11. Neurology

Question 1

describe the makeup of the esophagus

Answer 1

• internal circular layer + external longitudinal layer

- upper ⅔ is both smooth and skeletal muscle

Question 2

what landmarks define the thoracic region of the esophagus

Answer 2

T1 → esophageal hiatus

Question 3

what are the 4 constriction points of the esophagus

Answer 3

• Upper esophageal sphincter (cricopharyngeus muscle)
• Aortic arch
• Left bronchus
• Lower esophageal sphincter (esophageal hiatus of thoracic diaphragm)

Question 4

describe the course of the vagus nerve and where branch points are

Answer 4

superior thoracic aperture (L laryngeal, pulmonary and inferior cardiac branches)
→ posterior mediastinum (esophageal branches)
→ proximal to abdomen (anterior and posterior vagal trunk)

Question 5

what structures does the L recurrent laryngeal branch loop under to return to the larynx

Answer 5

under aortic arch and ligamentum arteriosum

Question 6

which nerve branch is derived from the L vagus nerve?

R vagus nerve?

Answer 6

L: anterior vagal trunk

R: posteRioR vagal trunk

Question 7

describe the course of the phrenic nerve

Answer 7

superior thoracic aperture

→ between mediastinal parietal pleura and fibrous pericardium

Question 8

what does the phrenic nerve innervate

Answer 8

• diaphragm

- sensory info from central diaphragmatic and mediastinal pleura and pericardium

Question 9

which intercostal nerves are typical

Answer 9

3-6

• Rami communicantes
• Collateral branches
• Lateral cutaneous branches
• Anterior cutaneous branches
• Muscular branches (supply intercostal ms, subcostal ms, and transversus thoracis)

Question 10

rami communicantes connects what

Answer 10

intercostal nerve to sympathetic trunk

Question 11

where are the collateral branches of typical intercostal ns found

Answer 11

superior edge of rib inferior to the intercostal space

Question 12

what do the lateral cutaneous branches of typical intercostal ns become?

innervate?

Answer 12

become anterior and posterior branches

supply skin of thoracic wall
T4-6 breast

Question 13

what do the anterior cutaneous branches of typical intercostal ns supply

Answer 13

anterior aspect of thoracic wall

T4-6 breast

Question 14

what do the muscular branches of typical intercostal ns supply (3)

Answer 14

• intercostal muscles
• subcostal muscles
• transversus thoracis muscle

Question 15

which intercostal nerves are atypical

Answer 15

1, 2, 7-11

Question 16

what is significant about the 1st atypical intercostal nerve

Answer 16

1st: no cutaneous branches, majority of superior portion joins brachial plexus

Question 17

what is significant about the 2nd atypical intercostal nerve

Answer 17

• travels in costal groove as a typical n w/ small part joining brachial plexus,
• lateral cutaneous branch supplies skin and subcutaneous tissue of axilla (INTERCOSTALBRACHIAL N .)

Question 18

what is significant about the 7-11th atypical intercostal nerves

Answer 18

• begins as intercostal but as they travel anteriorly

- run out of ribs and transition to THORACOABDOMINAL N.

Question 19

general principles of ANS

• sympathetic stimulation is usually ___
• parasympathetic stimulation is usually ___

Answer 19

S: catabolic
PS: anabolic (normal fxn, conserve energy)

Question 20

general principles of ANS

• ___ system distributes to all vascular area of the body
• ___ has a limited distribution (head, neck, and trunk viscera, never ___

Answer 20

• sympathetic

- parasympathetic, never in body wall or extremities

Question 21

general principles of ANS

• glandular secretion is stimulated by ___; except ___
• ___ can indirectly decrease non sweat gland glandular secretion through ___

Answer 21

• parasympathetic, except sweat glands

- sympathetic, vasoconstriction

Question 22

vasoconstriction of what arteries is not under sympathetic control

Answer 22

coronary a

***PS control via cardiac plexus

Question 23

what region is the sympathetic system found

Answer 23

thoracolumbar T1-L2

Question 24

describe presynaptic sympathetic fibers

• length
• cell bodies
• course

Answer 24

• short
• CBs in lateral horns of spinal cords
• always travel in anterior root into anterior ramus
• quickly exit anterior ramus into PARAvertebral ganglion

Question 25

describe post synaptic sympathetic fibers

Answer 25

- long | - CBs in paravertebral or prevertebral ganglia

Question 26

describe paravertebral vs prevertebral ganglia

Answer 26

PARA: linked vertically to form sympathetic trunk BL to vertebral column; 3 ganglia also exist in C/L/P regions PRE: ganglia and corresponding plexuses surround the main unpaired branches of abdominal aorta (celiac, superior mesenteric, aorticorenal, inferior mesenteric)

Question 27

what 3 options do presynaptic sympathetic fibers in the thorax have after entering paravertebral ganglia

Answer 27

- synpase on postsynaptic neuron of same level - ascend or descend to synapse on postsynaptic neuron of different level - exit without synapsing, become an abdominopelvic splanchnic nerve and head to postsynaptic neuron in prevertebral ganglion

Question 28

what are the 3 main sympathetics in the thorax

Answer 28

- thoracic sympathetic trunk - cardiopulmonary splanchnic nerves (cardiac and pulmonary branches) - abdominopelvic splanchnic nerves

Question 29

what happens in the thoracic sympathetic trunk

Answer 29

presynaptic sympathetic nerve fibers synapse on postsynaptic cell bodies

Question 30

where are the CBs of the cardiac splanchnic nerve? where do they synapse? where are fibers sent?

Answer 30

- CB at T1-5/6, - synapse in cervical and thoracic sympathetic trunks - → superficial and deep cardiac plexuses

Question 31

where are the CBs of the pulmonary splanchnic nerve? where do they synapse? where are fibers sent?

Answer 31

- CB at T2-3, - synapses in thoracic sympathetic trunk - → pulmonary plexus

Question 32

describe the course of the abdominopelvic splanchnic nerves

Answer 32

thoracic sympathetic trunk → prevertebral ganglia in abdomen

Question 33

where does the greater splanchnic nerve arise from? where does it send its fibers?

Answer 33

T5- 9/10 → esophageal plexus and celiac ganglion (plexus)

Question 34

where does the lesser splanchnic nerve arise from? where does it send its fibers?

Answer 34

T10/11 → celiac and superior mesenteric ganglion (plexus)

Question 35

where does the least splanchnic nerve arise from? where does it send its fibers?

Answer 35

T12 → aorticorenal ganglion

Question 36

what is responsible for parasympathetic innervation to the thorax and what structures are innervated

Answer 36

- vagus nerve | - lungs, bronchi, pleurae, heart, and pericardium

Question 37

what are the branches of the vagus nerve

Answer 37

- superior, middle and inferior cardiac branches - pulmonary branches - esophageal branches

Question 38

which branches of the vagus nerve originate in the neck and descend through the superior thoracic aperture and join the cardiac splanchnic n. to form the cardiac plexus?

Answer 38

neck: superior and middle cardiac branches

Question 39

which branches of the vagus nerve originate in the thorax and what do they form?

Answer 39

- inferior cardiac branch, forms cardiac plexus w/ cardiac splanchnic n. - pulmonary branch, forms pulmonary plexus with pulmonary splanchnic n.

Question 40

after producing pulmonary branches, what happens to the vagus nerve?

Answer 40

becomes indistinguishable from esophageal plexus that covers inferior 2/3 of esophagus

Question 41

what provides sympathetic stimulation to the pulmonary plexus? what effect does it have (3)?

Answer 41

- pulmonary splanchnic nerves | - bronchodilator; vasoconstrictor; inhibits glands

Question 42

what provides parasympathetic stimulation to the pulmonary plexus? what effect does it have (3)?

Answer 42

- pulmonary branches of vagus nerve | - bronchoconstrictor; vasodilator, stimulates glands

Question 43

what provides sympathetic stimulation to the cardiac plexus? what effect does it have (3)?

Answer 43

- cardiac splanchnic nerves | - increases HR and force of contractions, vasomotor to pericardium

Question 44

what provides parasympathetic stimulation to the cardiac plexus? what effect does it have (3)?

Answer 44

- superior, middle and inferior cardiac branches of vagus nerve - decreases HR and force of contractions, vasoconstrictor to coronary arteries

Question 45

where would you find the superficial and deep cardiac plexuses?

Answer 45

superficial: covers anterior surface of aorta deep: anterior to bifurcation of trachea, posterior to aortic arch and superior to bifurcation of pulmonary trunk

Question 46

the superficial cardiac plexus is continuous with what?

Answer 46

aortic plexus | - continues into abdomen feeding into intermesenteric plexus

Question 47

what provides sympathetic stimulation to the pulmonary plexus? what effect does it have (2)?

Answer 47

- greater splanchnic nerve | - inhibits peristalsis and glands

Question 48

what provides parasympathetic stimulation to the pulmonary plexus? what effect does it have (2)?

Answer 48

- esophageal branches of vagus nerve | - stimulates peristalsis and glands