PHYL2001 Study Guide - Final Guide: Sympathetic Trunk, Spinal Cord Injury, Postganglionic Nerve Fibers
PHYL2001: Revision CNS 4
Enteric = gut: third arm of ANS
Most organs are innervated by both SNS and PNS (have both input) = can change the
way organs behave by turning on/off one of the other"
PNS and SNS have nerves coming from different part of SC but to the same organs/
tissues = so all organs/tissues are connected to both SNS and PNS and can affect how
they behave by turning off one of the other (PNS/SNS) during an injury to certain region of
spinal cord"
Sympathetic trunk = intercommunication"
THORACO-LUMBAR nerves come out of here"
- Ganglia (between two autonomic neuron) CLOSER to spinal cord"
Longer postganglionic"
Shorter preganglionic"
Vagus control"
-Heart, lungs, most of intestines"
Ganglia nearer to organ!
-They all act independently, don't have intercommunication"
Spinal injuries:
-loss of functions depending on which part of spinal cord injured"
Sympathetic trunk:
-communication between groups of sympathetic neurones and nerves"
-= more coordinated response "
-= because when one of them turns on, it kinda bleeds through to other axons "
-= more coordinated response"
Nerve recording of a heart:
-electrical messages jump from heart cells to the next joined by gap junctions"
-one electrical message = one heart beat -> distance between the electrical messages"
-they stimulate (start AP) nerves (depending if SNS or PNS, it will increase/decrease in
HR respectively) artificially with electrodes"
When exercise:
-SNS kicks in, when resting, PNS kicks in"
Document Summary
Most organs are innervated by both sns and pns (have both input) = can change the way organs behave by turning on/o one of the other. Ganglia (between two autonomic neuron) closer to spinal cord. They all act independently, don"t have intercommunication. Loss of functions depending on which part of spinal cord injured. Communication between groups of sympathetic neurones and nerves. = because when one of them turns on, it kinda bleeds through to other axons. Electrical messages jump from heart cells to the next joined by gap junctions. One electrical message = one heart beat -> distance between the electrical messages. They stimulate (start ap) nerves (depending if sns or pns, it will increase/decrease in. Sns kicks in, when resting, pns kicks in. 1 is on more than the other = it is balanced!! More of one of them would then dominate the other, nothing is ever turned o ! Lie down, heart and brain on same plane.
