BRS: Back

6. After a 26-year-old man's car was broadsided by a large truck, he is brought to the emergency department with multiple fractures of the transverse processes of the cervical and upper thoracic vertebrae. Which of the following muscles might be affected? (A) Trapezius (B) Levator scapulae (C) Rhomboid major (D) Serratus posterior superior (E) Rectus capitis posterior major

B. Levator scapulae the LS arise from the transverse processes of the upper cervical vertebrae and inserts on the medial border of the scapula.

24. A 38-year-old woman with a long history of shoulder pain is admitted to a hospital for surgery. Which of the following muscles becomes ischemic soon after ligation of the superficial or ascending branch of the transverse cervical artery? (A) Latissimus dorsi (B) Multifidus (C) Trapezius (D) Rhomboid major (E) Longissimus capitis

C - *trapezius* receives blood from the superficial branch of transverse cervical a.

5. A 57-year-old woman comes into her physician's office complaining of fever, nausea, vomiting, and the worst headache of her life. Tests and physical examination suggest hydrocephalus (widening ventricles) resulting from a decrease in the absorption of cerebrospinal fluid (CSF). A decrease of flow in the CSF through which of the following structures would be responsible for these findings? (A) Choroid plexus (B) Vertebral venous plexus (C) Arachnoid villi (D) Internal jugular vein (E) Subarachnoid trabeculae

C. Arachnoid villi. CSF is absorbed into the venous system primarily through the arachnoid villi projecting into the cranial dural venous sinuses.

4. A 39-year-old woman with headaches presents to her primary care physician with a possible herniated disk. Her magnetic resonance imaging (MRI) scan reveals that the posterolateral protrusion of the intervertebral disk between L4 and L5 vertebrae would most likely affect nerve roots of which of the following spinal nerves? (A) Third lumbar nerve (B) Fourth lumbar nerve (C) Fifth lumbar nerve (D) First sacral nerve (E) Second sacral nerve

C. Fifth lumbar nerve. A herniation of the IV disk at L4-L5 affects the fifth lumbar nerve root but rarely affects the fourth lumbar nerve root.

12. A 27-year-old stuntman is thrown out of his vehicle prematurely when the car used for a particular scene speeds out of control. His spinal cord is crushed at the level of the fourth lumbar spinal segment. Which of the following structures would most likely be spared from destruction? (A) Dorsal horn (B) Ventral horn (C) Lateral horn (D) Gray matter (E) Pia mater

C. Lateral horn. They contain sympathetic preganglionic neuron cell bodies, are present between the first thoracic and second lumbar spinal cord levels (T1-L2)

25. A 25-year-old soldier suffers a gunshot wound on the lower part of his back and is unable to move his legs. A neurologic examination and magnetic resonance imaging (MRI) scan reveal injury of the cauda equina. Which of the following is most likely damaged? (A) Dorsal primary rami (B) Ventral primary rami (C) Dorsal roots of the thoracic spinal nerves (D) Ventral roots of the sacral spinal nerves (E) Lumbar spinal nerves

D - the cauda equine is a *collection of dorsal & ventral roots of the lower lumbar & sacral spinal nerves* below the spinal cord

17. A 44-year-old woman comes to her physician and complains of headache and backache. On examination, she is found to have fluid accumulated in the spinal epidural space because of damage to blood vessels or meninges. Which of the following structures is most likely ruptured? (A) Vertebral artery (B) Vertebral vein (C) External vertebral venous plexus (D) Internal vertebral venous plexus (E) Lumbar cistern

D. *Lumbar cistern* The internal vertebral venous plexus is located in the spinal epidural space. The vertebral artery and vein occupy the transverse foramina of the upper six cervical vertebrae.

20. A 37-year-old man is brought to the emergency department with a crushed second cervical vertebra (axis) that he suffered after a stack of pallets fell on him at work. Which of the following structures would be intact after the accident? (A) Alar ligament (B) Apical ligament (C) Semispinalis cervicis muscle (D) Rectus capitis posterior minor (E) Obliquus capitis inferior

D. *Rectus capitis posterior minor*. Whiplash injury of the neck is produced by a force that drives the trunk forward while the head lags behind. Hangman's fracture is a fracture of the neural arch through the pedicle of the axis that may occur as a result of hanging or motor vehicle accidents. Meningomyelocele is a protrusion of the spinal cord and its meninges. A herniated disk compresses the spinal nerve roots when the nucleus pulposus is protruded through the annulus fibrosus.

2. A 23-year-old jockey falls from her horse and complains of headache, backache, and weakness. Radiologic examination would reveal blood in which of the following spaces if the internal vertebral venous plexus was ruptured? (A) Space deep to the pia mater (B) Space between the arachnoid and dura maters (C)Subdural space (D)Epidural space (E)Subarachnoid space

D. Epidural. The space between the vertebral canal and the dura mater is the epidural space, which contains the internal vertebral venous plexus.

13. A 24-year-old woman comes to a hospital to deliver her baby. Her obstetrician uses a caudal anesthesia during labor and childbirth to block the spinal nerves in the epidural space. Local anesthetic agents are most likely injected via which of the following openings? (A) Intervertebral foramen (B) Sacral hiatus (C) Vertebral canal (D) Dorsal sacral foramen (E) Ventral sacral foramen

B. *Sacral hiatus*. The caudal anesthesia is used to block the spinal nerves in the epidural space by injecting the local anesthetic agents via the sacral hiatus located between the sacral cornua.

The spinal cord is crushed at the level of the upper part of the first lumbar vertebra. Which structure is most likely damaged?

- the *conus medullaris* terminates at the level of the L2 vertebrae (IV disk between L1 & L2)

Cerebrospinal fluid (CSF) is produced by vascular choroid plexuses in the ventricles of the brain and accumulated in which space?

- the CSF is found in the *lumbar cistern*, which is a subarachnoid space in lumbar area

7. A 27-year-old mountain climber falls from a steep rock wall and is brought to the emergency department. His physical examination and computed tomography (CT) scan reveal dislocation fracture of the upper thoracic vertebrae. The fractured body of the T4 vertebra articulates with which of the following parts of the ribs? (A) Head of the third rib (B) Neck of the fourth rib (C) Tubercle of the fourth rib (D) Head of the fifth rib (E) Tubercle of the fifth rib

D. Tubercle of the fifth. The body of vertebra T4 articulates with the heads of the fourth and fifth ribs. The body of the T3 vertebra articulates with the head of the third and fourth ribs.