Anatomy: Common Iliac Artery, IVC, Lymph Ducts (Reflection Week)

XY2141. ANATOMY. COMMON ILIAC ARTERY. INFERIOR VENA CAVA. LUMBAR PLEXUS Dr Viktoriia Yerokhina, Lecturer in Medical Sciences [email protected]  LEARNING OUTCOMES ANAT.26.02 - Discuss the origin of the lumbar plexus and list its branches and...

XY2141. ANATOMY. COMMON ILIAC ARTERY. INFERIOR VENA CAVA. LUMBAR PLEXUS Dr Viktoriia Yerokhina, Lecturer in Medical Sciences [email protected]  LEARNING OUTCOMES ANAT.26.02 - Discuss the origin of the lumbar plexus and list its branches and their distributions. ANAT.26.04 - List the approximate vertebral levels of the visceral branches of the abdominal aorta and its bifurcation into the common iliac arteries. ANAT.26.05 - Discuss the inferior vena cava and its tributaries, and list the vertebral level it begins from the common iliac veins. ANAT.26.06 - Summarize the cisterna chili, and the course and termination of the thoracic duct.  ABDOMINAL AORTA - AORTA ABDOMINALIS T12–L4 Course 1. Begins at the level of the aortic hiatus (T12) as the continuation of the thoracic aorta 2. Descends in front of the vertebral column, on the left of the inferior vena cava (IVC) 3. Bifurcates into the common iliac arteries at the level of the 4th lumbar vertebra Has parietal and visceral branches  COMMON ILIAC ARTERY - ARTERIA ILIACA COMMUNIS Paired continuation of the abdominal aorta from its bifurcation at the level of L4. Passes on the medial surface of the psoas major Divides into the external and internal iliac arteries at the level of the sacroiliac joint. Common iliac artery supplies the pelvis and lower extremities.  COMMON ILIAC ARTERY 1. Right common iliac artery (a. iliaca communis dextra) – crosses the left common iliac vein and descemds ventrally to the right common iliac vein 1.1 Internal iliac artery (a. iliaca interna) – passes across the sacroiliac joint to the lesser pelvis and supplies both the pelvic wall and organs 1.2 External iliac artery (a. iliaca externa) – passes medially to the psoas major and through the vascular space (under the inguinal ligament) – continues as the femoral artery and continues to the lower extremity which it supplies.  INTERNAL ILIAC ARTERY (PARIETAL BRANCHES) Medial branch of the common iliac artery. Descends behind the peritoneum to the lesser pelvis, where it passes in front of the sacroiliac joint and produces branches close to the sacral plexus. Parietal branches: supply the pelvic wall, gluteal muscles, and medial side of the thigh.  INTERNAL ILIAC ARTERY (PARIETAL BRANCHES) 1. Iliolumbar artery (arteria iliolumbalis) 2. Lateral sacral arteries (a. sacrales laterales) 3. Obturator artery (a. obturatoria) 4. Superior gluteal artery (a. glutea superior) 5. Inferior gluteal artery (a. glutea inferior) Mnemonic: I Love Odorous Sweet Ice-cream  INTERNAL ILIAC ARTERY (PARIETAL BRANCHES) 1. Iliolumbar artery – supplies the iliopsoas, quadratus lumborum, ilium, and vertebral column including the cauda equina 2. Lateral sacral arteries – two branches (each then bifurcate) supply the sacrum, cauda equina, and adjacent muscles of the back 3. Obturator artery – supplies the muscles of the medial femoral group, sacroiliac joint.  INTERNAL ILIAC ARTERY (PARIETAL BRANCHES) 4. Superior gluteal artery – supplies the gluteus maximus, medius, and minimus. 5. Inferior gluteal artery – supplies the gluteus maximus, tensor fasciae latae, as well as some skin over the sacrum.  INTERNAL ILIAC ARTERY (VISCERAL BRANCHES) Visceral branches: supply the perineum and the organs within the lesser pelvis except for the rectal ampulla and part of the ovary and uterine tube. 1. Umbilical artery (a. umbilicalis) 1.1 Superior vesical arteries (aa. vesicales superiores) 2. Inferior vesical artery (a. vesicalis inferior) 3. Middle rectal artery (arteria rectalis media) 4. Artery to ductus deferens (a. ductus deferentis) OR 4. Uterine artery (a. uterina) 5. Internal pudendal artery (a. pudenda interna)  INTERNAL ILIAC ARTERY (VISCERAL BRANCHES) 1. Umbilical artery – main fetal artery carrying deoxygenated blood from fetus to the placenta (after delivery obliterates → lateral umbilical ligament) 1.1 Superior vesical arteries – arise from the umbilical artery and supply the superior part of the urinary bladder, part of the ureter and the urethra 2. Inferior vesical artery – supplies the fundus of the urinary bladder – in female, it participates in the blood supply of the vagina, – in male supplies the prostate and seminal glands 3. Middle rectal artery – supplies the levator ani – in female, participates in the blood supply of the vagina, – in male supply the prostate and seminal glands.  INTERNAL ILIAC ARTERY (VISCERAL BRANCHES) 4. Artery to ductus deferens – in male, supplies the ductus deferens, prostate, seminal glands, and part of the ureter 4. Uterine artery – in female, supplies the uterus, part of the vagina, uterine tube, ovary, and ureter 4.1 Ureteric branch – arises where the uterine artery crosses the ureter 4.2 Uterine branches – travel to the uterine wall 4.3 Vaginal branches – travel to the vaginal fornices 4.4 Tubal branch – supply part of the uterine tube 4.5 Ovarian branch – forms the ovarian arcade with the ovarian artery.  INTERNAL ILIAC ARTERY (VISCERAL BRANCHES) 5. Internal pudendal artery - arterial trunk supplying blood to all of the perineal structures inferior to the pelvic diaphragm 5.1 Inferior rectal artery (a. rectalis inferior) – supplies the anal canal and anus 5.2 Perineal artery (a. perinealis) – runs forward along the perineum 5.2.1 Posterior scrotal/labial branches – supply the posterior part of the scrotum / labia majora 5.3 Dorsal artery of penis/clitoris (a. dorsalis penis/clitoridis) 5.4 Deep artery of penis/clitoris (a. profunda penis/clitoridis) 5.5 Urethral artery (a. urethralis) – in male, heads to the corpus spongiosum penis 5.6 Artery of bulb of penis/vestibule (a. bulbi penis / vestibuli) – supplies the bulb of the penis / vestibule of the vagina and bulb of the vestibule.  EXTERNAL ILIAC ARTERY Lateral branch After leaving the vascular space it continues as the femoral artery  EXTERNAL ILIAC ARTERY Supplies: majority of the lower extremity, anterior and lateral muscles of the abdominal wall, part of the wall of the greater pelvis part of the scrotum in males broad ligament of the uterus in females. External iliac artery issues two branches just medial to the inguinal ligament.  EXTERNAL ILIAC ARTERY 1. Inferior epigastric artery (a. epigastrica inferior) – ascends along the posterior surface of the anterior abdominal wall inside the lateral umbilical fold – anastomoses with the superior epigastric artery (terminal branch of the internal thoracic artery) within the rectus abdominis, which it supplies 1.1 Pubic branch (ramus pubicus) – runs to the pubic symphysis 1.2 Cremasteric artery (a. cremasterica) – in males, supplies the cremaster and spermatic cord 1.3 Artery of round ligament of uterus (a. ligamenti teretis uteri) – in females –to the round ligament of the uterus  EXTERNAL ILIAC ARTERY 2. Deep circumflex iliac artery (a. circumflexa ilium profunda) – passes on the inner surface of the inferior margin of the anterior abdominal wall and travels to the anterior superior iliac spine Contribute to the blood supply of the muscles of the anterolateral abdominal wall (deep level), the iliac crest and the skin overlying the anterior superior iliac spine.  ILIAC VEINS Veins of the pelvis drain deoxygenated blood and return it to the heart. There are three major vessels involved in the venous drainage of the pelvis – external iliac vein, internal iliac vein and common iliac vein (these correspond the major pelvic arteries). Left and right common iliac veins combine at L4-L5 to become the inferior vena cava, which empties into the inferior aspect of the right atrium.  INFERIOR VENA CAVA – VENA CAVA INFERIOR R L Largest vein in the human body. Collects blood from the inferior half of the body (below the diaphragm) and possesses no valves. Arises from the junction of the right and left common iliac veins at the level of L4–L5. Runs on the right of the abdominal aorta, courses dorsally to the liver in the groove for the inferior vena cava and passes through the diaphragm in the caval opening. Has both parietal and visceral tributaries.  INFERIOR VENA CAVA - PARIETAL TRIBUTARIES R L 1. Lumbar veins (vv. lumbales) – 4 pairs, follow the lumbar arteries 1.1 Ascending lumbar vein (v. lumbalis ascendens) – a vertical connection between the common iliac vein and the azygos/hemiazygos vein, intersecting the lumbar veins 2. Inferior phrenic veins (vv. phrenicae inferiores) – drain the inferior part of the diaphragm 3. External vertebral venous plexuses (plexus venosi vertebrales externi) – a venous networks surrounding the vertebral column.  INFERIOR VENA CAVA - VISCERAL TRIBUTARIES R L 4. Hepatic veins (vv. hepaticae) – 3 veins from the liver 5. Right suprarenal vein (v. suprarenalis dextra) – drains the right suprarenal gland 6. Renal veins (venae renalis) – arise from the kidneys – left one runs dorsally to the pancreas and ventrally to the abdominal aorta – right one runs dorsally to the descending part of the duodenum and head of the pancreas 6.1 Capsular veins (vv. capsulares) – drain adipose tissue surrounding the kidney 6.2 Left suprarenal vein (v. suprarenalis sinistra) – drains the left suprarenal gland 6.3 Left testicular/ovarian vein (v. testicularis/ovarica sinistra) – opens into the left renal vein.  INFERIOR VENA CAVA - VISCERAL TRIBUTARIES R L 7. Testicular vein (v. testicularis) – in male, begins on the dorsal aspect of the testis and epididymis, courses through the inguinal canal – doubled in most of its course and possesses valves 7.1 Right testicular vein – opens into the inferior vena cava 7. Ovarian vein (v. ovarica) – in female, begins in the ovary, doubled in most of its course, possesses valves 7.1 Right ovarian vein – opens into the inferior vena cava INFERIOR VENA CAVA - VISCERAL TRIBUTARIES  COMPRESSION OF THE INFERIOR VENA CAVA IVC is commonly compressed by an enlarged uterus during the last trimester of the pregnancy. Results: edema of the ankle and feet, and varicose veins in the lower limb. Compression and blockage of IVC by the malignant retroperitoneal tumors → dilatation of the anastomotic channel between IVC and superior vena cava (caval–caval shunt) so that the blood could be returned to the right atrium. Clinically, it presents as the prominent subcutaneous vein called thoraco-abdominal vein.  LYMPHATIC VESSELS – VASA LYMPHOIDEA 1. Lymphatic capillaries 2. Lymphatic vessels R L 2.1 Collectors of the upper extremity (lateral, medial, anterior) 2.2 Collectors of the lower extremity (medial, lateral, posterior) 2.3 Deep lymphatic vessels 3. Lymphatic trunks: Paired: 3.1. Jugular trunk - lymphatic drainage from half of the head and neck 3.2 Subclavian trunk – lymphatic drainage from the collectors of the upper extremity 3.3. Bronchomediastinal trunk – lymphatic drainage from half of the thorax 3.4 Lumbar trunk – lymphatic drainage from the lower extremity and half of the pelvis Unpaired 3.5 Intestinal trunk – lymphatic drainage from the unpaired abdominal organs  LYMPHATIC DRAINAGE R L 4. Lymphatic ducts – irregular drainage areas 4.1 Right lymphatic duct – a short duct originating from the 3 main lymphatic trunks: right jugular, right subclavian and right bronchomediastinal trunks – collects lymph from: right half of the head and neck, right upper extremity and right half of the thoracic cavity – there is an exception: lymphatic drainage from the right half of the heart goes to the thoracic duct  LYMPHATIC DRAINAGE R L 4.2 Thoracic duct – originates from the lumbar trunks – collects lymph from: both lower extremities, pelvis, abdominal cavity, left half of the thoracic cavity, left upper extremity and the left half of the head and neck – is divided into 4 parts according to its course: lumbar, abdominal, thoracic and cervical parts 4.2.1 Cisterna chyli – a widened situated at the beginning of the thoracic duct at the level of T11–L1 – there is an exception: lymphatic drainage from the 4th to 10th segment of the left lung and left half of the heart runs to the right lymphatic duct  Clinical correlation  LYMPHATIC DRAINAGE OF POSTERIOR ABDOMINAL WALL Lymph vessels draining the posterior abdominal wall and most of the abdominopelvic organs except part of the liver terminate in the cisterna chyli and thoracic duct. The lymphatic stream is intercepted by a series of lymph node groups before reaching the cisterna chyli and the thoracic duct. DEEP LYMPH NODES Lymph is ultimately drained into the systemic circulation via the subclavian veins. The right lymphatic duct only drains roughly the upper right area of the body (green), whereas the thoracic duct is responsible for the rest of the body. The deep lymph nodes are not palpable.  LUMBAR PLEXUS – PLEXUS LUMBALIS (T12–L4) Formed from the anterior branches of spinal nerves L1–L4 and contributing branch from T12. Plexus is located within the psoas major, lateral to the lumbar vertebrae. Lumbar plexus nerves: 1. Iliohypogastric nerve (nervus iliohypogastricus) 2. Ilioinguinal nerve (n. ilioinguinalis) 3. Genitofemoral nerve (n. genitofemoralis) 4. Lateral cutaneous nerve of thigh (n. cutaneus femoris lateralis) 5. Femoral nerve (n. femoralis) 6. Obturator nerve (n. obturatorius) LUMBAR PLEXUS – PLEXUS LUMBALIS (T12–L4) Motor innervation Lower abdominal muscles: external oblique, internal oblique, and transversus abdominis Pelvic muscles: Iliacus, pectineus, cremaster Muscles of the anterior and medial compartments of the thigh Sensory innervation Lower abdomen Lateral gluteal region External genitalia Thigh Medial aspect of the leg (via the saphenous nerve)  LUMBAR PLEXUS – PLEXUS LUMBALIS (T12–L4) 1. Iliohypogastric nerve (nervus iliohypogastricus) – T12–L1 – emerges laterally from the psoas major – passes between the internal oblique and the transversus abdominis – runs above the iliac crest travelling ventrocaudally – terminates in the hypogastric and inguinal regions 1.1 Muscular branches (rami musculares) – motor branches for the internal oblique and transversus abdominis 1.2 Lateral cutaneous branch (ramus cutaneus lateralis) – somatosensory innervation of the skin of the lateral abdomen 1.3 Anterior cutaneous branch (ramus cutaneus anterior) – innervates the skin around the superficial inguinal ring. LUMBAR PLEXUS – PLEXUS LUMBALIS (T12–L4) 2. Ilioinguinal nerve (n. ilioinguinalis) – L1 – emerges laterally from the psoas major and continues below the iliohypogastric nerve – travels through the inguinal canal – innervates skin of the anterior part of the scrotum (in men) and skin on the anterior part of the labia majora (in women). LUMBAR PLEXUS – PLEXUS LUMBALIS (T12–L4) 3. Genitofemoral nerve (n genitofemoralis) – L2–L3 – penetrates the psoas major and leaves it on its ventral surface 3.1 Genital branch (ramus genitalis) – passes through the inguinal canal – innervates the cremaster, dartos fascia and a small area on the medial side of the thigh (in men) – innervates part of the labia majora and a small area on the medial side of the thigh (in women) 3.2 Femoral branch (ramus femoralis) – passes through the vascular space – innervates the skin of the medial side of the thigh. LUMBAR PLEXUS – PLEXUS LUMBALIS (T12–L4) 4. Lateral cutaneous nerve of thigh / lateral femoral cutaneous nerve (n. cutaneus femoris lateralis) – L2–L3 – emerges laterally from the psoas major – runs laterocaudally on the iliacus towards the anterior superior iliac spine – provides somatosensory innervation for the lateral thigh  CLINICAL CORRELATION Meralgia paresthetica results from compression of the lateral cutaneous nerve of the thigh in the muscular space. SYMPTOMS: acute intermittent pain and loss of sensation on the lateral thigh above the knee. It is common in obese and diabetic patients.  LUMBAR PLEXUS – PLEXUS LUMBALIS (T12–L4) 5. Femoral nerve (nervus femoralis) – L2–L4 Course: emerges laterally from the psoas major, travels above the iliopsoas, passes medially through the muscular space to reach the anterior thigh and femoral triangle, then splits into muscular and cutaneous branches 5.1 Muscular branches (rami musculares) – innervate the iliopsoas, quadriceps femoris, sartorius and pectineus 5.2 Anterior cutaneous branches (rami cutanei anteriores) - somatosensory innervation for the anterior side of the thigh 5.3 Saphenous nerve (nervus saphenus) – terminal somatosensory branch, which follows the great saphenous vein distally on the leg 5.3.1 Infrapatellar branch (ramus infrapatellaris) – somatosensory innervation of the skin inferior to the patella 5.3.2 Medial cutaneous nerve of leg / medial crural cutaneous nerve (rami cutanei cruris mediales) – somatosensory innervation for the skin of the medial part of the leg.  CLINICAL CORRELATION Pelvic fractures, hip dislocations, surgeries and incorrectly applied intramuscular injections can harm the femoral nerve. Induration of the inguinal lymphatic nodes and aneurysms of the femoral artery are the most common non-traumatic causes of femoral nerve injury. Motor symptoms of femoral nerve injury occur as are a result of impaired function of the quadriceps femoris. Walking without support and walking upstairs become difficult. It is impossible for the patient to raise his/her lower limb when lying supine. Standing and squatting become unstable. In certain cases, hyperextension of the knee (genu recurvatum, back knee) may occur when standing.  LUMBAR PLEXUS – PLEXUS LUMBALIS (T12–L4) 6. Obturator nerve (nervus obturatorius) (L2–L4) - emerges medially from the psoas major and passes through the obturator canal 6.1 Muscular branches (rami musculares) – innervates obturator externus 6.2 Anterior branch (ramus anterior) – innervates gracilis, adductor longus, adductor brevis, pectineus (a diploneural muscle also innervated by the femoral nerve) and provides somatosensory innervation for the medial thigh 6.3 Posterior branch (ramus posterior) – innervates adductor magnus (a diploneural muscle, also innervated by the sciatic nerve) 6.3.1 Articular branches (rami articulares) – participate in the somatosensory innervation of the hip joint. REFERENCES