Anatomy of the Thorax Flashcards
Events at the Sternal Angle of Louis?
T4 = RAT PLANT
Rib2, Arch of aorta, tracheal bifurcation, pulmonary trunnk, ligamentum arteriosum, azygos vein drains into SVC, Nerves (loop RLN), thoracic duct crosses the thorax
3 muscles that run in the intercostal spaces? Neurovasular bundle location?
The spaces between the ribs contain three muscles of respiration: 1)the external intercostal, (EIM) 2)the internal intercostal, (IIM) 3)and the innermost intercostal muscle. The intercostal nerves and blood vessels run between the intermediate and deepest layers of muscles
What is the location for an Intercostal nerve block?
The needle is directed toward the rib near the lower border
They are arranged in the following order from above downward: intercostal vein, intercostal artery, and intercostal nerve (i.e., VAN).
The intercostal muscles are supplied by the corresponding intercostal nerves.
The intercostal nerves are the anterior rami of the first 11 thoracic spinal nerves . The anterior ramus of the 12th thoracic nerve lies in the abdomen and runs for- ward in the abdominal wall as the subcostal nerve.
What is the purpose of the pleural fluid?
The pleural cavity between the two layers of the pleural sac is empty, except for a lubricating film of pleural fluid. The pleural fluid prevents the lungs from collapse and causes the lungs to expand when the thorax expands for inhalation.
Where are the costo diaphragmatic recesses and the costo mediastinal recesses?
The costo diaphragmatic recesses are slit like spaces between the costal and diaphragmatic parietal pleurae that are separated only by a capillary layer of pleural fluid. During inspiration, the lower margins of the lungs descend into the recesses.
The costo mediastinal recesses are situated along the anterior margins of the pleura. They are slitlike spaces between the costal and mediastinal parietal pleurae, which are separated by a capillary layer of pleural fluid.
Surface features marking the right pleural sac?
Surface features marking the right pleural sac:
- right sternoclavicular joint to sternal angle in the midline
- to 4th costal cartilage level in the midline
- to posterior xiphisternal joint in the midline (level of 6th CC)
- to right 8th rib in the midclavicular line
- to right 10th rib in the midaxillary line
- to right 12th rib (neck) in the vertebral line
Surface features marking the left pleural sac?
Surface features marking the left pleural sac:
- left sternoclavicular joint to sternal angle in the midline
- to 4th costal cartilage level in the midline
- to left 6th costal cartilage
- (think cardiac notch, heart predominates the left*)
- to left 8th rib in the midclavicular line
- to left 10th rib in the midaxillary line
- to left 12th rib (neck) in the vertebral line
What is a pneumothorax?
What is a hemopneumothorax?
Fix? Sites for insertion?
- Entry of air into the pleural cavity (pneumothorax), resulting from a penetrating wound of the parietal pleura from a bullet, for example, or from rupture of a pulmonary lesion into the pleural cavity (bronchopulmonary fistula), results in collapse of the lung
- Fractured ribs may also tear the visceral pleura and lung, thus producing pneumothorax.
- If both air and fluid (hemopneumothorax, if the fluid is blood) accumulate in the pleural cavity, an air–fluid level or interface (sharp line, horizontal regardless of the patient’s position, indicating the upper surface of the fluid) will be seen on a radiograph.
- Major amounts of air, blood, serous fluid, pus, or any combination of these substances in the pleural cavity are typically removed by insertion of a chest tube.
- A short incision is made in the 5th or 6th intercostal space in the midaxillary line The tube may be directed superiorly (toward the cervical pleura for air removal, or inferiorly (toward the costodiaphragmatic recess) for fluid drainage.
What is the pericardium?
Which part of the mediastinum is it in?
Layers?
Attachment below?
What is the visceral pericardium also known as?
The visceral layer is closely applied to the heart and is often called the epicardium.
Nerve supply to the pericardium?
NERVE SUPPLY
The fibrous pericardium and the parietal layer of the serous pericardium are supplied by the phrenic nerves.
The visceral layer of the serous pericardium is innervated by branches of the sympathetic trunks and the Vagus nerves.
What is the inflammation of the serous pericardium called?
Clinical consequence?
Fix?
In inflammation of the serous pericardium, called pericarditis.
Pericardial fluid may accumulate excessively, which can compress the thin-walled atria and interfere with the filling of the heart during diastole. This compression of the heart is called cardiac tamponade.
Cardiac tamponade can result from fluid accumulation or bleeding into the pericardial sac. Bleeding may be caused by a ruptured aortic aneurysm, a ruptured myocardial infarct, or a penetrating injury that compromises the beating heart and decreases venous return and cardiac output.
Pericardial fluid can be aspirated from the pericardial cavity should excessive amounts accumulate in pericarditis. This process is called pericardiocentesis
Which part of the mediastinum does the heart lie in?
Surface marking of the heart position? Which costal cartilages? Which vertebrae?
Position of the heart
- Within the mediastinum (middle), between the two pleural sacs
- Posterior to sternum & costal cartilages (2-6)
- Anterior to thoracic vertebrate (T6-T9)
Surface markings of heart borders?
3 surfaces of the heart?
The heart has three surfaces:
a) sternocostal (anterior), RA and RV
b) diaphragmatic (inferior), RV and LV
c) and a base (posterior). LA and RA
It also has an apex, which is directed downward, forward, and to the left. It lies at the level of the fifth left intercostal space, 3.5 in. (9 cm) from the midline.
Which of the following is an anterolateral infarct? Which artery is blocked?
Myocardial infarction in which the anterior wall of the heart is involved. Anterior wall myocardial infarction is often caused by occlusion of the left anterior descending coronary artery.
(a)
Venous drainage of the heart?
- The heart is drained mainly by veins that empty into the coronary sinus and partly by small veins that empty into the right atrium
- The coronary sinus receives the great cardiac vein at its left end and the middle cardiac vein and small cardiac veins at its right end
What is the electrical impulse route through the heart?
The SA node initiates an impulse that is rapidly conducted to cardiac muscle fibers in the atria, causing them to contract
- The impulse spreads by myogenic conduction, which rap- idly transmits the impulse from the SA node to the AV node.
- The signal is distributed from the AV node through the AV bundle and its branches (the right and left bundles), which pass on each side of the IVS to supply subendocardial branches to the papillary muscles and the walls of the ventricles
Areas of referred cardiac pain?
Cardiac referred pain is a phenomenon whereby noxious stimuli originating in the heart are perceived by a person as pain arising from a superficial part of the body— the skin on the left upper limb, for example.
• Visceral referred pain is transmitted by visceral afferent fibers accompanying sympathetic fibers and is typically referred to somatic structures or areas such as a limb having afferent fibers with cell bodies in the same spinal ganglion, and central processes that enter the spinal cord through the same posterior roots
