CHP10TheMuscularSystem

I rt angles draws ribs down in to compress tc to force

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Unformatted text preview: obliquely • Lift ribs up and out when contracted…result is an expanded Lift rib cage that allows for inhalation rib • Relaxing of muscles causes ‘normal’ exhalation • Origin @ inferior margins of R1-11 & inserts on superior Origin margins of R2-12 margins Internal intercostals= iinvolved in forced exhalation (along w/ nvolved abdominal muscles); lie deep to e.i. @ rt angles • Draws ribs down & in to compress t.c. to force air out Draws to • Origin @ inferior margins of R1-11 & inserts on superior Origin margins of R2-12 margins Chest muscles Chest 3 chest muscles~ pectoralis major & minor, serratus anterior Pectoralis major- table 10.10 • Flexes, abducts, & medially rotates humerus (climbing, deep Flexes, inhalation) inhalation) Pectoralis minor- table 10.9 • W/ serratus anterior, moves scapula lateral & forward • Also helps rotate scapula & depresses apex of shoulder Serratus anterior- table 10.9 • Prime mover in pushing actions (‘boxer’s muscle’) (‘boxer’s • W/ pectoralis minor, moves scapula lateral & forward scapula Muscles of the Abdomen Muscles 4 muscles & fibrous sheaths comprise of abdominal region~ • Rectus abdominis, external & internal abdominal obliques, & Rectus transverse abdominis transverse • Fascicles run in 3 directions to ensure strong abdominal wall Rectus abdominis= medial straplike muscle w/ origin @ pubis medial & inserted on xiphoid & costal cartilage (5-7) inserted • Tendinous intersections separates into 4 sections • Rectus sheath encloses r.a. • Linea alba sep’s left/right sides External abdominal oblique= most most superficial, fascicles run anterior superficial, & down down Abdominal muscles (cont.) Abdominal Internal abdominal oblique • Deeper, run anterior & upwards Transversus abdominalis • Deepest, fascicles run horizontal Tendons (aponeuroses) extend medially to form rectum extend sheath & end @ linea alba sheath • Inferior end forms cordlike inguinal ligament from pubis to Inferior anterior superior iliac spine Muscles of Pelvic Floor Muscles Muscles of pelvic floor serve to support viscera of peritoneal Muscles cavity; help control movements of urine, semen, & feces; assist w/ erection of penis & clitoris assist Inferior surface of pelvic floor (‘pelvic outlet’’)= perineum )= perineum • • • Anal canal, urethra, vagina open into region Surrounded by pubic symphysis, coccyx, ischial tuberosities Divided into 2 triangles- urogenital & anal Divided urogenital anal Males/females have same muscle groups that form 3 ‘layers’ • Superficial perineal space; middle= urogenital diaphragm & middle= external sphincters; deepest= pelvic diaphragm external deepest= pelvic Back & ‘Scapula’ Muscles Back Muscles of back extend, rotate, & abduct vertebral column~ • They contract to return trunk upright (opposing ab’s) • 2 groups: superficial...
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This note was uploaded on 01/12/2014 for the course ZOO 250 taught by Professor Staff during the Fall '08 term at S.E. Louisiana.

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