Lateral sacral artery
The lateral sacral arteries arise from the posterior division of the internal iliac artery. The superior, of large size, passes medialward, after anastomosing with branches from the middle sacral, enters the first or second anterior sacral foramen, supplies branches to the contents of the sacral canal, escaping by the corresponding posterior sacral foramen, is distributed to the skin and muscles on the dorsum of the sacrum, anastomosing with the superior gluteal; the inferior runs obliquely across the front of the piriformis and the sacral nerves to the medial side of the anterior sacral foramina, descends on the front of the sacrum, anastomoses over the coccyx with the middle sacral and opposite lateral sacral artery. In its course it gives off branches. Median sacral artery This article incorporates text in the public domain from page 621 of the 20th edition of Gray's Anatomy Anatomy photo:43:13-0104 at the SUNY Downstate Medical Center - "The Female Pelvis: Branches of Internal Iliac Artery"
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 gluteus minimus, the smallest of the three gluteal muscles, is situated beneath the gluteus medius. It is fan-shaped, arising from the outer surface of the ilium, between the anterior and inferior gluteal lines, behind, from the margin of the greater sciatic notch; the fibers converge to the deep surface of a radiated aponeurosis, this ends in a tendon, inserted into an impression on the anterior border of the greater trochanter, gives an expansion to the capsule of the hip joint. It is a local stabilizer for the hip. A bursa is interposed between the greater trochanter. Between the gluteus medius and gluteus minimus are the deep branches of the superior gluteal vessels and the superior gluteal nerve; the deep surface of the gluteus minimus is in relation with the reflected tendon of the rectus femoris and the capsule of the hip joint. The gluteus medius and gluteus minimus abduct the thigh, when the limb is extended, are principally called into action in supporting the body on one limb, in conjunction with the tensor fasciæ latæ.
Their anterior fibers flex the hip, by drawing the greater trochanter forward, rotate the thigh inward, in which action they are assisted by the Tensor fasciæ latæ. Additionally, with the hip flexed, the gluteus minimus internally rotate the thigh. With the hip extended, the gluteus gluteus minimus externally rotate the thigh; the attachment to the superior capsule of the hip may serve to retract the capsule away from the joint during motion. This mechanism may prevent capsular impingement similar to the role of the articularis genus in the knee; the muscle may be divided into an anterior and a posterior part, or it may send slips to the piriformis, the superior gemellus or the outer part of the origin of the vastus lateralis. Paralysis of this muscle or gluteus medius, such as may be caused by the superior gluteal nerve palsy, can lead to difficulty abducting the leg. Patients will compensate for their difficulty walking by adopting a Trendelenburg gait; this article incorporates text in the public domain from page 475 of the 20th edition of Gray's Anatomy PTCentral Anatomy photo:13:st-0406 at the SUNY Downstate Medical Center
The hip bone is a large irregular bone, constricted in the center and expanded above and below. In some vertebrates it is composed of three parts: the ilium and the pubis; the two hip bones join at the pubic symphysis and together with the sacrum and coccyx comprise the skeletal component of the pelvis – the pelvic girdle which surrounds the pelvic cavity. They are connected to the sacrum, part of the axial skeleton, at the sacroiliac joint; each hip bone is connected to the corresponding femur through the large ball and socket joint of the hip. The hip bone is formed by three parts: ilium and pubis. At birth, these three components are separated by hyaline cartilage, they join each other in a Y-shaped portion of cartilage in the acetabulum. By the end of puberty the three regions will have fused together, by the age 25 they will have ossified; the two hip bones join each other at the pubic symphysis. Together with the sacrum and coccyx, the hip bones form the pelvis. Ilium is the largest region.
It makes up two fifths of the acetabulum. It is divisible into the ala or wing of ilium; the body of ilium forms the sacroiliac joint with the sacrum. The edge of the wing of ilium forms the S-shaped iliac crest, located through the skin; the iliac crest shows clear marks of the attachment of the three abdominal wall muscles. The ischium forms the lower and back part of the hip bone and is located below the ilium and behind the pubis; the ischium is the strongest of the three regions. It is divisible into three portions: the body, the superior ramus, the inferior ramus; the body forms one-third of the acetabulum. The ischium forms a large swelling, the tuberosity of the ischium referred to colloquially as the "sit bone"; when sitting, the weight is placed upon the ischial tuberosity. The gluteus maximus leaves it free in the seated position; the pubic region or pubis is the anterior of the three parts forming the hip bone. It is divisible into a body, a superior ramus, an inferior ramus; the body forms one-fifth of the acetabulum.
The body forms the wide, strong and flat portion of the pubic bone which unites with the other pubic bone in the pubic symphysis. The fibrocartilaginous pad which lies between the symphysial surfaces of the coxal bones, that secures the pubic symphysis, is called the interpubic disc; the pelvic brim is a continuous oval ridge of bone that runs along the pubic symphysis, pubic crests, arcuate lines, sacral alae, sacral promontory. The false pelvis is that portion superior to the pelvic brim; the true pelvis is the region inferior to the pelvic brim, entirely surrounded by bone. The pelvic inlet is the opening delineated by the pelvic brim; the widest dimension of the pelvic inlet is from left to right, that is, along the frontal plane. The pelvic outlet is the margin of the true pelvis, it is bounded anteriorly by the pubic arch, laterally by the ischia, posteriorly by the sacrum and coccyx. The superior pubic ramus is a part of the pubic bone, it extends from the body to the median plane where it articulates with its fellow of the opposite side.
It is conveniently described in two portions: a medial flattened part and a narrow lateral prismoid portion. The inferior pubic ramus is flat, it passes downward from the medial end of the superior ramus. It becomes narrower as it descends and joins with the inferior ramus of the ischium below the obturator foramen; the hip bone is ossified from eight centers: three primary, one each for the ilium and pubis, five secondary, one each for the iliac crest, the anterior inferior spine, the tuberosity of the ischium, the pubic symphysis, one or more for the Y-shaped piece at the bottom of the acetabulum. The centers appear in the following order: in the lower part of the ilium above the greater sciatic notch, about the eighth or ninth week of fetal life. At birth, the three primary centers are quite separate, the crest, the bottom of the acetabulum, the ischial tuberosity, the inferior rami of the ischium and pubis being still cartilaginous. By the seventh or eighth year, the inferior rami of the pubis and ischium are completely united by bone.
About the thirteenth or fourteenth year, the three primary centers have extended their growth into the bottom of the acetabulum, are there separated from each other by a Y-shaped portion of cartilage, which now presents traces of ossification by two or more centers. One of these, the os acetabuli, appears about the age of twelve, between the ilium and pubis, fuses with them about the age of eighteen; the ilium and ischium become joined, lastly the pubis and ischium, through the intervention of this Y-shaped portion. At about the age of puberty, ossification takes place in each of the remaining portions, they join with the rest of the bone between the twentieth and twenty-f
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
Sacral spinal nerve 1
The sacral spinal nerve 1 is a spinal nerve of the sacral segment. It originates from the spinal column from below the 1st body of the sacrum S1 supplies many muscles, either directly or through nerves originating from S1, they are not innervated with S1 as single origin, but by S1 and by other spinal nerves. The muscles are: gluteus maximus muscle gluteus medius muscle gluteus minimus muscle tensor fasciae latae piriformis obturator internus muscle inferior gemellus superior gemellus quadratus femoris semitendinosus gastrocnemius flexor hallucis longus abductor digiti minimi quadratus plantae
The obturator nerve in human anatomy arises from the ventral divisions of the second and fourth lumbar nerves in the lumbar plexus. It descends through the fibers of the psoas major, emerges from its medial border near the brim of the pelvis. Here it enters the thigh, through the obturator canal, divides into an anterior and a posterior branch, which are separated at first by some of the fibers of the obturator externus, lower down by the adductor brevis; the obturator nerve is responsible for the sensory innervation of the skin of the medial aspect of the thigh. The nerve is responsible for the motor innervation of the adductor muscles of the lower limb and the pectineus, it is, not responsible for the innervation of the obturator internus, despite the similarity in name. Anterior branch of obturator nerve Posterior branch of obturator nerve Cutaneous branch of the obturator nerve Obturator_nerve at the Duke University Health System's Orthopedics program Anatomy photo:12:st-0602 at the SUNY Downstate Medical Center Cross section image: pelvis/pelvis-female-17—Plastination Laboratory at the Medical University of Vienna posteriorabdomen at The Anatomy Lesson by Wesley Norman cutaneous field at neuroguide.com This article incorporates text in the public domain from page 953 of the 20th edition of Gray's Anatomy