01:119:116 Lecture Notes - Lecture 19: Hypothalamus, Starfish, Prefrontal Cortex
23 Apr 2016
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Document Summary
Ability to sense and react evolved billion of years ago in prokaryotes. Increases chances of survival and reproduction in changing environments. Nerve net = series of interconnected nerve cells. Impulses conducted both directions spreading through the net. Nerves formed from axons of multiple neurons that are bundled together. Radial nerves receive info from nerve ring and send signals to muscles. Ganglia segmentally arranged clusters of neurons. Numerous functions to nourish, support, and regulate neurons. Embryonic radial glia form tracks along which newly formed neurons migrate. Cilia promote circulation of cerebrospinal fluid (csf) Dilate blood vessels near active neurons increases oxygen and glucose to neurons. Regulate composition of cns fluid remove excess k+ and neurotransmitters. Stimulate endothelial cells in blood vessels to form tight junctions blood/brain barriers protect brain by restricting passage of most substances into brain. Plasma membrane rich in myelin lipid. Form myelin sheath around axons provides electrical insulation. Immune cells phagocytic cells clean up after injury or infection.
