Q) Distinguish between endocrine system and nervous system
Main points | |
Key idea: | Nature & mode of transmission |
Endocrine sys: · Info transmitted chemically · Hormones secreted directly into bloodstream, transported throughout body, regulate activities of target cells upon arrival Nervous sys: · Info transmitted electrically · Nerve impulses travel along nerve axons to a particular destination in body · But transmission of information a/x a synapse occurs chemically (i.e. neurotransmitter) | |
Key idea: | Nature of the signal molecule |
Endocrine sys: · Many types of hormones present (each affecting specific tissues) Nervous sys: · Fewer types of signal mol (e.g. acetylcholine, noradrenaline) | |
Key idea: | Nature of response |
Endocrine sys: · Graded response as strength of cellular response may be due to amount of hormone secreted by endocrine gland · Strength of cellular response subjected to regulation of activities of relay mol along signal transduction pathways in target cells (i.e. ‘cross-talk’ b/w diff signal transduction pathways) Nervous sys: · Action potential follows all-or-nothing principle · If stimulus is strong enough to achieve threshold potential, an AP of a fixed magnitude will be achieved | |
Key idea: | Speed and duration of effect |
Endocrine sys: · Speed is generally slow but long lasting effect (e.g. growth and development). Nervous sys: · Rapid but generally short-lived (e.g. withdrawal from a hot object). | |
Key idea: | Location of effect |
Endocrine sys: · Generally widespread as blood able to transport hormones to target tissues or organs Ref to which may be located far fr each other and fr source of the hormone Nervous sys: · As nerve impulses travel along nerve axons to a part destination in body, effect is localized (e.g. contraction of a particular muscle gp in one part of the body) | |
Comments: (i) Visualize the answer with the aid of a labelled diagram. (ii) Verbalize the answer + write down the main points w/o referring to the answer (use abbreviations e.g. AP – action potential) (iii) Read again within the next 24h & once more within 72h (do not spend more than 10min) | |
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