Radiology: Spine & Lower Limb
Osteoporosis is defined as a BMD of....
Phosphorylation of myosin light chains in smooth muscle...
activates myosin ATPase
A physician is trying to locate a patient's pulse on the dorsal aspect of the foot. Which artery should they be palpating?
Dorsalis pedis artery
Which of the following nerve roots is tested by the integrity of the patellar reflex
L4
A 14-year-old girl is diagnosed with an abnormal lateral curvature of her spine. Her shoulders and hips are uneven, and her scapula is pronounced. What is this condition
Scoliosis
A patient presents with a history suggestive of a medial meniscus tear in the knee. What is the most appropriate imaging modality for a definitive diagnosis?
MRI
According the Henneman's size principle, if a task requires progressively increasing force, in what order will motor units be recruited?
From smallest to largest (Type 1 -> Type 2a -> Type 2x)
A surgeon is performing a coronary artery bypass graft (CABG). They decide to harvest the longest vein in the body for the procedure. Which vein are they using?
Great saphenous vein
What is the primary function of the lumbosacral tank?
It connects the lumbar and sacral plexuses
A lumbar puncture is performed to collect cerebrospinal fluid from a patient. At which vertebral level is the needle most safely inserted to avoid damaging the spinal cord?
L3/L4 or L4/L5
What is depicted in this image? (1)
Abnormal pediatric growth arrest lines
Smooth muscle contraction depends upon an enzyme that phosphorylates _______, leading to the activation of myosin and initiation of the contractile process
the regulatory light chain of myosin
A patient suffers a severe mid-femur fracture that completely severs the deep femoral artery. Which of the following would be most likely to provide alternative blood supply to the distal part of the thigh and leg?
The perforating arteries of the deep femoral artery.
A patient with a gluteus maximum gait present with a waddling gait due to an inability to extend the hip fully during walking. This clinical presentation is a result of a lesion to which nerve?
Inferior gluteal nerve
A patient with long-standing rheumatoid arthritis develops a kyphosis. Which anatomical component of the vertebral column is the direct cause of the exaggerated posterior curvature in this context?
Compression fractures of vertebral bodies
What is represented by the turquoise arrows? (2)
Cauda Equina Nerve Roots
A patient is given the beta-2 adrenergic agonist albuterol to relieve an asthma attack. How does this drug promote the relaxation of airway smooth muscle?
By activating a Gs protein, which increases cAMP levels and inhibits MLCK activity.
A patient with a gunshot wound to the popliteal fossa has a damaged artery. The surgeon must identify the borders of the popliteal fossa to access the damaged vessel. Which of the following is NOT a border of the popliteal fossa?
Popliteal nerve
A 28-year-old male is recovering from a deep laceration to his posterior thigh. Following the injury, he is unable to perform dorsiflexion of his foot and experiences a 'step-page' or 'foot drop' gait. Based on the symptoms, which of the following nerves is most likely damaged?
Common fibular nerve
A patient complains of pain along their lower leg after a sudden, high-impact jump and landing. The physician notes swelling and bruising that ascends the leg from the ankle. What is the most likely injured anatomical structure, and why is the pain radiating upward?
The interosseous membrane and tibiofibular ligaments; the force is transmitted up the syndesmosis.
Name the following structures represented by 8, 9, 10, 11, and 12. (3)
Transverse Process, Transverse Foramen, Pedicle, Lateral Mass, Uncus
You and a colleague are embroiled in an academic debate regarding the pathophysiological basis of amyotrophic lateral sclerosis. He is a proponent of the "dying forward" hypothesis, which you subscribe to the "dying back" hypothesis. What is the main gist of your argument?
The disease starts within muscle cells or the neuromuscular junciton & the disease starts with a relative lack of a motor neurotrophic hormone.
A patient with an injured ankle needs to be assessed for arterial blood flow to the foot. The posterior tibial artery branches into which two arteries that supply the sole of the foot?
Medial plantar and lateral plantar arteries
A 65-year-old patient presents with a positive Trendelenburg sign, characterized by the inability to maintain a level pelvis when standing on one leg. Which of the following nerves is most likely a source of this deficit?
Superior gluteral nerve
A patient with a history of atherosclerosis presents with a palpable bulge in the popliteal artery. This places them at risk for a life-threatening complication. What is the primary cause of this condition, and what is its most dangerous potential outcome?
Arterial weakness due to atherosclerosis; rupture leading to fatal bleeding