Oesophagus, heart and mediastinum exam

Question 2

Describe the blood supply and lymphatic drainage of the oesophagus

Answer 2

Arterial supply:
–> upper 1/3rd: Inferior thyroid artery (thyrocervical trunk)
–> middle 1/3rd: Branches of descending thoracic aorta
–> lower 1/3rd: Branches from left gastric artery, inferior phrenic artery

Venous drainage
–> Upper 1/3rd: inferior thyroid vein
–> Middle 1/3rd: Azygous vein
–> lower 1/3rd: oesophageal branches left gastric vein

Lymphatic drainage:
–> upper 1/3rd: deep cervical nodes
–> Middle 1/3rd: superior and posterior mediastinal nodes
–> lower 1/3rd: Left gastric nodes and coeliac plexus

Question 3

Describe the musculature of the oesophagus

Answer 3

-Upper 1/3rd: striated
-MIddle 1/3rd: mixed
-Lower 1/3rd: smooth

Question 4

Answer 4

Question 5

What is the anatomical mechanism that normally prevents gastro-oesophageal reflux?

Answer 5

Lower oesophageal sphincter: functional sphincter which is a high pressure zone ~2-5cm

-Angle of his: oesophagus enters stomach at acute angle
-Phreno-oesophageal ligament which encircles gastro-oesophageal junction
-Prominent mucosal folds at gastro-oesophageal junction
-Increase in intra-abdominal pressure causes compression of abdominal part of oesophagus

Question 6

What type of diaphragmatic hernias do you know of?

Answer 6

Congenital
-Bochdalek
-Morgagni

Aquired

Hiatus hernia
–> sliding
–> rolling

Question 7

Risk factors for hiatus hernia

Answer 7

-Age related degeneration

Chronically raised intra-abdominal pressure
–> coughing
–> obesity
–> pregnancy

Question 8

Why is a sliding hiatus hernia a risk factor for gastro-oesophageal reflux?

Answer 8

-Migration of LES into chest results in loss of high-pressure zone. This predisposes pt to GORD

Question 9

What are the constrictions of the oesophagus?

Answer 9

Cricoid cartilage at C5/6 –> 15cm from incisors

Arch of aorta T4/5 –> 22.5cm from incisors

Left principal bronchus –> 27cm from incisors

Diaphragmatic hiatus T10/11 –> 40cm from incisors

ABCD:
-Arch of aorta
-left main bronchus
-Cricoid cartilage
-Diaphragm

Question 10

Answer 10

Question 11

What is the cell lining of oesophagus?

Answer 11

Stratified squamous

Question 12

What is barrett’s oesophagus?

Answer 12

Columnar metaplasia with increased risk of developing adenocardinoma

Question 13

What is achalasia?

Answer 13

-Oesophageal motility disorder involiving the smooth muscle layer of the oesophagus and LES. It is characterised by incomplete LES relaxation, increased LES tone and lack of peristalsis of the oesophagus

Question 14

What is the microscopic picture of achalasia?

Answer 14

-Hypertrophied musculature with the abscence of a myenteric plexus

Question 15

Course of oesophagus

Answer 15

-Originates at level of C6 (inferior border of cricoid cartilage)
-Runs in superior/posterior mediastinum
-Enters abdomen at diaphragmatic hiatus (T10)
-Abdominal part terminates by joining cardiac orifice of stomach at T11

Question 16

How many cusps does the pulmonary valve have?

Answer 16

3

Question 17

What is the vertebral level of the pulmonary valve?

Answer 17

T6

Question 18

Where would you auscultate the valves?

Answer 18

-Pulmonary: 2nd ICS left parasternal edge
-Aortic: 2nd ICS right sternal edge
-Mitral: 5th ICS mid clavicular line

Question 19

What are the tributaries of the azygous vein?

Answer 19

Right handed PM Loves Eating Burgers

-Right superior intercostal vein
-Hemiazygous and accessory hemiazygous
-Pericardial veins
-Mediastinal veins
-Lower right posterior intercostal veins
-esophageal veins
-Bronchial veins

Question 20

What are the branches of the ascending aorta?

Answer 20

-Right and left coronary arteries arising from the aortic sinus opposite the aortic valve

Question 21

Answer 21

Question 22

Answer 22

Question 23

Answer 23

Question 24

Answer 24

Question 25

also13, 19

Answer 25

Question 26

What are the branches of the aortic arch?

Answer 26

-Brachiocephalic (right subclavian, right common carotid)
-Left common carotid
-Left subclavian

Question 27

Describe subclavian steal syndrome

Answer 27

-Retrograde flow of blood down to the vertebral artery due to vertebral artery due to stenosis in the subclavian artery proximal to the vertebral artery
-This will lead to brainstem ischamemia on arm excercise
-symptoms include syncope, neurological deficit eg tinnitus, vascular insufficiency of arm

Question 28

Describe thoracic outlet syndrome

Answer 28

-Compression of the neurovascular bundle (brachial plexus, subclavian artery) between the scalenus medius and scalenus anterior–> neurological and vascular symptoms in the arm

Question 29

How on the skeleton where to put a chest tube

Answer 29

5th intercostal space mid axillary line

Question 30

Why do you get bradycardia after chest tube insertion?

Answer 30

-Due to irritation of the vagus nerve

Question 31

Thoracic inlet and mediastinum

Answer 31

Question 32

What are the boundaries of the posterior mediastinum?

Answer 32

Anterior: pericardium
Posterior: T5-T12 vertebrae
On either side: mediastinal pleura
Floor: diaphragm
Roof: imaginary line extending from sternal angle (T4)

Question 34

Contents superior mediastinum

Answer 34

PVTS Last BATTLE

Phrenic nerve
Vagus nerve
Thoracic ducts
Left recurrent laryngeal
Brachiocephalic vein
Aortic arch
Thymus
Trachea
Lymph node
Oesophagus

Question 35

What are the contents of the posterior mediastinum?

Answer 35

on the DATE Vivian Slapped Larry

Descending thoracic aorta
Azygous/hemiazygous vein
Thoracic duct
Esophagus

Vagus nerve
Splanchnic nerves
Lymphatics

Vessels: thoracic part of descending aorta, azygous and hemiazygous veins

Nerves: Vagus + splanchnic nerves (arising from sympathetic trunk to supply viscera in thorax + abdomen)

Viscera: oesohpagus

Others: Lymph nodes + thoracic duc

Question 36

Tributaries of azygous vein

Answer 36

Right handed PM Loves Eating Burgers

-Right superior intercostal vein
-Hemiazygous and accessory hemiazygous
-Pericardial veins
-Mediastinal veins
-Lower right posterior intercostal veins
-Oesophageal veins
-Bronchial veins

Question 37

Contents of middle mediastinum

Answer 37

-Pericardium
-Heart
-Aortic root
-Arch of azygous vein
-Main bronchi

Question 38

Where do preganglionic fibres of sympathetic trunk come from?

Answer 38

-Corresponding spinal nerves T1-L2

Question 39

What connects the sympathetic trunk to the spinal nerves?

Answer 39

Preganglionic fibres from the spinal nerves and the sympathetic ganglia. Post ganglionic fibres then arise from the sympathetic ganglia and travel to target organs throughout the body.

Question 40

How do sympathetic nerves leave the sympathetic chain?

Answer 40

Through the spinal nerves forming plexuses around blood vessels (cardiac and pulmonary plexuses, greater splanchnic nerve, lesser splanchnic nerve)