Thorax Anatomy Quiz PowerPoint PDF

Thoracoabdominal Nerves T7-T11 intercostal nerves change their name as they leave the rib space Innervate muscles of the lateral and anterior abdominal wall Provide Sensation-via cutaneous branches that pierce the Anterior Rectus sheath & lateral wall Are ventral rami with both m...

Thoracoabdominal Nerves T7-T11 intercostal nerves change their name as they leave the rib space Innervate muscles of the lateral and anterior abdominal wall Provide Sensation-via cutaneous branches that pierce the Anterior Rectus sheath & lateral wall Are ventral rami with both motor and sensory responsibilities Internal Oblique Muscle Arises from thoracolumbar fascia, iliac crest (intermediate line), lateral 1/2 of inguinal ligament Up towards the lower 3 ribs & costal margins, linea alba Down toward the pubis via conjoint tendon Innervation: lower 2-3 thoracoabdominal ns., subcostal n., & (L1 ventral ramus) Rectus Sheath Arises from aponeurotic sheath surrounding rectus abdominus ms.  formed by aponeuroses of E.O., I.O., & T.A.  rectus sheath-has ant & post components Linea alba-vertical midline structure between recti, stretching from xiphoid process to pubic symphysis Linea semi lunaris-curved vertical line at the lateral edge of the recti Rectus Sheath cont. Anterior rectus sheath (above arcuate line) comprised of:  aponeurosis of E.O.  1/2 aponeurosis of I.O. Posterior rectus sheath (above arcuate line) comprised of:  1/2 aponeurosis of I.O.  Aponeurosis of T.A. Deepest structure but not part of Rectus sheath=transversalis fascia followed by peritoneum Arcuate line (linea semicircularis)- a horizontal line on post rectus sheath which demarcates a point where all of the aponeuroses (EO, IO, TA) pass anterior to rectus abdominus ms. Rectus Sheath cont. (2) Anterior rectus sheath (below arcuate line) comprised of:  aponeuroris of E.O., I.O., T.A Posterior rectus sheath (below arcuate line) comprised of:  No aponeurosis Transversalis fascia is the only structure covering the post surface of rectus below the arcuate line Thoracic Outlet Syndrome Anatomical variations that can lead to signs & symptoms in the head, neck, & arm due to neural or arterial compression in the neck (scalenus anticus syndrome, cervical rib etc.) TOS: garbage bucket term for involvement of nerves, arterial & venous supply to UE that results in pain, numbness, tingling, weakness in arm chest, neck Causes: anatomical variations, physical trauma, tumors, poor posture, repetitive arm movements, sports. Ribs 12 paired ribs which protect thoracic & abdominal contents increase in length from 1-7; decrease in length 8-12 1-7 true ribs connected to sternum by costal cartilage 8, 9, 10 join costal cartilage above 11, 12 “floating ribs” do not connect to sternum or costal cartilage; but are attached at the costovertebral joints of course! Identify: head, neck, tubercle, body, angle of rib TV1: articulates with rib 1 superiorly and rib 2 inferiorly  Diaphragm Muscle Most important muscle of respiration Separates thoracic & abdominal cavities Has proximal attachments to 3 regions: sternal, costal & lumbar  sternal-from post aspect of xiphoid process  costal-from inner surfaces of lower 6 costal cartilages & lower 4 ribs  lumbar-from bodies of upper lumbar vertebrae and fibrous arches (med & lat arcuate ligaments) External Intercostal Muscle From lower margins of ribs 1-11; fibers pass down & forwards to upper margins of rib below Extend from tubercles of the rib (post); at costal cartilage become membranous and continues as membranous until the costochondral junction (ant) Orientation: like hands in a pocket of course! Innervation-corresponding intercostal ns. AXN-still in debate (emg) however evidence suggests it elevates the rib, hence a muscle of inspiration Internal Intercostal Muscle From lower margins of the ribs & costal cartilages & floor of costal groove; pass down and back to the upper margins of subadjacent ribs & costal cartilages Extend from sternum ant, to angle of the rib laterally Innervation-corresponding intercostal n. AXN- depress the rib; generally considered to be a muscle of expiration  Innermost Intercostal Muscle From internal aspects of adjoining ribs May be absent at high levels Fibers run in the same direction as internal intercostal muscles but not the full length of the rib (~middle 1/3 of rib) Innervation & AXN-same as with internal intercostal muscle VAN Complex Intercostal vein, artery, nerve travel between the innermost and internal intercostal ms. Run inferior to its corresponding rib Relationship: ¨intercostal vein most superior ¨intercostal artery in the middle ¨intercostal nerve inferior Azygos System Drains venous flow from the thoracic wall (intercostal veins) Intercostal veins on right lead to azygos vein on R Intercostal veins on the left lead to accessory hemiazygos (superiorly) & hemiazygos veins (inferiorly) Accessory hemiazygos & hemiazygos crosses over spinal column to dump into the azygos vein (~TV7-8) Azygos vein dumps into superior vena cava Inguinal Canal Oblique passage, 3-5 cm through abdominal wall Transmits in males-spermatic cord; females- round ligament of the uterus Also contains ilioinguinal n. in female and male  (L1 ventral ramus) Ant Wall of canal=aponeurosis of E.O. & ms. of I.O Post Wall of canal=aponeurosis of T.A. & transversalis fascia Floor-inguinal ligament & lacunar ligament Rings Deep inguinal ring-slitlike opening in transversalis fascia found just above midinguinal point  spermatic cord & round ligament of the uterus traverse the deep inguinal ring Superficial inguinal ring-triangular opening (variable size) in E.O. aponeurosis  spermatic cord, round ligament of uterus & ilio-inguinal nerve emerge through superficial inguinal ring to travel to the scrotum or labia Hernias Direct Inguinal  abdominal contents enter inguinal canal directly through abdominal wall; contents protrude toward and may enter superficial ring, but rarely extend to scrotum  Usually males > 40 Indirect Inguinal  abdominal contents enter inguinal canal through deep ring and extend through the superficial ring  more common than direct; more common in males  usually contributed to a congenital defect