PSYC BC 1129x Lecture Notes - Lecture 9: Grey Matter, Neural Tube, Myelin
Document Summary
Newborn"s head is of total body length. Adult"s head is 1/8 of total body length. Newborn"s brain is at 25% of adult brain weight. Brain grows faster physically than the rest of the body. Sensory input comes in, motor output goes out. Interneurons- intermediaries btwn sensory and motor neurons- many developmental problems are due to problems w/ interneurons. Nerve cells: basic units of brain"s info system. Ends in terminal button (axon terminal)- contain neurotransmitters. Neurons grow and multiply at a rapid pace during prenatal development. Glial cells are smaller and more numerous than neurons. Supporting cells - support and protect neurons (surround neurons+insulate them so impulses don"t spread in unwanted directions), supply nutrients+oxygen to neurons, and clean up (destroy and remove cell debris- when neurons die, glial cells get rid of them) Astrocytes in capillaries, brain, and spinal cord: form blood-brain barrier- restrict substances that enter the brain- also provide nutrients to tissues of nervous system.
