CSD 331 Exam 4 Questions With Complete Solutions

Passive exhalation correct answer: accomplished by recoil forces of the elastic tissues; Muscle action helps in this process- helps force air out of the lungs Internal Intercostals (interosseous portion) correct answer: Origin: superior margin of each rib (except 1st), top part of rib, Course upward and medially (at an angle), Insertion: inferior surface of rib above, When the interosseous portion contracts, the rib cage is depressed (pulls down, and rib cage becomes smaller) Transverse Thoracis correct answer: Located on inner surface of rib cage, Origin: margin of the sternum, Fibers course to inner chondral surface of ribs 2-6, Function: resists elevation of rib cage and decreases volume of thoracic cavity,If it resists elevation this would make it an antagonist. Innermost intercostals correct answer: Parallel internal intercostals, Deep to internal intercostals, Perform the same function as internal intercostals, Sometimes classified as an anterior muscle Subcostals correct answer: Parallel internal intercostals, Found on inner posterior wall of thorax, Unlike intercostals, may span more than one rib, Primary function: Support ribcage, Function for respiration: Pulls ribs down Serratus Posterior Inferior correct answer: Origin: spinous processes of T11, T12, and L1-L3, Course up and laterally, Insertion: lower margin of lower 5 ribs, Contraction pulls rib cage down Latissimus Dorsi correct answer: Origin: lower vertebral columns and ribs, Insertion: humerus, Primary moves UE (upper extremity: arm), but when arm is immobilized, may stabilize posterior abdominal wall and aid expiration, A