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.