Autonomics 1 Flashcards
Is the ANS purely a motor system?
yes
Which nervous system is more in control when we are at rest - sympathetic or parasympathetic?
parasympathetic
2 Parts of Peripheral Nervous System
- Somatic Nervous System
- Autonomic Nervous System
3 Parts of Autonomic Nervous System
- Sympathetic system
- Parasympathetic system
- Enteric nervous system (ENS)
2 Parts of Somatic Nervous System
- Motor system (signal out to skeletal muscles)
- Sensory system (signal back towards CNS)
The sympathetic branch of the ANS controls what region of nerves?
thoracic and lumbar regions
The parasympathic branch of the ANS controls what regions of nerves?
cranial and sacral region
target of the somatic nervous system
skeletal muscle
What nerves are heavily myelinated?
the somatic nervous system
What part of the brain provides central control for the ANS?
hypothalamus
Concept of Dual Control
most organs are innervated by both parasympathetic and sympaathic fibers
What things get only sympathetic innervation?
blood vessel, adrenal medulla, sweat glands, arrector pili,lymph nodes
Sympathetic 2-Neuron Chain
short lightly myelinated preganglionic fiber synapses and releases ACh to a long unmyelinated postganglionic fiber and release norepinephrine
Preganglionic fibers of the sympathetic system project to where?
sympathetic trunk and chain ganglia (of T1 to L4-5) OR collateral ganglia
3 Pathways of Sympathetic Preganglionic Neurons
- Synapse in sympathetic trunk at same level
- Travel up/down sympathetic trunk and synapse at different level
- Pass through sympathetic trunk into a splanchnic nerve and synapse on collateral ganglia
What nerves come from the dorsal side of the spinal cord?
nociception (pain) and other sensory stuff
From what aspect of the spinal cord do your sympathetic fibers of the ANS leave?
ventral side
In which sympathetic preganglionic pathway is the sympathetic trunk not stimulated?
splanchnic nerve to collateral ganglia
From which vertebrae do nerves synapse on the sympathetic trunk at the same level?
T1-T3
From which vertebrae do nerves travel up the sympathetic trunk?
T1-T4
From which vertebrae do nerves travel down the sympathetic trunk?
T5 to upper lumbar region (L2-L5 dependent on species)
From which vertebrae do nerves skip the sympathetic trunk and synapse on collateral ganglia?
T5 to upper lumbar
Explain the ANS of the adrenal medulla.
preganglionic go through sympathetic chain to collateral ganglia via splanchnic nn. to the adrenal medulla; preganglionic fibers release ACh on chromaffin cells and bind to nicotinic receptors to release epinephrine and NE which enter the bloodstream
Does the adrenal medulla have a two neuron chain?
no
Is the adrenal medulla innervated by the sympathetic or parasympathetic nervous system?
sympathetic
Which tends to have more specific/selective activation - sympathetic or parasympathetic?
parasympathetic
Parasympathetic 2-Neuron Chain
long lightly myelinated preganglionic fiber synapses and releases ACh to a nicotinic receptor on a short unmyelinated postganglionic fiber and release ACh to a muscarinic receptor
What cranial nerves in the parasympathetic system will project to ganglia NEAR target organs?
Cranial nerves III, VII, and IX (3, 7, and 9)
What cranial nerves in the parasympathetic system will project to ganglia ON target organs?
Cranial nerve X (10) aka the vagus nerve
What other nerve (not cranial) in the parasympathetic system will project to ganglia ON target organs?
pelvic nerve (from the sacral spinal cord)
Cranial nerve III
oculomotor nerve
Cranial nerve VII
facial nerve
Cranial nerve IX
glossopharyngeal nerve
Cranial nerve X
vagus nerve
What three organs do the parasympathetic fibers of CNN III, VII, and IX innervate?
lacrimal glands, eye, and salivary glands (from 4 ganglia)
Which cranial nerve branches and synapses on two different ganglia?
Cranial nerve VII (for salivary and lacrimal gland)
Which cranial nerve innervates the eye?
Cranial nerve III
Which salivary glands are innervated by the facial (VII) nerve?
mandibular and sublingual
Which salivary glands are innervated by the glossopharyngeal (IX) nerve?
parotid and zygomatic/buccal
What percent of parasympathetic outflow is provided by the vagus nerve?
75%
Postganglionic fibers of the vagus nerve innervate what organs?
heart, lungs, GI tract from stomach through transverse colon, liver, spleen, pancreas
Postganglionic fibers of the pelvic nerve innervate what organs?
bladder, descending colon and rectum, internal and external genitalia
