System: Musculoskeletal

Superior Pubic Ramus

Superior Pubic Ramus The structure indicated is the superior pubic ramus. 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 superior pubic ramus projects posteriorly and laterally from the body and joins the ilium and ischium. The superior pubic ramus consists of two parts: a medial part (the body of the pubis) and a lateral …

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Superior Pubic Ramus

External Abdominal Oblique Muscle

External Abdominal Oblique Muscle The muscle indicated is the external oblique muscle of the abdomen. The external oblique muscle is the most superficial lateral muscle of the anterior abdominal wall. The three muscles which make up the lateral part of the anterior wall of the abdomen from superficial to deep are the: External oblique Internal oblique Transversus abdominis Origin: ribs 5-12 Insertion: Iliac crest, pubic tubercle, linea alba Innervation: thoracoabdominal nerve and subcostal nerve Action: Flexion and rotation of the vertebral column – brings about contralateral rotation of the torso. Unilateral contraction causes lateral flexion of the vertebral column. Important …

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External Abdominal Oblique

Anulus Fibrosus

Anulus Fibrosus The structure indicated is the anulus fibrosus of the intervertebral disc. Intervertebral discs are found between adjacent vertebral bodies in the spinal column. Intervertebral discs are one of two major joint types found in the vertebrae, the other type being synovial joints between the articular processes. The symphyses between the vertebral bodies consists of hyaline cartilage which lines the vertebral body, and an intervertebral disc which is sandwiched between the two adjacent intervertebral bodies to form this fibrocartilaginous joint. The intervertebral disc consist of Anulus fibrosus (outer component) Nucleus pulposus (inner component) The anulus fibrosus forms the outer …

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Anulus Fibrosus

Greater Trochanter

Greater Trochanter The arrow is pointing to the greater trochanter of the femur. The greater trochanter is a large quadrilateral eminence which forms the site of origin and insertion for several muscles: Origins: vastus lateralis Insertions: gluteus medius, gluteus minimus, obturator internus, piriformis The greater trochanter has two surfaces: Lateral Medial At the base of the greater trochanter is a deep depression known as the trochanteric fossa. Posteriorly is the intertrochanteric crest. The trochanteric fossa serves as the point of insertion for four muscles: Obturator externus Obturator internus Superior gemellus Inferior gemellus The greater trochanter has four borders: Superior Inferior …

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Greater Trochanter

Lateral Rectus Muscle

Lateral Rectus Muscle The structure indicated is the lateral rectus muscle. 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 Origin: Lateral part of annulus of Zinn Insertion: Lateral (temporal) aspect of eyeball Action: Abducts the eyeball – moves it away from the midline Innervation: Abducens nerve (Cranial nerve VI) If the abducens nerve is damaged (abducens nerves palsy/sixth nerve palsy), there is failure to abduct …

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Lateral Rectus Muscle

Semitendinosus

Semitendinosus The semitendinosus muscle is one of three muscles in the posterior compartment of the thigh. The other muscles are the semimembranosus, 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 the medial tibia. The semitendinosus sits on …

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Semitendinosus

Subacromial Bursa

Subacromial Bursa The structure indicated is the subacromial bursa. The glenohumeral joint is a synovial ball and socket joint between the head of the humerus and the glenoid cavity of the scapula. It is a joint with great mobility, at the expense of joint stability. Movements include: abduction, adduction, medial rotation, lateral rotation, flexion, extension, and circumduction. The joint is stabilised by, surrounding musculature, tendons, ligaments and the bony processes of adjacent structures. The synovial membrane lines the fibrous membrane of the joint capsule and it forms bursae as it passes through various openings in this membrane. Synovial bursae are …

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subacromial bursa

Suprascapular Notch

Suprascapular Notch The structure indicated is the suprascapular notch. The suprascapular notch is a notch in the superior border of the scapula, and lies medial to the base of the coracoid process. The superior transverse scapular ligament runs across the top of the notch, converting it into an opening, or foramen. Below this ligament, the suprascapular nerve passes through. Above this ligament, the transverse scapular vessels pass.
Suprascapular Notch

Tibia and Fibula

Learn all about the anatomy of the tibia and fibula in this tutorial.
tibia and fibula

Gracilis

Gracilis The muscle indicated is the gracilis. The gracilis is one of six muscles in the medial compartment of the thigh. The thigh consists of three muscular compartments: 1)      Anterior 2)      Medial 3)      Posterior The medial compartments consists of the following muscles: 1)      Gracilis 2)      Pectineus 3)      Adductor longus 4)      Adductor brevis 5)      Adductor magnus 6)      Obturator externus The gracilis is the most superficial muscle in the medial compartment. It is a thin muscle which descends vertically down the medial aspect of the thigh. Origin: inferior pubic ramus, ramus of ischium Insertion: proximal shaft of tibia medially (pes anserinus) Action: …

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Gracilis