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Free STEP1 Exam Braindumps (page: 28)

Page 27 of 213
PDF with 845 Questions

A 38-year-old female patient suffers from pleurisy and requires pleural fluid sampling (thoracentesis). The attending physician asks you to perform the procedure at the midaxillary line on the right side. Which of the following would be the appropriate level to perform the procedure?

  1. above the level of the 7th rib
  2. at the level of the 10th rib
  3. at the level of the 5th rib
  4. below the level of the 10th rib
  5. between the level of the 8th and 10th ribs

Answer(s): E

Explanation:

The needle for thoracentesis should be inserted in the intercostals spaces between the 8th and 10th ribs.
Remember that the parietal pleura extends approximately two ribs inferior to the lung: at the midaxillary line, the inferior surface at the lung is at the level of the 8th rib and the parietal pleura at the 10th rib. Above the level of the 7th (choice A) and 5th (choice C) ribs, the needle will injure the lung. At (choice B) or below the level of the 10th rib (choice D), it will injure the liver or other abdominal organs.



A 45-year-old female patient develops Parinauds syndrome (vertical gaze palsy) and an MRI shows a large tumor of her pineal gland. The tumor is not only compressing her tectum, causing the vertical gaze palsy, but also obstructing the underlying cerebrospinal fluid pathway causing progressive noncommunicating hydrocephalus. The obstruction causes immediate accumulation of cerebrospinal fluid in which of the following?

  1. cerebral aqueduct of Sylvius
  2. fourth ventricle
  3. lateral ventricle
  4. subarachnoid space
  5. third ventricle

Answer(s): E

Explanation:

In this situation, the cerebrospinal fluid will accumulate immediately in the third ventricle and cause hydrocephalus. The flow of cerebrospinal fluid is normally from the lateral ventricles (choice C) to the third ventricle and then by way of the cerebral aqueduct of Sylvius (choice A) to the fourth ventricle (choice B).
From there the cerebrospinal fluid flows out of the brain into the subarachnoid space (choice D). A blockage of the cerebral aqueduct will result in immediate accumulation of cerebrospinal fluid in the third ventricle. Because the cerebrospinal fluid no longer flows from the ventricular system to the subarachnoid space, the resulting hydrocephalus is termed noncommunicating.



Apatient has been severely injured in the back of the head during a mugging attempt and imaging studies reveal possible fracture of the skull along with the C1 (atlas) vertebra. The patient is also hemorrhaging from the vertebral artery in this location, and the attending surgeon will attempt to stop the bleeding by access through the suboccipital triangle. Which of the following muscles attaches from the transverse process of C1 to the occipital bone and forms the lateral border of the suboccipital triangle?

  1. obliquus capitis inferior
  2. obliquus capitis superior
  3. rectus capitis posterior major
  4. rectus capitis posterior minor
  5. semispinalis cervicis

Answer(s): B

Explanation:

The obliquus capitis superior, attached between the transverse process of C1 and the suboccipital bone between the nuchal lines. It forms the lateral border of the suboccipital triangle. The obliquus capitis inferior (choice A) is the inferior border of the triangle, attaching from the spinous process of C2 to the transverse process of C1. The rectus capitis posterior major (choice C) inserts from the spinous process of C2 into the inferior nuchal line on the occipital bone; it forms the medial border of the suboccipital triangle. The rectus capitis posterior minor (choice D) lies medial to the rectus capitis posterior major. The semispinalis cervicis (choice E) does not participate in the formation of the suboccipital triangle.



Your patient presents in your office complaining of hoarseness. During your examination, you find that one vocal fold has deviated toward the midline and does not abduct during deep inspiration or vocalization. You also observe that touch sensation in the vestibule of the larynx appears to be intact. Which laryngeal muscle is most important in abduction of the vocal folds?

  1. cricothyroid
  2. lateral cricoarytenoid
  3. posterior cricoarytenoid
  4. thyroarytenoid
  5. transverse arytenoid

Answer(s): C

Explanation:

The vocal folds are abducted and the rima glottidis is widened by the posterior cricoarytenoid muscles that rotate the arytenoid cartilages laterally. The cricothyroid muscles (choice A) tense and lengthen the vocal ligament by tilting the thyroid cartilage forward. The lateral cricoarytenoid muscles (choice B) adduct the vocal folds by medially rotating the arytenoid cartilages. The thyroarytenoid muscles (choice D) decrease the tension and length of the vocal ligaments by tilting the thyroid cartilages posteriorly. The transverse arytenoids muscle (choice E) adducts the vocal folds by pulling the arytenoid cartilages together.






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