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Free STEP1 Exam Braindumps (page: 29)

Page 28 of 213
PDF with 845 Questions

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.
You suspect that a nerve has been damaged, but which nerve is most likely involved?

  1. external laryngeal
  2. glossopharyngeal
  3. inferior laryngeal
  4. internal laryngeal
  5. superior laryngeal

Answer(s): C

Explanation:

The inferior laryngeal nerve is motor to the intrinsic muscles of the larynx except the cricothyroid muscle, and is sensory to the larynx below the level of the vocal fold. The external laryngeal nerve (choice A) is the branch of the superior laryngeal nerve that contains the motor fibers to the cricothyroid muscle and to the cricopharyngeus muscle. The glossopharyngeal nerve (choice B) does not supply either motor or sensory fibers to the larynx. The internal laryngeal nerve (choice D) is the branch of the superior laryngeal nerve that contains the sensory fibers to the laryngeal mucosa above the vocal fold. The superior laryngeal nerve (choice E) is sensory to the laryngeal mucosa above the vocal fold and also includes motor fibers to the cricothyroid muscle.



During maturation of the oocytes, which of the following structures retain almost all of the cytoplasm after the first meiotic division?

  1. first polar body
  2. ovum
  3. primary oocyte
  4. second polar body
  5. zygote

Answer(s): B

Explanation:

The first meiotic division results in two secondary oocytes: the ovum retains almost all of the cytoplasm whereas the first polar body (choice A) does not. Primary oocytes (choice C) are the cells undergoing the first meiotic division. The second polar body (choice D) is formed after the second meiotic division. The zygote (choice E) is the fertilized ovum.



Your patient reports that several days earlier he "threw his back out" when he bent from the waist and picked up a very heavy package. The pain was immediate and extended from his hip, down the back of the thigh, and into his leg and foot. As he lies on the examining table, you raise his leg by the foot keeping the knee extended and elicit intense pain over the distribution of the sciatic nerve. An MRI scan confirms your conclusion that your patient has a herniated intervertebral disk between the fourth and fifth lumbar vertebrae.
Intervertebral disks may protrude or rupture in any direction, but they most commonly protrude in which direction?

  1. anteriorly
  2. anterolaterally
  3. laterally
  4. posteriorly
  5. posterolaterally

Answer(s): E

Explanation:

Intervertebral disks may protrude or rupture in any direction but do so most commonly in a posterolateral direction, just lateral to the strong central portion of the posterior longitudinal ligament. This is usually the weakest part of the disk, because the annulus is thinner here and is not supported by other ligaments.
Anteriorly (choice A) the intervertebral disks are supported by the broad and strong anterior ligament.
Herniation is less common in this direction. Anterolaterally (choice B) the intervertebral disk is supported by the broad anterior longitudinal ligament. The nucleus pulposus is also situated posteriorly in the disk, making herniation here less likely. Herniation of the intervertebral disk laterally (choice C) is not particularly common. Posteriorly (choice D) the intervertebral disks are supported by the posterior longitudinal ligament. Herniation is less common in this direction.



Your patient reports that several days earlier he "threw his back out" when he bent from the waist and picked up a very heavy package. The pain was immediate and extended from his hip, down the back of the thigh, and into his leg and foot. As he lies on the examining table, you raise his leg by the foot keeping the knee extended and elicit intense pain over the distribution of the sciatic nerve. An MRI scan confirms your conclusion that your patient has a herniated intervertebral disk between the fourth and fifth lumbar vertebrae.
Herniation of the intervertebral disk between the fourth and fifth lumbar vertebrae most likely impinges on the roots of which spinal nerve?

  1. L3
  2. L4
  3. L5
  4. S1
  5. S2

Answer(s): C

Explanation:

A bulging or protruded disk typically affects the traversing nerve root; that is, the nerve affected is one number greater than the number of the disk. The L3 spinal nerve (choice A) would be affected by protrusion of the L2 intervertebral disk. The L4 spinal nerve (choice B) would be affected by protrusion of the L3 intervertebral disk. The S1 spinal nerve (choice D) would be affected by protrusion of the L5 intervertebral disk. The S2 spinal nerve (choice E) exits through the foramina of the fused sacrum and, therefore, is not subject to compression by herniated intervertebral disks.






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