Adductor brevis muscle
The adductor brevis is a muscle in the thigh situated deep to the pectineus and adductor longus. It belongs to the adductor muscle group; the main function of the adductor brevis is to pull the thigh medially. The adductor brevis and the rest of the adductor muscle group is used to stabilize left to right movements of the trunk, when standing on both feet, or to balance when standing on a moving surface; the adductor muscle group is used pressing the thighs together to ride a horse, kicking with the inside of the foot in soccer or swimming. Last, they contribute to flexion of the thigh or against resistance, it is somewhat triangular in form, arises by a narrow origin from the outer surfaces of the body of the pubis and inferior rami of the pubis, between the gracilis and obturator externus. It widens in triangular fashion to be inserted into the upper part of the linea aspera lateral to the insertion of pectineus and above that of adductor longus. By its anterior surface, the adductor brevis is in relation with the pectineus, adductor longus, anterior branches of the obturator artery, the obturator vein, the obturator nerve.
By its posterior surface with the adductor magnus and the posterior branches of the obturator artery, the obturator vein, the obturator nerve. By its outer border with the obturator externus, the iliopsoas. By its inner border with the gracilis and adductor magnus, it is pierced near its insertion by the middle perforating artery. The adductor brevis is innervated dually by the anterior and posterior branches of the obturator nerve; the muscle is known as a hip adductor. It functions as a hip flexor. Whether it acts to rotate the femur laterally or medially is dependent on position; this article incorporates text in the public domain from page 473 of the 20th edition of Gray's Anatomy Cross section image: pembody/body18b—Plastination Laboratory at the Medical University of Vienna Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna PTCentral
Quadratus femoris muscle
The quadratus femoris is a flat, quadrilateral skeletal muscle. Located on the posterior side of the hip joint, it is a strong external rotator and adductor of the thigh, but acts to stabilize the femoral head in the acetabulum, it originates on the lateral border of the ischial tuberosity of the ischium of the pelvis. From there, it passes laterally to its insertion on the posterior side of the head of the femur: the quadrate tubercle on the intertrochanteric crest and along the quadrate line, the vertical line which runs downward to bisect the lesser trochanter on the medial side of the femur. Along its course, quadratus is aligned edge to edge with the inferior gemellus above and the adductor magnus below, so that its upper and lower borders run horizontal and parallel. At its origin, the upper margin of the adductor magnus is separated from it by the terminal branches of the medial femoral circumflex vessels. A bursa is found between the front of this muscle and the lesser trochanter. Sometimes absent.
Groin pain can be a disabling ailment with many potential root causes: one such cause overlooked, is quadratus femoris tendinitis. Magnetic resonance imaging can show abnormal signal intensity at the insertion of the right quadratus femoris tendon, which suggests inflammation of the area. Since the muscle works to laterally rotate and adduct the femur, actions involving the lower body can strain the muscle. In addition, patients present with hip pain and an increased signal intensity of the MRI of the quadratus femoris have been shown to have a narrower ischiofemoral space compared to the general populace; the ischiofemoral impingement may be a cause of the hip pain associated with quadratus femoris tendinitis. This article incorporates text in the public domain from page 477 of the 20th edition of Gray's Anatomy Mcminn, R. M. H.. Last's Applied. Elsevier Australia. ISBN 0-7295-3752-8. Platzer, Werner. Color Atlas of Human Anatomy, Vol 1: Locomotor system. Thieme. ISBN 3-13-533305-1. Thieme Atlas of Anatomy.
Thieme. 2006. ISBN 978-1-60406-062-1. PTCentral Anatomy photo:13:st-0409 at the SUNY Downstate Medical Center
The linea aspera is a ridge of roughened surface on the posterior surface of the shaft of the femur, to which are attached muscles and intermuscular septum. Its margins diverge below; the linea aspera is a prominent longitudinal ridge or crest, on the middle third of the bone, presenting a medial and a lateral lip, a narrow rough, intermediate line. It is an important insertion point for the adductors and the lateral and medial intermuscular septa that divides the thigh into three compartments; the tension generated by muscle attached to the bones is responsible for the formation of the ridges. Above, the linea aspera is prolonged by three ridges; the lateral ridge is rough, runs vertically upward to the base of the greater trochanter. It is termed the gluteal tuberosity, gives attachment to part of the gluteus maximus: its upper part is elongated into a roughened crest, on which a more or less well-marked, rounded tubercle, the third trochanter, is developed; the intermediate ridge or pectineal line is continued to the base of the lesser trochanter and gives attachment to the pectineus.
Below, the linea aspera is prolonged into two ridges, enclosing between them a triangular area, the popliteal surface, upon which the popliteal artery rests. Of these two ridges, the lateral is the more prominent, descends to the summit of the lateral condyle; the medial is less marked at its upper part, where it is crossed by the femoral artery. It ends below at the summit of the medial condyle, in a small tubercle, the adductor tubercle, which affords insertion to the tendon of the adductor magnus; the tension generated by muscle attached to the bones is responsible for the formation of the ridges. A number of muscles attach to the linea aspera: From the medial lip of the linea aspera and its prolongations above and below, the vastus medialis originates. From the lateral lip and its upward prolongation, the vastus lateralis takes origin; the adductor magnus is inserted into the linea aspera, to its lateral prolongation above, its medial prolongation below. Between the vastus lateralis and the adductor magnus two muscles are attached: the gluteus maximus inserted above, the short head of the biceps femoris originating below.
Between the adductor magnus and the vastus medialis four muscles are inserted: the iliacus and pectineus above. The linea aspera is perforated a little below its center by the nutrient canal, directed obliquely upward; this article incorporates text in the public domain from page 246 of the 20th edition of Gray's Anatomy University of Washington DartmouthAnatomy
Adductor tubercle of femur
The adductor tubercle is a tubercle on the Lower extremity of the femur. The medial lips of the linea aspera ends below at the summit of the medial condyle, in a small tubercle, the adductor tubercle, which affords insertion to the tendon of the vertical fibers of adductor magnus; this article incorporates text in the public domain from page 246 of the 20th edition of Gray's Anatomy Anatomy photo:12:os-0206 at the SUNY Downstate Medical Center Diagram at gla.ac.uk
Anatomical terms of muscle
Muscles are described using unique anatomical terminology according to their actions and structure. There are three types of muscle tissue in the human body: skeletal and cardiac. Skeletal striated muscle, or "voluntary muscle" joins to bone with tendons. Skeletal muscle maintains posture. Smooth muscle tissue is found in parts of the body; the majority of this type of muscle tissue is found in the digestive and urinary systems where it acts by propelling forward food and feces in the former and urine in the latter. Other places smooth muscle can be found are within the uterus, where it helps facilitate birth, the eye, where the pupillary sphincter controls pupil size. Cardiac muscle is specific to the heart, it is involuntary in its movement, is additionally self-excitatory, contracting without outside stimuli. As well as anatomical terms of motion, which describe the motion made by a muscle, unique terminology is used to describe the action of a set of muscles. Agonist muscles and antagonist muscles refer to muscles that inhibit a movement.
Agonist muscles cause a movement to occur through their own activation. For example, the triceps brachii contracts, producing a shortening contraction, during the up phase of a push-up. During the down phase of a push-up, the same triceps brachii controls elbow flexion while producing a lengthening contraction, it is still the agonist, because while resisting gravity during relaxing, the triceps brachii continues to be the prime mover, or controller, of the joint action. Agonists are interchangeably referred to as "prime movers," since they are the muscles considered responsible for generating or controlling a specific movement. Another example is the dumbbell curl at the elbow; the "elbow flexor" group is the agonist. During the lowering phase the "elbow flexor" muscles lengthen, remaining the agonists because they are controlling the load and the movement. For both the lifting and lowering phase, the "elbow extensor" muscles are the antagonists, they shorten during the dumbbell lowering phase.
Here it is important to understand that it is common practice to give a name to a muscle group based on the joint action they produce during a shortening contraction. However, this naming convention does not mean; this term describes the function of skeletal muscles. Antagonist muscles are the muscles that produce an opposing joint torque to the agonist muscles; this torque can aid in controlling a motion. The opposing torque can slow movement down - in the case of a ballistic movement. For example, during a rapid discrete movement of the elbow, such as throwing a dart, the triceps muscles will be activated briefly and to accelerate the extension movement at the elbow, followed immediately by a "burst" of activation to the elbow flexor muscles that decelerates the elbow movement to arrive at a quick stop. To use an automotive analogy, this would be similar to pressing your gas pedal and immediately pressing the brake. Antagonism is not an intrinsic property of a particular muscle group. During slower joint actions that involve gravity, just as with the agonist muscle, the antagonist muscle can shorten and lengthen.
Using the example above of the triceps brachii during a push-up, the elbow flexor muscles are the antagonists at the elbow during both the up phase and down phase of the movement. During the dumbbell curl, the elbow extensors are the antagonists for both the lifting and lowering phases. Antagonist and agonist muscles occur in pairs, called antagonistic pairs; as one muscle contracts, the other relaxes. An example of an antagonistic pair is the triceps. "Reverse motions" need antagonistic pairs located in opposite sides of a joint or bone, including abductor-adductor pairs and flexor-extensor pairs. These consist of an extensor muscle, which "opens" the joint and a flexor muscle, which does the opposite by decreasing the angle between two bones. However, muscles don't always work this way. Sometimes during a joint action controlled by an agonist muscle, the antagonist will be activated, naturally; this occurs and is not considered to be a problem unless it is excessive or uncontrolled and disturbs the control of the joint action.
This serves to mechanically stiffen the joint. Not all muscles are paired in this way. An example of an exception is the deltoid. Synergist muscles help perform, the same set of joint motion as the agonists. Synergists muscles act on movable joints. Synergists are sometimes referred to as "neutralizers" because they help cancel out, or neutralize, extra motion from the agonists to make sure that the force generated works within the desired plane of motion. Muscle fibers can only contract up to 40% of their stretched length, thus the short fibers of pennate muscles are more suitable where power rather than range of contraction is required. This limitation in the range of contraction affects all muscles, those that act over several joints may be unable to shorten sufficiently to produce
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
Anatomical terms of location
Standard anatomical terms of location deal unambiguously with the anatomy of animals, including humans. All vertebrates have the same basic body plan – they are bilaterally symmetrical in early embryonic stages and bilaterally symmetrical in adulthood; that is, they have mirror-image left and right halves if divided down the middle. For these reasons, the basic directional terms can be considered to be those used in vertebrates. By extension, the same terms are used for many other organisms as well. While these terms are standardized within specific fields of biology, there are unavoidable, sometimes dramatic, differences between some disciplines. For example, differences in terminology remain a problem that, to some extent, still separates the terminology of human anatomy from that used in the study of various other zoological categories. Standardized anatomical and zoological terms of location have been developed based on Latin and Greek words, to enable all biological and medical scientists to delineate and communicate information about animal bodies and their component organs though the meaning of some of the terms is context-sensitive.
The vertebrates and Craniata share a substantial heritage and common structure, so many of the same terms are used for location. To avoid ambiguities this terminology is based on the anatomy of each animal in a standard way. For humans, one type of vertebrate, anatomical terms may differ from other forms of vertebrates. For one reason, this is because humans have a different neuraxis and, unlike animals that rest on four limbs, humans are considered when describing anatomy as being in the standard anatomical position, thus what is on "top" of a human is the head, whereas the "top" of a dog may be its back, the "top" of a flounder could refer to either its left or its right side. For invertebrates, standard application of locational terminology becomes difficult or debatable at best when the differences in morphology are so radical that common concepts are not homologous and do not refer to common concepts. For example, many species are not bilaterally symmetrical. In these species, terminology depends on their type of symmetry.
Because animals can change orientation with respect to their environment, because appendages like limbs and tentacles can change position with respect to the main body, positional descriptive terms need to refer to the animal as in its standard anatomical position. All descriptions are with respect to the organism in its standard anatomical position when the organism in question has appendages in another position; this helps avoid confusion in terminology. In humans, this refers to the body in a standing position with arms at the side and palms facing forward. While the universal vertebrate terminology used in veterinary medicine would work in human medicine, the human terms are thought to be too well established to be worth changing. Many anatomical terms can be combined, either to indicate a position in two axes or to indicate the direction of a movement relative to the body. For example, "anterolateral" indicates a position, both anterior and lateral to the body axis. In radiology, an X-ray image may be said to be "anteroposterior", indicating that the beam of X-rays pass from their source to patient's anterior body wall through the body to exit through posterior body wall.
There is no definite limit to the contexts in which terms may be modified to qualify each other in such combinations. The modifier term is truncated and an "o" or an "i" is added in prefixing it to the qualified term. For example, a view of an animal from an aspect at once dorsal and lateral might be called a "dorsolateral" view. Again, in describing the morphology of an organ or habitus of an animal such as many of the Platyhelminthes, one might speak of it as "dorsiventrally" flattened as opposed to bilaterally flattened animals such as ocean sunfish. Where desirable three or more terms may be agglutinated or concatenated, as in "anteriodorsolateral"; such terms sometimes used to be hyphenated. There is however little basis for any strict rule to interfere with choice of convenience in such usage. Three basic reference planes are used to describe location; the sagittal plane is a plane parallel to the sagittal suture. All other sagittal planes are parallel to it, it is known as a "longitudinal plane".
The plane is perpendicular to the ground. The median plane or midsagittal plane is in the midline of the body, divides the body into left and right portions; this passes through the head, spinal cord, and, in many animals, the tail. The term "median plane" can refer to the midsagittal plane of other structures, such as a digit; the frontal plane or coronal plane divides the body into ventral portions. For post-embryonic humans a coronal plane is vertical and a transverse plane is horizontal, but for embryos and quadrupeds a coronal plane is horizontal and a transverse plane is vertical. A longitudinal plane is any plane perpendicular to the transverse plane; the coronal plane and the sagittal plane are examples of longitudinal planes. A transverse plane known as a cross-section, divides the body into cranial and caudal portions. In human anatomy: A transverse plane is an X-Z plane, parallel to the ground, which s