BIOC32H3 Lecture Notes - Lecture 5: Autonomic Nervous System, Sympathetic Nervous System, Postganglionic Nerve Fibers
Document Summary
Red lines: pre and post-ganglionic sympathetic nerve fibres. Chain of ganglia running parallel to the spinal cord => pre-ganglionic fibres terminate, post- ganglionic fibres have their cell bodies, interactions occurr. Fibres can arise from the thoracic region (t1 t12) and the lumbar region (l1 and l2: sympathetic system has a thoraco-lumbar outflow. No parasympathetic chain ganglia, as the ganglia are much further away from the spinal cord. Parasympathetic nerve fibres are shown here in blue. Fibres can arise from the brainstem or the saccharal (bottom) of the spinal cord: has a cranio-saccharal outflow. Autonomic nervous system => enteric system: nervous system that is found within the gut, has the capacity to operate completely independently from the cns and the pns. In-between the circular and longitudinal layer of muscle in the gut wall. Even if we severed the sympathetic/parasympathetic links, the enteric system will still relay info to other cells! In contact with gut wall, epithelial tissue where absorption takes place.
