11: The Central Nervous System (Brain)
The brain and the spinal cord are the central nervous system, and they represent the main organs of the nervous system. The spinal cord is a single structure, whereas the adult brain is described in terms of four major regions: the cerebrum, the diencephalon, the brain stem, and the cerebellum. A person’s conscious experiences are based on neural activity in the brain. The regulation of homeostasis is governed by a specialized region in the brain. The coordination of reflexes depends on the integration of sensory and motor pathways in the spinal cord.
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- 11.1: The Cerebrum
- This page describes the cerebrum as the largest brain part, divided into two hemispheres, covered by a folded cerebral cortex that enhances its surface area for advanced neurological functions. The cortex is organized into four lobes—frontal, parietal, temporal, and occipital—distinguished by grooves and ridges. These intricate folds help fit the brain within the skull and facilitate complex interrelated functions among the lobes.
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- 11.2: The Diencephalon
- This page explains the diencephalon, a vital brain structure that connects the cerebrum to the nervous system, facilitating information flow, except for the olfactory system. Positioned beneath the cerebrum, it forms the third ventricle's walls and encompasses the thalamus, hypothalamus, epithalamus, and subthalamus.
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- 11.3: The Brain Stem
- This page explains the structure and functions of the brain stem, which includes the midbrain, pons, and medulla. It emphasizes the midbrain's role in sensory information coordination and the pons as a vital connection to the cerebellum. The page also highlights the importance of the pons and medulla in regulating essential functions like cardiovascular and respiratory systems, while noting that the cerebellum, although attached to the brain stem, is considered a separate area.
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- 11.4: The Cerebellum
- This page describes the cerebellum, or "little brain," which resembles a smaller cerebrum and makes up about 10% of brain mass. It compares sensory feedback with its own information and is located on the posterior brain stem. The cerebellum receives input from the pons and inferior olive and sends output to the midbrain, facilitating communication of descending signals to the spinal cord.
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- 11.5: Exercises
- This page features labeling exercises centered on brain anatomy, including structures of the cerebrum, cerebellum, brainstem, and ventricular system. It guides users in identifying and labeling different lobes, gyri, sulci, limbic system parts, and CNS components, aiming to improve understanding of brain anatomy and functions.
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- 11.6: MODELS- 3D Brains, Ventricles, Sagittal and Coronal Brain Slices, Torsos, Sagittal Head
- This page provides a detailed overview of the human brain's anatomy, covering key structures such as the cerebrum, brain stem, cerebellum, ventricular system, and meningeal layers. It identifies specific components like gyri, sulci, and lobes, offering insights into the brain's complex organization and structural relationships.