Musculoskeletal System

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Anatomy › Musculoskeletal System

Questions 1 - 10
1

Which structure(s) would have a tensile force applied with hyperflexion of the knee?

Anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL)

Medial collateral ligament (MCL)

Lateral collateral ligament (LCL)

Medial collateral ligament (MCL) & lateral collateral ligament (LCL)

Iliotibial band (ITB) and medial collateral ligament (MCL)

Explanation

The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) are both affected with hyperflexion of the knee, as these two ligaments are located deep inside the knee capsule, and prevent anterior and posterior sheering forces. If this action occurred with enough force, these structures would be injured. The sedial collateral ligament (MCL) and lateral collateral ligament (LCL) would be injured with a valgus or varus force, both with occur in the coronal plane. The iliotibial band (ITB) and and medial collateral ligament (MCL) would require multiplaner forces in order to be injured.

2

Injury to the obturator nerve leads to __________.

both impaired thigh adduction and loss of sensation of the medial aspect of the thigh

impaired thigh abduction

loss of sensation of the medial thigh

both impaired thigh abduction and loss of sensation of the medial thigh

impaired thigh adduction

Explanation

The obturator nerve can be damaged in car accidents, abdominal surgeries. It descends thru the pelvis to innervate the medial side of the thigh and adductor muscles of the thigh (external obturator, adductors longus, brevis, magnus and gracilis muscles). Adduction is movement of an extremity closer to the midline of the body. Abduction is the reverse of adduction.

3

Your patient’s x-ray shows a “Terry Thomas/David Letterman” sign. This finding suggests injury to which structure?

Scahpolunate ligament

Anterior talofibular ligament

Radial collateral ligament of the wrist

Ulnar collateral ligament of the wrist

Triangular fibrocartilage complex

Explanation

The "Terry Thomas/David Letterman" sign is specific to the articulations of the wrist, and involves injury to the scapholunate ligament. When this ligament is damaged, the scaphoid and lunate drift apart, creating a gap on x-rays reminiscent of the gap in Terry Thomas'/David Letterman's front teeth.

4

Injury to the obturator nerve leads to __________.

both impaired thigh adduction and loss of sensation of the medial aspect of the thigh

impaired thigh abduction

loss of sensation of the medial thigh

both impaired thigh abduction and loss of sensation of the medial thigh

impaired thigh adduction

Explanation

The obturator nerve can be damaged in car accidents, abdominal surgeries. It descends thru the pelvis to innervate the medial side of the thigh and adductor muscles of the thigh (external obturator, adductors longus, brevis, magnus and gracilis muscles). Adduction is movement of an extremity closer to the midline of the body. Abduction is the reverse of adduction.

5

Which of the following best accounts for the symptoms described?

Radiating pain down back, weakness of function, numbness or tingling

Herniated disk

Lumbar lordosis

Lumbar kyphosis

Scoliosis

Annulal tear

Explanation

When the nucleus propulsus inside an intervertebral disk protrudes through a weakened area of the annulus fibrosus, the ability of that disk to respond to torsion forces is severely compromised. Further, the protruding nucleus itself puts pressure on the vertebrae, resulting in a "compressed" or herniated disk. This can impact nearby nerves, resulting in radiating pain, weakness, and numbness or tingling.

6

Which muscle holds the scapula tight to the posterior wall of the chest and when damaged, sometimes results in a "winged" scapula?

Serratus anterior

Levator scapulae

Deltoid

Teres major

Trapezius

Explanation

The serratus anterior holds the scapula tight to the posterior wall of the chest. Damage to it, and especially to the thoracic nerve (descending from the axilla) causes this muscle to become paralyzed. Because of this, the scapula can project posteriorly from the back when actions such as pushing against a wall are performed.

7

Your dad comes home from the doctor's office with a diagnosis of "golfer's elbow." Which of the following structures is involved in this injury?

Medial epicondyle

Lateral epicondyle

Biceps brachii muscle

Annular ligament

Median nerve

Explanation

Golfer's elbow, or medial epicondylitis, is due to inflammation of the medial epicondyle of the elbow. The tendons of several muscles involved in flexing the forearm, wrist, and fingers originate at the medial epicondyle of the humerus at the elbow and this insertion point can become inflamed in response to injury.

Lateral epicondylitis is sometimes associated with tennis elbow.

8

Which of the following best accounts for the symptoms described?

Radiating pain down back, weakness of function, numbness or tingling

Herniated disk

Lumbar lordosis

Lumbar kyphosis

Scoliosis

Annulal tear

Explanation

When the nucleus propulsus inside an intervertebral disk protrudes through a weakened area of the annulus fibrosus, the ability of that disk to respond to torsion forces is severely compromised. Further, the protruding nucleus itself puts pressure on the vertebrae, resulting in a "compressed" or herniated disk. This can impact nearby nerves, resulting in radiating pain, weakness, and numbness or tingling.

9

Your dad comes home from the doctor's office with a diagnosis of "golfer's elbow." Which of the following structures is involved in this injury?

Medial epicondyle

Lateral epicondyle

Biceps brachii muscle

Annular ligament

Median nerve

Explanation

Golfer's elbow, or medial epicondylitis, is due to inflammation of the medial epicondyle of the elbow. The tendons of several muscles involved in flexing the forearm, wrist, and fingers originate at the medial epicondyle of the humerus at the elbow and this insertion point can become inflamed in response to injury.

Lateral epicondylitis is sometimes associated with tennis elbow.

10

Which muscle holds the scapula tight to the posterior wall of the chest and when damaged, sometimes results in a "winged" scapula?

Serratus anterior

Levator scapulae

Deltoid

Teres major

Trapezius

Explanation

The serratus anterior holds the scapula tight to the posterior wall of the chest. Damage to it, and especially to the thoracic nerve (descending from the axilla) causes this muscle to become paralyzed. Because of this, the scapula can project posteriorly from the back when actions such as pushing against a wall are performed.

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