brain anat

Neurons and Neuroglia

• Type of Neuron: The focus is on Multipolar neurons, the most common type.

  • Found in regions where complex processes occur.

• Schwann Cells: Located in the Peripheral Nervous System (PNS), crucial for repair and myelination of neuronal axons.

  • Promote Saltatory Conduction, which occurs due to the nodes of Ranvier being insulated by Schwann cells. This allows impulses to 'jump' rather than travel continuously along the axon, enhancing speed.

• Mitochondria in Neurons: Neurons contain many mitochondria to power sodium-potassium pumps. These pumps maintain the resting membrane potential and are crucial during action potentials.

Gray Matter vs. White Matter

• Gray Matter: Contains neuronal cell bodies and unmyelinated axons, typically found in the inner regions of the spinal cord and the outer cortex of the brain.

• White Matter: Made up of myelinated axons, which appear white due to the high lipid content of myelin. It is mainly located in the inner brain structures.

  • Myelination is essential for efficient neural signal transmission.

Brain Structure and Function

• Brain Anatomy Overview:

  • Cerebrum: The largest part of the brain responsible for higher brain functions, including thought and action.

  • Diencephalon: Includes the thalamus and hypothalamus, serving as relay stations for sensory information and controlling autonomic functions.

  • Brain Stem: Regulates vital processes and is involved in autonomic functions.

    • Includes three parts: Midbrain, Pons, Medulla Oblongata.

  • Cerebellum: Coordinates motor control and balance.

• Gyri and Sulci:

  • Gyri: Bumps on the brain surface that increase surface area for neurons.

  • Sulci: Grooves between gyri that separate different brain regions.

  • The more folds (gyri and sulci), the higher the potential for complex behaviors and intelligence, especially in mammals.

Neurological Development

• Week 4 Gestation: Formation of the three primary brain vesicles:

  • Forebrain (Prosencephalon), Midbrain (Mesencephalon), Hindbrain (Rhombencephalon).

• Week 5 Gestation: Division of the forebrain into five regions, including the development of cerebral structures like the thalamus and hypothalamus.

CSF and Ventricular System

• Cerebrospinal Fluid (CSF): Produced by ependymal cells in the choroid plexus, plays a role in cushioning and providing chemical stability to the brain.

  • Flows through the ventricles, which include lateral ventricles, third ventricle, and fourth ventricle.

• Ventricles: Hollow spaces in the brain where CSF circulates, cleaning and removing waste material.

Protective Structures of the Brain

• **Mening