MBS Anatomy Winter 2021 Thoracic Wall (PDF)

MBS Anatomy 02/08/2021 FR; 4:10 - 5:00 WINTER 2021 A. T. Mariassy Lecture 11: Thoracic Wall - Bones, Muscles, Nerves, & Vasculature Skeleton of Thoracic Wall Thoracic Apertures Superior thoracic aperture, the anatomical thoracic inlet bounded by: posteriorl...

MBS Anatomy 02/08/2021 FR; 4:10 - 5:00 WINTER 2021 A. T. Mariassy Lecture 11: Thoracic Wall - Bones, Muscles, Nerves, & Vasculature Skeleton of Thoracic Wall Thoracic Apertures Superior thoracic aperture, the anatomical thoracic inlet bounded by: posteriorly by the T1 vertebra laterally by the first pair of ribs and their costal cartilages anteriorly by the superior border of the manubrium Inferior thoracic aperture, the anatomical thoracic outlet bounded by: posteriorly by the T12 vertebra posterolaterally by the 11th and 12th pairs of ribs anterolaterally by the joined costal cartilages of ribs 7–10, forming the costal margin anteriorly by the xiphisternal joint Rib The ribs are curved, flat bones that form most of the thoracic cage Ribs and Costal Cartilages The ribs are curved, flat bones that form most of the thoracic cage Ribs and Costal Cartilages Outline of the diaphragm Ribs and Costal Cartilages Outline of the diaphragm  Sternum a spinal column The sternum is the flat, vertically elongated bone that forms the middle of the anterior part of the thoracic cage. The sternum consists of three parts: manubrium, body, and xiphoid process Joints of Thoracic Wall Although movements of the joints of the thoracic wall are frequent (e.g., during respiration), the range of movement at the individual joints is small. Ribs and Costal Cartilages Vertebrae (intervertebral [IV] joints) Ribs and vertebrae (costovertebral joints: joints of the heads of ribs and the costotransverse joints) Sternum and costal cartilages (sternocostal joints) Sternum and clavicle (sternoclavicular joints) Ribs and costal cartilages (costochondral joints) Costal cartilages (interchondral joints) Parts of the sternum (manubriosternal and xiphisternal joints) in young people; usually, the manubriosternal joint and sometimes the xiphisternal joint are fused in elderly people. Movements of Thoracic Wall Ribs and Costal Cartilages Table 4.4 Muscle function Movements of thoracic wall during respiration. A. The primary movement of inspiration is contraction of the diaphragm, which increases the vertical dimension of the thoracic cavity (arrows). B. The thorax widens during forced inspiration (arrows). C. The thorax narrows during forced expiration (arrows). D. The combination of rib movements (arrows) that occur during forced inspiration increase the anteroposterior (AP) and transverse dimensions. The middle parts of the lower ribs move laterally when they are elevated (bucket-handle movement). E. When the upper ribs are elevated, the AP dimension of the thorax is increased (pendulum movement). Muscles of Thoracic Wall Muscles of Thoracic Wall The ribs are curved, flat bones that form most of the thoracic cage Intercostal space FIGURE 4.12 Thorax Ligaments and Innervation FIGURE 4.13  Thorax Innervation Dermatomes, Myotomes FIGURE 4.14 Tables from the 6th edition of Moore text book for: BONES 4.1; JOINTS 4.2; INNEVATION 4.5