The autonomic Nervous System Flashcards
cWhat are the divisions of the autonomic nervous system
- parasympathetic
- sympathetic (fight or flight)
What is the autonomic nervous system controlled by?
hypothalamus
autonomic vs somatic nervous system
-somatic is voluntary and effector is skeletal muscles
-autonomic controls glands (cardiac, smooth, and glands), deals with involuntarily world
dual innervation
-like 2 plugs, where one path works to keep normalcy, and the other pathway tries to change and make odds of survival greater
-receive competing inputs from the sympathetic and parasympathetic divisions
Two things in the autonomic nervous system your body is doing
- EITHER your body is in order (normal)
- OR your body interprets as if your body is on the line
List the three general structures of the autonomic nervous system
- preganglionic neuron
- autonomic ganglion
- postganglion neuron
Preganglionic neuron
-starts in the CNS and goes to ganglion (if spinal cord starts in the lateral horn)
-presynaptic efferent motor neuron (can also call it this)
autonomic ganglion
lose output if damaged (ganglion –> effector)
-they are motor ganglia, containing the cell bodies of motor neurons
postganglionic neuron
starts in ganglion, goes to effector (gland, cardiac, smooth)
sympathetic nervous: diameter of breathing tubes
dilated, and faster rate of breathing
sympathetic nervous: force of a contraction
forceful, and fast heart rate
What is the parasympathetic response to counteract sympathetic response
-return the body to homeostatic range of normalcy
sympathetic nervous: where is blood directed
-blood goes away from the skin, and goes towards the brain, blood to the skeletal muscles (gives physical stamina)
What are two ways to raise blood pressure
- shut down vessels
- add water to the pipes (no water, no saliva)
sympathetic nervous: digestive tract
-not important right now, real low in energy when over this phase
sympathetic nervous: spleen
-hold blood you do not have to have in circulation, so when you are in sympathetic mode it has very little time to be in the spleen
-white blood cells in the spleen that hang out and check for infection (we make cancer cells) and the spleen can catch them and deal with them
-spleen also gets rid of bad red blood cells
sympathetic nervous: adrenal gland
-gives off a hormone called adrenalin which is epinephrine. This boost everything (heart, breathing) all automatic
Somatic pathway
- motor neuron with the body in the CNS goes to effector (skeletal muscle)
-the efferent neuron will spill a chemical that will be received by a muscle cell (neuromuscular) neurotransmitter will always be acetylcholine
-if you see a pathway that has one motor neuron, body in the CNS (efferent neuron) the effector is a skeletal muscle
-the effect will always be stimulatory
Autonomic pathway
-if you see a motor neuron starting in the spinal cord and in lateral horn going out the ventral root. Then in the PNS synapsing with a second motor neuron
-the effector has to be cardiac, smooth muscle or gland
If you damage an autonomic ganglion what happens?
-lose output
How many motor neurons are involved in the nerve pathway of an autonomic pathway?
2
Receptor
-either separate or the dendrite beginning of the afferent sensory neuron
afferent neuron
carry information from sensory receptors of the skin and other organs to the central nervous system (i.e., brain and spinal cord)
association neuron
-does the processing
preganglionic neuron
1st motor neuron
postganglionic neuron
2nd motor neuron
effector
effectors that respond to autonomic regulation include cardiac muscle ( the heart ) , smooth ( visceral ) muscles , and glands
components of an autonomic reflex arc
- receptor
- afferent neuron
- association neuron (interneuron)
- preganglionic neuron
- postganglionic neuron
- effector
outflow from CNS: sympathetic
-starts at the level of thoracic vertebrae and lumbar vertebrae (thoracolumbar)
-thoracic and spinal lumbar segments if you start here the pathway will be sympathetic
-see lateral horns here
outflow from CNS: parasympathetic
-craniosacral
-that is why every cranial nerve that has any autonomic function always have to be normalcy
What percentage of parasympathetic outflow is the vagus nerve
90%
-vagus goes down into the stomach
Location of Body of preganglionic neuron: sympathetic
-body of the first neuron will be in the thoracic or lumbar segment of the spinal cord, in the lateral horn and going out the ventral root
Location of the Body of preganglionic neuron : parasympathetic
-somewhere in the brain, or sacral segment of the spinal cord, lateral horn
Location of ganglia: sympathetic
-sympathetic chain of ganglia, close to spinal cord on either side or in front in a pattern (look like a chain) (in the front called pre ganglia chain)
In the first synapse what is the neurotransmitter?
acetylochline
In the effector what is the neurotransmitter?
norepinephrine
Location of the ganglia: parasympathetic
-the ganglia is not in a pattern, it is very close to the effector or even in the effector (intramural ganglion)
Number of postganglionic neurons synapsing with each preganglionic neuron: sympathetic
-there is no exact number
- 1-22 give or take
Number of postganglionic neurons synapsing with each preganglionic neuron: parasympathetic
-there is no exact number
-almost feels like one organ at a time (slow at getting back to parasympathetic)
- 1-4
Effect on energy: sympathetic
-sympathetic state is using energy, using any glucose being delivered to the blood and all glycogen resources
Effect on energy: parasympthetic
-in charge of reestablishing energy reserves in skeletal muscles back
neurotransmitter substance secreted by postganglionic neurons: sympathetic and parasympathetic
Sympathetic secretes norepinephrine
parasympathetic: secretes acetylcholine
