Exhalation (major muscles)Rectus AbdominusExternal ObliquesInternal ObliquesTransverse AbdominusAbdominal AponeurosisExtends from…Lower fibers of pectoralis majorXiphoid process of sternumCostal cartilagesInferiorly to…Pubic symphysis and anterior iliac spine(white is aponeurosis; tendon sheet)running down the midlin is linea alba (dark white line)Rectus AbdominusLong ribbon-like muscle on ventral aspect of abdominal cavityAlmost entirely enclosed by aponeurosisOrigin—anterior edge of pubic boneCourse—superior, parallel to midlineInsertion—cartilages of ribs 5-7, xiphoid process(tendonous tissue ties down the abs)External Obliquelargest, strongest, and most superficial abdominal musclebroad, flat muscle on lateral and anterior portions of lower thorax and abdomenorigin—iliac crest and aponeurosisCourse—superior and lateral/posteriorInsertion—ribs 5-12(finger looking things are serratus muscles pulling scapula forward)Internal Obliquemiddle layer of abdominal musculaturelies just deep to external obliqueslarge, flat muscle on later and ventral aspect of abdomenOrigin—anterior ½ of iliac crest and inguinal ligamentCourse—fans out superiorly and anteriorly/mediallyInsertion—abdominal aponeurosis and cartilagesTransverse AbdominusDeepest abdominal muscleLies just deep to internal obliquesOrigin—ribs 6-12, ¾ of iliac crest, and lateral 1/3 of inguinal ligamentCourse—horizontalInsertion—deepest layer of abdominus aponeurosisAbdominal muscle action1. Flexor of vertebral column2. Enclose and support abdominal contentsHernea- weakness in the aponeurosis, opens up and allows abdominal contents to squeeze through3. Respiration1. Displace abdominal contents and increase abdominal pressure2. Draw ribs inferiorlyObliques more efficient rib depressorsTransverse abdominus more efficient compressorComing around the abdominal domeExhalation (accessory muscles)SubcostalsInternal IntercostalsTransverse thoracisSerratus PoSubcostalsOn posterior aspect of inner wall of lower thoracic cageHighly variable (some of us have some don’t have them)Some more, others lessOrigin—inner surface of ribs, close to vertebral columnCourse—superior and lateralInsertion—inner surface of rib 1 or 2 aboveAction—presumes to depress ribsInternal IntercostalsNot as prominent and strong as external intercostalsLie just deep to external intercostalsOrigin—superior surface of lower rib of pairCourse—superior and towards sternumInsertion—lower border of rib aboveAction—depress ribsTransverse ThoracisOn inner surface of anterior thoracic wallOrigin—inner surface of sternum and costal cartilages 5-7Course—fan out superiorly and laterallyInsertion—inner surface of ribs 2-6Action—presumed to depress ribsSerratus PosteriorOn lower posterior portion of thoraxOrigin—via aponeurosis from T11-12 and L1-3Course—superior and lateralInsertion –lower border or ribs 8-12 just beyond angleAction—presumed to pull down on lower ribsQuadratusLumborumPosterior muscle of abdomenFlat sheet of muscle on lateral dorsal aspect of abdominal wallOrigin—iliac crest and iliolumbar ligamentCourse—superiorInsertion—transverse process of L1-4 and rib 12Action—depress rib 12CSD 3112 1st EditionLecture 10Outline of Last Lecture I. Respiratory System Anatomy cont.a. External Intercostalsb. Inhalationc. LevatoresCostarumd. Serratus Posterior Superiore. Pectoralisf. Subclaviusg. Serratus Anterior h. Sternocleidomastoideusi. ScalenesOutline of Current Lecture II. Respiratory System Anatomy cont.III. Exhalationa. Major musclesi. Abdominal Aponeurosisii. Rectus Abdominusiii. Obliqueiv. Transverse Abdominusv. Abdominus muscle actionb. Accessory Musclesi. Subcostalsii. Internal intercostalsiii. Transverse thoracisiv. Serratus posteriorv. QuadratuslumborumCurrent LectureThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Exhalation (major muscles)- Rectus Abdominus- External Obliques- Internal Obliques- Transverse Abdominus Abdominal Aponeurosis- Extends from…o Lower fibers of pectoralis majoro Xiphoid process of sternumo Costal cartilages- Inferiorly to…o Pubic symphysis and anterior iliac spine- (white is aponeurosis; tendon sheet)- running down the midlin is linea alba (dark white line) Rectus Abdominus- Long ribbon-like muscle on ventral aspect of abdominal cavity- Almost entirely enclosed by aponeurosis- Origin—anterior edge of pubic bone- Course—superior, parallel to midline- Insertion—cartilages of ribs 5-7, xiphoid process- (tendonous tissue ties down the abs)External Oblique- largest, strongest, and most superficial abdominal muscle- broad, flat muscle on lateral and anterior portions of lower thorax and abdomen- origin—iliac crest and aponeurosis- Course—superior and lateral/posterior- Insertion—ribs 5-12- (finger looking things are serratus muscles pulling scapula forward)Internal Oblique- middle layer of abdominal musculature- lies just deep to external obliques- large, flat muscle on later and ventral aspect of abdomen- Origin—anterior ½ of iliac crest and inguinal ligament- Course—fans out superiorly and anteriorly/medially- Insertion—abdominal aponeurosis and cartilagesTransverse Abdominus- Deepest abdominal muscle- Lies just deep to internal obliques- Origin—ribs 6-12, ¾ of iliac crest, and lateral 1/3 of inguinal ligament- Course—horizontal- Insertion—deepest layer of abdominus aponeurosis Abdominal muscle action- 1. Flexor of vertebral column- 2. Enclose and support abdominal contentso Hernea- weakness in the aponeurosis, opens up and allows abdominal contents to squeeze through-- 3. Respirationo 1. Displace abdominal contents and increase abdominal pressureo 2. Draw ribs inferiorly - Obliques more efficient rib depressors- Transverse abdominus more efficient compressoro Coming around the abdominal dome Exhalation (accessory muscles)- Subcostals- Internal Intercostals- Transverse thoracis- Serratus PoSubcostals- On posterior aspect of inner wall of lower thoracic cage- Highly variable (some of us have some don’t have them)o Some more, others less- Origin—inner surface of ribs, close to vertebral column- Course—superior and lateral - Insertion—inner surface of rib 1 or 2 above- Action—presumes to depress ribsInternal Intercostals- Not as prominent and strong as external intercostals- Lie just deep to external