FACTS & HINTS

High-Yield Facts

Clinical Points

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Important Vertebral Landmarks

Spine of the scapula T2:

Sternal angle (of Louis); level of the bifurcation of trachea, arch T4/T5: of aorta Level of the heart T5-T8:

Aortic hiatus of the diaphragm; also transmits the thoracic duct T12:

Esophageal hiatus of the diaphragm; also transmits the right and left T10: vagal trunks, esophageal branches of left gastric vessels and lymphatics

Caval opening of the diaphragm; also terminal branches of the right T8: phrenic nerve

Thoracocentesis

Thoracocentesis is the insertion of a needle into the pleural cavityto withdraw a sample of fluid or blood. To avoid damage to the intercostal vein, artery, and nerve that run in the costal groove on the inferior surface of each rib, the needle is inserted well below the rib. The needle also must be placed sufficientlyabove the rib below to avoid the collateral branches of intercostal nerve and vessels that run along the superior surface of each rib.

Importance of Certain Intercostal Spaces

Second intercostal space at the midclavicular line: Insertion of tube for an apical pneumothorax(thoracostomy)

Fourth to 6th intercostal space at the midaxillaryline: Insertion of chest drains for a hemothorax(thoracostomy)

Left 5th intercostal space: apexbeat of the heart and this is shifted in heart enlargement

Cervical Ribs

Cervical ribs are not common (less than 1% of all persons). Theyarticulate with the C7 vertebra, but do not attach to the sternum. Theymay fuse with the first rib. If a cervical rib is present, however, it maycompress the subclavian arteryor inferior trunk of the brachial plexus and cause ischemic pain and numbness in the shoulder and upper limb. This condition is called thoracic outlet syndrome.

Bone Marrow Biopsyand Aspiration.

Bone marrow aspiration and biopsyhelp diagnose manyblood disorders and can be used to detect if cancer has spread to the bone marrow.

Bone marrow biopsy: The removal of bone and marrow for examination under the microscope. The sternum is a site of red marrow, even in adulthood, and is a good site for a bone marrow biopsy.Another common site is the posterior iliac crest.Abiopsyis usually conducted before performing a bone marrow aspiration.

Bone marrow aspiration: The removal of a small amount of bone marrow fluid through a needle inserted into the bone. Fluid is examined to determine if there are anyproblems with the blood cells made in the bone marrow

Mnemonics

Memory Aids

Vertical order of the contents of the neurovascular bundle in the costal groove on the lower border of each rib:

VANVein, Artery, Nerve.

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