Thorax Flashcards
Which vertebra does the suprasternal plane correspond to
T2 posteriorly
Which vertebra does the sternal angle plane correspond to
T4/5 posteriorly
Which vertebra does the xiphisternal plane correspond to
T9 posteriorly
What are intercostal muscles innervated by
Intercostal nerves
What type of joint are intervertebral joints
Symphysis joints
What type of joint are costovertebral joints
Synovial joints
What type of joint are sternocostal joints
1st- primary cartilaginous
2-7- synovial plan joints
What type of joint is a sternoclavicular joint
Synovial
What type of joint is the costochondrial joint
Primary cartilaginous joint
What type of joint is an interchondral joint (adjacent border of 6-7, 7-8, 8+9 costal cartilage)
Synovial joint
Where does the phrenic nerve arise from
C3,4,5 (C345 keeps the diaphragm alive)
What is the course of the right phrenic nerve
Wall of SVC
Along side of fibrous pericardium over right atrium
What is the course of the left phrenic nerve
Over the arch of the aorta and pulmonary trunk
What does the phrenic nerve innervate
Diaphragm, pleura of mediastinum and pericardium
What symptoms does neurogenic thoracic outlet syndrome present with
Pain
Weakness and loss of muscle at base of thumb
What symptoms does venous thoracic outlet syndrome present with
Swelling, pain and blueness of light
What symptoms does arterial thoracic outlet syndrome present with
Pain, coldness and paleness of the arm
Where do internal thoracic arteries run and where does it arise from
Subclavian artery and runs along the anterior side of the ribcage (either side of the sternum)
What does the internal thoracic artery supply
Intercostal muscles in spaces 1-6
What does the internal thoracic artery divide into and what do these supply and run
Superior epigastric artery
Musculophrenic artery (supplies ics 7-9 and lower part of pericardium; also splits into anterior intercostals and pass between internal and innermost intercostal muscles to supply the intercostals, overlying skin, and parietal pleura)
How can you tell if the diaphragm is paralysed and why does this happen
One side is risen up because the R and L phrenic nerves supply different sides of the diaphragm. If the RHS is paralysed, then when the left contracts, the contents of abdomen push up against the diaphragm
What arteries does the subclavian artery give rise to that supply the thoracic wall and what do they supply
Internal thoracic (ics1-6) Supreme intercostal arteries (gives rise to the first and second posterior intercostal arteries, which supply blood to their corresponding intercostal space)
What arteries does the axillary artery give rise to that supply the contents of the thorax and what do they supply
Superior thoracic artery (supplies Serratus anterior)
Lateral thoracic artery (supplies Serratus anterior and breast)
What arteries supply the breast and where do they arise from
Internal thoracic artery (from subclavian)
Lateral thoracic artery and thoracoacromial arteries (from axillary artery)
Lateral mammary branches (from posterior intercostal arteries)
Mammary branch (from anterior intercostal artery)
Where do the veins of the breast drain into
Axillary and internal thoracic veins
Where does the vagus nerve appear from
Between the common carotid artery and internal jugular vein
Course of the right vagus nerve
Runs anterior to beginning of subclavian artery
[gives off right recurrent laryngeal nerve at origin of subclavian artery]
Then forms oesophageal plexus
Course of left vagus nerve
Runs along lateral wall of common carotid artery
Passes between the descending aorta and left pulmonary trunk
[left recurrent laryngeal nerve branches off and loops around the arch of the aorta]
Joins the right vagus nerve to make plexus
Which vagus nerve passes between the descending aorta and left pulmonary trunk
Left
Which vagus nerve gives off a laryngeal nerve which loops around the arch of the aorta
Left
Which vagus nerve runs anterior to the beginning of subclavian artery
Right
Which vagus nerve forms the oesophageal plexus
Both
Why is long lasting hoarseness sometimes a sign of lung cancer
Because laryngeal nerves innervate laryngeal muscles so if there’s a lung tumour there can be pressure on laryngeal nerves causing hoarseness
What does the thoracic duct drain
lower extremities, pelvis, abdomen, left side of the thorax, left upper extremity, and left side of the head and neck
Where does the thoracic duct drain into (terminate)
junction of the left subclavian and left internal jugular veins
How does the thoracic duct enter the abdomen
through the aortic hiatus
Which structures pass through the diaphragm at level T8
Vena cava
R Phrenic
Which structures pass through the diaphragm at level T10
Oesophagus
Left phrenic
Vagus nerve
Which structures pass through the diaphragm at level T12
Thoracic duct
Aortic Hiatus
Azygos system
What’s the diaphragm attached to anteriorly
Inferior 6 ribs and their costal margins and the xiphoid process
What is the supply of the diaphragm
Phrenic arteries
What is the origin of the pec minor muscle
3rd-5th ribs near costal cartilage
Where does the pec minor muscle insert
Medial border and superior surface of coracoid process
What is the action of the pec minor
Stabilise scapula by drawing it in inferably and anteriorly against the thoracic wall
What is the innervation of the pec minor
Medial pectoral nerves
What is the artery that supplies the pec minor
Thoracoacromial artery
Where is the origin of the pec major muscle
Anterior sternal half of clavicle
Manubrium and sternum up to 6 costal cartilages
Aponeurosis of abdominal external oblique
Where does the pec major insert
Bicipital groove of the humerus
What is the action of the pec major
Humerus flexion (lifting arm up)
Humerus adduction (bringing arm towards body)
Rotate humerus medially
Keep arm attached to trunk
What is the innervation of the clavicular head of the pec major
C5,6 (lateral pectoral nerve)
What is the innervation of the sternocostal head of the pec major
C7, C8, T1 (medial pectoral nerve)
What are some of the structures that run through the superior thoracic aperture
Trachea Oesophagus Lung apex Thoracic duct L&R common carotids and subclavian aa Brachiocephalic and internal jugular vv Vagus and phrenic nerves
What are some of the structures that run through the inferior thoracic aperture
OSeophagus
Thoracic duct
Abdominal aorta
Inferior vena cava
What is the origin of the Serratus anterior mm
Superior 8 or 9 ribs
What is the insertion of the serratus anterior mm
Vertebral border and inferior angle of scapula
What is the action of the serratus anterior mm
Abduction and rotate scapula upwards
Elevate ribs when scapula stabilised
What is the nerve supply of the serratus anterior mm and its roots
Long thoracic nerve (C5-7)
What is the blood supply of the serratus anterior mm
Lateral thoracic artery (from the axillary artery)
In the RHS of the body, where do all the posterior intercostal veins drain into (except the first) and in turn where does this drain into
Azygos vein -> Right superior vena cava
Where does the azygos vein drain into
Right superior vena cava
In the LHS of the body, where do all the intercostal veins drain into (except upper 3 accessory hemiazygos veins)
Hemiazygos vein
Where do the upper 3 accessory hemi-azygos veins drain into (these are only found on the LHS)
Left brachiocephalic vein
Where do the anterior intercostal veins drain into and where does this drain into in turn
Internal thoracic vein -> Brachiocephalic vein
What are the accessory inspiratory muscles
Scalene muscles
Infra-hyoid muscles
Erector Spinae muscles
Quadratus lamborum
What is the role of the scalene muscles in inspiration
Stabilise first ribs so when intercostal muscles contract, ribs are moved up to first rib
What is the role of the quadrates labour during inspiration
Stabilises 12th ribs so when diaphragm, contracts, ribs are moved away from 12th
How are external intercostals positioned
Inferiomedially
How are internal intercostals positioned
Inferolaterally
How are innermost intercostals positioned
Inferolaterally
What is thoracocentesis used for
Obtain sample for histology or to treat primary tension pneumothorax
where is the needle inserted in thoracocentesis
Inferior half of ics in;
- 4th/5th midaxillary line
- or 2nd ics in midaxillary line
What does the needle pass through in thoracocentesis
Intercostal muscles and parietal pleura
When is intercostal nerve block used
When there is pain due to shingles or localised chest wall pain
Where does the lateral thoracic artery come from and what does it supply
Axillary artery and supplies the
- Serratus anterior
- Breast
What is the origin of the lateral pectoral nerve (including the root values) and what does it supply
C5,6,7 –> Lateral cord of brachial plexus –> Lateral pectoral nerve –> Pec major
What is the origin of the medial pectoral nerve (including the root values) and what does it supply
C8+T1 –> Medial cord of brachial plexus –> Medial pectoral nerve –>Pec minor and major
What do the intercostal nerves supply
IC muscles Transverse thoracic muscle Subcostal muscle Levator costarum muscle Serratus posterior muscles Abs Thoracic and abd. skin Pleura
Where are the sites of oesophageal constriction
ABCD=
- Cricoid cartilage (C6)
- Arch of Aorta
- Bronchus (LMB T4/5)
- Diaphragm (oesophageal hiatus T11)
Why are the sites of oesophageal constriction important
Where foreign objects/food are most likely to become stuck and cause choking
What’s winging of the scapula a sign of
Paralysis of the long thoracic nerve (C5-C7) which innervates serratus anterior
