Autonomic Nervous System Flashcards
What does the sensory component of the SNS deal with?
Information related to our external environment.
What does the sensory component of the ANS deal with?
Information related to our internal environment.
What type of sensory input do we generally perceive?
Somatic sensory input, not autonomic sensory input.
Where does the motor component of the SNS transmit signals to?
Skeletal muscle.
Where does the motor component of the ANS transmit signals to?
Cardiac muscle, smooth muscle, and glands.
Do we generally have conscious control over somatic motor output?
Yes
Do we generally have conscious control over autonomic motor output?
No
How many neurons are involved in the pathway from the central nervous system to the target effector in the SNS?
One neuron.
How many neurons are involved in the pathway from the central nervous system to the target effector in the ANS?
Two neurons.
sensory input of the SNS
external environment
Somatic sensory receptors (touch, pain)
Special sensory receptors (vision, hearing
Sensory input ANS
Internal environment
Chemoreceptors (chemicals)
Mechanoreceptors (stretch)
perception of sensory input SNS vs ANS
SNS, yes - generally
ANS, No - generally
motor output SNS vs ANS
SNS: skeletal
ANS: Visceral organs
Conscious control of motor output: SNS vs ANS
SNS: yes (cerebral cortex)
ANS: NO: subcortical areas
peripheral motor pathway: SNS VS ANS
SNS: 1 neuron
ANS: 2 neurons
Where is the cell body of the preganglionic neuron located?
In the brain stem or lateral horn of the spinal cord.
What type of axon does the preganglionic neuron have and where does it exit the CNS?
Myelinated axon. It exits the CNS as part of a cranial nerve or anterior root of a spinal nerve.
Where does the preganglionic neuron carry signals to?
To a peripheral ganglion.
Where is the cell body of the postganglionic neuron located?
In a peripheral ganglion.
What type of axon does the postganglionic neuron have?
Unmyelinated axon.
Where does the axon of the postganglionic neuron carry signals to?
To an effector.
What are the two neurons in the peripheral autonomic motor pathways?
Preganglionic neuron and postganglionic neuron.
What is a ganglion?
A cluster of neuronal cell bodies outside of the central nervous system.
Where are the cell bodies of preganglionic neurons located?
In the central nervous system.
Where do the axons of preganglionic neurons transmit signals to?
Peripheral ganglia.
Where are the cell bodies of postganglionic neurons located?
In the peripheral ganglia.
Where do the axons of postganglionic neurons transmit signals to?
To the target effectors.
Which neurons come before the peripheral ganglia?
Preganglionic neurons.
Which neurons come after the peripheral ganglia?
Postganglionic neurons.
What is the main difference between the peripheral motor pathways of the SNS and ANS?
The SNS pathways involve skeletal muscle, while the ANS pathways involve cardiac muscle, smooth muscle, and glands.
Where are the cell bodies of lower motor neurons located in somatic motor pathways?
In the anterior horn of the spinal cord.
Where do the axons of lower motor neurons transmit signals to? (SNS)
To skeletal muscle.
Where are the cell bodies of preganglionic neurons located in autonomic motor pathways?
In the lateral horn of the spinal cord or in the brainstem.
Where do the axons of preganglionic neurons exit and transmit signals to?
They exit the spinal cord or brainstem and transmit signals to postganglionic neurons with cell bodies in peripheral ganglia.
What do the axons of postganglionic neurons transmit signals to?
To cardiac muscle, smooth muscle, and glands.
what does the somatic nervous system consist of?
1 neuron
lower motor neuron
what does the autonomic nervous system consist of?
2 neurons
pre and post ganglionic
How can the ANS be divided?
Into sympathetic and parasympathetic divisions.
What tends to be the relationship between the effects of the sympathetic and parasympathetic divisions on visceral organs and tissues?
They tend to have opposing effects.
Where do the preganglionic neurons of the sympathetic nervous system originate?
In the lateral horns of the T1 to L2 spinal cord segments.