Vocab Terms 4

HSLS 4130 Vocab Set 4: Focus on Spinal Cord Tracts

Key Terminology

  • Ganglia

    • Definition: A connection of neuronal bodies located in the Peripheral Nervous System (PNS).
    • Function: Acts as synaptic relay stations between neurons, facilitating communication within the nervous system.

  • Nuclei

    • Definition: Clusters of neurons situated in the Central Nervous System (CNS).
    • Function: Involved in various functions such as processing information and relaying signals within the CNS.

  • Nerve

    • Definition: A bundle of nerve fibers found in the PNS.
    • Function: Transmits motor, sensory, and autonomic information between the CNS and the rest of the body.

  • Fasciculi

    • Definition: White matter tracts, essentially bundles of nerve fibers, connecting areas within the CNS.
    • Function: Facilitates communication between different brain regions and between the brain and spinal cord.

  • Fossa

    • Definition: Anatomically, a hollow or depressed area within the body.
    • Function: Can indicate areas involved in various physiological functions depending on the location.

  • Decussation

    • Definition: The action of crossing, particularly referenced regarding the axonal pathways in the nervous system.
    • Function: Describes how some neural pathways cross over from one side of the CNS to the other, important for motor and sensory functions.

  • Proprioception

    • Origin: Latin term meaning "one's own perception."
    • Definition: Our awareness of our body's position in space.
    • Importance: Critical for coordinated movement and balance.

  • Discriminative touch

    • Definition: Sensory information that allows us to interpret what we are touching.
    • Aspects: Includes fine pressure, vibration, and texture detection.

  • Crude touch

    • Definition: A basic sense of pressure and contact, indicating that "my body is touching something."
    • Function: Provides a general understanding of contact without fine details.

  • Thalamus

    • Definition: A collection of nuclei associated with the diencephalon and the third ventricle.
    • Function: Acts as the brain's "sensory relay," sending sensory information to different areas of the cortex, essential for processing sensory data.

Spinal Cord Tracts

  • Corticospinal Tract

    • Type: Descending tract.
    • Function: Carries motor information to skeletal muscles.
    • Course: Motor directives from the cortex cross in the medullary pyramids to innervate the contralateral side of the body.

  • Medial Lemniscal Tract

    • Type: Ascending tract, also known as the Dorsal columns.
    • Function: Carries discriminative touch and proprioceptive information.
    • Crosses at: The level of the medulla (sensory decussation) to become internal arcuate fibers, facilitating the processing of touch and position sensation.

  • Spinothalamic Tract

    • Type: Ascending tract.
    • Function: Carries information related to pain, temperature, and crude touch.
    • Crosses at: The spinal cord at the level it enters, allowing for the rapid relay of pain and temperature sensation.

Sensory Receptors

  • Visceral

    • Definition: Relates to organs, especially their functions and responses within the body.
    • Importance: Understanding visceral sensation is critical for comprehending internal physiological responses.

  • Chemoreceptors

    • Function: Detect chemical information, including taste and smell.
    • Role: Monitor levels of CO2 in the blood, crucial for respiratory regulation and metabolic processes.

  • Mechanoreceptors

    • Definition: Receptors that are stimulated by mechanical pressure or deformation.
    • Function: Essential for sensing touch, pressure, and sound within the environment, playing a key role in reflexes and responses.