160 likes | 295 Views
Nervous system. Fun facts about neurons. Most specialized cell in animals Longest cell blue whale neuron 10-30 meters giraffe axon 5 meters human neuron 1-2 meters. Nervous system allows for 1 millisecond response time. Evolution of:.
E N D
Fun facts about neurons • Most specialized cell in animals • Longest cell • blue whale neuron • 10-30 meters • giraffe axon • 5 meters • human neuron • 1-2 meters Nervous system allows for 1 millisecond response time
Evolution of: • The simplest animals with nervous systems, the cnidarians, have neurons arranged in nerve nets~ • A nerve net is a series of interconnected nerve cells, these are not specialized at all Nerve net
Evolution of: • All these do is contract and relax the gastrovascular cavity… THAT’S IT!!!~ • A nerve net is a series of interconnected nerve cells, these are not specialized at all Nerve net
Evolution of: • More complex animals actually have multiple nerve cells bound together • Information flows along a specific route Nerve net
Eyespot Brain Brain Nervecords Simplest CNS Ventralnerve cord Transversenerve Segmentalganglia (c) Planarian (flatworm) (d) Leech (annelid)
Evolution of: • Elongated, bilaterally symmetrical organism are CEPHALIZED • Clustering of neurons at at the front end of the body…
Evolution of: • In vertebrates • The CNS is composed of the brain and spinal cord • The peripheral nervous system (PNS) is composed of nerves and ganglia. Nerve net
Organization of Vertebrate Nervous System The spinal cord conveys information from and to the brain