Anatomy 3 - Anatomy of the Mediastinum

Question 1

Where is the anterior mediastinum located?

Answer 1

Between the sternum and the fibrous pericardium

Question 2

What is located within the anterior mediastinum of children?
What is the purpose of this?
What happens after puberty?

Answer 2

The thymus
A gland/ lymphoid organ that produces T Lymphocytes in childhood
It involutes and becomes replaced by adipose tissue

Question 3

What clinical conditions can affect the thymus gland? (3)

Answer 3

Thymoma
Thymic carcinoma
Lymphoma

Question 4

What is located within the middle mediastinum?

Answer 4

The pericardium
Heart
Parts of the great vessels that connect with the heart

Question 5

Where does the azygous vein drain blood to?

Answer 5

From the intercostal veins to the SVC

Question 6

What nerves can be seen on the posterior mediastinum?

Answer 6

Vagus nerves

Sympathetic chains/ trunks

Question 7

What level is the dividing point between the inferior and superior mediastinum?

Answer 7

Sternal angle

Question 8

What part of the mediastinum is the trachea located in?

Answer 8

The superior mediastinum

Question 9

What part of the aorta lies in the posterior mediastinum?

Answer 9

The thoracic aorta

Question 10

How do the vagal trunks pass through the diaphragm?

Answer 10

With the oesophagus onto the stomach

Question 11

On what side of the vertebrae does the azygous vein run?

Answer 11

Right anterior surface

Question 12

Where does the azygous vein arch to drain into the lung root?

Answer 12

Superior to the lung root

Question 13

What does the right lymphatic duct drain?

Answer 13

into the right venous angle

Question 14

Where does the thoracic duct drain?

Answer 14

Into the left venous angle

Question 15

What lymph nodes surround the main bronchus at the lung root?

Answer 15

The bronchopulmonary lymph nodes (hilar lymph nodes)

Question 16

What lymph nodes surround the bifurcation of the trachea?

Answer 16

The trachea-bronchial lymph nodes

Question 17

What pulmonary lymph nodes does the lymph drain first to?

Answer 17

The broncho-pulmonary lymph nodes and then to the trachea-bronchial lymph nodes
Lymph will then drain bac tot he right lymphatic duct or thoracic duct

Question 18

What is one break of the rule regarding drainage of lymph from the lungs?

Answer 18

in some patients the lymph from the left inferior lobe drains into the right lymphatic duct

Question 19

What hiatus is anterior in the diaphragm?

Answer 19

IVC hiatus
Oesophageal hiatus
Aortic hiatus is posterior

Question 20

What is the name of the swollen start of thoracic duct in the abdomen?

Answer 20

Cisterna chyli

Question 21

How does the vagus nerve pass through the diaphragm?

Answer 21

Along with the IVC to supply the diaphragm from the inferior part

Question 22

How does the vagus and phrenic nerves sit in relation to the root of the lung?

Answer 22

Vagus = posterior
Phrenic = anterior

Question 23

Where do the recurrent laryngeal branches branch from?

Answer 23

The vagus nerves

Question 24

What do the recurrent laryngeal nerves supply?

Answer 24

All the intrinsic muscles of the pharynx except from the cricothyroid muscles

Question 25

What is the ligemanetum arteriosum a remnant of?

Answer 25

The ductus arteriosus

Question 26

Where does the left recurrent laryngeal branch hook under?

Answer 26

The ligamentum arteriosum (under the arch of the aorta)

Question 27

What are the structures of the superior mediastinum from anterior to posterior and then from lateral to medial?

Answer 27

``` Braciocephalic veins and SVC Arch of aorta and the origin of its 3 branches Trachea Oesophagus Thoracic duct Phrenic nerves Vagus nerves Recurrent laryngeal nerves ```

Question 28

What are the central veins defined as?

Answer 28

Those large veins close enough to the heart such that the pressure within them is said to approximately reflect the pressure within the right atrium (depending on posture)

Question 29

What are the central veins?

Answer 29

``` Internal jugular veins Subclavian veins Brachiocephalic veins superior vena cava Inferior vena cava iliac veins Femoral veins ```

Question 30

What causes the double pulsation characteristic of the JVP?

Answer 30

Atrial contraction then filling of the right atrium against a closed tricuspid valve

Question 31

In what central vein is the JVP observed in?

Answer 31

The internal jugular vein

Question 32

At 45 degrees, what should the JVP be no more than?

Answer 32

3cm superior to the sternal angle

Question 33

Does the right recurrent laryngeal nerve enter the chest?

Answer 33

No, it hooks under the right subclavian artery

Question 34

Does the left recurrent laryngeal nerve enter the check?

Answer 34

Yes, it hooks under the arch of the aorta

Question 35

How can a liver abscess cause referred pain on the tip of the shoulder?

Answer 35

Liver irritates the parietal peritoneum lining the inferior surface of the diaphragm which is supplied by the phrenic nerve (C3, 4, 5) The supraclavicular nerves supply the dermatomes over the shoulder tip and enter the spinal cord at the same levels as the phrenic nerve The brain refers the pain to the more superficial structure = the shoulder tip

Question 36

What type of axons does the vagus nerves contain?

Answer 36

Somatic sensory nerves Somatic motor nerves Autonomic parasympathetic nerves

Question 37

Where does the vagus nerve provide somatic sensory nerves for? (3)

Answer 37

the palate, laryngopharynx and larynx

Question 38

Where does the somatic motor nerves from the vagus nerve supply? (2)

Answer 38

Pharynx | Larynx

Question 39

Where does autonomic parasympathetic nerves from the vagus nerve supply?

Answer 39

The thoracic and abdominal organs

Question 40

What is the name of the branch of the vagus nerve which supplies the pharynx and larynx?

Answer 40

Recurrent laryngeal nerves

Question 41

Once the vagus nerves have given off their recurrent laryngeal branches, what type of fibres do they contain?

Answer 41

Parasympathetic fibres

Question 42

What is the name of a superficial vein of the upper limb?

Answer 42

Cephalic vein

Question 43

What artery is the pulse in the neck felt over?

Answer 43

The bifurcation of the common carotid artery