Anatomy 534 Anterior Abdominothoracic Wall PDF

differentes get tested Anatomy 534 Anterior Abdominothoracic Wall 83 breast a "dimpled" or orange peel appearance in advanced stages of carcinoma. Anterior Thoracic Wall I The ribs are used to anchor muscles from - upper limb - p...

differentes get tested Anatomy 534 Anterior Abdominothoracic Wall 83 breast a "dimpled" or orange peel appearance in advanced stages of carcinoma. Anterior Thoracic Wall I The ribs are used to anchor muscles from - upper limb - pectoralis major - pectoralis minor an - abdomen - external oblique - back - serratus anterior III These can all be considered as accessory muscles of respiration that can be utilized in breathing distress by fixing the pectoral If girdles (scapula and clavicle) so these muscles thenact on the rib cage. WE pitoralis I anteriorly iiiiiii it mitiisei kiddsteade 9th  Anatomy 534 Anterior Abdominothoracic Wall 84 The Lateral Wall Muscles of the Trunk The muscles forming the lateral walls of the thorax and abdomen are paired oblique and transverse muscle groups. Although these three layers are found in both regions, we will look at them separately beginning in the thorax: Muscles of the Thoracic Wall: The intercostal muscles fill the space between the ribs and are found organized into 3 layers: i) external intercostals extend from the posterior aspect around to the costochondral junction where they become a membrane - the anterior intercostal membrane. The fibers are directed inferomedially (like putting your hands into your pockets). They are continuous with the fibers of the external oblique mm. of the anterior abdominal wall. Bitten and 3rd jfof.ly nmi iawan ftp.fififiifffd fIfffftfffd if.FI fiiiiiei iifiiiiiiiiii.it i.ie i.EE iif ste ii) internal intercostals extend from the sternum around to the angle of the ribs where they become a membrane - the internal intercostal membrane. The fibers of this layer run at right angles to those in the external layer - inferoposterior in direction. They are  Anatomy 534 Anterior Abdominothoracic Wall 85 continuous with the internal oblique mm. of the anterior abdominal wall. iii) the third layer is composed of three muscles linked in a membrane. These will not be seen until the thorax is opened and the lungs removed as they are the innermost layer. - the transversus thoracis attach to the back of the sternum and xiphoid process. They are obliquely oriented inferoposteriorly and may skip up to two ribs before reattaching. They are considered to be continuous with the transversus adbominis mm. of the anterior abdominal wall. - innermost intercostals are found along the mid-axillary line. They are similar in direction to the internal intercostals and may be considered a subset of them, separated by the intercostal neurovascular bundle. - the subcostals are found posteriorly near the angle of the ribs. They characteristically cross one rib before reattaching. All these muscles function in elevating the ribs, expanding the thoracic diameter and keeping the intercostal spaces rigid to prevent the lungs pushing the muscle outward. The muscles of the a intercostal spaces are innervated segmentally by the 2st ventral rami of the spinal nerves which from T1-T12 are referred to as inter- costal nerves. The sep intercostal nerves also give rise to lateral and anterior cutaneous br. that supply the over- lying skin in a band- it iiill like (dermatome) fashion. The post- erior (dorsal) aspect is supplied segmentally as well by the dorsal II rami of the spinal nerves. I in Section Through an Intercostal Space The muscles receive their arterial supply from branches of the anterior and posterior inter- costal arteries that arise from the internal thoracic and aorta respectively. These vessels also Anatomy 534 Anterior Abdominothoracic Wall 86 give rise to posterior, lateral and anterior (perforating) cutaneous br. that supply the overlying skin in a band-like fashion. The anterior and posterior intercostal arteries anastomose within the intercostal space. Venous drainage of the intercostal spaces is accomplished through intercostal veins that drain either to the internal thoracic veins (anteriorly) or the azygous/hemiazygous system (poster- iorly) of the thorax. Muscles of the Anterolateral Abdominal Wall: Three muscle layers form the anterolateral abdominal wall. 1. the external oblique is the most t extensive layer with fibers that extend inferoanteriorly/medially, in a similar fashion to those of theexternal intercostal. It takes origin from the lower 8 ribs. It has a free posterior border that does not fuse with the lumbar fascia. It's extensive anterior happy aponeurosis doubles back on itself between the anterior superior iliac spine and the pubic tubercle to form the inguinal ligament. There is a deficiency in the lower hmm medial aspect of the aponeurosis - the superficial ring of the inguinal canal. o Igg Spermatic omatic cord Anatomy 534 Anterior Abdominothoracic Wall 87 2. the internal oblique is the middle layer. Its fibers extend supero- anteriorly similar to those of the internal intercostal. The sheet-like muscle fuses with lumbar fascia posteriorly and also exhibits a deficiency in its aponeurosis in the region of iii the inguinal canal. dddie fold.gl a 3. the transversus abdominis is the innermost layer and also has the smallest extent. It fuses posteriorly with the lumbar fascia and its aponeurosis also extends anteriorly to the mid- line to participate in the Attaffed composition of the sheath of the rectus abdominis with the two overlying oblique mm. thregatisea It also exhibits an even larger deficiency in the region of the inguinal canal. I leads to sift in tasia p inal.is  Anatomy 534 Anterior Abdominothoracic Wall Large mat 88 All 3 of these sheet-like muscles and their aponeuroses function in forming a strong expandable support component for the trunk as well as providing protection for the abdominal viscera. Acting together they can increase intrabdominal pressure as required during defecation, micturation and childbirth. In addition, the external and internal obliques can flex and rotate the trunk. The 4th muscle is strap-like and see straight, rectus abdominis. The rectus is enclosed in a sheath www formed by the aponeuroses of the 3 sheet-like muscles. At about the mid-point between the umbilicus and the pubic crest, the posterior aspect of the rectus sheath becomes deficient leaving only fascia transversalis between the posterior aspect of the rectus and the peritoneum. This forms the arcuate line. All 3 affair Delano aponeuroses then contribute to the anterior aspect of the sheath. The rectus exhibits tendinous intersections that attach to the posterior aspect of the anterior maYff sheath. These muscles function iiiiifi.fi danhq i in flexing the trunk as well as assisting in compression of the abdominal viscera. m iiiix i II i aoti It nano EI Aurateline Abdomen a f teia eeeoea k it FaÉÉ sheath calil no posterior  Anatomy 534 Anterior Abdominothoracic Wall 89 All four muscles of the abdominal wall are innervated segmentally by the ventral rami of the spinal (thoracoabdominal) nerves. A above Below 5,1 5 1 I ftp.gi didikiki pay mean the point fiftieth Hath