Brain Structure and Functions

Brain Structure & Functions

Methods of Understanding Brain Structure and Function

  • Lesioning

    • Definition: The process of destroying parts of the brain to observe the effects on behavior or function.

    • Applications: Commonly used in animal studies; notable case of Phineas Gage who survived a severe brain injury, leading to insights about brain localization of function.

  • Electrical Stimulation

    • Definition: Technique where electric currents are used to stimulate specific areas of the brain.

    • Purpose: To observe resultant behavioral or physiological effects.

  • Transcranial Magnetic Stimulation (TMS)

    • Definition: A non-invasive method involving magnets to stimulate specific brain areas.

    • Purpose: To observe changes in brain function in response to stimulation.

  • Electroencephalography (EEG)

    • Definition: A technique that uses electrodes to monitor electrical activity (brain waves) of the brain.

    • Use: Helps in diagnosing conditions like epilepsy, sleep disorders, and more.

  • Computed Tomography (CT)

    • Definition: An imaging technique that uses X-rays to create detailed pictures of the brain's structure.

    • Application: Useful in identifying structural abnormalities or injuries.

  • Positron Emission Tomography (PET)

    • Definition: An imaging test that uses a radioactive dye to show metabolic activity in the brain.

    • Purpose: Helps in assessing brain function and detecting conditions such as tumors.

  • Magnetic Resonance Imaging (MRI)

    • Definition: An imaging technique that uses strong magnets and radiofrequency pulses to examine brain structure.

    • Application: Provides high-resolution images of brain anatomy.

  • Functional Magnetic Resonance Imaging (fMRI)

    • Definition: A method that examines brain function by measuring changes in blood flow while a person performs a task.

    • Purpose: Used to understand which areas of the brain are involved in specific cognitive functions.

Brain Structure

  1. Cerebral Cortex

    • Overview: The outer layer of the brain involved in complex brain functions such as perception, thought, and decision-making.

  2. Hemisphere Division

    • Left Hemisphere

    • General Functions: Associated with language, analytical tasks, and logical reasoning.

    • Right Hemisphere

    • General Functions: Linked to creativity, intuition, artistic abilities, and spatial tasks.

  3. Individual Lobes

    • Frontal Lobe

    • Includes:

      • Prefrontal Cortex: Involved in complex cognitive behavior, decision making, and personality expression.

      • Motor Cortex: Coordinates voluntary movements.

    • Parietal Lobe

    • Includes:

      • Somatosensory Cortex: Processes sensory information from the body, such as touch and temperature.

    • Occipital Lobe

    • Function: Contains the visual cortex, which is essential for visual processing.

    • Temporal Lobe

    • Function: Involved in processing auditory information and is key for memory and emotion regulation.

Brain Functions

  1. Basic Life Functions (hind brain)

    • Cerebellum: Coordinates voluntary movements and maintains posture and balance.

    • Medulla: Controls autonomic functions such as heart rate and breathing.

    • Pons: Serves as a relay station between different parts of the brain; involved in regulating sleep and arousal.

  1. Midbrain

-substania Nigeria : important in fluidity and inhibiting movement

-reticular formation (extends from hindbrain to midbrain) : responsible for arrousal and consciousness

  1. Higher Order Functions (forebrain)

    • Cerebrum: Responsible for higher cognitive functions, including reasoning, problem-solving, and planning.

    • Thalamus: Acts as the brain's relay station, channeling sensory and motor signals to the cerebral cortex.

    • Hypothalamus: Regulates vital bodily functions such as temperature, hunger, thirst, and circadian rhythms.

    • Pitituary gland (controls endocrine system) : emotions, hormone regulation

    • Amygdala- Agression part

    • Hippocampus - Memory

    • Basil Gland - Groups of nuclei that cohesively function, good for cognitive flexibility and movement. 

    • Limbic System: Involved in emotional responses, memory processing, and motivation; includes structures such as the hippocampus and amygdala.

GLIAL CELLS (part of mylien sheath)

-astroglia: creation of blood brain barrier

-Oligobendroglia : Provides a fatty coating that insulates the axons of neurons from nearby neural activity (protecter)

^if this is lacking in the brain multiple sclerosis is common.

-ependymal cells : produce and circulate cerebro spinal fluid, using its cilia maintains brain health.

-Microglia- cleans up debree of dead neurons and glia.