📹 47- Relations of the arch of aorta
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: 📹360p

📹 46- Divisions of the thoracic aorta
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: 📹360p

Ascending Aorta:
(middle mediastinum)

🔺Begins at the base of Left Ventricle.
🔺Ends at level of sternal angle

🔹Course: Upward and forward to come to lie behind the right half of the sternal body.

🔺Branches:
1⃣ Right Coronary artery:
Origin: from the Right aortic sinus of ascending aorta.

🔹Ends by anastomosing with Left coronary artery in the Post.interventricular groove.


📍Course:
runs forward between the right side of pulmonary trunck and Right auricle →descends in right atrioventricualr groove (coronary sulcus) →Continues posteriorly in Posterior interventricular groove.


📌Branches:
1-Ant.ventricular brs supply ant. surface of the right ventricle.

2-Marginal artery supplies:
★right border of Right ventricle
★part of the apex of left ventricle.
3-Right conus artery supplies:
★ant.surface of pulmonary conus
★Upper part of the ant.wall of Right ventricle.
4-Posterior ventricular brs supply:
★Diaphragmatic surface of Right ventricle
★atrioventricular nodal br. supplies AV node.
5-Posterior interventrcular supplies posterior surface of Right ventricle
6-Atrial brs supply Right atrium.


2⃣ Left coronary artery:
🔹Origin: from the Left aortic sinus of ascending aorta.

🔺Ends by dividing into:
Left circumflex and Left ant. descending (LAD) arteries in atrioventricualr groove (coronary sulcus).

🔹Course:
arises from the left side of pulmonary trunk and left auricle →enters the atrioventricualr groove.

📌Branches:
1-Left ant. descending artery (LAD)
2-Left circumflex artery supplies left margin of heart.
3-Marginal artery is a branch of Left circumflex artery which anastomosing with Right cornary artery.




🔴An injury to right half of sternal body → May lead to Ascending Aorta rupture.


Aortic Arch:
(Superior mediastinum)

👉A continuation of ascending aorta.

🔹Begins as a continuation from level of sternal angle.
🔹Ends at level of T4 and continues as Descending thoracic aorta.

🔺Course:
upward,backward to the left behind the manubrium

🔴An injury to Manubrium → affects on:
1-Arch of Aorta.
2-Superior vena cava
3-Right Innominate vein
4-Left Innominate vein

🔺Branches:
👉Two from the L.t sid:
-L.t common carotid:
enters the carotid sheath at the root of neck
-L.t subclavian:
supplies the left upper limb.

👉One from the right side of the aortic arch:
-Brachiocephalic (Innominate) a
ascending upward, backward to the right to the right sternoclavicular joint where it bifurcates into:
👉Right common carotid →right head and neck
👉Right subclavian→right upper limb.


Descending thoracic aorta
(Posterior mediastinum)

🔹Begins as a continuation of aortic arch at the left side of T4
🔹Ends at the level of T12

🔺Course:
descends downward at the anterior surface of vertebral column.

🔺Branches:
-Lower 9 posterior intercostal arteries
-Bronchial brs
-Eosophagal brs
-Pericardial brs
-Subcostal artery (T12)
-Sup.pherinc a.

Pulmonary Trunk:
(Middle mediastinum)

🔹Begins at the base of right ventricle (infundibulum).
🔹Ends below the concavity of aortic arch by dividing into:
1-Right pulmonary artery 👇
behind (Ascendig Aorta arch and S.V.C)
2-Left pulmonary artery 👇
in front of (Aortic arch and descending aorta)

※Ligamentum arteriosm is a connection between aorta arch and pulmonary trunck.
Opened therapeutically in case of Aortic coarctation by:
→PGE2 or Misoprol.


Head and Neck

🔹Behind right sternoclavicualr
joint, Brachiocephalic divides into:
1-Right subclavian

2-Right common carotid:
enters carotid sheath at the root of the neck.

Carotid sheath is a layer of deep fascia contains the followin:
1-Common carotid arteries
2-Internal jugular veins
3-Vagus nerves

🔴Its pulse is on the middle 1/3 of Sternomastoid muscle


🔹At the level of Thyroid cartilage(Adam's Apple), common carotid divides into:

★External common carotid which has the following branches:
1-Superior thyroid
2-Ascending pharyngeal
3-Lingual
4-Fiscal
5-Occibital
6-post.auricular
7-Superficial temporal
8-Maxillary



★Internal common carotid:
enters carotid channel →supplies the Brain