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In general, cellular response to stimuli is defined as a change in state or activity of a cell in terms of movement, secretion, enzyme production, or gene expression. [9] Receptors on cell surfaces are sensing components that monitor stimuli and respond to changes in the environment by relaying the signal to a control center for further ...
Stimulation, in general, refers to how organisms perceive incoming stimuli. As such it is part of the stimulus-response mechanism. Simple organisms broadly react in three ways to stimulation: too little stimulation causes them to stagnate, too much to die from stress or inability to adapt, and a medium amount causes them to adapt and grow as they overcome it.
A number of studies have shown that a human fetus will respond to sound stimuli coming from the outside world. [ 8 ] [ 9 ] In a series of 214 tests conducted on 7 pregnant women, a reliable increase in fetal movement was detected in the minute directly following the application of a sound stimulus to the abdomen of the mother with a frequency ...
Response to stimuli: a response can take many forms, from the contraction of a unicellular organism to external chemicals, to complex reactions involving all the senses of multicellular organisms. A response is often expressed by motion; for example, the leaves of a plant turning toward the sun (phototropism), and chemotaxis.
Pharotaxis is the movement to a specific location in response to learned or conditioned stimuli, or navigation by means of landmarks. [20] [21] Phonotaxis is the movement of an organism in response to sound. Phototaxis is the movement of an organism in response to light: that is, the response to variation in light intensity and direction.
External receptors that respond to stimuli from outside the body are called exteroreceptors. [4] Exteroreceptors include chemoreceptors such as olfactory receptors and taste receptors, photoreceptors (), thermoreceptors (temperature), nociceptors (), hair cells (hearing and balance), and a number of other different mechanoreceptors for touch and proprioception (stretch, distortion and stress).
There are several different types of stimuli to which adequate stimuli respond. The following are examples of stimuli to which receptors may: Light – When the adequate stimulus of a sensory receptor is light, the sensory receptors contain pigment molecules whose shape is transformed by light, and the changes in these molecules activate ion ...
Startle response interrupts and disengages the organism from ongoing activity, directs attention to stimuli, and protects the organism from potential harmful stimuli. Orienting response is an organism's innate reaction to a novel stimulus, and it is a defensive response. [7] Heart rate increases after the onset of startle stimuli.