Brainstem: Composed of the medulla oblongata, pons, and midbrain.
Diencephalon: Includes the thalamus, hypothalamus, and epithalamus.
Pineal Gland: Located in the epithalamus.
Protection of the Brain
Cranial Bones: Surround the brain and part of the cranium.
Meninges:
Dura Mater: Tough, dense outer layer of connective tissue with two layers.
Arachnoid Mater: Lies beneath the dura mater.
Pia Mater: Innermost layer.
Cerebrospinal Fluid (CSF): Circulates around the brain and spinal cord, providing nutrients and removing waste.
Cerebrospinal Fluid (CSF) Flow
CSF made in the ventricles by choroid plexuses.
Flows from lateral ventricles → interventricular foramen → third ventricle → cerebral aqueduct → fourth ventricle → subarachnoid space and central canal.
Reabsorbed into the venous blood flow via arachnoid villi.
Brainstem
Medulla Oblongata
Continuous with the spinal cord.
Pyramidal Tracts: Cross over at the decussation of pyramids.
Controls heart rate, respiration, and reflexes (swallowing, coughing, etc.).
Pons
Links parts of the brain.
Involved in motor control and respiratory regulation.
Midbrain
Contains Tectum with superior and inferior colliculi (visual and auditory reflexes).
Cerebral Peduncles: Transmit motor and sensory impulses.
Diencephalon
Thalamus
Major relay station for sensory inputs (except olfaction).
Hypothalamus
Controls homeostatic conditions.
Epithalamus
Contains the pineal gland (produces melatonin).
Regulatory role in circadian rhythms.
Cerebrum
Composed of two hemispheres with gray and white matter.
Cerebral Cortex: Gray matter, functions as conscious brain.
Basal Nuclei and Limbic System: Involved in motor control and emotions.
Divided into lobes: frontal, parietal, occipital, and temporal.
Primary Motor Area: Precentral gyrus.
Primary Somatosensory Area: Postcentral gyrus.
Cranial Nerves
12 pairs of cranial nerves.
Know names, numbers (Roman numerals), and functions (sensory, motor, or both).
Examples:
Cranial Nerve I (Olfactory): Smell (sensory).
Cranial Nerve II (Optic): Vision (sensory).
Use mnemonics to remember the names and order.
Study Resources
Review animations and slides for additional understanding.
Contact instructor for questions or clarifications.