Nerves & Vessels of Lower Limb MCQs

C. i.e. Obturator nerve Psoas major, iliacus & pectineus muscles, femoral vessels and nerve, femoral branch of genitofemoral nerve, lateral cutaneous nerve of thigh and lymphatics pass below inguinal ligament. 'PIN' structures i.e. Pudendal nerve, Internal Pudendal vessels, Nerve to obturator internus come out of greater sciatic foramen, cross the dorsal surface of ischial spine & enter into lesser sciatic foramen.

The obturator nerve runs along the medial border of the psoas major muscle, eventually passing through the obturator canal to innervate muscles of the medial thigh. So, it might be damaged by an injury to the medial portion of psoas major. The femoral nerve runs along the lateral border of psoas major, where psoas major contacts iliacus. The genitofemoral nerve pierces through psoas major at the level of L3 or L4. The iliohypogastric and ilioinguinal nerves run under psoas major, emerging at the lateral border of psoas major to run over quadratus lumborum. The way to distinguish between these two nerves is to remember that the iliohypogastric is superior to the ilioinguinal nerve. Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Abdomen, Page number - 182

The posterior compartment is divided by deep transverse fascia into deep and superficial sections. The superficial posterior compartment muscles include the gastrocnemius, the plantaris and the soleus. No major arteries or nerves are within this compartment. Pain and a palpable tense and tender compartment suggest the diagnosis. The deep posterior compartment muscles include the popliteus, the flexor digitorum longus, the flexor hallucis longus and perhaps the tibialis posterior. The neurovascular supply to the posterior compartment is provided by the tibial nerve and the posterior tibial artery. Increased pressure in this compartment may cause plantar foot hypesthesia, weakness of toe flexion and pain with passive extension of the toes. Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Lower Limb, Page number: 573

The obturator nerve lies along the medial border of the psoas major muscle. The femoral nerve lies along the lateral border of the psoas major muscle, between psoas major and iliacus. The genitofemoral nerve pierces psoas major then lies on top of that muscle. The ilioinguinal nerve emerges at the lateral border of psoas major, then travels laterally Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Abdomen, Page number - 186

In 25-50% of cases, the inferior portion of the thoracic duct includes a dilated portion called the cisterna chyli. When present, all of the lymph trunks draining the abdomen and lower limbs dump into it, as well as the most inferior intercostal lymph trunks. When it is not present, these trunks simply empty into the thoracic duct. So, the cisterna chyli is a portion of the thoracic duct, and the thoracic duct passes through the diaphragm with the aorta at the T12 level. The inferior vena cava passes through the central tendon of the diaphragm at the T8 level. The esophagus and vagal branches pass through the right crus of the diaphragm at the T10 level. The greater thoracic splanchnic nerves pass through the fibers of the left and right crus. Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Abdomen, Page number - 186

From lateral to medial, these are the structures in the femoral triangle: femoral nerve, artery, vein, and canal. The artery, vein, and canal are in the femoral sheath, but the nerve is not! So, the vein would be found medial to the arterial pulse. Although the femoral triangle is lateral to the pubic tubercle, that answer is too general. If you were entering the femoral vein, you would find the femoral pulse, use that as a landmark, then insert the instrument medial to that pulse. Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Lower Limb, Page number - 558

Avascular necrosis is the death of bone tissue due to a lack of blood supply. Also called osteonecrosis, it can lead to tiny breaks in the bone and cause the bone to collapse. The process usually takes months to years. A broken bone or dislocated joint can stop the blood flow to a section of bone. Avascular necrosis is also associated with long-term use of high-dose steroid medications and too much alcohol. Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Lower Limb, Page number - 554

The trochanteric anastomosis forms part of the blood supply of the femoral head along with the cruciate anastomosis and the ligamentum teres. The medial circumflex femoral artery and the lateral circumflex femoral artery form a ring around the femoral neck. The ascending branches of these two arteries then form an anastomosis with the descending branch of the superior gluteal artery (from the posterior division of the internal iliac artery). Damage to these blood vessels, either from direct trauma or other causes (e.g. long-term steroids, chronic alcohol use, among others) can result in avascular necrosis of the femoral head. Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Lower Limb, Page number - 664