The spinal cord and Autonomic nervous system Flashcards
What does the sympathetic nervous system refer to? Autonomic nervous system and its branches?
Sympathetic nervous system: peripheral nervous system which is associated with voluntary movement of skeletal muscle.
Autonomic nervous system: part of the nervous system which is associated with involuntary control.
What is a ganglia in the PNS?
A collection of cell bodies.
Where are the two enlargements of the spinal cord and why?
Where does the spinal cord extend to?
The cervical and lumbosacral area because this is where major plexuses are formed.
L1-L2
What is the name of the connective tissue which connects the bottom of the cordae tendinae to the coccyx?
The filum terminale
Name each of the arrows (hint: name the layers of the spinal cord).
What areas of the spinal cord are associated with what?
What are the columns associated with?
Ascending and descending nerve tracts.
What is a mixed spinal nerve ‘made out’ of?
Anterior/ventral root which is purely made from motor neurons.
The dorsal root will be purely made from sensory neurons.
What is the purpose of the dorsal spinal ganglion?
Cell bodies for sensory neurons.
What is the word for the area that are the arrows showing?
Segments : A segment of the spinal cord.
What areas of the body do the anterior and posterior ramus supply?
What are the different sizes of these?
Posterior ramus=intrinsic back muscles (such as erector spinalus).
Anterior ramus=everything else (the anterior ramus is MUCH bigger than the posterior ramus).
Explain how the sympathetic ganglia work?
Sympathetic fibres originate from the lateral horn, travel through the mixed nerve, then enters the white ramus communicans where it synapses. It will then connect to the grey ramus communicans where it enters to either the anterior or posterior ramus. This system doesn’t occur with the parasympathetic nervous system.
What are the areas of the spinal cord where the sympathetic and parasympathetic nervous system exit?
Just remember that the sympathetic exit from T1 to L2 (thoracolumbar area)
What are the 4 pathways of a sympathetic preganglionic nerve?
What are the places that a postganglionic sympathetic nerve can enter?
Neurotransmitter released from postganglionic neurons in both the sympathetic and parasympathetic nervous system?
Sympathetic: Noradrenaline mostly and sometimes Ach.
Parasympathetic: Ach.
What is the outermost layer of the meninges?
Middle layer?
Innermost layer?
Explain its function
The dura mater: tough outer layer.
Arachnoid matter: inbetween the arachnoid and the pia are the subarachnoid space which is where the CSF is.
Pia mater: innermost layer which is a thin, vascular membrane which the lateral extensions make the denticulte ligament and the filum terminale.
Where would you insert your needle to do a lumbar puncture; and an epidural anaesthetic?
What lies in the space between L1 and S2?
What is the blood supply to the spinal cord?
Plus venous drainage.
So Arterial supply is from the anterior (1) and 2 posterior spinal arteries. The anterior is from the vertebral artery which is a branch of subclavian and runs in the anterior fissure of the cord, Posterior is from posterior inferior cerebellar a which is a branch of vertebral on the posterior aspect. They are supplemented by radicular a from other sectional arteries.
Veinous drainage is by the veins accompanying these arteries- anterior and posterior spinal veins which leave via the intervertebral formina same as the radicular spinal arteries as they enter in the same area. The spinal veins also communicate with the internal vertebral venous plexuses which communicate with the external vertebral plexus. All These veins drain into veins at various sections of body eg in the lumbar region they drain into lumbar veins.
(see lecture 5 at the bottom).
