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Crura Of The Diaphragm
The crus of diaphragm (pl. crura), refers to one of two tendinous structures that extends below the diaphragm to the vertebral column. There is a right crus and a left crus, which together form a tether for muscular contraction. They take their name from their leg-shaped appearance – '' crus'' meaning ''leg'' in Latin. Structure The crura originate from the front of the bodies and intervertebral fibrocartilage of the lumbar vertebrae. They are tendinous and blend with the anterior longitudinal ligament of the vertebral column. * The ''right crus'', larger and longer than the left, arises from the front of the bodies and intervertebral fibrocartilages of the upper three lumbar vertebrae. * The ''left crus'' arises from the corresponding parts of the upper two lumbar vertebrae only. The medial tendinous margins of the crura pass anteriorly and medialward, and meet in the middle line to form an arch across the front of the aorta known as the median arcuate ligament; this arch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thoracic Diaphragm
The thoracic diaphragm, or simply the diaphragm ( grc, διάφραγμα, diáphragma, partition), is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm is the most important muscle of respiration, and separates the thoracic cavity, containing the heart and lungs, from the abdominal cavity: as the diaphragm contracts, the volume of the thoracic cavity increases, creating a negative pressure there, which draws air into the lungs. Its high oxygen consumption is noted by the many mitochondria and capillaries present; more than in any other skeletal muscle. The term ''diaphragm'' in anatomy, created by Gerard of Cremona, can refer to other flat structures such as the urogenital diaphragm or pelvic diaphragm, but "the diaphragm" generally refers to the thoracic diaphragm. In humans, the diaphragm is slightly asymmetric—its right half is higher up (superior) to the left half, since the large li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aortic Hiatus
The aortic hiatus is a hole in the diaphragm. It is the lowest and most posterior of the large apertures. It is located approximately at the level of the twelfth thoracic vertebra (T12). Structure Strictly speaking, it is not an aperture in the diaphragm but an osseoaponeurotic opening between it and the vertebral column, and therefore behind the diaphragm (meaning that diaphragmatic contractions do not directly influence the aorta or aortic supply). Occasionally some tendinous fibers prolonged across the bodies of the vertebræ from the medial parts of the inferior ends of the crura pass posterior to the aorta, and thus convert the hiatus into a fibrous ring. The hiatus is situated slightly to the left of the mid line, and is bound anteriorly by the crura, and posteriorly by the body of the first lumbar vertebra. Structures passing through The structures that pass through the aortic hiatus are the aorta, the azygous vein and the thoracic duct In human anatomy, the thoraci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vena Caval Foramen
The thoracic diaphragm, or simply the diaphragm ( grc, διάφραγμα, diáphragma, partition), is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm is the most important muscle of respiration, and separates the thoracic cavity, containing the heart and lungs, from the abdominal cavity: as the diaphragm contracts, the volume of the thoracic cavity increases, creating a negative pressure there, which draws air into the lungs. Its high oxygen consumption is noted by the many mitochondria and capillaries present; more than in any other skeletal muscle. The term ''diaphragm'' in anatomy, created by Gerard of Cremona, can refer to other flat structures such as the urogenital diaphragm or pelvic diaphragm, but "the diaphragm" generally refers to the thoracic diaphragm. In humans, the diaphragm is slightly asymmetric—its right half is higher up (superior) to the left half, since the large liver re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esophageal Hiatus
In human anatomy, the esophageal hiatus is an opening in the diaphragm through which the esophagus and the vagus nerve pass. Structure It is located in the right crus, one of the two tendinous structures that connect the diaphragm to the spine. Fibers of the right crus cross one another below the hiatus. It is located approximately at level of the tenth thoracic vertebra ( T10) and the 8th or 9th intercostal spaces. The esophageal hiatus is situated in the muscular part of the diaphragm at the level of the tenth thoracic vertebra, and is elliptical in shape. It is placed superior, anterior, and slightly left of the aortic hiatus, and transmits the esophagus, the vagus nerve, the left inferior phrenic vessels, and some small esophageal arteries from left gastric vessels. The right crus of the diaphragm loops around forming a sling around the esophagus. Upon inspiration, this sling would constrict the esophagus, forming a functional (not anatomical) sphincter that prevents sto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Lumbocostal Arch
The lateral arcuate ligament (also lateral lumbocostal arch and external arcuate ligament) is a ligament under the diaphragm that arches across the upper part of the quadratus lumborum muscle. It is traversed by the subcostal nerve, artery and vein. Structure The lateral arcuate ligament runs from the front of the transverse process of the first lumbar vertebra, and, laterally, to the tip and lower margin of the twelfth rib. It forms an arch over the quadratus lumborum muscle. Variations The lateral arcuate ligament is commonly described in anatomy textbooks as attaching at the first lumbar vertebra (L1). However, other instances have been found in cadaver studies with attachments at either the second (L2) or third (L3) lumbar vertebra. In around 5% of people, inferolateral extensions of the lateral arcuate ligaments, such as thickened nodular areas, are found adjacent to the lateral diaphragmatic surface which can be visualized with computed tomography (CT) scans. History The l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aponeurotic
An aponeurosis (; plural: ''aponeuroses'') is a type or a variant of the deep fascia, in the form of a sheet of pearly-white fibrous tissue that attaches sheet-like muscles needing a wide area of attachment. Their primary function is to join muscles and the body parts they act upon, whether bone or other muscles. They have a shiny, whitish-silvery color, are histologically similar to tendons, and are very sparingly supplied with blood vessels and nerves. When dissected, aponeuroses are papery and peel off by sections. The primary regions with thick aponeuroses are in the ventral abdominal region, the dorsal lumbar region, the ventriculus in birds, and the palmar (palms) and plantar (soles) regions. Anatomy Anterior abdominal aponeuroses The anterior abdominal aponeuroses are located just superficial to the rectus abdominis muscle. It has for its borders the external oblique, pectoralis muscles, and the latissimus dorsi. Posterior lumbar aponeuroses The posterior lumbar aponeu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiphoid Process
The xiphoid process , or xiphisternum or metasternum, is a small cartilaginous process (extension) of the inferior (lower) part of the sternum, which is usually ossified in the adult human. It may also be referred to as the ensiform process. Both the Greek-derived ''xiphoid'' and its Latin equivalent ''ensiform'' mean 'swordlike' or 'sword-shaped' Structure The xiphoid process is considered to be at the level of the 9th thoracic vertebra and the T7 dermatome. Development In newborns and young (especially small) infants, the tip of the xiphoid process may be both seen and felt as a lump just below the sternal notch. At 15 to 29 years old, the xiphoid usually fuses to the body of the sternum with a fibrous joint. Unlike the synovial articulation of major joints, this is non-movable. Ossification of the xiphoid process occurs around age 40. Variation The xiphoid process can be naturally bifurcated or sometimes perforated (xiphoidal foramen). These variances in morphology are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Tendon Of Diaphragm
The central tendon of the diaphragm is a thin but strong aponeurosis situated slightly anterior to the vault formed by the muscle, resulting in longer posterior muscle fibers. It is inferior to the fibrous pericardium, which fuses with the central tendon of the diaphragm via the pericardiacophrenic ligament. The caval opening (at the level of the T8 vertebra) passes through the central tendon. This transmits the inferior vena cava and right phrenic nerve. Structure The central tendon is shaped somewhat like a trefoil leaf, consisting of three divisions or leaflets separated from one another by slight indentations. The right leaflet is the largest, the middle (directed toward the xiphoid process) the next in size, and the left the smallest. The central tendon is composed of several planes of fibers, which intersect one another at various angles and unite into straight or curved bundles—an arrangement which gives it additional strength. Action during respiration During ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Median Arcuate Ligament
The median arcuate ligament is a ligament under the diaphragm that connects the right and left crura of diaphragm. Structure The median arcuate ligament is formed by the right and left crura of the diaphragm. The crura connect to form an arch, behind which is the aortic hiatus, through which pass the aorta, the azygos vein, and the thoracic duct. Variation In between 10% and 24% of people, the median arcuate ligament occurs very low. Clinical significance Compression of celiac artery and celiac ganglia by the median arcuate ligament can lead to the median arcuate ligament syndrome, which is characterized by abdominal pain, weight loss, and an epigastric bruit. See also * Medial arcuate ligament The medial arcuate ligament (also medial lumbocostal arch and internal arcuate ligament) is a tendinous fascia that arches over the psoas major muscle as it passes posterior the diaphragm. Structure The medial arcuate ligament is an arch in the f ... * Lateral arcuate ligamen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability to withstand significant amounts of tension. Tendons are similar to ligaments; both are made of collagen. Ligaments connect one bone to another, while tendons connect muscle to bone. Structure Histologically, tendons consist of dense regular connective tissue. The main cellular component of tendons are specialized fibroblasts called tendon cells (tenocytes). Tenocytes synthesize the extracellular matrix of tendons, abundant in densely packed collagen fibers. The collagen fibers are parallel to each other and organized into tendon fascicles. Individual fascicles are bound by the endotendineum, which is a delicate loose connective tissue containing thin collagen fibrils and elastic fibres. Groups of fascicles are bounded by the epi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aorta
The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes oxygenated blood to all parts of the body through the systemic circulation. Structure Sections In anatomical sources, the aorta is usually divided into sections. One way of classifying a part of the aorta is by anatomical compartment, where the thoracic aorta (or thoracic portion of the aorta) runs from the heart to the diaphragm. The aorta then continues downward as the abdominal aorta (or abdominal portion of the aorta) from the diaphragm to the aortic bifurcation. Another system divides the aorta with respect to its course and the direction of blood flow. In this system, the aorta starts as the ascending aorta, travels superiorly from the heart, and then makes a hairpin turn known as the aortic arch. Following the aortic arch, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intervertebral Fibrocartilages
An intervertebral disc (or intervertebral fibrocartilage) lies between adjacent vertebrae in the vertebral column. Each disc forms a fibrocartilaginous joint (a symphysis), to allow slight movement of the vertebrae, to act as a ligament to hold the vertebrae together, and to function as a shock absorber for the spine. Structure Intervertebral discs consist of an outer fibrous ring, the anulus fibrosus disci intervertebralis, which surrounds an inner gel-like center, the nucleus pulposus. The ''anulus fibrosus'' consists of several layers (laminae) of fibrocartilage made up of both type I and type II collagen. Type I is concentrated toward the edge of the ring, where it provides greater strength. The stiff laminae can withstand compressive forces. The fibrous intervertebral disc contains the ''nucleus pulposus'' and this helps to distribute pressure evenly across the disc. This prevents the development of stress concentrations which could cause damage to the underlying vertebrae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
