What are the types of information transmitted
Somatic and Autonomic
What are the functions of Somatic and Autonomic
Somatic - The stuff we are aware of and have control over
Autonomic - The stuff we are not aware of have no control over eg the control of cardiac muscle to regulate your heart beat.
What are the functions of the Upper and Lower Motor
Upper:
- Cell body in brain
- Axon in spinal cord
Lower:
- Cell body in spinal cord
- Axon in spinal nerve
Somatic Efferent: anatomical organisation
UPN - Cell body in brain, Axon in spinal cord, Axon is myelinated
LMN - Cell body in spinal cord, axon in spinal nerve, Axon is myelinated
Somatic Efferent: communication with effector cells
CNS = UMN (Brain and Spinal cord) synapsing to PNS = LMN (Spinal cord)
Neurotransmitter synapsed which is called Acetylcholine (AcH)
Summary of Somatic Efferent:
- Voluntary movement
- Two neurons between brain and effector (upper and lower)
- Axons are myelinated
- Neurotransmitter = Ach
- Effector = Skeletal muscle
Autonomic Efferent
- Involuntary control
- Two divisions - sympathetic and parasympathetic
- Effectors = smooth, cardiac muscle, glands, adipose and fat.
- 3 neurons between brain and effector
Autonomic NS features - Neuron 2
- Cell Body in CNS
- Axon extends in PNS
- Myelinated
- Synapse in Autonomic Ganglion
- Preganglionic neuron
Autonomic NS Features - Neuron 3
- Cell body in PNS. Autonomic ganglion
- Axon extends in PNS to effector organ
- Unmyelinated
- Synapse on effector organ
- Postganglionic neuron
What are the synaptic neurotransmitters for Neuron 2 and 3?
2 = Acetylcholine (ach)
3= Acetylcholine or Norepinehrine
What are the divisions on the Autonomic System?
Sympathetic - “Fight or flight”
Parasympathetic - “Rest and Digest”
Structure of Sympathetic Nervous System:
- Preganglionic (neuron 2) is a short Axon
- Sympathetic ganglion close to CNS
- Postganglionic (neuron 3) is long axon
Structure of Parasympathetic Nervous System:
- Preganglionic (neuron 2) is a long axon
- Parasympathetic ganglion is distant from CNS.
- Postganglionic (neuron 3) is a short axon
Sympathetic NS - Exit from CNS and position ganglia:
PRE: Cell bodies in thoracolumbar levels of the spinal cord, axons are short, axon terminals synapse in sympathetic ganglion
POST: cell body in sympathetic ganglion, axon is long
Sympathetic chain ganglia:
- Either side of vertebral column
- 21-23 pairs
- place where preganglionic axons synapse then onto postganglionic input zone
Parasympathetic Preganglionic neuron - Exit from CNS and position of ganglia
- cell bodies in cranial brainstem and spinal cord levels
- axon is long
- axon terminals synapse in parasympathetic ganglia
Parasympathetic Postganglionic neuron - Exit from CNS and position of ganglia
- cell body in arasympathetic ganglia in or near effector
- axon is short
