Class Notes: Brains

Brain

  • Also known as the cerebrum.

  • Functions:

    • Sensory: Perception and memory.

    • Motor: Skeletal and smooth muscle regulation.

    • Association: Responsible for memory and reasoning.

Brain Development

  • Begin as a tube that had three cavities:

  1. Forebrain: Cerebrum, basal ganglia, portion of the brain stem.

  2. Midbrain: midbrain

  3. Hindbrain: Cerebellum, pons, medulla, oblongata.

Brain Structure

  • Hemisphere: Connected by corpus callosum

  • Convultion: Ridges

  • Longitudinal: Separates left and right side.

  • Transure Fissure: Separates cerebrum from cerebellum.

  • Lobes: Frontal, parietal, temporal, occipital, insula (area deep within these previous four lobes)

  • Cerebral Cortex: Outer part of the cerebrum (gray matter).

Motor Function

  • Frontal lobe:

    • Front portion: Impulse sent to thighs and leg muscles.

    • Middle portion: impulse sent to arms and shoulder muscles.

    • Back portion: impulses sent to head and face muscle.

    • Motor Speech Area: Makes talking possible.

    • Frontal Eye Field: Controls eye movement.

Sensory Function

  • Parietal Lobe: Sensations of touch, temperature, pressure, and pain.

  • Occipital Lobe: Vision.

  • Temporal Lobe: Hearing.

Association Function

  • Frontal Lobe: Concentration , organization, problem solving, and ethics.

  • Parietal Lobe: Understanding speech and forming words.

  • Temporal Lobe: Interpreting sensory experiences: music and art.

  • Occipital Lobe: Combines visual experience with our sensory experiences.

Hemisphere Dominance

  • One side of the cerebrum acts as the dominant one for certain functions.

  • 90 percent of the left side: Used for speech, writing, and reading.

  • Non-dominant side specializes in motor functions.

Memory:

  • Short Term: Processed in the frontal lobe and thalamus.

  • Long Term: Stored in the cerebral cortex of the temporal lobe.

Other Cerebral Structures:

Basal Ganglia

  • Gray matter located within the cerebrum.

  • Dopamine is produced here.

  • Relaxes motor impulses from cerebral cortex to the spinal cord.

Ventricles

  • Cavities within the cerebrum.

  • Filled with spinal fluid.

Spinal Fluid

  • 500 mL total, but only 140 mL filled with ventricles.

  • Remaining portion absorbed by the blood.

  • High concentration of soda, some sugar, and potassium.

  • Functions: Protect CNS and transport ions to the blood.

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