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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 |