The Autonomic Nervous System Flashcards
Does the ANS control smooth muscle directly, indirectly or both?
Both - directly and indirectly
What does the ANS control?
Heart Activity
Smooth Muscle Activity
Some Endocrine and Exocrine Activity
What are the two parts of the ANS ?
Sympathetic Nervous System and Parasympathetic Nervous System
Which Nervous system controls the activity of skeletal muscle?
The Somatic nervous system. This control includes the muscle controlling limbs, trunk, face and diaphragm
Does both the ANS and SNS have sensory and motor components?
Yes, both do
What makes up the peripheral nervous system?
The SNS (somatic nervous system) and the ANS (autonomic nervous system - includes the parasympathetic and sympathetic systems)
The ____ system keeps your body working through integration of the sensory messages it receives
Autonomic Nervous System (ANS)
What sensory information relevant to the ANS is transferred from organs and tissues through the ANS?
Stretches of muscle
temperature of the skin and visceral organs
pain
What sensory information is relayed via the CNS?
plasma pH
plasma O2 concentration
plasma CO2 concentration
What sensory information is transferred via the somatic nervous system?
transferred from skin to connective tissue including:
touch
temperature
pain
Proprioceptors
receptors that can transfer sensory information relevant to the somatic nervous system
these sensors provide information on tension within a muscle and on the positional relationships of the 2 bones to which a muscle is attached
In the Somatic Nervous System, if there is a change in sensory information given to the CNS what may happen?
There will be a change in activity of skeletal muscle that is either an increase or decrease of muscle tension leading to altered relationship of the bones to which the muscle is attaches
Where does the output of the ANS originate?
Brain and Spinal Cord
How does the brain and ANS sensors/information work?
There are centers in the brain that integrate sensory information from cells, tissues and organs under ANS control and modify output to those cells, tissues and organs
Is modification of the output of the PSNS and SNS occur mostly dependent of each other or independently?
Independent
Which systems are ganglionated?
Sympathetic and parasympathetic systems
Where is the cell body of each preganglionic neuron found?
In the CNS
Where is the cell body of each postganglionic neuron found?
In the ganglion
Autonomic Ganglion
Is a relay point and is a site for information integration and distribution
Within each ganglion _____ makes synapses onto the dendrites and cell body of postganglionic neurons
Preganglionic neurons
Where does the axon of a preganglionic neuron in the SNS exit from?
The CNS from the lumbar or thoracic spinal cord
In the SNS, is the axon of the preganglionic or postganglionic neurons longer?
The axon of the postganglionic neurons are longer
What tissue ganglion in the SNS does not have axons?
The post ganglionic neurons of the adrenal medulla
Which systems ganglia is closest to innervated cells?
The PSNS
Are SNS ganglia close or far from innervated cells?
Far
If a ganglia is far away from innervated cells what would it do to the output?
It would make the output more diffuse - meaning it goes to a greater number of tissues and organs
What is Norepinephrine (NE)?
A transmitter at most junctions between the postganglionic neurons of the SNS and the effector cells innervated by these neurons and in some parts of the brain
What are adrenergic synapses?
These are synapses where NE is the transmitter
What is Acetylcholine (ACh)?
A transmitter at all junctions between the postganglionic neurons of the PSNS and the effector cells innervated by these neurons; a transmitter between somatic neurons and skeletal muscle fibers and in some parts of the brain; also a transmitter at junctions between preganglionic neurons and postganglionic neurons
What are cholinergic neurons?
neurons that synthesize and release acetylcholine
What are adrenergic neurons?
Neurons that synthesize NE
What are cholinergic synapses?
Synapses where ACh is the transmitter
What organs are innervated by the PSNS?
Brain, Spinal Cord, Eyes, Heart, Lungs, Liver, Colon, Rectum, Bladder, Uterus, Stomach, Pancreas, GI
What organs are controlled by the SNS?
Brain, spinal cord, skin, sweat glands, eye, heart, lungs, liver, stomach, pancreas, GI, adrenal, uterus, kidney, rectum, bladder
What does it mean if a cell is innervated?
If a cell compromises tissues and organs which are already influenced by the activity of neurons then they are innervated
What do innervated cells express?
receptors for the transmitter released by the neuron which innervate them
What is a synapse?
the communication point between neurons and innervated cells which is the site of manipulation by drugs
What is an effector cell?
Cells in the Somatic and Autonomic Nervous Systems that are innervated by the motor neuron and by the postganglionic neuron
Is a neuron that receives input from another neuron an effector cell? Why or Why not?
Yes because it responds to the input and then an effect is produced
Explain the output of information in the Autonomic Nervous System
It originates in the brain and exits the CNS via the spinal cord.
Centers in the brain integrate sensory information relevant to cells, tissues, organs under the ANS control and modify the output to those cells, tissues and organs
Can you alter output to a certain tissue/organ without altering output to another organ/tissue in the PSNS and SNS?
Yes, output can be discretely controlled
Are both the PSNS and SNS non-ganglionated systems?
No. They are ganglionated systems.
The cell body of each of the preganglionic neurons are found in the CNS
The cell body of every postganglionic neuron is in the ganglion
In a ganglion what makes synapses onto the dendrites and cell bodies of postganglionic neurons?
preganglionic neurons
Can the output from one ganglion effect more than one tissue/organ at a time?
Yes
Give detail of axons and ganglia in the PSNS
axon of preganglionic neurons exit via the CNS directly from brain or sacral spinal cord
ganglia are close to the cells receiving input from the postganglionic neurons
the output of a single ganglion is to a limited number of tissues and organs
Explain the Axon and ganglia of the SNS
axon exits the CNS via the lumbar or thoracic spinal cord
most ganglia form a chain running parallel and close to the lumbar and thoracic regions of the spinal cord
ganglia are a long distance from the cells receiving input from the postganglionic neurons
What is a neuroeffector junction?
a synapse between postganglionic neuron and cells with activity controlled by that neuron (effector cells)
Where does output originate in the somatic nervous system?
Brain and spinal cord
Where do neurons exit in the somatic nervous system?
the spinal cord at all levels
What is a presynaptic cell or presynaptic neuron?
the transmitter releasing neuron
What is a receiver cell called?
Postsynaptic neuron or postsynaptic neuron
What are effector cells?
may be other neurons, or other cell types including skeletal muscle cells, smooth muscle cells, muscle and non-muscle cells within the heart and secretory cells
What is required for a functional synapse?
Mechanisms to synthesize and store the transmitter
Mechanisms to release the transmitter
Mechanisms to rapidly remove the transmitter
Who are the key players at a typical synapse?
Transmitters
Axon terminals
Synaptic gap
Astrocytes
What is an astrocyte?
aka glee cells
present at all synapses but action is dependent on the transmitter
How many axons does a neuron have?
Most have one but some have two
What type of molecules are transmitters?
Most are small non-peptides (ACh, NE, epinephrine (E), dopamine (DA), gamma-aminobutyric acid (GABA), serotonin (5-HT), glutamate, adenosine triphosphate (ATP) and nitic oxide (NO)
Some are peptides, lipophobic comprised of a short chain of amino acid residues
What are the two main neurotransmitters of the autonomic and somatic nervous system?
NE and ACh
What happens when you target CNS and PSN (peripheral nervous system) in the autonomic and somatic peripheral nervous systems?
Likely to have effects on CNS and targeting these transmitter systems in the CNS will likely have an effect in the autonomic and somatic nervous system
Why does the transmitter have to be removed from the synaptic gap?
The discrete linkage of “presynaptic input” (transmitter release) and “postsynaptic output” (response) can not be maintained and part of the message is lost
Slow removal would lead to prolonged postsynaptic cell response
Can a transmitter be released by neurons at sites other than its axon terminals?
Yes - the chromaffin cell of the medulla of the adrenal gland, transmitter release only occurs from the cell body
Chromaffin cells don’t have axons
What types of cell doesn’t have axons?
Chromaffin cells
What are dendrites?
Branched processes projecting from the cell body of each neuron and are considered to be structural elements of neurons on which receptors for transmitters are located
What is considered the “input” site for information from other neurons?
Dendrites
Is the transmitter released from dendrites the same as the one released from the axon terminals of that neuron?
Yes
What systems innervate the eye?
ANS - including the SNS and PSNS
