Nervous system (central & peripheral) | Control & Coordination | Biology | Khan Academy

Summary

The nervous system acts like the body's wiring, enabling the brain to control muscles and process sensory information using electrical signals. When you decide to move or respond to touch, these signals travel through nerves to muscles or the brain. The nervous system has two main parts: the central nervous system (brain and spinal cord) processes information, while the peripheral nervous system (cranial and spinal nerves) communicates between the brain, muscles, and senses. Together, they manage all bodily functions and sensations, making everyday actions automatic and seamless.

Takeaways

• 🔌 The nervous system acts like the body's wiring system, controlling muscles and enabling communication between the brain and the body.
• ⚡ Electrical signals generated by the brain control muscle movements, like raising your hand to wave goodbye.
• 🧠 The nervous system is responsible for both motor control and sensory perception, helping the brain understand the surrounding environment.
• 👋 Nerves transmit electrical signals to muscles, causing them to contract and move the body.
• 👂 Sensory nerves detect stimuli (e.g., touch, sight, smell) and send signals to the brain for processing.
• 📡 The nervous system converts stimuli like light or touch into electrical signals that the brain interprets.
• 🔬 The nervous system is made of specialized cells called neurons, which conduct electricity and communicate information.
• 🏛 The nervous system is divided into two parts: the central nervous system (CNS) and the peripheral nervous system (PNS).
• 🎯 The CNS, which includes the brain and spinal cord, processes information and makes decisions.
• 🚚 The PNS, composed of cranial and spinal nerves, sends information between the CNS and the rest of the body.

Q & A

What is the primary function of the nervous system?

The primary function of the nervous system is to act like a wiring system in the body, allowing the brain to control muscles and enabling communication between the brain and different parts of the body using electrical signals.

How does the brain control muscle movements, such as waving goodbye?

When you decide to wave, an electrical signal is generated in the brain, which travels down the nerves to the bicep muscles. This causes the bicep to contract, pulling the forearm up. When the signal stops, the muscle relaxes and the arm lowers.

How does the nervous system help you sense things, like someone touching your shoulder?

When someone taps your shoulder, nerves near the skin generate an electrical signal, which is sent to the brain. The brain processes this information and determines where the touch occurred, allowing you to react appropriately.

What are the two main functions of the nervous system?

The nervous system controls muscle movements by sending electrical signals to muscles, and it also helps the brain process sensory information from the environment, such as touch, sight, smell, and sound.

What are neurons, and how are they related to the nervous system?

Neurons are specialized cells that make up the nerves. They are responsible for conducting electrical signals throughout the nervous system, allowing communication between the brain and other parts of the body.

How is the nervous system divided, and what are its two main parts?

The nervous system is divided into two parts: the Central Nervous System (CNS), which includes the brain and spinal cord, and the Peripheral Nervous System (PNS), which consists of nerves branching from the brain and spinal cord to the rest of the body.

What is the role of the Central Nervous System (CNS)?

The Central Nervous System, made up of the brain and spinal cord, is responsible for processing information, making decisions, and coordinating the body's response to various stimuli.

What does the Peripheral Nervous System (PNS) do?

The Peripheral Nervous System connects the CNS to the rest of the body, transmitting information between the brain, muscles, organs, and sensory receptors, facilitating communication and response.

What are cranial and spinal nerves?

Cranial nerves are nerves that branch from the brain, while spinal nerves branch from the spinal cord. Both types of nerves are part of the Peripheral Nervous System and help transmit signals between the CNS and the body.

How do the central and peripheral nervous systems work together?

The central nervous system processes and decides how to respond to information, while the peripheral nervous system communicates signals between the CNS and the muscles, organs, and sensory receptors, enabling the body to function in response to the environment.