Anatomy: Applied Regional and Clinical Anatomy
Anatomy: what is tested
Anatomy in this exam tests applied regional and clinical anatomy: anatomical position and planes, osteology and arthrology, muscle compartments, neurovascular bundles, dermatomes and lymphatics, and embryological derivatives. Questions usually present a lesion and ask which structure is injured or which deficit follows.
Core rules
- Describe position relative to the anatomical position: proximal/distal, medial/lateral, superficial/deep, and use median, sagittal, coronal and transverse planes.
- Learn structures as bundles: nerve, artery, vein and lymphatics travel together, so a fracture or compartment syndrome threatens the whole bundle.
- Map nerve lesions to function: radial nerve causes wrist drop; median nerve causes thenar wasting and loss of thumb opposition; ulnar nerve causes claw hand and weak finger adduction.
- Know high-yield relationships: axillary nerve at the surgical neck of the humerus; common peroneal nerve at the fibular neck; recurrent laryngeal nerve in the tracheo-oesophageal groove; ureter crossed by the uterine artery, described as water under the bridge.
- Lymph drainage follows fascial planes: the breast drains mainly to axillary nodes, with medial quadrants draining to parasternal nodes.
Worked example. A fall on the shoulder causes a midshaft humeral fracture with wrist drop and numbness over the dorsum of the first web space. Reasoning: the radial nerve runs in the spiral groove against the humeral shaft; injury paralyses wrist extensors and causes sensory loss in its superficial distribution. The axillary nerve is tested by deltoid power and the regimental badge area, and is at risk at the surgical neck, not midshaft.
Traps that cost marks
- Mixing median and ulnar sensory territories.
- Naming the radial artery instead of the brachial artery in a supracondylar fracture.
- Forgetting that the femoral nerve supplies the anterior thigh and the obturator nerve the medial thigh.
- Confusing the anatomical and surgical necks of the humerus.