SCIENCE 3RD (Nervous System)

• Nervous System is referred as the control unit of the body and acts as a storehouse of information.
• Nervous System controls and coordinates essential body functions.
• Nervous System consists of two major divisions: Central Nervous System and Peripheral Nervous System.
• Central Nervous System controls most functions of the body and mind. it includes the brain and spinal cord.
• Peripheral Nervous System connects the central nervous system to the organs and limbs.
• Central Nervous System consists of two components: Brain and Spinal Cord.
• Brain is an organ that sends and receives messages to and from all the body parts and is covered by the skull.
• Spinal Cord is part of the nervous system that runs down the center of your back, made up of thousands of neurons, and serves as a channel signal between the brain and the majority of the body parts, controlling some simple musculoskeletal reflexes even without the processing of the brain.
• Brain consists of three main parts: Cerebrum, Cerebellum, and Brainstem.
• Cerebrum is the largest part of the brain, controls thought, reason, and the senses, and many of its jobs are voluntary.
• The Sympathetic Nervous System is activated when the body is in a dynamic role or stress, for instance, when you got angry, your heart rate increased.
• Neurons are the main part or the basic unit of any nervous system, carrying messages through the nervous system and your body contains billions of nerve cells.
• The Autonomic Nervous System is associated with the involuntary control of body movements.
• Each neuron is made up of a cell body, which contains the nucleus and cytoplasm and threadlike extensions called the nerve fibers.
• Cranial nerves are associated with the nerve fibers that carry information into and out of the brain stem, involved in facial expressions, mastication, phonation, and swallowing.
• Cerebellum is a part of the brain that helps make our movements smooth and graceful, rather than robot-like, and is called little brain because it looks like a small version of the cerebrum, with jobs that are involuntary.
• Neurons are the basic functional unit of the nervous system, specialized for the transmission of messages from an organ or tissue to another, often compared to electrical wires.
• Axon is the longer end nerve fiber in a neuron, carries impulse away from the cell body, and may be wrapped in a myelin sheath, a fatty insulating layer made up of Schwann cells.
• The Parasympathetic Nervous System maintains body functions and restores the body to normal or relaxed mode, for example, salivation.
• Dendrite is the shorter end nerve fiber in a neuron, parts of the neuron that receive messages from nearby neurons, and are fibers that carry impulses toward the cell body.
• Spinal nerves are responsible for motor and sensory signals such as temperatures, touch, pain, and pressure.
• Brainstem is responsible for controlling heartbeat, breathing, and blood pressure, and looks like as if it was part of the spinal cord, with all its jobs being involuntary.
• Peripheral Nervous System consists of two main parts: Somatic Nervous System and Autonomic Nervous System.
• Somatic Nervous System is associated with voluntary movements of the body.