THORAX IV Flashcards
What are the anterior, posterior, superior and inferior borders of the posterior mediastinum?
Anterior- pericardial sac
Posterior- bodies of T5-T12 vertebrae
Superior- transverse thoracic plane
Inferior- thoracic surface of the diaphragm
Where does the descending aorta begin and end?
T4-T12
What are the 7 groups of branches off the thoracic aorta?
The bronchial arteries, the mediastinal arteries, the oesophageal arteries, the pericardial arteries, the superior phrenic arteries and the intercostal and subcostal arteries
What do vessels in the azygous system run between?
The pleura and the the vertebral column
What does the azygous system of veins drain?
The posterior thoracic wall
What does the azygous system of veins provide collateral circulation to?
The venae cavae
How many posterior intercostal veins are there?
11
Where does the 1st posterior intercostal vein drain into?
Into the brachiocephalic vein or the vertebral vein
Where do the 2nd and 3rd (and often 4th) posterior intercostal veins drain?
Into the superior intercostal vein
Where do posterior intercostal veins 5-11 drain?
Into the azygous vein on the right, or the hemiazygous and accessory hemiazygous veins on the left
What’s the thoracic duct inferior to?
The coeliac trunk
Where do the left and right vagus nerves run in relation to the oesophagus in the thorax?
The left vagus runs anterior and the right vagus runs posterior to the oesophagus
Where do the thoracic splanchnic nerves arise?
The sympathetic trunk
What do the thoracic splanchnic nerves supply?
They run inferiorly to supply the abdomen
What spinal nerve roots does the greater splanchnic nerve originate from?
T5-T9 or T10
What spinal nerve root(s) does the lesser splanchnic nerve originate from?
T10-T11
What spinal nerve root(s) does the least splanchnic nerve originate from?
T12
What is in the posterior mediastinum?
The mediastinal parts of the lungs
What is an annulus of the heart?
The base of a heart valve that supports the valve’s cusps
What’s the moderator band in the right ventricle and what’s its purpose?
A muscular band of heart tissue which carries part of the bundle branch of the AV bundle of the conductive system of the heart to the anterior papillary muscle, which facilitates conduction time
What runs in the anterior atrioventricular groove of the heart?
The right coronary artery
What runs in the interventricular groove of the heart?
The anterior inter ventricular artery
What’s the function of the ductus arteriosus in a foetus?
The ductus arteriosus connects the pulmonary artery to the aortic arch, allowing most of the blood from the right ventricle to bypass the foetal lungs
Along what side of T5-T7 does the descending thoracic aorta pass?
Along the left side
What nerve supplies the muscle of the diaphragm?
The phrenic nerve
What does the diaphragm initially develop as and at what vertebral level?
The diaphragm begins as a central tendon at C2
What causes the diaphragm to descend?
Differential growth
What is hemidiaphragm?
Paralysis of half of the diaphragm due to its motor supply from the phrenic nerve becoming injured
What is the median arcuate ligament?
A ligament under the diaphragm that links the right and left crura of the diaphragm
What is the medial arcuate ligament?
A tendinous fascia that arches over the psoas major muscle as it passes through the diaphragm
What is the lateral arcuate ligament?
A ligament under the diaphragm that arches across the upper part of the quadratus lumborum muscle. It’s traversed by the subcostal nerve, artery and vein
What do the ganglia associated with levels T1-T5 supply?
Cardiac branches to the heart
What do rami communicates do?
Connect the trunks to the spinal nerves (intercostal nerves), providing sympathetic thoracic supply to parietal structures
What bounds the anterior triangle of the neck?
The midline of the neck, the anterior border of the SCM and and the inferior border of the mandible
What bounds the posterior triangle of the neck?
The middle 2/3 of the the clavicle, the anterior border of the trapezius muscle and the posterior border of the SCM
Where does the SCM originate and insert?
Originates on the anterior surface of the manubrium and the superior border of the anterior surface of the medial 1/3 of the clavicle. It inserts on the lateral surface of the mastoid process and the nuchal line of the occipital bone
What’s the nerve supply to the SCM?
The accessory nerve on the same side supplies motor innervation, while the cervical plexus supplies sensation from the ventral primary rami of C2 and C3
What’s the action of the SCM?
Contralateral cervical rotation, ipsilateral cervical flexion
What is torticollis?
Also known as wry-neck, this is a dystonic condition defined by an abnormal, asymmetrical head or neck position
Where does trapezius originate and insert?
It originates on the occipital bone, the ligamentum nuchae, and the spinous processes of T1-T12. It inserts on the lateral 1/3 of the clavicle, the acromion and the scapular spine
What is the nerve supply to the trapezius muscle?
The accessory nerve provides motor innervation, while the ventral primary rami of spinal nerves C3 and C4 provide sensory innervation (cervical plexus)
What is the action of the trapezius?
The upper descending fibres are responsible for elevation of the scapulae. The lower, ascending fibres are responsible for depression of the scapulae. The middle fibres retract the scapulae.
What are the contents of the posterior triangle of the neck?
The accessory nerve, branches of the cervical plexus, roots and trunks of the brachial plexus, the phrenic nerve, the subclavian artery, the transverse cervical artery, the supra scapular artery, the external jugular vein, occipital and supraclavicular lymph nodes, the inferior belly of the omohyoid, the anterior, middle and posterior scalene, levator scapulae and splenius
