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September 27, 2013. Neural and Hormonal Systems P.47-51. Divisions of the Nervous System. Parts of the Nervous System. Central Nervous System (CNS) Brain + spinal cord Peripheral Nervous System (PNS)
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September 27, 2013 Neural and Hormonal SystemsP.47-51
Parts of the Nervous System • Central Nervous System (CNS) • Brain + spinal cord • Peripheral Nervous System (PNS) • Neurons through which CNS communicates with rest of body (connects muscles, glands, sense organs to brain)
PNS • Two parts: • Somatic • Enables voluntary control of skeletal muscles • Autonomic • Controls glands and muscles of internal organs • E.g. heartbeat, digestion • On “auto-pilot”
Autonomic Nervous System • Two functions: • Sympathetic (ready for action) • Arouses and expends energy • Parasympathetic • Conserves energy and calms Both work together to create equilibrium
SympatheticNervous System Flight or Fight Response
Parasympatheticm • Conserves energy, calming
Contracts pupil
CNS-most complex • Neural Networks • Neurons connected with other neurons • Feedback strengthens connections LEARNING • Spinal Cord (our reflexes-automatic responses to stimuli) • Connects PNS to brain • Ascending sensory neurons • Descending motor neurons • Through interneurons • Reflexes only need S.C., not brain – If top S.C. severed, won’t feel pain/pleasure/sensation –Why? • knee jerk/headless wonder
A Simplified Neural Network Brain receives info, interprets it, decides response. Neurons learn to work together as a team. Selective
Chicago CTA System, Clark & Lake stop Friendships - connections
Endocrine System = Communication center • Its glands secret hormones, which are similar to neurotransmitters • Hormones travel through the bloodstream and are slower than neurotransmitters Hormones Neurotransmitters
Major Endocrine Glands • Pituitary • sends signals to other glands • growth hormone • Thyroid • metabolism • Adrenal • adrenaline (“fight or flight”) • Gonads (ovaries & testes) • receive signal to secret sex hormones
Pituitary Gland • “Master P” • triggers sex hormones, influences brain/behavior through hypothalamus • Growth hormone
Thyroid • metabolism • Problems: Hyper or hypo
Adrenal • Adrenaline • Fight or Flight (emergency) hormone
Gonads – ovaries or testes • Gets the signal to secrete sex hormones • Estrogen, testosterone