Internal obturator muscle
The internal obturator muscle or obturator internus muscle originates on the medial surface of the obturator membrane, the ischium near the membrane, the rim of the pubis. It exits the pelvic cavity through the lesser sciatic foramen; the internal obturator is situated within the lesser pelvis, at the back of the hip-joint. It functions to help laterally rotate femur with hip extension and abduct femur with hip flexion, as well as to steady the femoral head in the acetabulum, it arises from the inner surface of the antero-lateral wall of the pelvis, where it surrounds the greater part of the obturator foramen, being attached to the inferior pubic ramus and ischium, at the side to the inner surface of the hip bone below and behind the pelvic brim, reaching from the upper part of the greater sciatic foramen above and behind to the obturator foramen below and in front. It arises from the pelvic surface of the obturator membrane except in the posterior part, from the tendinous arch which completes the canal for the passage of the obturator vessels and nerve, to a slight extent from the obturator fascia, which covers the muscle.
The fibers converge toward the lesser sciatic foramen, end in four or five tendinous bands, which are found on the deep surface of the muscle. The tendon inserts on the greater trochanter of the proximal femur; the internal obturator muscle is innervated by the nerve to internal obturator. This bony surface is covered by smooth cartilage, separated from the tendon by a bursa, presents one or more ridges corresponding with the furrows between the tendinous bands; these bands leave the pelvis through the lesser sciatic foramen and unite into a single flattened tendon, which passes horizontally across the capsule of the hip-joint, after receiving the attachments of the superior and inferior gemellus muscles, is inserted into the forepart of the medial surface of the greater trochanter above the trochanteric fossa. A bursa and elongated in form, is found between the tendon and the capsule of the hip-joint; this article incorporates text in the public domain from page 477 of the 20th edition of Gray's Anatomy Anatomy photo:13:st-0407 at the SUNY Downstate Medical Center - "Gluteal Region: Muscles" Anatomy photo:43:st-0603 at the SUNY Downstate Medical Center - "The Female Pelvis: Muscles" Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna pelvis at The Anatomy Lesson by Wesley Norman perineum at The Anatomy Lesson by Wesley Norman Int.
J. Morphol. 25:95-98, 2007
The sartorius muscle is the longest muscle in the human body. It is a long, superficial muscle that runs down the length of the thigh in the anterior compartment; the sartorius muscle originates from the anterior superior iliac spine and part of the notch between the anterior superior iliac spine and anterior inferior iliac spine. It runs obliquely across the anterior part of the thigh in an inferomedial direction, it passes behind the medial condyle of the femur to end in a tendon. This tendon curves anteriorly to join the tendons of the gracilis and semitendinosus muscles in the pes anserinus, where it inserts into the superomedial surface of the tibia, its upper portion forms the lateral border of the femoral triangle, the point where it crosses adductor longus marks the apex of the triangle. Deep to sartorius and its fascia is the adductor canal, through which the saphenous nerve, femoral artery and vein, nerve to vastus medialis pass. Like the other muscles in the anterior compartment of the thigh, sartorius is innervated by the femoral nerve.
It may originate from the outer end of the inguinal ligament, the notch of the ilium, the ilio-pectineal line or the pubis. The muscle may be split into two parts, one part may be inserted into the fascia lata, the femur, the ligament of the patella or the tendon of the semitendinosus; the tendon of insertion may end in the fascia lata, the capsule of the knee-joint, or the fascia of the leg. The muscle may be absent in some people; the sartorius muscle can move the hip joint and the knee joint, but all of its actions are weak, making it a synergist muscle. At the hip, it can flex, weakly abduct, laterally rotate the thigh. At the knee, it can flex the leg. Turning the foot to look at the sole or sitting cross-legged demonstrates all four actions of the sartorius. One of the many conditions that can disrupt the use of the sartorius is pes anserine bursitis, an inflammatory condition of the medial portion of the knee; this condition occurs in athletes from overuse and is characterized by pain and tenderness.
The pes anserinus is made up from the tendons of the gracilis and sartorius muscles. When inflammation of the bursa underlying the tendons occurs they separate from the head of the tibia. Sartorius comes from the Latin word sartor, meaning tailor, it is sometimes called the tailor's muscle; this name was chosen in reference to the cross-legged position. In French, the muscle name itself "couturier" comes from this specific position, referred to as "sitting as a tailor". There are other hypotheses as to the genesis of the name. One is that it refers to the location of the inferior portion of the muscle being the "inseam" or area of the inner thigh that tailors measure when fitting trousers. Another is that the muscle resembles a tailor's ribbon. Additionally, antique sewing machines required continuous cross body pedaling; this combination of lateral rotation and flexion of the hip and flexion of the knee gave tailors enlarged sartorius muscles. The sartorius is called the honeymoon muscle; this article incorporates text in the public domain from page 470 of the 20th edition of Gray's Anatomy Anatomy photo:14:st-0407 at the SUNY Downstate Medical Center Cross section image: pembody/body15a—Plastination Laboratory at the Medical University of Vienna Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna
External obturator muscle
The external obturator muscle, obturator externus muscle is a flat, triangular muscle, which covers the outer surface of the anterior wall of the pelvis. It is sometimes considered part of the medial compartment of thigh, sometimes considered part of the gluteal region, it arises from the margin of bone around the medial side of the obturator membrane and surrounding bone, viz. from the inferior pubic ramus, the ramus of the ischium. The fibers springing from the pubic arch extend on to the inner surface of the bone, where they obtain a narrow origin between the margin of the foramen and the attachment of the obturator membrane; the fibers converge and pass posterolateral and upward, end in a tendon which runs across the back of the neck of the femur and lower part of the capsule of the hip joint and is inserted into the trochanteric fossa of the femur. The obturator vessels lie between the obturator membrane. In 33 % of people a supernumerary muscle is found between the adductor minimus. While this muscle, when present, is similar to its neighbouring adductors, it is formed by separation from the superficial layer of the external obturator, is thus not ontogenetically related to the adductor muscles of the hip.
This muscle originates from the upper part of the inferior pubic ramus from where it runs downwards and laterally. In half of cases, it inserts into the anterior surface of the insertion aponeurosis of the adductor minimus. In the remaining cases, it is either inserted into the upper part of the pectineal line or the posterior part of the lesser trochanter, it has been demonstrated by the course of the posterior branch of obturator nerve that the obturator externus is divided into a superior muscle fascicle and a main belly. The supernumerary muscle described above originates from the superior fascicle, while an anomalous fascicle — derived from the external obturator — originates from the main belly; the "original" external obturator, i.e. without these supernumerary muscular parts occurs in only 20% of cases, the external obturator undergoes ontogenetic variations. The external obturator muscle acts as the lateral rotator of the hip joint; as a short muscle around the hip joint, it stabilizes the hip joint as a postural muscle.
This article incorporates text in the public domain from page 477 of the 20th edition of Gray's Anatomy Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna lljoints at The Anatomy Lesson by Wesley Norman PTCentral
In human anatomy, the thigh is the area between the hip and the knee. Anatomically, it is part of the lower limb; the single bone in the thigh is called the femur. This bone is thick and strong, forms a ball and socket joint at the hip, a modified hinge joint at the knee; the femur is the only bone in the thigh and serves for an attachment site for all muscles in the thigh. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with the tibia and kneecap forming the knee. By most measures the femur is the strongest bone in the body; the femur is the longest bone in the body. The femur is categorised as a long bone and comprises a diaphysis, the shaft and two epiphysis or extremities that articulate with adjacent bones in the hip and knee. In cross-section, the thigh is divided up into three separate compartments, divided by fascia, each containing muscles; these compartments use the femur as an axis, are separated by tough connective tissue membranes.
Each of these compartments has its own blood and nerve supply, contains a different group of muscles. Medial fascial compartment of thigh, adductor Posterior fascial compartment of thigh, hamstring Anterior fascial compartment of thigh, extensionAnterior compartment muscles of the thigh include sartorius, the four muscles that comprise the quadriceps muscles- rectus femoris, vastus medialis, vastus intermedius and vastus lateralis. Posterior compartment muscles of the thigh are the hamstring muscles, which include semimembranosus and biceps femoris. Medial compartment muscles are pectineus, adductor magnus, adductor longus and adductor brevis, gracilis; because the major muscles of the thigh are the largest muscles of the body, resistance exercises of them stimulate blood flow more than any other localized activity. The arterial supply is by the obturator artery; the lymphatic drainage follows the arterial supply and drains to the lumbar lymphatic trunks on the corresponding side, which in turn drains to the cisterna chyli.
The deep venous system of the thigh consists of the femoral vein, the proximal part of the popliteal vein, various smaller vessels. The venae perfortantes connect the deep and the superficial system, which consists of the saphenous veins. Thigh weakness can result in a positive Gowers' sign on physical examination; the thigh meat of some animals such as chicken and cow is consumed as a food in many parts of the world
The iliacus is a flat, triangular muscle which fills the iliac fossa. It forms the lateral portion of iliopsoas, providing flexion of the thigh and lower limb at the acetabulofemoral joint; the iliacus arises from the iliac fossa on the interior side of the hip bone, from the region of the anterior inferior iliac spine. It joins the psoas major to form the Iliopsoas as which it proceeds across the iliopubic eminence through the muscular lacuna to its insertion on the lesser trochanter of the femur, its fibers are inserted in front of those of the psoas major and extend distally over the lesser trochanter. The iliopsoas is innervated by direct branches from the lumbar plexus. In open-chain exercises, as part of the iliopsoas, the iliacus is important for lifting the femur forward. In closed-chain exercises, the iliopsoas bends the trunk forward and can lift the trunk from a lying posture because the psoas major crosses several vertebral joints and the sacroiliac joint. From its origin in the lesser pelvis the iliacus acts on the hip joint.
Platzer, Werner. Color Atlas of Human Anatomy, Vol. 1: Locomotor System. Thieme. ISBN 3-13-533305-1. Thieme Atlas of Anatomy: General Anatomy and Musculoskeletal System. Thieme. 2006. ISBN 1-58890-419-9. PTCentral Anatomy figure: 40:07-05 at Human Anatomy Online, SUNY Downstate Medical Center - "Muscles and nerves of the posterior abdominal wall." Pelvis at The Anatomy Lesson by Wesley Norman
The phalanges are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges; the phalanges are classed as long bones. The phalanges are the bones that make up the toes of the foot. There are 56 phalanges in the human body, with fourteen on each foot. Three phalanges are present on each finger and toe, with the exception of the thumb and large toe, which possess only two; the middle and far phalanges of the fourth and fifth toes are fused together. The phalanges of the hand are known as the finger bones; the phalanges of the foot differ from the hand in that they are shorter and more compressed in the proximal phalanges, those closest to the body. A phalanx is named according to whether it is proximal, middle, or distal and its associated finger or toe; the proximal phalanges are those that are closest to foot. In the hand, the prominent, knobby ends of the phalanges are known as knuckles; the proximal phalanges join with the metacarpals of the hand or metatarsals of the foot at the metacarpophalangeal joint or metatarsophalangeal joint.
The intermediate phalanx is not only intermediate in location, but also in size. The thumb and large toe do not possess a middle phalanx; the distal phalanges are the bones at the tips of the toes. The proximal and distal phalanges articulate with one another through interphalangeal articulations; each phalanx consists of a central part, called the body, two extremities. The body is flat on either side, concave on the palmar surface, convex on the dorsal surface, its sides are marked with rough areas giving attachment to fibrous sheaths of flexor tendons. It tapers from above downwards; the proximal extremities of the bones of the first row present oval, concave articular surfaces, broader from side to side than from front to back. The proximal extremity of each of the bones of the second and third rows presents a double concavity separated by a median ridge; the distal extremities are smaller than the proximal, each ends in two condyles separated by a shallow groove. In the foot, the proximal phalanges have a body, compressed from side to side, convex above, concave below.
The base is concave, the head presents a trochlear surface for articulation with the second phalanx. The middle are rather broader than the proximal; the distal phalanges, as compared with the distal phalanges of the finger, are smaller and are flattened from above downward. In the hand, the distal phalanges are flat on their palmar surface and with a roughened, elevated surface of horseshoe form on the palmar surface, supporting the finger pulp; the flat, wide expansions found at the tips of the distal phalanges are called apical tufts. They support the fingertip nails; the phalanx of the thumb has a pronounced insertion for the flexor pollicis longus, an ungual fossa, a pair of unequal ungual spines. This asymmetry is necessary to ensure that the thumb pulp is always facing the pulps of the other digits, an osteological configuration which provides the maximum contact surface with held objects. In the foot, the distal phalanges are flat on their dorsal surface, it is tapers to the distal end.
The proximal part of the phalnx presents a broad base for articulation with the middle phalanx, an expanded distal extremity for the support of the nail and end of the toe. The phalanx ends in a crescent-shaped rough cap of bone epiphysis — the apical tuft which covers a larger portion of the phalanx on the volar side than on the dorsal side. Two lateral ungual spines project proximally from the apical tuft. Near the base of the shaft are two lateral tubercles. Between these a V-shaped ridge extending proximally serves for the insertion of the flexor pollicis longus. Another ridge at the base serves for the insertion of the extensor aponeurosis; the flexor insertion is sided by two fossae — the ungual fossa distally and the proximopalmar fossa proximally. The number of phalanges in animals is expressed as a "phalangeal formula" that indicates the numbers of phalanges in digits, beginning from the innermost medial or proximal. For example, humans have a 2-3-3-3-3 formula for the hand, meaning that the thumb has two phalanges, whilst the other fingers each have three.
In the distal phalanges of the hand the centres for the bodies appear at the distal extremities of the phalanges, instead of at the middle of the bodies, as in the other phalanges. Moreover, of all the bones of the hand, the distal phalanges are the first to ossify; the distal phalanges of ungulates carry and shape nails and claws and these in primates are referred to as the ungual phalanges. The term phalanx or phalanges refers to an ancient Greek army formation in which soldiers stand side by side, several rows deep, like an arrangement of fingers or toes. Most land mammals including humans have a 2-3-3-3-3 formula in feet. Primitive reptiles had the formula 2-3-4-4-5, this pattern, with some modification, remained in many reptiles and in the mammal-like reptiles; the phalangeal formula in the flippers of cetaceans is 2-12-8-1. In vertebrates, proximal phalanges have a similar placement in the corr
Anterior compartment of thigh
The anterior compartment of thigh contains muscles which extend the knee and flex the hip. The anterior compartment is one of the fascial compartments of the thigh that contains groups of muscles together with their nerves and blood supply; the anterior compartment contains the sartorius muscle and the quadriceps femoris group, which consists of the rectus femoris muscle and the three vasti muscles – the vastus lateralis, vastus intermedius, the vastus medialis. The iliopsoas is sometimes considered a member of the anterior compartment muscles, as is the articularis genus muscle; the anterior compartment is separated from the posterior compartment by the lateral intermuscular septum and from the medial compartment by the medial intermuscular septum. The nerve of the anterior compartment of thigh is the femoral nerve. Innervation for the quadriceps muscles come from the posterior division of the femoral nerve, while the anterior division gives a lateral and a medial branch, the second being responsible for the innervation of the sartorius muscle.
The iliacus and the psoas major and psoas minor muscles, sometimes considered part of the anterior compartment, do not share the same innervation. Whereas the iliacus is innervated by the femoral nerve, the psoas is innervated by ventral rami of L1-L3; when the external iliac artery crosses the inguinal ligament, it becomes the femoral artery, which supplies blood to the anterior compartment and is the largest blood vessel of the inferior member. The anterior compartment of thigh contains muscles which are extensors of the knee and flexors of the hip joints; the anterior compartment may be affected as part of a compartment syndrome. Antthigh at The Anatomy Lesson by Wesley Norman knee/muscles/thigh1 at the Dartmouth Medical School's Department of Anatomy Overview at stanford.edu