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4 The Brain - Anatomy

Biological Psychology: The Brain Anatomy

Protection: The Meninges

  • Meninges: Three protective membranes surrounding the brain and spinal cord.

    • Dura mater: Tough outer layer.

    • Arachnoid mater: Middle layer, spider-web like.

    • Pia mater: Inner layer, tender and protective.

  • Structures include skin, aponeurosis, periosteum, and bone.

Blood Supply and Circulation

Cerebral Arteries

  • Main arteries:

    • Right anterior cerebral artery

    • Anterior communicating artery

    • Right internal carotid artery

    • Left middle cerebral artery

    • Right posterior communicating artery

    • Right posterior cerebral artery

    • Basilar artery

    • Left vertebral artery

Circle of Willis

  • A vascular system that supplies blood to the brain.

    • Major components include anterior communicating artery, anterior cerebral artery, middle cerebral artery, and posterior cerebral artery.

The Blood-Brain Barrier

  • Function: Protects the brain from harmful substances while allowing necessary nutrients to pass.

  • Different types of capillaries:

    • Fenestrated: Loose junctions in the body.

    • Non-fenestrated: Tight junctions in the brain.

The Ventricular System

  • Composed of lateral ventricles, third ventricle, cerebral aqueduct, and fourth ventricle.

  • Function: Production and circulation of cerebrospinal fluid (CSF).

Cerebrospinal Fluid (CSF)

  • Functions:

    • Cushions brain and spinal cord against mechanical shock.

    • Provides buoyancy and nutrients, and removes waste products.

  • Location: In ventricles, central canal, and subarachnoid space.

  • Production: Choroid plexus in ventricles.

Brain Structure

Cortical Cell Layers

  • Composed mainly of dendrites and axons.

  • Different types of cells:

    • Small pyramidal cells: Target for sensory info.

    • Large pyramidal cells: Source of motor output.

Brain Lobes and Functions

  • Frontal Lobe: Motor functions, planning, control, memory, inhibition of behaviors.

  • Parietal Lobe: Processes somatosensory and proprioceptive information.

  • Occipital Lobe: Primary visual processing.

  • Temporal Lobe: Auditory processing, visual memory, emotional recognition.

Topographical Organization

  • Mapping of body sensations and motor control in the brain.

    • Areas include: nose, face, lips, toes, and genitalia.

    • Corresponding sections in the motor and somatosensory cortices.

Limbic System & Brain Components

  • Important for emotional processing and memory formation.

  • Includes the cingulate gyrus, hippocampus, and other components.

Brainstem and Other Structures

  • Composed of thalamus, pons, medulla, and others.

  • Controls basic life functions and connections to the cerebellum.

Brain Sections

  • Coronal, Sagittal, and Transverse Sections: Views of brain structures including putamen, thalamus, corpus callosum, and more.

    • Important for understanding the localization of functions within the brain.

Tracts in the Brain

  • Comprised of connections between different brain regions.

  • Includes internal capsule, fornix, and various gyrus connections.

  • Vital for communication within the neural networks of the brain.