Lecture 17: Functional information flow Flashcards
What are the two types of information transmitted in the nervous system
Somatic and Autonomic
What does somatic information mean
Stuff we are aware of
What does autonomic information mean
Stuff that happens without our control
What is somatic efferent information
Voluntary muscle control (motor)
What is somatic afferent information
Sensory information we are aware of (like sight)
What is autonomic efferent information
Involuntary muscle control (like heart)
What is autonomic afferent information
Sensory information that we don’t know about
(eg. blood pressure)
Describe the Somatic efferent division of the nervous system
Motor control. Two neurons between brain and effector. Axons are myelinated and the effector is skeletal muscle
Upper motor neuron
- Cell body in brain
- Axon in spinal cord
Lower motor neuron
- Cell body in spinal cord
- Acon in spinal nerve
What is the neurotransmitter in somatic efferent communication with effector cells
Acetylcholine (ACh)
What is the neuro-muscular junction
a specialized synapse where a motor neuron communicates with a muscle fiber, facilitating muscle contraction
What is the the autonomic efferent nervous system
Involuntary control of muscles.
What are the effectors of the autonmomic efferent nervous sysytem
Smooth muscle, Cardiac muscle, glands, Adipose (fat) tissue
Explain the three neurons between brain and effector
Neuron 1
- Cell body in brain
- Axon in brain or spinal cord (CNS)
Neuron 2
- Cell body in brain or spinal cord (CNS)
- Axon in PNS
Neuron 3
- Cell body in PNS
- Axon in PNS
What is an autonomic ganglion
Cell body + synapse + axon terminal
What are the neurotransmitters for Neuron 2 and 3 in the autonomic nervous system
ACh for Neuron 2
ACh or norepinephrine (NE) for Neuron 3 to effector
What are the two subdivisions of the autonomic nervous system
Sympathetic (NE)
Parasympathetic (ACh)
What is the role of the sympathetic subdivision of the autonomic nervous system
Prepares the body for stress responses
Fight or flight system
What are some effects of the sympathetic subdivision of the autonomic nervous system
Increased heart rate, constricting blood vessels,
Pupil size increase, sweating, decrease gastric motility ect
What is the role of the parasympathetic subdivision of the autonomic nervous system
Prepares the body for restful situations
Rest and Digest system
What are some effects of the parasympathetic subdivision of the autonomic nervous system
Decreased heart rate, decreased pupil size,
Increased gastric motility, increased salivation
What are the structural differences between sympathetic and parasympathetic nervous systems
Sympathetic ganglion is close to the CNS
Sympathetic uses NE
Parasympathetic ganglion is distant from CNS
Parasympathetic uses AcH
Describe exit form the CNS and position of ganglia in the sympathetic nerve system
Preganglionic neuron
Cell body in thoracolumbar levels of spinal cord (CNS)
Axon is short
Axon terminals and synapse in sympathetic ganglion
Post-ganglionic neuron
Axon is long
What are ganglia
collections of nerve cell bodies located outside the central nervous system (CNS), specifically within the peripheral nervous system (PNS).
What is the sympathetic chain ganglia
Post-ganglionic cell bodies in ganglion (unmyelinated)
On either side of the vertebral column
21-23 pairs, usually 22
Place where preganglionic (neuron #2) axons synapse onto postganglionic (neuron #3) input zone
Describe Exit from CNS and position of ganglia in parasympathetic nervous system
Preganglionic neuron
Cell bodies in cranial (brainstem) and sacral (spinal cord) levels
Axon is long
Axon terminals and synapse in parasympathetic ganglia (in or near effector)
Postganglionic neuron
Cell body in parasympathetic ganglia in or near the effector organs
Axon is short
What neurotransmitter is used by a somatic efferent neuron?
Acetylcholine
