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Nervous system 1
basics
| Question | Answer |
|---|---|
| Functions of the nervous system | Sensory: detects change tot he internal and external environment (ex: you see a red light) Integration: processes sensory input (ex: red light means stop) Motor: causes a response, activates muscles and glands (ex: muscle moves foot to the brake) |
| Central Nervous System (CNS) | Composed of the brain and spinal cord |
| Peripheral Nervous System (PNS) | Composed of the nerves that extend from the brain and spinal cord |
| Somatic Nervous System | Under conscious control (ex: skeletal muscles) |
| Autonomic Nervous System | Under unconscious control (ex: smooth muscle and cardiac muscle, glands) |
| Sympathetic Nervous System | Prepares the body for activity (ex: "fight or flight") |
| Parasympathetic Nervous System | Oversees digestion and gland function (ex: "rest and digest") |
| Astrocytes (neuroglia) | Provide support, regulate nutrients from capillaries, "clean up" excess neurotransmitters and ions. The nervous system's version of scar tissue. |
| Microglia (neuroglia) | Phagocytize bacteria cells and dead neurons. |
| Ependyma (neuroglia) | Lines cavities of the brain and spinal cord, forms a semipermeable barrier between cerebrospinal fluid and brain. |
| Obgodendrocytes (neuroglia) | Provide support to axons and produce Myelin sheath. |
| Neurons | Conduct impulses |
| Dendrites | Receive stimuli |
| Axon | Transmits nerve impulses from the cell body |
| Myelin sheath | Increases the speed of impulse transmission |
| Node of Ranvier | Gaps in the Myelin sheath |
| Multipolar | Have 3 or more processes |
| Bipolar | Have 2 processes |
| Unipolar | Have 1 process that divides into 2 branches |
| Sensory neuron | Conducts impulses from receptors to CNS |
| Motor neuron | Conducts impulses from the CNS to effectors (muscles or glands) |
| Interneuron | Found primarily in CNS, links sensory and motor neurons |