ANS reflex arcs?
- sensory receptor
- sensory neuron
- integrating center (brainstem and hypothalamus only)
- motor neurons (preganglionic and postganglionic motor neurons)
- visceral effectors
what are the most abundant type of receptors in the ANS based on location?
interoceptors
ex. chemoreceptors, basoreceptors
what is the difference in sensory input between somatic and autonomic nervous system?
somatic: from somatic and special senses
autonomic: mostly from interoceptors, some somatic and special senses
what is the difference in control of motor output between somatic and autonomic nervous system?
somatic: voluntary control from cerebral cortex, corpus striatum, cerebellum, brainstem, spinal cord
autonomic: involuntary control from hypothalamus, brainstem, limbic system, spinal cord
what is the difference in motor neuron pathway between somatic and autonomic nervous system?
somatic: one-neuron pathway, synapses directly w/ effector
autonomic: two-neuron pathway, preganglionic synapses w/ postganglionic at a ganglion, postganglionic synapses w/ visceral effector/suprarenal medullae
what is the difference in neurotransmitters and hormones between somatic and autonomic nervous system?
somatic: all somatic motor neurons release only ACh
autonomic: motor neurons can release ACh and norepinephrine
what is the difference in effectors between somatic and autonomic nervous system?
somatic: skeletal muscle
autonomic: cardiac and smooth muscle, glands
what is the difference in responses of the effectors between somatic and autonomic nervous system?
somatic: contraction
autonomic: contraction/relaxation, change in secretion amount of glands, change in rate and force of contraction of cardiac muscle
what are the subdivisions of the ANS?
- sympathetic NS
- parasympathetic NS
- enteric plexuses
what is the sympathetic nervous system?
regulates “fight-or-flight” response, prepares body for emergency
what is the parasympathetic nervous system?
regulates “rest-and-digest” response, facilitates energy storage and conservation
what is dual innervation in the ANS?
one effector is innervated by both sympathetic and parasympathetic division of the ANS, allowing for it to receive signals from either subdivision as needed
what are the enteric plexuses?
network of neurons that regulate the organs of the digestive canal autonomously
sensory info from interoceptors or somatic/special senses are processed mostly by the what?
the hypothalamus
what is autonomic tone?
the balance between the sympathetic and parasympathetic activity levels
what regulates autonomic tone of the ANS?
the hypothalamus
why are autonomic responses subconscious?
control centres are in LOWER brain regions, not in cerebral cortex
what colour are preganglionic motor neurons?
white, they are myelinated
what colour are postganglionic motor neurons?
grey, they are unmyelinated
what is the thoracolumbar division?
cell bodies that lie in lateral grey horn of SC in segments T1-L2
part of sympathetic division
what is thoracolumbar outflow?
axons of motor neurons from the thoracolumbar division
part of sympathetic division
what is the craniosacral division?
cell bodies that lie in:
- nuclei of cranial nerves III, VII, IX, and X in brainstem
- lateral grey horn of SC’s S2-S4
- part of parasympathetic division
what is craniosacral outflow?
axons of motor neurons originating from the craniosacral division
what are autonomic ganglia?
ganglia where preganglionic and postganglionic motor neurons synapse
what are the two types of sympathetic ganglia?
- sympathetic trunk
- prevertebral ganglia