大學(xué)英語(yǔ)nervoussystem

1、12 The nervous system and the endocrine system coordinate and control the body. Together they regulate our responses to the environment and maintain homeostasis. Whereas the endocrine system functions by means of hormones, the nervous system functions by means of electric impulses. For study purpose

2、s, the nervous system may be divided into the central nervous system (CNS), consisting of the brain and spinal cord, and the peripheral nervous system (PNS), consisting of all nervous tissue outside the brain and spinal cord.31. Peripheral nervous system (PNS) autonomic nervous system: which control

3、s smooth muscle, cardiac muscle, and glands sympathetic nervous system parasympathetic nervous system somatic nervous system: control the skeletal muscle sensory nerve fibers :sense internal and external changes and transmit these signals to CNS motor nerve fibers : carry signals to skeletal muscles

4、 to produce action4 The sympathetic nervous system motivates our response to stress, the so-called “fight-or-flight” response. It increases heart rate and respiration rate, stimulates the adrenal gland, and delivers more blood to skeletal muscles. The parasympathetic system returns the body to a ste

5、ady state and stimulates maintenance activities, such as digestion of food. Most organs are controlled by both systems and, in general, the two systems have opposite effects on a given organ.52.Nervous tissue6neurons: transmit nerve messagesglial cells: surround neurons and serve as supportive, nutr

6、itive facilities3.Structure of a common neuron dendrites(樹(shù)突): receive stimuli or message from other cells, and transmit the message to the cell bodycell body（細(xì)胞體）: contains nucleus, mitochondria and other organellesaxon(軸突)：conduct message away from the cell bodySynapse(突觸)：the connection between a

7、nerve cell axon and target cells, which may be other nerve cells, muscle cells, or gland cells. At the synapse the axon releases neurotransmitter that relay the transmission of nerve impulse73. Direction of nerve message transmission84.Structure of synaptic cleft9 5. Receptor, agonist (stimulator) a

8、nd antagonist (blocker) Receptor is a molecule (usually a protein) that spans a cell membrane and “receive” extracellular signals and transmits them into the cell. Membrane-bound receptors have at least two or three domains: an extracellular domain that receives the signal; a membrane-spanning domai

9、n that is hydrophobic in character and a cytoplasmic domain that transmit the signal into the cell. Agonist is a molecule that can bind with and stimulate the receptor, thus mimicking the function of naturally occurring neurotransmitter. Antagonist is a molecule that can bind with receptor but witho

10、ut stimulation, it can inhibit the function of naturally occurring neurotransmitter by competitive binding.10111213automatic14cerebrum cerebral hemorrhage cerebralgia cerebrovascularn cran/o:crania epicranium hemicranian phren/o: mind, intelligence brain encephalitis encephaloma encephalorrhagia 151617The science dealing with the study of mental processes and behaviorThe medical science that deals with the origin, diagnosis,