9th Thoracic muscle.pptx

Thoracic muscles

1. Thoracic cavity

2. Thoracic cavity It is the region of the body between the neck and the abdomen. It is bounded by 12 pairs of ribs, vertebrae and sternum. It contains trachea, two lungs, heart and great vessels, esophagus and lymph nodes. There are two openings of the thorax, the superior thoracic opening which is also called thoracic inlet and inferior thoracic opening. Head and neck and upper limbs are attached with the thoracic cavity through thoracic inlet. Inferior thoracic opening opens into the abdominal cavity.

3. Structure of the Thoracic wall I t is covered by skin and muscles. These are attached to the skeletal part of the thoracic wall. The thoracic wall is formed posteriorly by the thoracic part of the vertebral column, anteriorly by the sternum and costal cartilages, laterally by the ribs and intercostal spaces, superiorly by the supra pleural membrane and inferiorly by the diaphragm.

4. Muscles of the chest wall 1. Intercostal muscles (External , internal and innermost) 2. Pectoralis major muscles 3. Pectoralis minor muscles 4. Serratus anterior 5. Serratus Posterior Superior Muscle 6. Serratus Posterior Inferior Muscle 7. Rectus abdominis 8. External oblique 9. Internal oblique 10.Transversus thoraces 11 Transversus abdomens 12 Latissimus dorsi 13. Trapezius 14. Lavatories Costarum (12 pairs)

5. External and internal intercostal Muscle of Thorax E xternal intercostal muscles The are responsible for forced and quiet inhalation. They raise the ribs and expand the chest cavity, and originate from ribs one through 11, with insertion from ribs two to 12 . I nternal intercostal muscles   The are responsible for forced exhalation. They depress the ribs and decrease space in the chest cavity. They originate from ribs two through 12, with insertion from ribs one to 11

6. (3) Innermost intercostal muscle It forms the deepest layer of the thoracic wall. It is an incomplete muscle layer and crosses more than one intercostal space within the ribs. It is related internally to fascia (endothoracic fascia) and parietal pleura and externally to the intercostal nerves and vessels . It is formed of 3 muscles 1- Innermost Intercostal. 2- Sternocostalis. 3- Subcostalis

7. Pectoralis muscle of Thorax P ectoralis major muscle The has four actions which are primarily responsible for movement of the shoulder joint. The first action: is flexion of the humerus , The Second action: it adducts the humerus, as when flapping( move up and down ) the arms pectoralis minor muscle This  muscle begins from the third through fifth ribs and then extends diagonally ( crosswise. ) up the chest and attaches to the scapula (shoulder blade). The pectoralis minor muscle functions to move the scapula both forward and downward, which helps to maintain the mobility of the shoulder joint

8. Serratus Muscle of Thorax serratus anterior The muscle that originates on the surface of the 1st to 8th ribs at the side of the chest and inserts along the entire anterior length of the medial border of the scapula. The serratus anterior acts to pull ( attract )the scapula forward around the thorax . serratus posterior superior muscle The serratus posterior superior muscles contribute to the movement and stabilization of the vertebral column and the thorax. The serratus posterior superior elevates( higher than the surrounding area ) the ribs and thus supports the inspiration (accessory muscle of inspiration ) Serratus Posterior Inferior Muscle The serratus posterior inferior draws the lower ribs backward and downward to assist in rotation and extension of the trunk. This movement of the ribs also contributes to forced expiration of air from the lungs

9. Muscle of Thoracic Rectus abdominis The main action for rectus abdominis is flexion of the trunk (flexion of thoracic and lumber spine), while it works by drawing symphysis(growing together.) and Sternum toward each other. Also, it works on posterior pelvic move with other abdominal muscles Transversus abdominis The transversus abdominis muscle has various functions in the body. It is involved in moving the trunk, but also stabilizes the vertebral column, creates tension of the anterior body wall and increases the intraabdominal pressure upon contraction. Transversus thoraces The contraction of the transversus thoraces pulls the rib cartilages caudally ,( احتیاط سے ) thus supporting expiration. However, it is not considered to be among the primary respiratory muscles such as the intercostal muscles or the diaphragm. Firstly, it is barely ( بمشکل )active in the supine position.

10. External oblique muscles and Internal oblique muscle External oblique muscles The external oblique on either side not only help rotate the trunk, but they perform a few other vital functions. These muscles help pull the chest, as a whole, downwards, which compresses the abdominal cavity.   external oblique muscle also supports the rotation of the spine I nternal oblique muscle The internal abdominal oblique muscle is located closer to the skin than the transverse abdominal muscle. This muscle supports the abdominal wall, assists in forced respiration, aids in raising pressure in the abdominal area, and rotates and turns the trunk with help from other muscles

11. M uscle of thorax Latissimus dorsi The latissimus dorsi is the largest muscle in the upper body. The latissimus dorsi is responsible for extension, adduction, transverse extension also known as horizontal abduction, flexion from an extended position, and (medial) internal rotation of the shoulder joint Trapezius The  trapezius (or trapezoid) is a large paired surface muscle that extends longitudinally(lengthways) from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It moves the scapula and supports the arm Levatores costarum The Levatores costarum twelve in number on either side, are small tendinous and fleshy ... (Levatores costarum longi). They have a role in forceful inspiration