Lecture 4: Autonomic Nervous System Flashcards
Label an axon slide 4
Ya
Understand how the extension of the meninges envelop the peripheral nerves. Name which meninges surround what part of the nerve.
Dura mater becomes epineurium
Arachnoid mater becomes perineurium
Pia mater becomes endoneurium
The diameter of a nerve fibre is correlated with its function
Slide 5
What forms the sheath around axons in the CNS?
What forms the sheath around the axons in the PNS?
CNS = oligodendrocytes PNS= Schwann cells
What is multiple sclerosis?
Oligodendrocytes are damaged but shwann cells are not
Ie peripheral myelin sheath remain in tact while central myelin sheaths degenerate
Describe the autonomic nervous system
Refer to slide 10
The ANS consist of motor fibres that stimulate involuntary smooth muscle, cardiac muscle and glands.
What are each of the types of neurons for each function ie refer to slide 11
Ya
What is the 2 divisions of the autonomic nervous system, and how are they different?
And what are they concerned with?
Sympathetic and parasympathetic. They are divided by their location of pre-synaptic cell bodies and ganglia. They are concerned with involuntary processes (heart rate, respiration, digestive processes etc
Memorise the table on slide 14
Do it
All sympathetic and parasympathetic nerves contain both general and visceral afferent SENSORY and general visceral efferent MOTOR fibres true or false?
True
Genera visceral afferent (sensory) -mostly sympathetic mediate visceral reflexes ie gag reflex and organic sensations. True or false?
True
Wear is the pre-synaptic cell bodies of the sympathetic NS?
What does its stimulation prepare the body for?
in the lateral horn of grey matter of T1-L12
The para vertebral ganglia in the sympathetic trunk
Stimulation prepares the body for fight or flight
List some of the sympathetic NS activity?
Contracts pupils Reduces secretions from lacrimal and salivary glands Increases heart rate and cardiac output Relaxes bronchial muscles Dilates or constricts skeletal muscle? Constricts arteries to skin and viscera Reduces gut motility and secretions Sphincters contract Relaxes gallbladder Increases secretions from sweat glands
Where are the pre-ganglionic sympathetic neurons for the entire body?
In the interomediolateral cell collumn. Lies between segments T1-L2
What is the course for the pre-synaptic sympathetic motor fibres?
4 pathways:
1. Ascend and then synapse
2. Synapse at same level
3. Descend and then synapse
4. Pass through and continue on through abdominopelvic splanchnic nerve.
They synapse in para vertebral or pre vertebral ganglia
Visceral efferent motor fibres
Axons leave spinal cord through anterior (motor) root
Enter anterior rami of spinal nerves (T1-L2)
Enter into white rami communicantes and pass into sympathetic trunk
4 possible courses (same level, up, down, through)