Regional anat Flashcards
Describe middle mediastinum
Middle mediastinum consists of the heart and sac. The parietal wall is the wall layer and the visceral layer stays on top of the organ and cant separate. There are 4 layers of the heart. Inside the heart is called endocardium which keeps the blood flow smooth. Muscular part which is the myocardium. Parietal layer which is the serous pericardium, the visceral layer which is epicardium and the potential space such as the pericardium cavity.
Describe anatomy of the thoracic wall boundaries and describe one of the possible surgical approaches to access thoracic cavity
Superior apetures of thoracic wall you will find manubrium of the sternum, the first pair of ribs and the body of vertebrae T1. The inferior apeture is completely covered by diaphragm seaprating from abdominal cavity. The ribs are divided into 3 sub divisions, true ribs are from 1-7 which have their own anterior articulation such are the sternum. False ribs such as 8-10 which attach to the ribs above & floating ribs 11-12 which have no articulation. Lateral view of the ribs are on a slope due to lungs when inhaling it brings the diaphragm up, if it was horizontal then it wouldnt be good for breathing. Bony parts of ribs, theres the head then laterally theres the neck and separating neck and body is the costal tubercle then costal cartilage then sternum attachment. Sternum has manibrium which has jugular notch then clavicular notch. Rubs 1,6,7 are syndremosis and 1,3,5 are true joints. Main joints of the thoax region include IVD, costovertebral joint which has 2 sub joints, aball & socket joint which is secured by a intra-articular and radiant ligament. & costotransverse joint which is a pivot joint where costal tubercle articulates which costal facets of tranverse process . Both these joints result in a hinge joint where one articulates and one is restricting.
Intercostal muscles are between the ribs, there are eleven in total containing the intercostal muscles such as
-external moves around inferiorly & laterally which is for inhaling.
-Internal moves inferiorly & medially for expiration.
-Innermost is for expirations and contains the VAN. Subcostal is with the innermost and its for exhalation.
VANs-Ascending aortic arch through posterior intercostal to the anterior intercostal coming out of internal thoracic artery out of subclavian. Intercostal vein to the azygos to the SVC.
Inferior apeture is covered by diaphragm separating abdominal cavity. Right side of diaphragm is bigger due to the liver. Lumbar origin which have many subarts such as the costalpart which is laterally and anteriorly and a sternal part. Has central tendon where many muscles fuse. There are three openings 1) caval opening where the IVC is tihgtly connected to the opening so it wont collapse for efficient blood drainage and to keep infusion open. 2) Esophagus opening: Contraction of diaphragm theres a mechanism of closing the esophagus so food doesnt come back up. 3)Aortic opening is the median arcuate ligament when contraction of diaphragm then it doesnt compress ascending aorta - safety mechanism.
Pleura-free triangle. Pleura doesnt fill anterior part of thorax, vital for fluid collection due to fluid around. So tube goes somewhere there isnt pleura such as pleura free triangle to access pericardium but dont pierce the pleura as there will be separation between parietal and visceral layers.
Describe in order from anterior to posterior the structures that would be seen in a transverse section of the thorax at the level of the sternal angle and IVD found between T4 and T5
The thoracic plane is a vital plane at the level of the sternal angle and the T4/T5 IVD. Serves imaginary boundary of superior and inferior mediastinum.
Anteriorly the main vessels are the internal thoracic artery which is a branch of the subclavian artery running laterally to the sternum towards the femoral arterty. Aortic coarcatation is where babies have a red head meaning they have high BP but have blue legs meaning low BP. The aorta is narrowed in babie safter the aortic arch therefore there isn’t blood flow through the internal thoracic artery so the femoral artery is another way it reaches the subclavian artery which connects to the intercostal artery to the aorta. Lymph nodes of anterior mediastinum is the parasternal lymph node which is alongside of the sternum, ANT mediastinum consists of thymus which is bigger in children due to immune system.
Posteriorly theres the esophagus, thoracic aorta, vagus nerves, lymphatic ducts & sympathetic trunks. Descending thoracic aorta, azygos, hemiazygos vein & thoracic ducts.
Describe the structures forming superior and inferior boundaries of the thorax wall and structures you would expect to find contained within these boundaries
Superior apertures of thoracic wall you will find manubrium of the sternum, the first pair of ribs and the body of vertebrae T1. The inferior aperture is completely covered by diaphragm separating from abdominal cavity. The ribs are divided into 3 sub divisions, true ribs are from 1-7 which have their own anterior articulation such are the sternum. False ribs such as 8-10 which attach to the ribs above & floating ribs 11-12 which have no articulation. Lateral view of the ribs are on a slope due to lungs when inhaling it brings the diaphragm up, if it was horizontal then it wouldnt be good for breathing. Bony parts of ribs, theres the head then laterally theres the neck and separating neck and body is the costal tubercle then costal cartilage then sternum attachment. Sternum has manubrium which has jugular notch then clavicular notch. Rubs 1,6,7 are syndesmosis and 1,3,5 are true joints. Main joints of the thorax region include IVD, costovertebral joint which has 2 sub joints, ball & socket joint which is secured by a intra-articular and radiant ligament. & costotransverse joint which is a pivot joint where costal tubercle articulates which costal facets of transverse process . Both these joints result in a hinge joint where one articulates and one is restricting.
Intercostal muscles are between the ribs, there are eleven in total containing the intercostal muscles such as
-external moves around inferiorly & laterally which is for inhaling.
-Internal moves inferiorly & medially for expiration.
-Innermost is for expirations and contains the VAN. Subcostal is with the innermost and its for exhalation.
VANs-Ascending aortic arch through posterior intercostal to the anterior intercostal coming out of internal thoracic artery out of subclavian. Intercostal vein to the azygos to the SVC.
Inferior aperture is covered by diaphragm separating abdominal cavity. Right side of diaphragm is bigger due to the liver. Lumbar origin which have many subsets such as the costal part which is laterally and anteriorly and a sternal part. Has central tendon where many muscles fuse. There are three openings 1) caval opening where the IVC is tightly connected to the opening so it wont collapse for efficient blood drainage and to keep infusion open. 2) Esophagus opening: Contraction of diaphragm theres a mechanism of closing the esophagus so food doesn’t come back up. 3)Aortic opening is the median arcuate ligament when contraction of diaphragm then it doesn’t compress ascending aorta - safety mechanism
Describe the regional anatomy of superior mediastinum, outlining the relationship of the structures found in each layer from superficial to deep.
The superior mediastinum is above the thoracic plane which is divided between the T4/5 + discs + manubriosternal joint. Superior mediastinum consists of three layers such as the superficial, middle & deepest layer.
Superficial layer has small vessels such as the internal thoracic artery & also the parasternal lymph nodes. The superior mediastinum also has the thymus which is important for the immune system. Children have a much larger thymus compared to adults due to their immune system is not matured compared to children. Also contains SVC and brachiocephalic trunks.
Middle layer consists of the large vessels such as the aortic arch & pulmonary trunks & also the vagus and phrenic nerve. The phrenic nerve aids in the voluntary system whereas the vagus nerve (parasympathetic) & sympathetic trunk (sympathetic) both are involuntary.
-Vagus nerve comes out from recurrent laryngeal nerve giving branches to the subclavian artery to the right and the aortic arch from the left. Vagus nerves aims for the esophagus on its way to the abdomen.
- Phrenic nerve is anterior to scalene muscles going between subclavian vein & artery which is on top of SVC tight and the aortic arch left going down to anterior to lung root. Carries fibres enable diaphragm to feel voluntary pain.
3) Deep layer is posteriorly containing the esophagus & trachea where lymph nodes can be found. The recurrent laryngeal nerve is between the trachea and esophagus belonging to the deep layer (also comes off the vagus nerve). vessels of the deep layer are the azygos vein, intercostal arteries and the sympathetic trunks. Lymphatics are bronchomediastinal trunk and thoracic duct between the esophagus and trachea
