Lecture 2 RH

Question 1

What are the types of neurones (muh freedom) in the parasympathetic nervous system?

Answer 1

2 neurons in parasympathetic nervous system. A preganglionic neurone and a post ganglionic neurone. Post ganglionic neurone is found in the target tissue.

Question 2

How do parasympathetic preganglionic neurons travel to the upper abdominal viscera?

Answer 2

Through the vagus nerve

Question 3

How do sympathetic nerves travel?

Answer 3

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.

Question 4

What is interesting about some viscera’s sympathetic innervation?

Answer 4

in some abdominal viscera some preganglionic neurones travel through the sympathetic trunk through ganglia without synapsing and instead synapse at the target organs.

Question 5

What does the grey communicating ramus contain?

Answer 5

Grey ramus contains post ganglionic neurons. It is more proximal

Question 6

What does the white communicating ramus contain?

Answer 6

White communicating ramus is distal and contains preganglionic neurones (too much peanut butter and jelly).

Question 7

What happens to preganglionic neurones before exiting the sympathetic trunk?

Answer 7

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.

Question 8

What is the function of visceral afferent neurons?

Answer 8

Provide sensory information from viscera.

Sense distension of viscera.

Cause sensing of visceral pain.

Question 9

How do visceral afferent neurons reach the CNS?

Answer 9

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.

Question 10

What causes referred pain?

Answer 10

visceral pain is cause by the convergence of 2 inputs of a population of neurons at a given spinal segment.

Question 11

What kind of ribs are there and which ones are they?

Answer 11

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)

Question 12

What are the features of typical ribs?

Answer 12

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.

Question 13

What does the sternum look like?

Answer 13

sternum is angled with many attachment sites for ribs.

Question 14

What structures on vertebrae articulate with ribs?

Answer 14

Each thoracic vertebra has a superior and inferior demifacet for the head of a rib.

Question 15

Which vertebral structure articulates with the rib of the same number?

Answer 15

inferior demifacet articulates with rib of same number, and the transverse process

Question 16

What is the function of the costal facet?

Answer 16

costal facet on vertebra articulates with ribs at articular facet.

Question 17

What motion is allowed at the thoracic vertebrae?

Answer 17

Thoracic vertebra mainly permit rotation.

Question 18

What are the 3 layers of the costal muscles?

Answer 18

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.

Question 19

What do internal intercostal muscles do?

Answer 19

They do the opposite of external intercostal muscles and depress the thoracic cage during expiration.

Question 20

What do external intercostal muscles do?

Answer 20

They raise and expand the thoracic cage during inspiration.

Question 21

Where do the intercostal vein, artery, and nerve run?

Answer 21

between innermost and internal intercostal muscles. Under the costal groove.

Question 22

Where do intercostal nerves originate from?

Answer 22

Each intercostal nerve is an extension of each spinal cord segment.

Question 23

What do intercostal nerves innervate?

Answer 23

intercostal muscles and gives off branches laterally and anteriorly to the skin. Making it easy to determine dermatomes.

Question 24

What are some landmarks to remember dermatomes?

Answer 24

T4 where the nipples

T10 incorporates umbilicus (belly button)

Question 25

Where does blood supply come from for intercostal arteries?

Answer 25

Thoracic aorta supplies intercostal arteries. There is an anastomoses with the anterior intercostal artery.

Question 26

What is the internal thoracic artery?

Answer 26

internal thoracic artery (aka internal mammary artery) is a branch of the subclavian artery it runs posterior and lateral to the sternum. It is another anastomosis with the posterior intercostal artery.

*It can often be used for cornary bypass surgery.