Recording-2025-02-19T19:20:10.011Z

Fissures and Sulci

  • Importance of understanding fissures and sulci in studying the brain.

White Matter vs. Gray Matter

  • White Matter

    • Composed of myelinated neurons.

    • Appears white due to the myelin covering.

  • Gray Matter

    • Comprised of unmyelinated or slightly myelinated neurons.

    • Has a grayish appearance.

Muscular System

  • Quadriceps Femoris Muscle

    • Key muscle group involved in extension of the knee.

  • Flexor Muscles

    • Responsible for bending joints.

  • Extensor Muscles

    • Responsible for straightening joints.

Neuromuscular Junction

  • Points of communication between neurons and muscles.

  • Essential for muscle contraction signaling.

Patellar Reflex

  • Testing the patellar ligament with a reflex hammer activates sensory neurons.

  • Path of Sensation

    • Sensory information travels to the posterior horn of gray matter.

    • Pathway diverges towards the brain for further processing.

Spinal Nerves

  • Structure of Spinal Nerves

    • Formed from the union of dorsal roots (sensory neurons) and ventral roots (motor neurons).

    • Located between vertebrae and organized into three plexuses:

      • Cervical Plexus

        • Composed of spinal nerves C1 to C4.

        • Innervates neck skin and muscles, including the phrenic nerve which controls diaphragm function.

      • Brachial Plexus

        • Originates from spinal nerves C5 to T1.

        • Supplies nerves to shoulders, upper limbs, and hand.

      • Lumbosacral Plexus

        • Originates from spinal nerves L1 to S4.

        • Supplies nerves to lower limbs and parts of the pelvis.

Cutaneous Sensory Distribution

  • Each spinal nerve, except C1, correlates with specific areas of skin for sensory functions.

  • Cutanous refers to the skin, indicating the areas supplied by sensory branches.