Central Nervous System Anatomy and Functions

Central Nervous System and Brain Anatomy

CNS: The brain is the part of the nervous system housed within the central skull or cranium.

The Medulla Oblongata

The medulla oblongata (also known as the rachidian bulb) is the prolongation of the spinal cord. In it, there are several areas of gray matter surrounded by white matter. The rachidian bulb is responsible for regulating various bodily functions such as heartbeat, blood pressure, and pulmonary ventilation, among others.

The Brain Stem

The brain stem encompasses several parts of the brain located between the medulla and the cerebrum. These parts regulate states of sleep and wakefulness, monitor visual and auditory reflexes, facilitate communication between the brain and other parts of the nervous system, and manage the selection of stimuli that pass into the brain.

The Cerebellum

Located in the back of the brain, the cerebellum consists of gray matter in the outer zone and white matter in the inner zone. The cerebellum is the organ responsible for receiving information concerning equilibrium that the ear sends, as it regulates the activity of muscles involved in equilibrium maintenance.

The Cerebrum

The cerebrum is the largest part of the brain and the most important organ of the nervous system. It is composed of white matter in the inner zone and gray matter in its outer zone, which forms the cerebral cortex.

Functions of the Cerebrum

• Receives information from all sensory organs, except the organ of equilibrium, and produces the corresponding sensations.
• Processes the information received and prepares responses and orders for effector organs.
• Processes the information received and prepares responses and orders for effector organs.
• Coordinates and controls the operation of all parts of the nervous system.
• Hosts intellectual faculties and higher nervous functions such as memory, reasoning, and intelligence.

Nervous Acts and Reflex Actions

Nervous acts involve currents flowing through very complex networks. Reflex actions function as follows:

• Sensory neurons: Derived from the skin, their axons enter via the posterior roots of the spinal cord.
• Interneurons: These intercalated neurons synapse with sensory neurons and transmit nerve impulses to motor neurons.
• Motor neurons: These exit by the spinal anterior roots to reach muscles, causing their contraction and the reflex movement.