L1.2.1.1.1.2: Functional Areas

• Primary Somatosensory Area

  • Structural name: Postcentral gyrus
  • Function: Allows us to recognize pain, differences in temperature, and feel light touches
  • Spatial map: Sensory homunculus
  • Location: Parietal lobe
  • Location in relation to the central sulcus: Posterior
• Primary Motor Area

  • Structural name: Precentral gyrus
  • Function: Allows us to consciously move skeletal muscles
  • Spatial map: Motor homunculus
  • Location: Frontal lobe
  • Location in relation to the central sulcus: Anterior
• ● PRIMARY SOMATOSENSORY (somatic sensory) AREA

  ○ Receives impulses from the body’s sensory receptors

  ○ The sensory homunculus (homunculus = “little man”) shows how much tissue is devoted to various sensory functions
• ● PRIMARY SOMATOSENSORY (somatic sensory) AREA

  ○ Contralateral / Crossed Sensory Pathways

  ■ Left side of the area receives impulses from the right side of the body, vice versa
• ● PRIMARY SOMATOSENSORY (somatic sensory) AREA

  ○ Lips and Fingertips — body regions with the most sensory receptors

  ○ Impulses from special sense organs interpreted in cortical areas

  -- Visual area: Occipital lobe

  -- Auditory area: Temporal lobe

  -- Olfactory area: Temporal lobe
• ● PRIMARY MOTOR AREA

  ○ Pyramidal / Corticospinal tract

  ■ The major voluntary motor tract formed by the axons of motor neurons

  ■ Descends to the spinal cord

  ○ Face, Mouth, and Hands — body control areas with the finest motor control