Did You Know Interval 6 Flashcards
The anatomic reason the aorta is relatively close to the umbilicus?
The normal lumbar lordosis positions the aorta relatively close to the umbilicus. This makes it vulnerable to laparoscopic port insertion injury.
What is the clinical significant of the cervical rib?
Cervical ribs do not uncommonly arise off of C7 and can cause thoracic outlet syndrome by narrowing/compressing the exit of the subclavian artery, vein or brachial plexus. They can be visualized on a plain chest X-ray.
What is Batson’s venous plexus and its clinical significance?
It is a network of valveless veins that connect the deep pelvic and thoracic veins to the internal vertebral plexuses. This provides a route for hematogenous spread of breast, bladder and prostate cancers to the vertebral column or brain. Named after Oscar Batson of Penn Anatomy Dept. who first described it in 1940.
What is the significance of the great anterior segmental artery (of Adamkiewicz )?
It arises from a left posterior intercostal artery and supplies the lumbar and sacral cord. Occlusion by atherosclerosis or surgical trauma can cause spinal cord ischemia with paraplegia and loss of bladder and rectal control. Can be occluded during repair of thoraco-abdominal aortic aneurysms.
What is the importance of popliteal artery aneurysms? How is it treated?
They rarely rupture but often embolize clots distally, threatening the viability of the lower leg and foot. They are often bilateral and associated with abdominal aortic aneurysms. Can also cause tibial nerve pressure and popliteal vein pressure causing pain, edema and DVT (deep vein thrombosis). Treatment is surgical ligation & bypass or endovascular stenting if > 2 cm.
What is the location and clinical usefulness of the sural nerve?
The sural nerve is formed by the junction of the medial sural cutaneous (from tibial nerve) with the fibular anastomotic branch of the lateral sural cutaneous nerve (from common fibular nerve). It lies close to the lesser/small saphenous vein and runs down to the interval between the lateral malleolus and calcaneus. It is cutaneous and its removal results in a relatively trivial deficit. It is often used for nerve biopsy to diagnose several diseases as well as a donor nerve for nerve grafting.
What is the anatomic landmarks for lumbar puncture (spinal tap or to administer a spinal anesthetic)?
With the patient in the lateral decubitus position ( i.e., lying on their right or left side ) with the back flexed, you extend & adduct all your fingers. Place tip of 5th finger on top of iliac crest and your thumb will be at approximately L3 or L4. Since cord in adults ends at L2, this is a safe place for needle entry through the dura.
What is the piriformis syndrome?
Muscle shortening or spasm of the piriformis can compress the sciatic nerve beneath it. In 17% of population, the common fibular nerve (part of the sciatic nerve) actually passes through the muscle. Gluteal weakness can also cause piriformis to hypertrophy. Can also be due to overuse in rowing or cycling. Suspect when sciatica occurs without spine pathology. Treatment is NSAIDS, stretching and physical therapy.
What is the clinical significance of the small saphenous vein?
Valvular incompetence here can be a cause of posterior calf varicosities. It can also be harvested for arterial bypass purposes if great saphenous vein is unavailable or phlebitic (inflamed… usually in conjunction with thrombosis).
How would you visually diagnose a hip fracture?
The lower limb will be externally rotated due to unopposed action of the external rotators. Limb is also shortened due to muscle spasm. Can suspect diagnosis simply by looking at a supine patient’s feet.
