Flashcards in Lecture 2 RH Deck (26)
What are the types of neurones (muh freedom) in the parasympathetic nervous system?
2 neurons in parasympathetic nervous system. A preganglionic neurone and a post ganglionic neurone. Post ganglionic neurone is found in the target tissue.
How do parasympathetic preganglionic neurons travel to the upper abdominal viscera?
Through the vagus nerve
How do sympathetic nerves travel?
Originate in lateral horn and leave spinal cord through ventral roots through preganglionic roots to postganglionic neurone. The synapse between pre and post ganglionic neurons occur near spinal cord.
What is interesting about some viscera's sympathetic innervation?
in some abdominal viscera some preganglionic neurones travel through the sympathetic trunk through ganglia without synapsing and instead synapse at the target organs.
What does the grey communicating ramus contain?
Grey ramus contains post ganglionic neurons. It is more proximal
What does the white communicating ramus contain?
White communicating ramus is distal and contains preganglionic neurones (too much peanut butter and jelly).
What happens to preganglionic neurones before exiting the sympathetic trunk?
preganglionic neurons can synapse with other preganglionic neurons and then can travel up the sympathetic trunk to the viscera of the head.
Synapse with postganglionic neurons and travel to thoracic viscera
continue through the trunk and synapse with the postganglionic neurons at the target tissue.
What is the function of visceral afferent neurons?
Provide sensory information from viscera.
Sense distension of viscera.
Cause sensing of visceral pain.
How do visceral afferent neurons reach the CNS?
They typically follow sympathetic pathways to the CNS.
They can also follow parasympathetic pathways to the CNS.
This is the reason for feeling referred pain.
What causes referred pain?
visceral pain is cause by the convergence of 2 inputs of a population of neurons at a given spinal segment.
What kind of ribs are there and which ones are they?
Ribs 1 - 7 are considered true.
Ribs 8 - 10 are considered false (They do not connect to the sternum)
Ribs 10 and 12 are considered floating (have no connection at costal cartilage)
What are the features of typical ribs?
typical ribs (ribs 3 - 9) have angles(posterolaterally), a head, neck, articular facet, and shaft. At its costal end it has costal cartilage.
Typical ribs have a costal groove for nerves and blood vessels to pass through protected.
What does the sternum look like?
sternum is angled with many attachment sites for ribs.
What structures on vertebrae articulate with ribs?
Each thoracic vertebra has a superior and inferior demifacet for the head of a rib.
Which vertebral structure articulates with the rib of the same number?
inferior demifacet articulates with rib of same number, and the transverse process
What is the function of the costal facet?
costal facet on vertebra articulates with ribs at articular facet.
What motion is allowed at the thoracic vertebrae?
Thoracic vertebra mainly permit rotation.
What are the 3 layers of the costal muscles?
External intercostal muscles run anteroinferiorly (front pocket muscles). They attach to costal cartilage via a membrane.
Internal intercostal muscles run through entire length of intercostal space and run opposite to the external intercostal muscles
Innermost intercostal muscles. Broken up and deficient posteriorly allowing visualization of blood vessels and nerves.
What do internal intercostal muscles do?
They do the opposite of external intercostal muscles and depress the thoracic cage during expiration.
What do external intercostal muscles do?
They raise and expand the thoracic cage during inspiration.
Where do the intercostal vein, artery, and nerve run?
between innermost and internal intercostal muscles. Under the costal groove.
Where do intercostal nerves originate from?
Each intercostal nerve is an extension of each spinal cord segment.
What do intercostal nerves innervate?
intercostal muscles and gives off branches laterally and anteriorly to the skin. Making it easy to determine dermatomes.
What are some landmarks to remember dermatomes?
T4 where the nipples
T10 incorporates umbilicus (belly button)
Where does blood supply come from for intercostal arteries?
Thoracic aorta supplies intercostal arteries. There is an anastomoses with the anterior intercostal artery.