Brain Parts

Major Brain Regions

• Cerebrum: Largest part, responsible for thinking, memory, and voluntary movements.

• Cerebellum: Coordinates movement, balance, and posture.

• Brainstem: Controls essential life functions (breathing, heart rate).

Cerebral Cortex (Lobes of the Brain)

• Frontal Lobe: Decision-making, reasoning, voluntary movements (includes the motor cortex).

• Parietal Lobe: Processes sensory information (touch, spatial awareness).

• Occipital Lobe: Responsible for vision.

• Temporal Lobe: Processes sound, language, and memory.

Deep Brain Structures

• Hippocampus: Critical for memory formation and spatial navigation.

• Amygdala: Processes emotions like fear and pleasure.

• Thalamus: Relays sensory signals to different brain regions.

• Hypothalamus: Regulates hunger, temperature, and hormones.

• Basal Ganglia: Controls movement and habit formation.

Brain’s Protective and Support Systems

• Meninges: Protective layers around the brain (dura mater, arachnoid mater, pia mater).

• Ventricles & Cerebrospinal Fluid (CSF): Cushion and nourish the brain.

• Blood-Brain Barrier (BBB): Prevents harmful substances from entering the brain.

Brain Communication Pathways

• Corpus Callosum: Connects the left and right hemispheres.

• Spinal Cord: Sends messages between the brain and body.

• Optic Nerve: Transmits visual information to the brain.

Blood Supply to the Brain

• The brain receives blood from carotid and vertebral arteries, merging to form the Circle of Willis, a network for stable blood flow. The middle cerebral artery (MCA) supplies blood to major brain areas.

Brain Veins and Drainage

• Jugular veins drain blood from the brain to the heart. Dural sinuses (e.g., superior sagittal sinus) collect and direct blood out of the brain.

Blood-Brain Barrier (BBB)

• The BBB is a protective filter, allowing oxygen and nutrients while blocking harmful substances.

Stroke and Blood Flow Issues

• Stroke results from blocked blood flow (ischemic) or a vessel burst (hemorrhagic), leading to brain damage.

Meninges Layers

• Dura Mater: Tough outer layer, composed of dense tissue; has periosteal and meningeal layers, forming dural sinuses.

• Arachnoid Mater: Thin, web-like middle layer with a subarachnoid space filled with CSF.

• Pia Mater: Delicate inner layer that closely follows brain contours and supplies blood vessels.

Gray Matter (Processing Center)

• Composed of neuron cell bodies, responsible for thinking, memory, sensory processing, and voluntary movement. Found in the cerebral cortex, basal ganglia, and thalamus.

White Matter (Communication Network)

• Consists of myelinated axons for signal transmission, found in the corpus callosum and spinal cord, allowing efficient communication.

Key Differences: Gray Matter vs. White Matter