Systems Physiology II 6010

1
Systems Physiology II 6010
Lecture 16 Autonomic Nervous System
Bradley Greger, PhD
2
MEG lab

• Center for Advanced Medical Technologies
• 729 Arapeen Drive
• Park in front
• Meet in lobby

3
Autonomic Nervous System

• Sympathetic
• Parasympathetic
• Complementary systems
• Modulation and regulation of nearly all organ
  systems

4
Sympathetic

• Paravertebral Ganglion
• flight or fight response
• Inhibits maintenance functions
• Digestion
• Increases functions which support activity
• Heart rate
• Respiration
• Blood pressure
• Blood flow to muscles

5
Sympathetic

• Pre-ganglion cells in the intermediolateral (IML)
  nucleus of the lateral column
• Thoracic spinal cord

6
Sympathetic

• Sympathetic chain ganglion
• Target of IML pre-ganglionic cells
• Lateral to spinal cord
• Outside of vertebral column

7
Parasympathetic

• Individual ganglia
• Cranio-sacral system
• rest and digest
• Synapse on ganglion near target organ
• Increases maintenance functions
• Digestion
• Blood flow to gut
• Inhibits functions which support activity
• Heart rate
• Respiration
• Blood pressure

8
Autonomic Nervous System

• Parasympathetic
• Long pre-ganglionic axons
• Synapse on ganglia near, or in (e.g. enteric
  plexus), of organs
• Pre-ganlionic neurotransmitter Ach
• Post-ganlionic neurotranmitter Ach

9
Autonomic Nervous System

• Sympathetic
• Short pre-ganglionic axons
• Synapse on paravertebral ganglia near spinal cord
• Pre-ganlionic neurotransmitter Ach
• Post-ganlionic neurotranmitter NE

10
Autonomic Nervous System

• Non-directional synapses
• Neurotransmitters have diffuse effects on target
  organs
• Similar reticular activating system in CNS
• En passant synapses

11
Raphe Nuclei

• Located in the rhombencephalon
• Uses serotonin as neurotransmitter
• Widely ramifying projections to thalamus and
  cerebral cortex
• Involved in regulation of sleep and arousal,
  depression
• Firing rate decreases during sleep

12
Autonomic Nervous System

• Involuntary
• reflexive
• Complementary functions
• Homeostasis of bodily functions
• Responding to changes in external environment
• Influence/controlled by CNS
• Limbic system