Anatomy 3 - Anatomy of the Mediastinum Flashcards
Where is the anterior mediastinum located?
Between the sternum and the fibrous pericardium
What is located within the anterior mediastinum of children?
What is the purpose of this?
What happens after puberty?
The thymus
A gland/ lymphoid organ that produces T Lymphocytes in childhood
It involutes and becomes replaced by adipose tissue
What clinical conditions can affect the thymus gland? (3)
Thymoma
Thymic carcinoma
Lymphoma
What is located within the middle mediastinum?
The pericardium
Heart
Parts of the great vessels that connect with the heart
Where does the azygous vein drain blood to?
From the intercostal veins to the SVC
What nerves can be seen on the posterior mediastinum?
Vagus nerves
Sympathetic chains/ trunks
What level is the dividing point between the inferior and superior mediastinum?
Sternal angle
What part of the mediastinum is the trachea located in?
The superior mediastinum
What part of the aorta lies in the posterior mediastinum?
The thoracic aorta
How do the vagal trunks pass through the diaphragm?
With the oesophagus onto the stomach
On what side of the vertebrae does the azygous vein run?
Right anterior surface
Where does the azygous vein arch to drain into the lung root?
Superior to the lung root
What does the right lymphatic duct drain?
into the right venous angle
Where does the thoracic duct drain?
Into the left venous angle
What lymph nodes surround the main bronchus at the lung root?
The bronchopulmonary lymph nodes (hilar lymph nodes)
What lymph nodes surround the bifurcation of the trachea?
The trachea-bronchial lymph nodes
What pulmonary lymph nodes does the lymph drain first to?
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
What is one break of the rule regarding drainage of lymph from the lungs?
in some patients the lymph from the left inferior lobe drains into the right lymphatic duct
What hiatus is anterior in the diaphragm?
IVC hiatus
Oesophageal hiatus
Aortic hiatus is posterior
What is the name of the swollen start of thoracic duct in the abdomen?
Cisterna chyli
How does the vagus nerve pass through the diaphragm?
Along with the IVC to supply the diaphragm from the inferior part
How does the vagus and phrenic nerves sit in relation to the root of the lung?
Vagus = posterior Phrenic = anterior
Where do the recurrent laryngeal branches branch from?
The vagus nerves
What do the recurrent laryngeal nerves supply?
All the intrinsic muscles of the pharynx except from the cricothyroid muscles
What is the ligemanetum arteriosum a remnant of?
The ductus arteriosus
Where does the left recurrent laryngeal branch hook under?
The ligamentum arteriosum (under the arch of the aorta)
What are the structures of the superior mediastinum from anterior to posterior and then from lateral to medial?
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
What are the central veins defined as?
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)
What are the central veins?
Internal jugular veins Subclavian veins Brachiocephalic veins superior vena cava Inferior vena cava iliac veins Femoral veins
What causes the double pulsation characteristic of the JVP?
Atrial contraction then filling of the right atrium against a closed tricuspid valve
In what central vein is the JVP observed in?
The internal jugular vein
At 45 degrees, what should the JVP be no more than?
3cm superior to the sternal angle
Does the right recurrent laryngeal nerve enter the chest?
No, it hooks under the right subclavian artery
Does the left recurrent laryngeal nerve enter the check?
Yes, it hooks under the arch of the aorta
How can a liver abscess cause referred pain on the tip of the shoulder?
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
What type of axons does the vagus nerves contain?
Somatic sensory nerves
Somatic motor nerves
Autonomic parasympathetic nerves
Where does the vagus nerve provide somatic sensory nerves for? (3)
the palate, laryngopharynx and larynx
Where does the somatic motor nerves from the vagus nerve supply? (2)
Pharynx
Larynx
Where does autonomic parasympathetic nerves from the vagus nerve supply?
The thoracic and abdominal organs
What is the name of the branch of the vagus nerve which supplies the pharynx and larynx?
Recurrent laryngeal nerves
Once the vagus nerves have given off their recurrent laryngeal branches, what type of fibres do they contain?
Parasympathetic fibres
What is the name of a superficial vein of the upper limb?
Cephalic vein
What artery is the pulse in the neck felt over?
The bifurcation of the common carotid artery
