System: Musculoskeletal

Extensor Digitorum Longus

Extensor Digitorum Longus The structure indicated is the extensor digitorum longus muscle. The extensor digitorum longus is one of the four muscles of the anterior compartment of the leg. The muscles of the leg consist of three compartments: Anterior Posterior Lateral In the anterior compartment are the four following muscles: Tibialis anterior Extensor hallucis longus Extensor digitorum longus Fibularis tertius The muscles of the anterior compartment of the leg serve to dorsiflex the ankle joint, extend the toes and invert the foot, and they are supplied by the deep fibular (peroneal) nerve. Origin: Proximal ½ of medial surface of fibula. …

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extensor digitorum longus

Extensor Digiti Minimi

Extensor Digiti Minimi The structure indicated is the extensor digiti minimi muscle. The extensor digiti minimi muscle is one of 7 muscles located in the superficial compartment of the posterior forearm. The posterior forearm consists of a superficial and a deep compartment. The superficial compartment contains 7 muscles, whereas the deep compartment contains 5 muscles. The superficial compartment of the posterior forearm includes the following 7 muscles: Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum Extensor digiti minimi Extensor carpi ulnaris Anconeus The muscles of the posterior compartment of the forearm originate from the lateral epicondyle of the humerus and the supraepicondylar ridge and they are all innervated by …

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extensor digiti minimi


Brachialis The structure indicated is the brachialis muscle. The brachialis muscle is one of three muscles in the anterior compartment of the arm: Biceps brachii Brachialis Coracobrachialis The muscles of the anterior compartment are innervated by the musculocutaneous nerve and generally serve to flex the forearm at the elbow joint. The brachialis muscle lies deep to the biceps brachii muscle and is synergistic in its action, assisting with flexion of the forearm at the elbow joint. Origin: Distal half of anterior humerus Insertion: Ulna tuberosity Action: Flexion of elbow Innervation: Musculocutaneous nerve Learn more about the anatomy of the arm …

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Lateral Femoral Condyle

Lateral Femoral Condyle The structure indicated is the lateral femoral condyle. The distal end of the femur forms two rounded condyles which articulate with the tibia below and the patella anteriorly – the medial condyle and the lateral condyle. The linea aspera is a roughened crest of bone on the posterior aspect of the femur. Distally the linea aspera forms two ridges known as the lateral supracondylar line and the medial supracondylar line which as the name suggests, terminate just superiorly to the lateral and medial femoral condyles respectively. At the end of the medial supracondylar line is a tubercle …

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Lateral femoral condyle

Pubic Tubercle

Pubic Tubercle The structure indicated is the pubic tubercle. The pelvic bone consists of three components: Ilium Pubis Ischium The pubis is the anterior and inferior part of the pubic bone and consists of a body connected to two branches (rami) – a superior ramus and an inferior ramus. Several muscles of the abdomen and thigh attach to the superior pubic ramus. The pubic tubercle serves as a point of attachment for the medial aspect of the inguinal ligament. Learn more about the bones of the pelvis in this anatomy tutorial.
pubic tubercle


Semimembranosus The structure indicated is the semimembranosus muscle. The semimembranosus muscle is one of three muscles in the posterior compartment of the thigh. The other muscles are the semitendinosus, and the biceps femoris. The muscles in the posterior compartment are often referred to as the “hamstrings” muscles. Collectively, these muscles are responsible for extending the hip joint, and flexing the knee joint. The biceps femoris lies laterally, and the semitendinosus and semimembranosus lie medially. The semitendinosus gets its name from its structure which is comprised of a muscle belly which tapers into a long tendon that extends to insert onto …

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Trochlea of Humerus

Trochlea of Humerus The structure indicated is the trochlea of the humerus. The distal end of the humerus consists of several features: Condyle, consisting of the capitulum and trochlea Medial and lateral epicondyles Medial and lateral supracondylar ridges Radial fossa, coronoid fossa, olecranon fossa A large central condyle which has two articular components – the capitulum is the lateral articular component and articulates with the radius, and the trochlea is the medial component which articulates with the ulna. Learn more about the anatomy of the elbow joint in this tutorial.

Gluteus Medius

Gluteus Medius The structure indicated is the gluteus medius muscle. The gluteus medius muscle is one of the muscles of the gluteal region. The muscles in the gluteal region are divided into a superficial and deep group. There are four muscles of the superficial group: Gluteus maximus Gluteus medius Gluteus minimus Tensor fasciae latae There are 5 muscles in the deep group: Gemellus superior Gemellus inferior Quadratus femoris Piriformis Obturator internus Origin: Dorsal ilium inferior to iliac crest Insertion: Lateral and superior surfaces of greater trochanter Action: Hip abduction. Hip medial rotation (medial fibres). Hip lateral rotation (posterior fibres) Innervation: …

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gluteus medius

Teres Minor

Teres Minor The structure indicated is the teres minor muscle. The teres minor muscle is one of the four muscles of the rotator cuff. The rotator cuff muscles are located in the posterior scapula region and serve to stabilise the glenohumeral joint. There are 4 rotator cuff muscles which can be remembered using the mnemonic SITS: Supraspinatus Infraspinatus Teres minor Subscapularis The supraspinatus and infraspinatus, as their names suggest originate in the fossae above and below the spine of the scapula respectively (supraspinatous and infraspinatous fossae). The supraspinatus, infraspinatus and teres minor muscles insert on to the greater tubercle of …

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Teres minor

Inferior Oblique Muscle of the Eye

Inferior Oblique Muscle of the Eye The structure indicated is the inferior oblique muscle of the eye. This muscle is one of six muscles that are involved in the movements of the eye. The muscles which move the eye are referred to as the extraocular muscles, these include: Superior rectus Inferior rectus Lateral rectus Medial rectus Superior oblique Inferior oblique The oculomotor nerve innervates the superior, inferior and medial rectus muscles as well as the inferior oblique muscle. The trochlear nerve innervates the superior oblique muscle The abducent nerve innervates the lateral rectus muscle. When the inferior oblique muscle is …

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inferior oblique