Mediastinum

Question 1

Why do diaphragm have flat muscles unlike othere

Answer 1

Cause inferior vena cava, aorta and oesophagus pass through. If muscles are solid and they contract, could cause constriction of those vessels

Question 2

Boundaries of mediastinum

Answer 2

Superior thoracic inlet
Sternum and costal cartilage
Diaphragm
Thoracic vertebral columns
*Laterally by mediastinal pleura

Question 3

Contents of superior mediastinum

Answer 3

Arch of aorta
Brachiocephalic trunk roots
Oesophagus
Trachea
Thymus
Brachiocephalic vein
Superior vena cava
Phrenic nerve
Vagus 
Thoracic duct and right lymphatic duct

Question 4

Boundaries of anterior mediastinum

Answer 4

Posterior boundary is pericardium
Anterior boundary is body of sternum
Can add trans thoracic plane and diaphragm I suppose

Question 5

Contents of anterior mediastinum

Answer 5

Loose connective tissue and fat
Thymus
Lymph nodes

Question 6

Contents of middle mediastinum

Answer 6

Mostly pericardium
Ascending aorta, superior vena cava, pulmonary trunk
Phrenic nerve laterally
Lymph nodes
Tracheal bifurcation and main bronchi

Question 7

Mediastinal pleura and pericardium are supplied by

Answer 7

Phrenic nerve

Question 8

Posterior mediastinum boundaries?

Answer 8

Anteriorly by bifurcation of trachea, pulmonary vessels, pericardium and upper surface of diaphragm

Posteriorly by t5 to t12 vertebrae

Laterally by mediastinal pleura

Question 9

Contents of the posterior mediastinum?

Answer 9

Descending thoracic aorta
Azygos, hemizygos and accessory azygos veins
Right and left sympathetic chains, splanchnic nerves(branches of sympathetic chain) and left and right vagi nerves
Oesophagus
Thoracic duct
Posterior mediastinal lymph nodes

Question 10

Descending thoracic aorta lies in which side of thoracic vertebrae and inferior vena cava lies on which side?

Answer 10

Left and right

Question 11

Which part of diaphragm does inferior vena cava pass and why?

Answer 11

Pass through central tendon and not muscle bc, blood flows through veins slowly so if it is placed in muscle and it contracts it will prevent backflow of blood and venous return, which will in turn affect cardiac output

Question 12

Length of trachea, diameter, begins, ends?

Answer 12

10cm, 2cm, C6 vertebra, lower border of cricoid cartilage level and ends at the T5 or sternal angle.
Relations. Oesophagus posteriorly, aortic arch anteriorly

Question 13

Which arteries supply the trachea

Answer 13

Bronchial artery, inferior thyroid artery

Question 14

Nerve supply to the arteries?

Answer 14

Vagus supply mucosa, sympathetic chain supply smooth muscle structure

Question 15

Thoracid duct receives lymph from the while body except

Answer 15

Right upper limb and right side of the head and the nexk

Question 16

Where does the thoracic duct empty

Answer 16

Junction between left internal jugular vein and left subclavian vein

Question 17

Where do sympathetic and parasympathetic supply of heart come from

Answer 17

Sympathetic supply from sympathetic chain

Parasympathetic supply from vagus nerve

Question 18

Vagus?

Answer 18

Cranial nerve X

Major parasympathetic supply to thoracic and abdominal viscera

Question 19

Course of vagus nerve

Answer 19

Runs parallel to oesophagus and innervate
Passes posterior to root of lung on each side
Pierces diaphragm with oesophagus

Question 20

Course of 9hrenic nerve

Answer 20

Arises from central rami of C3-C5. C4 majorly

Passes anterior pulmonary root on each side. Only nerve to do that

Question 21

Phrenic nerve supplies?

Answer 21

Pericardium, mediastinal pleura, pleura and peritoneal coverings of diaphragm

Question 22

What are mediastinal shifts?

Answer 22

Shifting of organs and tissues of mediastinum to one side of the chest
Note that increased volume of air causes mediastinum to shift to opposite side
Fibrosis or tumour makes lung heavier and pushes mediastinum towards ir

Question 23

Haemothorax

Answer 23

Haemothoraxrefers to a collection of blood within the pleural cavity.

Question 24

Cardiac tamponade?

Answer 24

Accumulation of fluid in the pericardiuma round the heart causing it to work harder and enlarge as a result

Question 25

Pneumothorax?

Answer 25

A collapsed lung.

This condition occurs when air leaks into the space between the lungs and chest wall.

Question 26

Pleural effusion?

Answer 26

A build-up of fluid between the tissues that line the lungs and the chest.

Fluid can accumulate around the lungs due to poor pumping by the heart or by inflammation

Question 27

Pyothorax?

Answer 27

Pyothoraxrefers to the presence of inflammatory fluid or pus within the chest cavity, which is the area between the lungs and the inner walls of the ribs.

Question 28

Phrenic nerve accompanied by

Answer 28

Pericardiacophrenic arteries