Abdominal Wall and Cavity Spring 2024.pdf

Block III Abdominal Wall and Cavity Spring 2024 Author: Dr. Daniel Rivera Adapated by. Dr. Dávalos and Dr. Rocha Welcome to the New Year 2024! OBJECTIVES 1. Describe the Surface Anatomy of the Abdomen a. Anterolateral & Posterior Wall. b. Description of the four quadrants & nine regions. 2. Des...

Block III Abdominal Wall and Cavity Spring 2024 Author: Dr. Daniel Rivera Adapated by. Dr. Dávalos and Dr. Rocha Welcome to the New Year 2024! OBJECTIVES 1. Describe the Surface Anatomy of the Abdomen a. Anterolateral & Posterior Wall. b. Description of the four quadrants & nine regions. 2. Describe the Layers of the Abdominal Wall. 3. List the Skeletal & Muscular elements of the Abdominal Wall. 4. Describe the components and functions of the Peritoneum. SURFACE ANATOMY: ANTEROLATERAL & POSTERIOR • Umbilicus • Linea Alba • Linea Semilunaris • Tendinous Intersections ABDOMINALLAYERS SKELETALELEMENTS • Xiphoid Process • Costal Margin • Lumbar Vertebrae • IV Discs • Ilia • Sacrum • Ribs XI and XII Muscular structures Rectus Abdominis Origin: Pubic symphysis and crest. Insertion: Xiphoid process and costal cartilage of ribs 5.7 Nerve Supply: Thoraco-abdominal and subcostal nerves T7-T12 Action: Flexes trunk. Compresses internal viscera. Muscular structures External Oblique Origin: Outer surface of ribs 5-12 Insertion: Linea Alba (Rectus Sheet), pubic tubercule and iliac crest. Nerve Supply: Thoraco-abdominal and subcostal nerves T7-T12 Action: Flexes and rotates the trunk. Compresses and supports internal viscera. Muscular structures Internal Oblique Origin: Anterior iliac crest, thoracolumbar fascia and latera third of inguinal ligament. Insertion: Outer surface of ribs 10-12 and Linea Alba (Rectus Sheet) Nerve Supply: Thoraco-abdominal and subcostal nerves T7-T12 Action: Flexes and rotates the trunk. Compresses and supports internal viscera. Muscular structures Transversus Abdominis Origin: Inner surface of ribs 7-12 costal cartilages, iliac crest, thoracolumbar fascia and lateral third of inguinal ligament. Insertion: Linea Alba (Rectus Sheet) Nerve Supply: Thoraco-abdominal and subcostal nerves T7-T12 Action: Flexes and rotates the trunk. Compresses and supports internal viscera. NERVES The skin, muscles, and parietal peritoneum of the anterolateral abdominal wall are supplied by T7 to T12 and L1 spinal nerves. The anterior rami of these spinal nerves pass around the body, from posterior to anterior, in an inferomedial direction. As they proceed, they give off a lateral cutaneous branch and end as an anterior cutaneous branch. NERVES Along their course, nerves T7 to T12 and L1 supply branches to the anterolateral abdominal wall muscles and the underlying parietal peritoneum. All terminate by supplying skin. T7 to T9 supply the skin from the xiphoid process to just above the umbilicus. T10 supplies the skin around the umbilicus. T11, T12, and L1 supply the skin from just below the umbilicus to, and including, the pubic region. Additionally, the ilio-inguinal nerve (a branch of L1) supplies the anterior surface of the scrotum or labia majora and sends a small cutaneous branch to the thigh. ARTERIALSUPPLY Parts of the Abdominal Wall: • Superior: SUPERIOR EPIGASTRIC ARTERY , a terminal branch of the Internal Thoracic Artery. • Lateral: Branches of the TENTH and ELEVENTH INTERCOSTAL ARTERIES and the SUBCOSTAL ARTERY . • Inferior: Medially placed INFERIOR EPIGASTRIC ARTERY and the laterally placed deep CIRCUMFLEX ILIAC ARTERY, both branches of the External Iliac Artery . Posterior Wall Boundaries • Lumbar vertebrae iliac crest Muscles • Diaphragm / Psoas / Quadratus Lumborum / Iliacus Vasculature • Abdominal Aorta / Inferior Vena Cava Nerves • Somatic The posterior abdominal wall is a muscular region along side the 5 lumbar vertebrae. It supports the retroperitoneal organs. Posterior Wall Muscles PSOAS QUADRATUS LUMBORUM ORIGIN:Transverse processes, bodies and intervertebral discs of lumbar vertebrae. ORIGIN:12th rib and transverse processes of lumbar vertebrae. INSERTION: Lesser trochanter of femur. INSERTION:Iliac Crest NERVE SUPPLY: L2-L4 nerves from lumbar plexus. NERVE SUPPLY: L1-L4 nerves. ACTION:Flexes thigh, flexes trunk when sitting ACTION:Extends and laterally flexes vertebral column ILIACUS ORIGIN:Iliac Crest INSERTION: Lesser trochanter of femur. NERVESUPPLY: Femoral Nerve (L”-L4) ACTION:Flexes thigh. Diaphragm ABDOMINAL CAVITY PERITONEUM A thin membrane (PERITONEUM) lines the walls of the abdominal cavity and covers much of the viscera. The parietal peritoneum lines the walls of the cavity, and the visceral peritoneum covers the viscera. Between the parietal and visceral layers of peritoneum is a potential space (THE PERITONEAL CAVITY). Peritoneal Relations → https://www.youtube.com/watch?v=ZwK95Rax6 _8&ab_channel=Kenhub-LearnHumanAnatomy The GREATER OMENTUM is a large peritoneal fold that attaches to the greater curvature of the stomach and the first part of the duodenum. It drapes inferiorly over the transverse colon and the coils of the jejunum and ileum. Turning posteriorly, it ascends to associate with, and become adherent to, the peritoneum on the superior surface of the transverse colon and the anterior layer of the transverse mesocolon before arriving at the posterior abdominal wall. The other two-layered peritoneal omentum is the LESSER OMENTUM. It extends from the lesser curvature of the stomach and the first part of the duodenum to the inferior surface of the liver MESENTERIES are peritoneal folds that attach viscera to the posterior abdominal wall. They allow some movement and provide a conduit for vessels, nerves, and lymphatics to reach the viscera and include: ▪ THE MESENTERY—associated with parts of the small intestine. ▪ THE TRANSVERSE MESOCOLON—associated with the transverse colon. ▪ THE SIGMOID MESOCOLON—associated with the sigmoid colon. 4Quadrants & 9Regions USING ABDOMINAL QUADRANTS TO LOCATE MAJOR VISCERA BIBLIOGRAPHY • Gray's Basic Anatomy, 2nd Edition. Drake, Richard L., PhD. 2021. Elsevier. Chapter 4: Abdomen. Pages 280-303 • Gray's Atlas of Anatomy, 3rd Edition. Drake, Richard L., PhD. 2021. Elsevier. Chapter 4:Abdomen • Gray's Anatomy, 42nd Edition. Standring, Susan, MBE, PhD, DSc, FKC, Hon FAS, Hon FRCS. 2021. Elsevier. Chapter 61: Posterior abdominal wall and retroperitoneum Thank you