Spinal Cord Touro Neuroscience Quiz

The spinal cord extends from the foramen magnum to the L1-L2 level. The foramen magnum is the opening at the base of the skull through which the spinal cord passes. The L1-L2 level refers to the first and second lumbar vertebrae, which are located in the lower back. Therefore, the correct answer is L1-L2.

VII is intermediate zone

VIII & IX are in ventral horn

X is in central canal

The statement "Spinocerebellar tract motor information is under conscious control" is false. The spinocerebellar tract is responsible for transmitting proprioceptive information from the muscles and joints to the cerebellum, which is involved in coordinating movement and balance. This transmission occurs unconsciously and does not require conscious control.

The internal arcuate fibers of the dorsal column tract decussate in the medulla. Decussation refers to the crossing over of nerve fibers from one side of the body to the other. In this case, the fibers cross from one side of the spinal cord to the opposite side in the medulla, which is located at the base of the brainstem. This crossing allows sensory information from the body to be transmitted to the opposite side of the brain for processing and interpretation.

They are also arranged so that more medially you will find nuclei for the trunk and more laterally nuclei for the extremeties

Spinal nerves C1-7 emerge above their corresponding vertebrae and C8 emerges between C7-T1, therefore nerves below C8 begin emerging below their corresponding vertebrae.

GVA=receptors in smooth muscles, cardiac muscle and glands
Hearing and vision are special sensory

The spinocerebellar tract is responsible for transmitting sensory information from the spinal cord to the cerebellum, which is involved in coordinating movement and balance. If coordination problems begin to occur, it suggests that there may be a lesion or damage in the spinocerebellar tract, disrupting the transmission of sensory information to the cerebellum and affecting motor coordination.

The corticospinal tract is responsible for conveying skilled, volitional movement. This means that it carries signals from the brain to the spinal cord, which then controls precise and intentional movements of the body. This includes activities such as writing, playing an instrument, or performing complex motor tasks.

Lateral:
90% in the medulla
2% uncrossed tract of Barnes

Anterior:
8% cross in spinal cord segment

Lamina I (posteromarginal nucleus),
Lamina IIo (substantia gelatinosa)
Both are in dorsal horn and don't have specific vertebrae locations

The intermediolateral cell column (IML) is found in spinal segments T1-L2. in the small lateral horn of the intermediate zone. These neurons give rise to preganglionic sympathetic efferent fibers.

Epidural anesthesia involves injecting local anesthetic drugs into the epidural space, which is located just outside the dura mater (the outermost layer of the spinal cord). This technique is commonly used during operative procedures and for postoperative pain control, as it allows for the anesthetization of the lumbar and sacral spinal nerves. By targeting this specific area, the drugs can effectively numb the nerves and provide pain relief without affecting the entire body.

The correct answer is C4-T1, brachial plexus for upper limbs making the dorsal gray matter bigger. The cervical enlargement is located between the C4 and T1 vertebrae. It is enlarged due to the presence of the brachial plexus, which is responsible for innervating the upper limbs. This increased innervation requires a larger amount of gray matter in the spinal cord, specifically in the dorsal region.

The correct answer is "No, because this white matter tract is only above T6 as it has signals from upper extremities." The cuneatus tract is a white matter tract that carries sensory information from the upper extremities. It is located above the T6 level in the spinal cord. Therefore, if an axial CT scan is taken at the level of S3, it would not be able to visualize the cuneatus tract.

The phrenic nucleus is located in spinal segments C3-C5. The phrenic nerve originates from this nucleus and innervates the diaphragm, which is the primary muscle responsible for respiration. Therefore, the phrenic nucleus plays a crucial role in controlling breathing.

The correct answer is dorsal columns. The posterior intermediate sulcus is a groove that runs along the upper thoracic and cervical spinal cord. It divides the spinal cord into two parts: the dorsal columns, which carry sensory information such as touch and proprioception, and the anterolateral tract, which carries pain and temperature sensation. Therefore, the posterior intermediate sulcus divides the dorsal columns.

The correct answer is anterior medial fissure. The anterior spinal artery branches are located in the anterior medial fissure. This is a groove that runs along the front of the spinal cord, dividing it into two halves. The anterior spinal artery supplies blood to the front part of the spinal cord, including the motor neurons that control voluntary movement.

The crossed extensor reflex refers to the signal transversing the midline and activating extensors contralaterally to support the body on the opposite leg. This means that when one leg is stimulated with a nocioceptive stimulus, the signal crosses over to the other side of the body and activates the extensor muscles on the opposite leg to provide support and balance. This reflex helps to maintain stability and prevent falls when one leg is suddenly withdrawn or injured.

The rubrospinal tract is a descending motor pathway that primarily controls voluntary movements of the upper limbs. It originates in the red nucleus of the midbrain and crosses over to the opposite side of the spinal cord. From there, it sends motor signals to the muscles of the upper limbs, allowing for precise and coordinated movements. This pathway does not play a significant role in controlling the lower limbs, respiratory muscles, or intrinsic back muscles.

The myotactic reflex refers to the automatic response of a muscle to a stretching stimulus. When the tendon is tapped, the myotactic reflex stimulates the same muscles that are being stretched, causing them to contract and resist further stretching. At the same time, it inhibits the opposite muscles, preventing them from contracting and opposing the stretch. Therefore, the correct answer is "same, opposite."

The filum internim is not a continuation of a pial thread that caudally pierces the thecal sac to become surrounded by dura and attach to the coccyx.

The correct answer is VI, dorsal horn. The dorsal horn of the spinal cord is responsible for receiving sensory information from the periphery, including proprioceptive input, and it also receives descending motor pathways. This region is involved in processing and relaying sensory information to higher brain centers for further integration and interpretation.

The spinal cord is stabilized by the denticulate ligaments and the filum terminale. The denticulate ligaments are extensions of the pia mater that attach the spinal cord to the dura mater, providing lateral stability. The filum terminale is a fibrous strand that extends from the tip of the spinal cord to the coccyx, providing longitudinal stability. These structures work together to keep the spinal cord in place and prevent excessive movement or displacement.

vestibulospinal keeps you balanced and oriented

spinocerebellar provides coordination

rubrospinal flexes forearms and arms

The human body has 31 pairs of spinal nerves. The region that has one more pair of spinal nerves than the number of associated vertebrae is the cervical region. The cervical region has 8 pairs of spinal nerves, but only 7 associated vertebrae.