Respiratory Anatomy - Thorax Flashcards
Describe what the thoracic inlet is bounded by
First thoracic vertebrae posteriorly
First pair of ribs laterally
Costal cartilage of the first rib
Superior border of the manubrium anteriorly
Describe what the thoracic outlet is bounded by
12th thoracic rib posteriorly
11th and 12th pair of ribs laterally
Costal cartilages of ribs 7-10
Xiphisternal joint anteriorly
What level is the sternal angle?
At lower border of T4 vertebrae
What are the 2 grooves on the first rib separated by and what do the grooves hold?
Scalene tubercle
Anterior vein lodges subclavian vein
Posterior groove lodges subclavian artery and lowest trunk of brachial plexus
Describe features of the first rib
First rib is flat and broad, head possesses a single articular facet
Scalene tubercle
Describe some features of a typical rib
Body, costal groove, head with 2 articular facts, Neck, tubercle, and angle
What are the costovertebral joints for the head of the rib?
Head articulates with body of thoracic vertebrae with same number as rib as well as the body of vertebrae above
What type of joints are the costovertebral joints?
Synovial plane joints
What is the costovertebral joint of the tubercle of the rib?
Tubercle articulates with the transverse process of the thoracic vertebrae of same number as rib
This is a costotransverse joint - synovial plane
What are the 3 intercostal muscles of the thorax?
External, Internal and innermost
Between which of the intercostal muscles do the intercostal vein, artery and nerve lie?
Between internal and innermost intercostal muscles
Describe the arterial supply of the thoracic wall
Posterior intercostal arteries (mainly descending aorta)
Anterior intercostal arteries (branches of internal thoracic artery) and branches of axillary arteries
Describe the venous drainage of the thoracic wall
Azygous, hemiazygos accessory venous system and internal thoracic veins
Describe the lymphatic drainage of the thoracic wall
Left side drains to thoracic duct then to left subclavian vein
Right side drains to right lymphatic duct to right subclavian vein
Describe the lymphatic drainage of the breasts
Drain to axillary LN, then parasternal LN, and then abdominal LN
Where is the transverse thoracic plane?
Between T4 and T5 vertebrae
What are the 3 peripheral attachments of the diaphragm?
Lumbar vertebrae and arcuate ligaments, costal cartridges of ribs 7-12 and xiphoid process of the sternum
What is the central attachment of the diaphragm?
Central tendon
What are the left and right crura?
The parts of the diaphragm that arise from the vertebrae are tendinous in structure
Where is the right crus?
Arises form L1 to L3
Some fibres of right crus surround the oesophagus opening and help prevent reflux of gastric contents into the oesophagus
Where is the left crus?
Arises from L1 to L2 and their intervertebral discs
What is the primary muscle of inspiration?
Diaphragm
Describe diaphragm movement during inspiration and expiration?
Diaphragm contracts (flattens) and increases thoracic volume
Diaphragm relaxes and decreases thoracic volume
What are the 3 hiatuses of the diaphragm?
The caval opening
The oesophageal hiatus
The aortic Hiatus
At what level is the caval opening and what passes through?
T8
Passes through central tendon of the diaphragm
Transmits the inferior vena cava
What level is the oesophageal opening and what passes through?
T8
Located through muscular sling of the right crus
Transmits oesophagus and both vagus nerves
What level is the aortic opening and what passes through?
T12
Between the left and right crus
Transmits the aorta, azygos vein, hemiazygos vein and the thoracic duct
What are the nerve roots of the phrenic nerve?
Anterior rami of C3-C5 (mainly C5)
Is both motor and sensory
What are the motor function of the phrenic nerve?
Pierces and innervates the diaphragm
What are the sensory functions of the phrenic nerve?
Supplies the central part of the diaphragm
What is the sensory innervation of the diaphragm?
Phrenic nerve supplies central part
Intercostal nerves T7-T12 supply peripheral portion of the diaphragm
