Respiratory Anatomy 1.2 Flashcards
What are the external intercostal muscles replaced with anteriorly?
External intercostal membranes
What are the internal intercostal muscles replaced with posteriorly?
Internal Intercostal membrane
Where do innermost muscles exist?
Only in the middle of the thoracic cage.
What is the arterial supply of this thoracic wall?
Posterior intercostal arteries which are a branch of the descending thoracic aorta. Anterior intercostal arteries are a branch of the internal thoracic arteries which are a branch of the subclavian artery. It is also suppled by branches from axillary arteries.
What is the venous supply of this thoracic wall?
The azygous vein which drains into the superior vena cava.
Accessory hemiazygous vein and hemiazygous vein which both drain into azygous vein
Internal thoracic vein which drains into the subclavian vein which all go the vena cava superior to the right atrium.
What is the lymphatic drainage of the thoracic wall?
Right side of the chest drains into the right lymphatic duct which drains into the right subclavian vein.
Left side of the chest drains into the thoracic duct which drains into the angle between the subclavian vein and the internal jugular vein
Breast drains into the axillary lymph nodes, parasternal lymph nodes and abdominal lymph nodes.
What is a dermatome?
Area of the skin supplied by a single spinal nerve.
How may pairs of spinal nerves are supplied to the thoracic wall?
12
What is a myotome?
A single spinal nerve that supplies a muscle.
What is the cavity in the middle of the thorax called?
Mediastinum
What can the mediastinum be divided into?
Superior and inferior
What 3 sections can be the inferior mediastinum be divided into?
Anterior, middle and posterior.
What does the mediastinum contain?
It contains the heart , vessels, oesophagus, thymus and lymph nodes.
What splits the thoracic cavity?
Pericardial sac
What covers the mediastinum?
It’s covered by the mediastinal pleura
What is the diaphragm?
Fibro-muscular septum
What does the diaphragm do?
It separates the thoracic cavity from the abdominal cavity.
Where are the three attachments of the diapragm?
Lumbar vertebrae
Costal cartilages of rib 7 to 12
Xiphoid process of sternum
Where is the central attachment?
Cetral tendon of the diaphragm which is attached to fibrous pericardium
What are crura?
They are the right and left part of the diaphragm that arise from the vertebrae and are tendinous in nature
Where does the right crus arise from?
L1 - L3
Where do some of the fibres of the right crura surround?
the oesophageal opening and help prevent reflux of gastric contents back into the oesophagus.
Where does the left crus arise from?
L1 - L2 and their intervertebral discs
What are the three openings of the diaphragm?
The caval opening
The oesophegeal hiatus
The aortic hiatus
Where is the caval opening located?
T8
Where is the oesophagus hiatus?
T10
Where is the aortic hiatus located?
T12
What does the vena caval opening pass through?
The central tendon
What does the vena caval opening transmit?
inferior vena cava and the right phrenic nerve.
What does the oesophageal opening pass through
muscular sling of the right crus
What does the oesophageal opening pass through?
It passes through the oesophagus and the vagus nerve.
What does the aortic hiatus pass through?
between the right and left crus
What does the aortic hiatus pass though?
aorta, the azygous vein, the hemiazygous vein and the thoracic duct.
What innervates the diaphragm?
The phrenic nerve
How many phrenic nerves are there?
2
Where do the phrenic nerves pass through?
In front of the hilium on the sides of the heart.
Is the phrenic nerve a mixed nerve?
Yes (both motor and sensory)
What are the roots of the phranic nerve?
C3 - C5
What are the sensory functions of the phranic nerve?
Supply the central part of the diaphragm
What are the innervations of peripheral portions of the diaphragm?
Sensory fibres of intercostal nerves T7-T12
What will happen if the right phrenic nerve is damaged?
Right dome will be paralysed and it goes upwards instead of downwards becasue the active part will contract and go down and will push the abdominal viscera to the other side so the paralysed part will go higher instead of lower.
