Download Arch of aorta and its relations

22-10-2013
Anatomy lab.4
This sheet is more like a theoretical lec than a lab one, but those who attended
the lab would find it a bit useful. Anyways, lets start the lab!
Arch of aorta and its relations
The Ascending aorta and pulmonary trunk are inside the pericardium.
Near the heart, the beginning of the pulmonary trunk is anterior to the ascending
aorta. As it ascends, it becomes on the left side of the ascending aorta and then it
terminates posterior to the aortic arch giving the right and left pulmoary arteries.
The right artery lies behind the ascending aorta, so can’t be seen on the corpse.
Note: one important relation with respect to the ascending aorta is the trasverse
sinus which lies posteriorly.
Aortic arch and its relations:
 It starts and ends at the same level (a:sternal angle;p:vertebra T4)
 It moves anterior to posterior
 It has 2 surfaces:
 superficial
1. Anterior and to the left
2. Posterior and to the right  deep
 It gives 3 branches(medial to lateral):
1) Brachiocephalic [most anterior]
2) Left common carotid artery
3) Left subclavian artery [most posterior]
Note: The arch terminates at the point where the left subclavian appears and it
continues as descending aorta.
These 3 branches lie superior to the arch. One other structure that lies superior is
the left brachiocephalic vein. The 5th and the last structure is the remnant of the
thymus gland.
Inferior to the arch are 5 structures too. These are:
1. Bifurcation of pulmonary trunk
2. Deeper is the left bronchus
3. Ligamentum arteriosum (to find it look for the left pulmonary artery and
move it gently. There u will find a structure that connects the artery
with the arch of aorta. This is the ligament) note: this ligament was a
duct in the fetal life and was called ductus arteriosus and it carries
poorly oxygenated blood. It extends from beginning of the left
pulmonary artery to the end of the aortic arch (where the left
22-10-2013
Anatomy lab.4
subclavian artery appears). This has a sgnificance; it prevents the brain
from receiving poorly oxygenated blood {{this is important in lab exam}}
4. Superficial cardiac plexus: this is formed of 2 small nerves (sympathetic
and parasympathetic) which lie anterior to the ligamentum arteriosum
5. Posterior to the ligamentum arteriosum is a branch of the vagus nerve
called left recurrent larengeal nerve. [the right recurrent larengeal
nerve doesn’t enter the thorax, but it reaches the root of the neck and
then it winds round the right subclavian artery].
Superior relations:
1. Vagus nerve
2. Phrenic nerve
3. Between these 2 nerves is the left superior intercostal vein(was cut on the
corpse)
4. 2 nerves
5. Left lung and pleura(most superficial)
 There are 2 important Impresssions on the interior surface of the lung:
 Arch of aorta forms a deep groove above the hilum
 Descending aorta forms a groove behind the hilum(the doctor
maybe meant below here)
Deep relations:
1.
2.
3.
4.
5.
Trachea
Oesophagus
Left recurrent larengeal nerve (between the previous 2 structures)
Vertebral column
Thoracic duct
Only the 1st three structures can be seen and in the following order:
Most anterior -trachea--left recurrrent larengeal nerve--oesophagus-most
posterior
I tried my best to include everything the doctor said. Hope it helps and sorry
for any mistakes:$
Your colleague: Mohammad Farhan