3/16/20081Nervous systemFigure 45.5 Human endocrine glands surveyed in this chapterGonadal hormones:-Produced by the gonads (ovaries and testes)-Steriods that regulate growth, development, maturation, repro., bone development and maintenance-Three types found in both sexes, but in differing amountsEndocrine organs-Balances change with cycles in females-Controlled by gonadotropins (FSH, LH) from AP, which are controlled by GnRH from Hypothalamusgonadal hormones:1.Androgens (testosterone)- stimulates devel. and maintenance of male reprod.- production during development will determine whether female will become male- increased androgens cause 2°sexual Endocrine organsincreased androgens cause 2development2.Estrogen- main form is estradiol- similar function as androgen except in females- also important in reproductive cycling in uterine lining developmentgonadal hormones:3.Progesterone- works with estrogen- aids in preparing and maintaining uterus during menstrual cycleEndocrine organsFigure 45.5 Human endocrine glands surveyed in this chapter
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3/16/20082Pineal hormones:-Not well understood-Produces melatonin, mostly at night-Thought to regulate circadian rhythms-Has external port in lower vertebrates and inverts. Endocrine organs•Body has two control systems:Endocrine– uses hormones to regulate body function, moderate to slow in transmission speedNervous– chemical and electrical signals, very fast transmission speedThe nervous systemvery fast transmission speed.Nervous system organization:•Input, Integration, Output•All achieved by conducting electrical signals or impulses via nervesInput= sensory (afferentreceptors)The nervous system- eyes, nose, ears, skin, hair…- blood glucose receptors, osmoreceptors- incoming part of Peripheral Nervous System(PNS): neurons and nerves carrying sensory and motor (receptor/effector) impulses to and fromthe CNSFigure 48.1 Overview of a vertebrate nervous systemIntegration= central nervous system (CNS)- integration of sensory and motor and other functions (memory, learning, cognition, etc.)- in spinal cord and brain via interneurons or association neurons 1) Spinal cordintegrates simple responsesThe nervous system-- carries information to and from...2) Brain-Major integration of complex responses, thought, memory, unconscious responses (e.g., posture, orientation, sensory integration, etc.) Output= efferent motor neurons (CNS)- sends signal from brain to effectors (muscles or gland)- also part of the peripheral nervous system (PNS) The nervous system