Lower Limb and Thorax: 2006 Answer Guide for Part III - Short Answer 30 pts
Dorsal Venous Arch 3Pts
The Dorsal Venous arch is larger vein that is a component of the Dorsal Venous Plexus. It receives deoxygenated blood from the Dorsal Digital Veins Drain via Metatarsal Veins which then anastamose to form the Dorsal Venous Arch. The Dorsal Venous Arch gives origin to the The Great Saphenous Vein which drains medially and the small Saphenous Vein which drain the arch laterally. The arch is Located in the superficial fascia, and contains valves preventing backflow of blood.
Flexor Retinaculum 4pts
A specialized reinforcement of deep fascia consisting of transverse collagen fiber bundles. Binds the tendons around the ankle joint. Located between the medial malleolus and the calcaneus. Space below is divided into 3 septa. Most anterior is the posterior tibialis tendon and next is flexor digitorum longus, third is the tibial nerve and posterior tibial vessels flexor hallucis longus. All tendons passing through retinaculum are invested by a tendon sheath.
Superior Gemellus 4pts
Short lateral rotator of the hip, originates from the isichial spine and inserts onto the tendon of the obturator internus which then inserts onto the greater trochanter of the femur, innervated by minor branches from the sacral plexus, by a branch of the nerve to the obturator internus/ nerve to the superior gemullus. Their blood supply is from the inferior gluteal artery. It is superior to the obturator internus. Several nerves and arteries course superficially over the muscle as they extend into the thigh. They include: The sciatic nerve, femoral cutaneous n., inf, glutial nerve and artery, internal pudendal nerve and artery to name a few.
Gluteus Medius 4Pts
Chief Abductor of the hip and medial rotator. Originate on the lateral surface of the ilium, specifically the ala, between the iliac crest, the anterior gluteal line, and the posterior gluteal line. Inserts onto the large posterior part of the greater trochanter of the femur. Important in normal gait. Maintains pelvic tilt by contracting on the stance side of the leg, functionally reversing the origins and insertions of the muscle. Supplied by L-4,5 and S1 via the superior gluteal nerve. Blood supply is from the superior gluteal artery.
Lymphatic Drainage of Lungs 3pts
Lymphatic capillaries are found throughout the visceral pleura, submucosa, wall of bronchi, interalveolar septa, of the lungs. Help clear inhaled minute particualate matter. Drained towad the hilum by vessels that follow bronchi. Most peripherily, pulmonary nodes which send lymph to bronchopulmonary nodes in hilum. Then to trachebronchial nodes on the bifurcation of the trachea. The largest being the paratracheal nodes on each side of trachea. These nodes further drain into parasternal lymphatics to form bronchomediastinal lymph trunks that empty independantly to drain into the subclavian and internal jugular vein on each side of the neck. Possibly the thoracic duct on left side.
Posterior Intercostal Arteries 4pts
All but the first 2 spaces are branches of the descending aorta. Arteries on the right are longer than the left as they have to pass over the body of the verterbral bones. Arteries on 1st two spaces arise from the supreme intercostal artery a branch of the costo cervical trunk. Upper six terminate by anastomosing with the anterior intercostal arteries of the same space. Those of the lower spaces continue to supply the abdominal wall. Travels on the lower border of the rib sandwiched between the vein (superiorly) and nerve (inferiorly).
Transversus Thoracis Muscles 4pts
Thin layer of muscle fibers that fan out from the posterior surface of the lower part of the sternum to neighboring cartilages superiorly. Run from costal cartilages II to VI. They are innervated by associated intercostal nerves. Their blood supply are from associated intercostal arteries. Assist in moving the ribs for forcible expiration.
Arise from the tendons of the flexor digitorum longus. The first arises from the medial side of the tendon to the second tow, but each of the other three arise from both the tendons between which it lies. Run forward to the medial side of the 4 lateral toes. Pass below the deep transvers metatarsal ligaments then turn dorsally to join the dorsal expansions or hood. 1st lumbrical is supplied by the medial plantar nerve and the other 3 are intervated by the twigs of the deep branch of the lateral plantar nerve. Contribute to flexion of the metatarsal joint.
- 14 Sep 2006