BIO304H5 Lecture Notes - Lecture 1: Repolarization, Visual System, Exocytosis
Document Summary
Not every animal has a brain, which is essentially just a conglomeration of neurons: ex; honey bees have ganglion" not exactly a brain though, ex; animals like jellyfish and hydra have neural nets. So, we can"t define a nervous system as a brain because not all animals have one. How about by defining it as cells that generate electric impulses & move thru structures": well, we cannot necessarily say this either because even bacteria can generate electric impulses. Synapses sites of contact where 1 neuron communicates with another. This propagation can be via a graded potential or action potential: cells convey the information to each other across synapses, the nervous system needs to compute an output in order for the organism to survive. Ex; movement, change in heart rate, change in smooth muscle motility, behaviour . A spanish researcher in the late 1800s/early 1900s researched on how an image is transmitted.
