Anatomy

Question 1

which 3 nerve types does the cardiac plexus contain?

Answer 1

• sympathetic nerves
• parasympathetic nerves
• visceral afferent nerves

Question 2

where do the sympathetic nerves to the heart come from?

Answer 2

cardiopulmonary splanchnic nerves

Question 3

which route do cardiac visceral afferents follow to get back to the CNS?

Answer 3

the route of cardiopulmonary splanchnic nerves (where the sympathetic nerves go). (Not just sensory afferents, but also REFLEX afferents - from the baroreceptors)

Question 4

what is the sensory route of a sharp prod in the chest (T5 dermatome)?

Answer 4

• skin mechanoreceptors stimulates in T5 dermatome (specifically the ANTERIOR RAMUS (which supplies the anterolateral chest wall) - since it’s the anterior chest wall being prodded)
• AP passes through posterior rootlet (sensory) then synapses with CNS and is propagated centrally
• pain pathway crosses over at spinal cord: prod on right is perceived by left side of brain

Question 5

parietal lobe and frontal lobe are separated by the ___

Answer 5

central sulcus

Question 6

postcentral gyrus of parietal lobe is somatosensory/ somatomotor?

Answer 6

somatosensory

Question 7

postcentral gyrus of frontal lobe is somatosensory/ somatomotor?

Answer 7

somatomotor

Question 8

sources of sharp (somatic) central chest pain?

Answer 8

• Herpes Zoster virus
• muscle, joint, bone
• parietal pleura and fibrous pericardium

Question 9

sources of dull (visceral) chest pain?

Answer 9

• tracheitis
• ruptured aneurysm of aortic arch
• oesophagitis
• angina
• MI
• gastritis
• cholecystitis
• pancreatitis
• hepatitis

Question 10

phrenic nerve is anterior/ posterior to lung root?

Answer 10

anterior

Question 11

vagus nerve is anterior/ posterior to lung root?

Answer 11

posterior

Question 12

path of right vagus nerve?

Answer 12

passes down lateral surface of trachea, ten forms a vagal plexus on oesophagus - and passes down with oesophagus to reach abdomen

Question 13

path of left vagus nerve?

Answer 13

crosses aortic arch, dives deep to form a plexus

Question 14

which range of levels do the visceral afferents from the heart enter the spinal cord?

Answer 14

cervical ganglia and T1-T5 spinal nerves

Question 15

what causes referred and radiating pain?

Answer 15

a lack of precision in route taken by visceral afferents to the spinal cord

Question 16

what is an MI?

Answer 16

irreversible death of part of the myocardium due to occlusion of its arterial blood supply

Question 17

what are the branches of the right coronary artery?

Answer 17

• anterior interventricular artery

- right marginal artery

Question 18

what are the branches of the left coronary artery?

Answer 18

-diagonal (lateral) branch
-circumflex artery
-left anterior descending (LAD)
left marginal artery

Question 19

what are common sites for coronary atherosclerosis?

Answer 19

• RCA
• left (main stem) coronary artery
• circumflex branch
• anterior interventricular branch (LAD)

Question 20

where is the oesophageal plexus?

Answer 20

on the superficial surface of the oesophagus

Question 21

which types of nerves make up the oesophageal plexus?

Answer 21

-parasympathetic nerves from the vagus nerve
-sympathetic nerves from both sympathetic chains)
These nerves innervate the oesophageal smooth muscle, oesophageal arterioles and the mucus glands of the oesophageal mucosa

Question 22

what is the function of the azygous vein?

Answer 22

to drain blood from the intercostal spaces (the intercostal veins drain into the azygous vein) into the SVC (the anterior parts of the intercostal spaces are drained via the internal thoracic/ internal mammary veins).

Question 23

where is the azygous vein?`

Answer 23

it runs up the side of the thoracic vertebral column, and then arches anteriorly, to drain into the SVC

Question 24

what is the thoracic duct? what is its function?

Answer 24

It is the largest lymph vessel in the body. It carries chyle (lymph and emulsified fats) - (if it ruptured into the pleural cavity - would be called a “chylothorax”).
Its function is to collect most of the lymph from the body (apart from from the right thorax, arm, head and neck - which are all drained by the right lymphatic duct) and drain into the systemic circulation at the left venous angle (junction between the left subclavian and left brachiocephalic vein).

Question 25

where is the thoracic duct?

Answer 25

it commences in the superior retroperitoneum, passes through diaphragm via aortic hiatus, ascends through posterior mediastinum at the left side of the azygous vein, posterior to the oesophagus, at level of sternal angle - it passes left towards the left venous angle

Question 26

the thoracic aorta is anterior/ posterior to the lung root?

Answer 26

posterior (and left of the midline)

Question 27

what are the branches of the thoracic aorta?

Answer 27

coronary arteries brachiocephalic trunk LCC artery L subclavian artery bilateral posterior intercostal arteries (1 per intercostal space) branches from the anterior surface (bronchial arteries, oesophageal arteries, mediastinal arteries, pericardial arteries, phrenic arteries)

Question 28

what are the landmarks at the axial plane of the superior/ inferior mediastinum border?

Answer 28

the sternal angle and the T4/T5 vertebrae

Question 29

what makes up the thoracic inlet (outlet)?

Answer 29

ribs 1, T1 vertebrae, jugular notch

Question 30

what structures are the in anterior mediastinum (between sternum and fibrous pericardium)?

Answer 30

thymus (gland/ lymphoid organ producing T lymphocytes in childhood) --> it becomes replaced by fat after puberty

Question 31

what structures are in the middle mediastinum?

Answer 31

``` pericardium heart (parts of great vessels) oesophagus tracheal bifurcation thoracic duct (which lies behind oesophagus) ```

Question 32

what are the structures in the posterior mediastinum?

Answer 32

azgous vein (drains posterior intercostal veins into SVC) sympathetic chains (R and L: has a ganglion at each intercostal space) thoracic duct (between azygous vein and oesophagus) thoracic aorta oesophagus vagus nerves (these descend and form plexuses, they then have vagal trunks passing through diaphragm with oesophagus) trachea and 2 main bronchi

Question 33

what is the aorta called once it passes through the diaphragm?

Answer 33

abdominal aorta

Question 34

what are the bilateral branches from the aorta in the mediastinum?

Answer 34

posterior intercostal arteries

Question 35

what are the anterior branches from the aorta's anterior surface in the mediastinum?

Answer 35

``` bronchial arteries oesophageal arteries mediastinal arteries pericardial arteries phrenic arteries ```

Question 36

what does the right lymphatic duct drain?

Answer 36

the right thorax, right arm, right half of the head | drains into the right venous angle

Question 37

what does the left lymphatic duct drain?

Answer 37

the rest of the body | drains into the left venous angle - between the Left internal jugular and the LSV

Question 38

superficial lymphatics accompany superficial veins. What do deep lymphatics accompany?

Answer 38

deep veins

Question 39

how does lymph drain from the lungs?

Answer 39

right lymphatic duct tracheobronchial lymph nodes thoracic duct (L lymphatic duct) bronchopulmonary lymph nodes

Question 40

where is the cisterna chyli?

Answer 40

found in the abdomen (it's the start of the thoracic duct)

Question 41

what is the path of the R vagus nerve?

Answer 41

it's lateral to the trachea passes onto oesophagus - where it forms the vagal plexus branches vagal trunks - which pass into diaphragm the right recurrent laryngeal nerve (branch of the R vagus) and loops under the subclavian artery)

Question 42

with what structure does the R phrenic nerve pass through the diaphragm with?

Answer 42

the IVC

Question 43

path of the L vagus nerve?

Answer 43

descends and crosses over the arch of aorta passes onto oesophagus and forms part of the vagal plexus and trunk - which passes through to abdomen recurrent laryngeal branch (branch of the left vagus) hooks under the ligamentum arteriosum and also the arch of aorta - then heads back to the larynx

Question 44

what structures are in the superior mediastinum?

Answer 44

``` brachiocephalic veins and SVC arch of aorta trachea oesophagus thoracic duct phrenic nerves vagus nerves recurrent laryngeal branches ```

Question 45

what clinical use are the internal jugular veins and the femoral veins?

Answer 45

they are common access points in central venous cannulation / catheterisation

Question 46

does the R recurrent laryngeal artery enter the chest?

Answer 46

no, it's already branched off the R vagus and hooked back up before reaching the chest

Question 47

what kind of nerves are in the phrenic nerves?

Answer 47

anterior rami of C3, 4 and 5 somatic motor to diaphragm somatic sensory to diaphragmatic parietal pleura, diaphragmatic parietal peritoneum, fibrous pericardium, mediastinal parietal pleura

Question 48

where can pain from the diaphragm be referred to? Why?

Answer 48

``` the shoulder tip phrenic nerve (C3,4,5) supraclavicular nerves (C3,4) So there is overlap - they plug into the spinal cord at the same levels- so brain refers pain to a more superficial structure ```

Question 49

which nerve types does the vagus contain?

Answer 49

CNX somatic sensory for palate, laryngophrarynx and larynx somatic motor for pharynx and larynx autonomic parasympathetic for thoracic and abdominal organs recurrent laryngeal branches (supply larynx and pharynx)

Question 50

what nerve types does the vagus contain after giving off the recurrent laryngeal branches?

Answer 50

parasympathetic nerves only