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.