The nervous system is a network of nerves and cells that carry messages to and from the brain and spinal cord to different parts of the body. The nervous system is the center of all mental activity, and is the major regulatory and communicating system of the body.
THE NERVOUS SYSTEM
PARTS OF NERVOUS SYSTEM
THE NERVOUS SYSTEM
PARTS OF THE BRAIN
PARTS OF THE BRAIN
“Brain and Nervous System (for Parents) - Nemours KidsHealth.” Edited by KidsHealth Medical Experts, KidsHealth, Nemours Children's Health System, kidshealth.org/en/parents/brain-nervous-system.html.
The brain controls all the body’s functions. The brain controls both what we are aware of, such as our thoughts, feelings, and movements, as well as things we are less aware of such as our heartbeat and digestion. The nervous system is a network which relays messages from the brain to different areas of the body and back via the spinal cord. The spinal cord contains thin nerves which branch out to every organ and body part.
The nervous system has two parts, the central nervous system and the peripheral nervous system. The central nervous system consists of the brain and the spinal cord, while the peripheral nervous system is made up of the nerves that go through the whole body. Despite only weighing about 3 pounds, the human brain is covered in folds which give it extra surface area for storing information. The spinal cord is a bundle of nerve tissue that extends from the lower part of the brain down the spine. Nerves branch off the spinal cord to the entire body. The brain and spinal cord are both protected by our skeletal system: the brain is protected by the skull and the spinal cord is protected by bones called vertebrae.
The autonomic nervous system is a part of the peripheral nervous system which controls involuntary body processes like breathing, sweating, shivering, and digesting. There are two parts of the autonomic nervous system: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic nervous system controls the body’s response to dangerous or stressful situations. If something scary happens, the sympathetic nervous system will make the heart beat faster so blood can be sent to body parts where it is needed, and cause the adrenal glands in the kidneys to release adrenaline. The parasympathetic nervous system, on the other hand, prepares the body for rest, and also helps the digestive system move so we can take in nutrients from our food.
The nervous system depends on cells called neurons. There are billions of neurons in the brain, and they have specialized jobs. For example, sensory neurons transmit information from the sensory organs to the brain. Neurons also share information with each other, making connections which affect the way we learn, think, and behave. Over time, messages travel from one neuron to another again and again, creating connections in the brain. This is why activities might be challenging at first but get easier: the connection becomes established in the brain.
Two neurons connected
The brain has three main sections: the forebrain, the midbrain, and the hindbrain. The forebrain is the larger, more complex part of the brain. It includes the cerebrum, the area with folds typically seen in representations of the brain. The cerebrum contains all the information that makes us who we are: memory, intelligence, emotion, personality, speech, and the ability to feel and move. There are four lobes in the cerebrum to process these different types of information: the frontal, temporal, parietal, and occipital lobes. The cerebrum also has halves known as hemispheres that are connected by the corpus callosum, a band of nerve fibers which lets them communicate. The cortex is the outer layer of the cerebrum. The information we collect from our five senses comes to the cortex, and is then directed to other areas of the nervous system for processing. In the inner part of the forebrain are the thalamus and hypothalamus. The thalamus carries messages from the sensory organs to the cortex, while the hypothalamus controls thirst, appetite, pulse, sleep, and other automatic processes in our bodies.
The brain has three main sections: the forebrain, the midbrain, and the hindbrain. The midbrain coordinates all the messages going in and out of the brain to the spinal cord. The hindbrain consists of three parts: the cerebellum, pons, and medulla. The cerebellum handles balance, movement, and coordination. The pons and the medulla sends, receives, and coordinates the brain’s messages. They also control many of the body’s automatic functions such as heart rate, blood pressure, breathing, digestion, swallowing, and blinking.