Transcript 4/14
Your grade: in class and homework, experiment, 3 X exams... Final Plus up to 3 points for discussions Exam 3 in-class Th 5/5 take-home will be due Th 4/28 Final exam is cumulative and optional no take-home for the final exam Nerves allow us to perceive the environment while the brain integrates the incoming signals to determine an appropriate response. Fig 46.1 Response Responses can be release of hormones, change in cell activity, or muscle contraction Muscles allow movement An earthworm: without something to push against, muscles are not much use. The skeleton, made of bones, gives support Fig 50.34 Bones (connective tissue) are alive Connections between bones and muscles Muscles can only contract. Therefore, two muscles are needed for each range of motion. Fig 50.32 2 nerve signals for every movement: excitatory and inhibitory Fig 50.32 How do muscles contract? Excitatory neurotransmitters released by motor neurons cause muscle cells to contract Fig 50.29 Muscle cells are comprised of series of sarcomeres. Fig 50.25 Fig 50.25 Each sarcomere is a repeating unit of actin and myosin proteins Fig 50.25 As each sarcomere contracts, the muscle cell contracts Fig 50.27 ATP provides the energy for myosin movement along the actin Fig 50.25 How is this regulated? Neurotransmitters released at nerve/ muscle junction cause calcium to be released in muscle Fig 50.29 Fig 50.28 A third protein, tropomyosin controls when the muscle contracts The contraction of muscle cells causes the muscle to contract muscle contraction animation: http://www.blackwellpublishing.com/matthews/myosin.html Cadavers and muscles http://www.youtube.com/watch?v=xdZR4znKRV0 In class 4/14: What is consciousness? Who has it? People? Non-human animals? Plants? Computers? How can you measure consciousness? Is consciousness important? Your grade: in class and homework, experiment, 3 X exams... Final Plus up to 3 points for discussions