BMS Anatomy Asynchronous Lecture 3 PDF

BMS Anatomy Asynchronous Lecture 3 Muscles, Vessels, and Nerves of Thoracic and Anterior Abdominal Walls, Breast Presented By: (Toronto Campus) Moore's Clinically Oriented Anatomy, by Arthur F. Dalley II PhD FAAA (Author), Anne M. R. Agur BSc (OT) MSc PhD FAAA (Author), 9th ed. Dr. M. Doroudi; mdoro...

BMS Anatomy Asynchronous Lecture 3 Muscles, Vessels, and Nerves of Thoracic and Anterior Abdominal Walls, Breast Presented By: (Toronto Campus) Moore's Clinically Oriented Anatomy, by Arthur F. Dalley II PhD FAAA (Author), Anne M. R. Agur BSc (OT) MSc PhD FAAA (Author), 9th ed. Dr. M. Doroudi; [email protected] Chapter 4 (Thorax): Pages 296 – 324 Boucher Campus) Chapter 5 (Abdomen): Pages 421 – 425 Dr. K. Lumsden; [email protected] Thoracic Cage (Review) - Intercostal Spaces: 11 intercostal spaces filled with the intercostal muscles and intercostal nerves, arteries and veins - Intercostal muscles – are 3 flat layers, external, internal and innermost intercostal muscles. Muscles Origin Insertion Actions Nerves External Intercostal Inferior border of the rib above superior border of the rib below moves rib superiorly during inspiration Intercostal nerves (T1- T11) Internal Intercostal superior border of the rib below Inferior border of the rib above moves rib inferiorly during expiration Intercostal nerves (T1- T11) 3 5 Diaphragm Attachments: xiphoid process, costal margin, end of ribs 11 and 12, lumbar vertebra (LI - LIII). - Muscle fibers converge from the peripheral attachments of the muscle to join to the central tendon. - Three main foramina in the diaphragm: Aortic hiatus or opening (TXII level), esophageal hiatus or opening (TX Level) and caval opening (TVIII level) - Nerve Supply: R. & L. phrenic nerves (C3,4,5) - Action: depresses domes (i.e. move inferiorly) therefore Increases the volume of the thoracic cavity - ↑ Volume, ↓ pressure, therefore it is the major muscle of inspiration. 4 Movements of the Thoracic Wall Pectoral Region - Is external to the anterior thoracic wall and anchors the upper limb to the trunk. - Mammary glands are modified sweat glands in the superficial fascia in this region. The nipple is surrounded by a circular pigmented area of skin termed areola. Mammary Gland Arterial supply of the breast: - Axillary A. (mainly by its lateral thoracic branch) - Internal thoracic A. - 2nd to the 4 th intercostals arteries. Venous drainage of the breast: - Axillary, internal thoracic & intercostal veins. Innervation of the breast: -2nd to 6th intercostal nerves. - Nipple is innervated by the 4 th intercostal N. Lymphatic drainage of the breast: - 75% into axillary nodes. - The rest, mainly into the parasternal lymph nodes. Arterial supply of the thoracic wall: Mainly is done by: - Posterior intercostal arteries. Mainly branches of the thoracic aorta - Anterior intercostal arteries. Branches of the internal thoracic artery directly or indirectly 8 Venous drainage of the thoracic wall: - Posterior intercostal veins: mainly drain on the R. side into azygos vein and on the L. side into the hemiazygos or accessory hemiazygos. - Anterior intercostal veins: drain (directly or indirectly) into internal thoracic veins which in turn drain into R. & L. brachiocephalic veins. 9 Nerve supply of the thoracic wall - Is mainly done by the anterior rami of the upper thoracic spinal nerves [called intercostal Nerves (T1 – T11)]. The Ant. ramus of the spinal N. T12 (The subcostal N) is under rib #12. - They supply the intercostal muscles, skin of the chest wall and parietal pleura. - The lower intercostal nerves supply the skin & muscles and parietal peritoneum of the abdominal wall. 10 Nerve supply of the Anterior Abdominal Wall 12 Vessels of the Anterolateral Abdominal Wall 13 Superficial Veins of the Anterolateral Abdominal Wall Vessels of Anterolateral Abdominal Wall Superior epigastric artery, which is a direct continuation of the internal thoracic artery Inferior epigastric; branch of the external iliac artery Branches of intercostal arteries Venous drainage of the abdominal wall is accomplished through veins that run parallel to the above mentioned arteries. 15