thoracic regional anatomy

Question 1

what are phrenic nerves formed in

Answer 1

cervical plexus from C3, C4 and C5

Question 2

what do motor phrenic nerves innovate

Answer 2

diaphragm

Question 3

what 4 structures do sensory phrenic nerves innovate

Answer 3

central tendon to diaphragm, mediastinal pleura, pericardium, peritoneum of central diaphragm

Question 4

what phrenic nerve reaches diaphragm

Answer 4

right and left separately

Question 5

what 3 structures does the right phrenic nerve lie on the surface of

Answer 5

right brachiocephalic vein, superior vena cava, right side of heart and pericardium in front of lung root

Question 6

where do vagus nerves lie in relation to common carotids

Answer 6

lateral

Question 7

where does left vagus pass in relation to aortic arch

Answer 7

anterior

Question 8

where does left phrenic cross the vagus in relation to aortic arch

Answer 8

more anteriorly

Question 9

where does left phrenic descend

Answer 9

in front of lung root

Question 10

where does left vagus cross in relation to root lung

Answer 10

behind

Question 11

what does left vagus give off

Answer 11

left recurrent laryngeal nerve

Question 12

where does the left recurrent laryngeal nerve recur around

Answer 12

ligamentum arteriosum and aortic arch

Question 13

where does the left recurrent laryngeal nerve break up into many branches

Answer 13

round oesophagus

Question 14

where does the right vagus nerve lie

Answer 14

on trachea

Question 15

where does right vagus cross in relation to root lung

Answer 15

behind

Question 16

what does right vagus give off

Answer 16

right recurrent laryngeal nerve

Question 17

where does the right recurrent laryngeal nerve recur around

Answer 17

right subclavian artery

Question 18

where does the right recurrent laryngeal nerve break up into many branches

Answer 18

round oesophagus

Question 19

what type of nerve are phrenic nerves

Answer 19

somatic, so no autonomic function or visceral distribution

Question 20

what do phrenic motor fibres supply

Answer 20

skeletal muscle of diaphragm

Question 21

what do phrenic sensory fibres supply

Answer 21

central diaphragm, its plueral covering, mediastinal pleura, pericardium, peritoneum on inferior surfacr of central diaphragm

Question 22

pulmonary plexuses

Answer 22

left vagus nerve, right vagus nerve, anterior pulmonary plexus, posterior pulmonary plexus

Question 23

effect of parasympathetic efferents (vagus) on heart rate and diameter of coronary arteries

Answer 23

decrease heart rate via pacemaker tissue and constrict coronary arteries

Question 24

what do parasympathetic afferents (vagus) relay

Answer 24

blood pressure and chemistry information from heart

Question 25

where does vagus nerve arise from and leave skull through

Answer 25

arises from medulla and leaves skull through jugular foramina

Question 26

where does the vagus nerve descend in the neck

Answer 26

posterolateral to common carotid artery

Question 27

where does left vagus cross

Answer 27

anterior to aortic arch then posterior to left lung root

Question 28

where does right vagus pass

Answer 28

posterior to right lung root

Question 29

where do both vagi form a plexus

Answer 29

round oesophagus

Question 30

what do the vagi separate to form

Answer 30

anterior and posterior oesophageal/gastric nerves

Question 31

what are the branches to chest and abdomen

Answer 31

parasympathetic, with large sensory (enteroceptor) content from gut and lungs

Question 32

difference between parasympathetic and sympathetic

Answer 32

parasympathetic provide no autonomic supply to body wall (e.g. arterioles and sweat glands)

Question 33

recurrent laryngeal branch of vagus nerve

Answer 33

not parasympathetic - runs back up neck to supply most skeletal muscles of larynx

Question 34

vagi in posterior mediastinum

Answer 34

mainly right vagus contributes to oesophageal plexus; nerves also acquire many sympathetic fibres

Question 35

vagi in posterior mediastinum: inferior continuation

Answer 35

posterior oesophageal nerve, taking right vagal fibres through diaphragm to abdominal viscera

Question 36

vagi in posterior mediastinum: left vagus

Answer 36

provides fibres to oesophageal plexus then continues as anterior oesophageal nerve

Question 37

positions of phrenic and vagus nerves and sympathetic trunks in superior mediastinum

Answer 37

slide 42

Question 38

nerves in inferior mediastinum

Answer 38

phrenics (anterior to lung roots), vagi (posterior to lung roots - plexus - follow oesophagus to abdomen)

Question 39

vagus nerves inferior mediastinum

Answer 39

chest and abdomen are parasympathetic; large sensory from gut and airways, recurrent laryngeal nerve not parasympathetic - runs back up neck to supply most skeletal muscles of larynx

Question 40

left vagus

Answer 40

becomes anterior vagal trunk

Question 41

right vagus

Answer 41

becomes posterior vagal trunk