Anatomy is on of the foundations of medical knowledge, but it's important to be able to apply that knowledge in clinical practice. Here are just a few examples of how you can link anatomy knowledge to practicing medicine.

Injuries in the cervical spine

The cervical spine is prone to hyperextension injuries, such as “whiplash,” which can occur when the head extends back much farther than it normally would. The most common injuries of the cervical spine are fractures of the dens of the axis, traumatic spondylolisthesis (anterior slippage of a vertebral body), and atlas fractures. Patient prognosis is largely dependent on the spinal level of the injuries.

 

 

This patient hit the dashboard of his car while not wearing a seat belt. The resulting hyperextension caused the traumatic spondylolisthesis of C2 (axis) with fracture of the vertebral arch of C2, as well as tearing of the ligaments between C2 and C3. This injury is often referred to as “hangman’s fracture.”

 

Breast cancer

Stem cells in the intralobular connective tissue give rise to tremendous cell growth, necessary for duct system proliferation and acini differentiation. This makes the terminal duct lobular unit (TDLU) the most common site of origin of malignant breast tumors.

 

 

Tumors originating in the breast spread via the lymphatic vessels. The deep system of lymphatic drainage (level III) is of particular importance, although the parasternal lymph nodes provide a route by which tumor cells may spread across the midline. The survival rate in breast cancer correlates most strongly with the number of lymph nodes involved at the axillary nodal level. Metastatic involvement is gauged through scintigraphic mapping with radiolabeled colloids (technetium [Tc] 99m sulfur microcolloid). The downstream sentinel node is the first to receive lymphatic drainage from the tumor and is therefore the first to be visualized with radiolabeling. Once identified, it can then be removed (via sentinel lymphadenectomy) and histologically examined for tumor cells. This method is 98% accurate in predicting the level of axillary nodal involvement.

 

 

Pneumothorax

The pleural space is normally sealed from the outside environment. Injury to the parietal pleura, visceral pleura, or lung allows air to enter the pleural cavity (pneumothorax). The lung collapses due to its inherent elasticity, and the patient’s ability to breathe is compromised. The uninjured lung continues to function under normal pressure variations, resulting in “mediastinal flutter”: the mediastinum shifts toward the normal side during inspiration and returns to the midline during expiration. Tension (valve) pneumothorax occurs when traumatically detached and displaced tissue covers the defect in the thoracic wall from the inside. This mobile flap allows air to enter, but not escape, the pleural cavity, causing a pressure buildup. The mediastinum shifts to the normal side, which may cause kinking of the great vessels and prevent the return of venous blood to the heart. Without treatment, tension pneumothorax is invariably fatal.

 

 

Assessing elbow injuries

The fat pads between the fibrous capsule and synovial membrane are part of the normal anatomy of the elbow joint. The anterior pad is most readily seen on a sagittal MRI while the posterior pad is often hidden within the bony fossa. With an effusion of the joint space, the inferior edge of the anterior pad appears concave as it gets pushed superiorly by the intra-articular fluid. This causes the pad to resemble the shape of a ship’s sail, thus creating a characteristic “sail sign.” The alignment of the prominences in the elbow also aids in the identification of fractures and dislocations.

 

 

Diagnosing hip dysplasia and dislocation

Ultrasonography, the most important imaging method for screening the infant hip, is used to identify morphological changes such as hip dysplasia and dislocation. Clinically, hip dislocation presents with instability and limited abduction of the hip joint, and leg shortening with symmetry of the gluteal folds.

 

 

The Middle meningeal artery and Sphenopalatine artery

The middle meningeal artery supplies the meninges and overlying calvaria. Rupture of the artery (generally due to head trauma) results in an epidural hematoma.

 

 

The sphenopalatine artery supplies the wall of the nasal cavity. Excessive nasopharyngeal bleeding from the branches of the phenopalatine artery may necessitate ligation of the maxillary artery in the pterygopalatine fossa.

 

 

Adapted from Atlas of Anatomy, Third Edition by Anne Gilroy and Brian MacPherson

Atlas of Anatomy, Third Edition has over 1,900 exquisitely detailed and accurate illustrations to help you master the details of human anatomy, plus dozens of clinical correlates, radiologic and sectional images, and more!

What students say about the Atlas of Anatomy:
"… this book surpasses them all. It's the artwork. The artist has found the perfect balance of detail and clarity. Some of these illustrations have to be seen to be believed.... The pearls of clinical information are very good and these add significance to the information and make it easier to remember."