Nervous System Overview

The nervous system is a complex network responsible for gathering and processing information from sense organs. It consists of three main components:

• Brain
• Spinal cord
• Nerves

Brain Structure and Function

The brain is divided into several key regions, each with specific functions:

1. Cerebrum

   • Largest part of the brain
   • Interprets messages from sense organs
   • Controls memory, personality, reasoning, and conscious thought

2. Cerebellum

   • Controls balance and coordination

3. Medulla

   • Controls automatic actions and survival behaviors
   • Regulates heart rate, breathing, coughing, sneezing, swallowing, and blinking

Highlight: The cerebrum is often referred to as the "thinking" part of the brain, while the medulla is sometimes called the "reptilian brain" due to its control of basic survival functions.

Spinal Cord

The spinal cord extends from the base of the brain and connects to the brain stem. It consists of nerve cells that transmit messages between the brain and the rest of the body.

Vocabulary: Central Nervous System (CNS) - Comprises the brain and spinal cord, serving as the main control center for the nervous system.

Example: The spinal cord is protected by the spinal column, which helps prevent damage to this vital structure.

Synapses and Neurotransmission

A synapse is the small gap between neurons where information is transmitted from one neuron to another.

Synaptic Transmission

1. Electrical impulses travel along neurons
2. At the synapse, neurotransmitters are released
3. Neurotransmitters cross the synaptic gap
4. They bind to receptors on the next neuron, continuing the signal

Vocabulary: Neurotransmitters - Chemical messengers that transmit signals across synapses.

Information Flow in the Nervous System

1. Stimuli detected by sense organs (receptors)
2. Sensory neurons carry signals to the CNS
3. Interneurons process information in the CNS
4. Motor neurons carry signals to effectors (muscles and glands)
5. Response is generated

Example: When you touch a hot plate, sensory neurons quickly transmit the pain signal to your CNS, which then sends a signal via motor neurons to pull your hand away.