This lesson explains the nervous system: what it is, its main cell types and structures, how signals flow, the distinction between CNS and PNS, core functions (sensory input, integration, motor output), reflexes, interactions with other organ systems, homeostasis, common disorders, and classroom activities to explore concepts practically.
Nervous System — Your Body's Dramatic, Extremely Efficient Conductor "If the body is an orchestra, the nervous system is the conductor who also moonlights as a fire alarm, traffic controller, and emergency medic." You already know cells build tissues, tissues build organs, and org...
What the nervous system actually is (short & spicy) Definition (plain): The nervous system is a network of specialized cells that sense , process , and respond to information. It coordinates nearly every action and reaction in the body. Key players: neurons (the message-carrying specialists...
CNS vs PNS — quick table (because your brain likes organized brains) Feature Central Nervous System (CNS) Peripheral Nervous System (PNS) Main parts Brain & Spinal cord All other nerves (sensory & motor) Primary role Process & integrate info Carry info to/from CNS ...
Reflexes: the nervous system's instant-response mode Reflexes are like autopilot safety features. They bypass the brain for speed and use the spinal cord instead. Ordered steps of a simple reflex (example: touching a hot object): Receptor in skin detects excessive heat. Sensory neuron c...
How the nervous system integrates with other organ systems (the juicy examples) Respiratory system: The brainstem (medulla oblongata) monitors blood CO2 and O2 and adjusts breathing rate. When CO2 rises, the nervous system tells your diaphragm to inhale faster. (Tie-back: we already saw how respi...
Problems, common disorders, and why they matter Concussion: traumatic brain injury that disrupts neural signaling — can cause memory loss, headaches, dizziness. Peripheral neuropathy: damaged peripheral nerves causing numbness or weakness. Multiple sclerosis: immune attack on myelin (axon ins...
Key takeaways — the nervous system in one (dramatic) paragraph The nervous system is the body's rapid-response communication network. It senses the world, integrates information in the CNS, and sends instructions through the PNS. It coordinates with respiratory and digestive systems (and othe...
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