Understanding the muscles of the human body is a core part of anatomy. However, with over 600 skeletal muscles, knowing where to start can be difficult. By using a consistent structure, you can learn each muscle in a logical and memorable way. This guide outlines a six-part approach to describing muscles: site, shape, attachments, action, nerve supply, and blood supply. Whether you’re revising for exams or trying to build your clinical knowledge, this framework will help you learn muscle anatomy efficiently. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Site The site refers to the location of the muscle in the body. This gives you an immediate understanding of which region the muscle acts on. Examples: The pectoralis major is a muscle of the anterior chest. The flexor carpi radialis lies in the anterior forearm. The gastrocnemius is located in the posterior leg. Shape Muscles come in a variety of shapes, and these often relate to their function. Examples: The biceps brachii is a two-headed, fusiform muscle. The pectoralis major is triangular in shape. The rectus abdominis is a strap-like muscle running vertically down the abdomen. Recognising muscle shapes can help with identification during dissection, imaging, or surgery. Attachments Every muscle has a proximal attachment (closer to the centre of the body) and a distal attachment (further away). These bony landmarks are important for understanding how a muscle creates movement. Example: The pectoralis major originates from the clavicle and sternum and inserts into the humerus. Action Muscles act by producing movement at joints. Describing a muscle’s action tells you what it does and which joint it affects. Examples: The iliopsoas causes flexion at the hip joint. The quadriceps femoris extends the knee joint. Visualising these actions during active movement can help consolidate your understanding. Nerve Supply Each muscle receives motor innervation from a specific peripheral nerve. This is important both in anatomy and clinical neurology. Example: The median nerve supplies several muscles in the anterior forearm. Knowing the nerve supply allows you to localise neurological lesions and understand patterns of weakness. Blood Supply Muscles receive oxygen and nutrients via an arterial blood supply. Identifying this can help in understanding surgical planning and vascular compromise. Example: The brachial artery supplies many muscles of the upper limb. Summary Print Article Rate This Article