biolpsy_03

Biological Psychology: Macroscopic and Microscopic Neuroanatomy

• Instructor: Dr. Richárd Reichardt

• Email: reichardt.richard@ppk.elte.hu

Planes in Gross Anatomy

• The body is divided by anatomical planes to help with descriptions.

• Directions noted assist with memorization of nervous system structures.

Rostro-Caudal Axis in Humans

• Unlike most vertebrates, humans have a curved rostro-caudal axis due to upright stance.

• Common anatomical terms:

  • Superior/Inferior: Above/Below

  • Anterior/Posterior: Front/Back

Central Nervous System Protection

• CNS is protected by bones and meninges.

• Meninges provide structural support (e.g., falx cerebri and tentorium cerebelli).

Gross Anatomy of the Nervous System

• Major structures visible to the naked eye:

  • Central Nervous System (CNS):

    • Brain

    • Spinal cord

  • Peripheral Nervous System (PNS):

    • Cranial nerves

    • Spinal nerves

Gray Matter and White Matter

• Distinctions in nervous system:

  • Gray Matter: Darker regions, forms nuclei in CNS, ganglia in PNS.

  • White Matter: Lighter regions, forms tracts (CNS) and nerves (PNS).

Somatic and Autonomic Nervous System

• Somatic nervous system connects with muscles and tactile receptors.

• Autonomic nervous system connects with internal organs.

Autonomic Nervous System Overview

• Includes three systems:

  • Sympathetic Nervous System (Thoracolumbar): Fight-or-flight response.

  • Parasympathetic Nervous System (Craniosacral): Rest-and-digest response.

Anatomy of the Brain: Major Structures

• Key brain parts:

  • Cerebrum: Two hemispheres, covered by cerebral cortex.

  • Cerebellum: Coordinates movement and maintains posture.

  • Brain Stem: Contains medulla oblongata and pons.

Brain Surface Characteristics

• Cerebral cortex consists of:

  • Gyri: Ridges (⅓ of surface).

  • Sulci: Grooves (⅔ of hidden surface).

Medial View of Brain

• Midline structures visible in a cut brain:

  • Diencephalon (interbrain)

  • Mesencephalon (midbrain)

Gray Matter of the Cerebrum

• Includes structures lateral to the thalamus:

  • Basal Ganglia:

    • Dorsal striatum (caudate and lentiform nuclei)

    • Subthalamic nucleus

    • Ventral striatum (nucleus accumbens)

  • Substantia Nigra: Midbrain structures.

Limbic System

• Important for emotional regulation, bordering telencephalon.

• Key components:

  • Cingulate gyrus

  • Fornix: Output from hippocampus

  • Stria terminalis: Output from amygdala

White Matter Tracts

• Bundles connecting different brain areas:

  • Intra-hemispheric: Connections within a hemisphere.

  • Inter-hemispheric: Connections between hemispheres.

  • Projection Tracts: Run to/from cerebral cortex.

Modern Brain Imaging Techniques

• Visualization techniques:

  • CT Scan: Uses X-rays for tissue density.

  • MRI: Nuclear magnetic resonance for soft tissue.

  • DTI: Measures water diffusion in white matter tracts.

Levels of Organization in the Nervous System

• Structure: Cells -> Organelles -> Organic molecules -> Atoms.

• Estimated 86 billion neurons in human brain with 10^15 synapses.

Neurons

• Fundamental cells of the nervous system, composed of:

  • Cell Body

  • Dendrites: Receive signals.

  • Axons: Transmit signals.

Neuron Morphology

• Diverse shapes indicating functional roles in information flow.

Synapses in Neurons

• Connections made through:

  • Dendritic spines (dendrites)

  • Synaptic boutons (axon terminals)

Glial Cells: Overview

• Originally thought to act merely as fillers; now known to support neuronal function and signaling.

• Astrocytes: Connect brain capillaries with neurons.

Types of Glial Cells: Microglia

• Function in brain cleaning and maintenance.

Types of Glial Cells: Oligodendroglia

• Comprise 75% of glial cells; provide myelin sheaths in CNS.

• Schwann cells perform similar functions in PNS.

Brodmann Areas

• Developed by Korbinian Brodmann; map based on microstructural differences in cerebral cortex.

• Commonly referred to in anatomical studies.

Neurodegenerative Diseases: Microscopic Changes

• Brain tissue may show characteristic lesions associated with various diseases.

• Diagnosis based on observed pathological changes.

Alzheimer’s Disease and Key Features

• Most prevalent neurodegenerative disorder; causes dementia.

• Characterized by neurofibrillary tangles and amyloid plaques.

Parkinson’s Disease Characteristics

• Second most common neurodegenerative disorder.

• Notable for Lewy bodies, primarily affecting substantia nigra and causing movement-related symptoms (slowness, rigidity, tremor).

Multiple Sclerosis Overview

• A demyelinating disease leading to disrupted signal propagation.

• Causes could involve oligodendrocytes or microglia.

Conclusion

• Thank you for your attention! Next class will cover The Physiology of the Brain.