He returned to this question again and again in his philosophy, a line of inquiry motivated by personal experience. Augustine lived in an era when the pillar of strength and stability, the Roman Empire, was being shattered, and his own life, too, was filled with turmoil and loss.
General considerations of sensation Basic features of sensory structures One way to classify sensory structures is by the stimuli to which they normally respond; thus, there are photoreceptors for lightmechanoreceptors for distortion or bendingthermoreceptors for heatchemoreceptors e.
This classification is useful because it makes clear that various sense organs can share common features in the way they convert transduce stimulus energy into nerve impulses.
Thus, auditory cells and vestibular balance receptors in the ear and some receptors in the skin all respond similarly to mechanical displacement distortion.
Because many of the same principles apply to other animalstheir receptors can be studied as models of the human senses. In addition, many animals are endowed with specialized receptors that permit them to detect stimuli that humans cannot sense.
Some insects have receptors for ultraviolet light and for pheromones chemical sex attractants and aphrodisiacs unique to their own speciesthereby also exceeding human sensory capabilities.
The structures of the outer, middle, and inner ear. Regardless of their specific anatomical form, all sense organs share basic features: Often the sensory organ incorporates accessory structures to guide the stimulating energy to the receptor cells; thus, the normally transparent cornea and lens within the eye focus light on the retinal sensory neurons.
Retinal nerve cells themselves are more or less shielded from nonvisual sources of energy by the surrounding structure of the eye. In some receptors, such as the skinthe individual primary cells possess threadlike structures axons that may be yards long, winding from just beneath the skin surface through subcutaneous tissues until they reach the spinal cord.
Here, each axon from the skin terminates and synapses with the next second-order neuron in the chain. By contrast, each primary receptor cell in the eye has a very short axon that is contained entirely in the retina, which synapses with a network of several types of second-order neurons called internuncial cells, which, in turn, synapse with third-order neurons called bipolar cells —all still in the retina.
The bipolar-cell axons extend afferently beyond the retina, leaving the eyeball to form the optic nervewhich enters the brain to make further synaptic connections. If this visual system is considered as a whole, the retina may be said to be an extended part of the brain on which light can directly fall.
Chemical transmission of a nerve impulse at the synapseThe arrival of the nerve impulse at the presynaptic terminal stimulates the release of neurotransmitter into the synaptic gap.
The binding of the neurotransmitter to receptors on the postsynaptic membrane stimulates the regeneration of the action potential in the postsynaptic neuron. From such afferent nerves, still higher-order neurons make increasingly complex connections with anatomically separate pathways of the brainstem and deeper parts of the brain e.
Different sensory receiving areas are localized in particular regions of the cortex—e. Functional areas of the human brain. Approaches to the study of sensing The science of the human senses is truly interdisciplinary.
Philosophers, physicians, anatomists, physical scientists, physiologists, psychologists, and others all study sensory activities. Some of their earliest work was anatomical, an approach that continues to be fruitful.
Physical scientists, particularly physicists and chemists, made important contributions to an understanding of the nature of stimulus energies e. Hermann von Helmholtza 19th-century German scientist who was a physicist, physiologist, and psychologist, studied the way in which sound waves and light are sensed and interpreted.
Modern studies of sensation have been enhanced by devices permitting the precise production and control of sensory stimuli. With other instruments, physiologists have been able to probe the electrical signals generated by sensory cells and afferent nerve fibres to provide a biophysical analysis of sensory mechanisms.
Psychophysics embraces the study of the subjective aspects of sensation in terms of objective stimulus energies. Psychophysical research continues as an active enterprise particularly among modern psychologists.Here is the Lesson Plan that goes with this Unit And the different components that go with the Unit.
Cover Page Human Body Flashcards Human Body Flashcards Storage Pocket Label the Body Part.
Description and explanation of the major themes of Saint Augustine (A.D. –). This accessible literary criticism is perfect for anyone faced with Saint Augustine (A.D. –) essays, papers, tests, exams, or for anyone who needs to create a Saint Augustine (A.D.
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|General considerations of sensation||Related Courses Humans have 5 senses: The senses are based on receptor cells or groups of receptor cells called sense organs.|
|Themes, Arguments, and Ideas||References and Further Reading 1. The word "knowledge" and its cognates are used in a variety of ways.|
This lesson introduces the major skeletal muscle groups of the human body. It includes illustrations, examples, and descriptions for each major group. A sense is a physiological capacity of organisms that provides data for timberdesignmag.com senses and their operation, classification, and theory are overlapping topics studied by a variety of fields, most notably neuroscience, cognitive psychology (or cognitive science), and philosophy of timberdesignmag.com nervous system has a specific sensory nervous system, and a sense organ, or sensor, dedicated.
Read chapter 4 How Children Learn: First released in the Spring of , How People Learn has been expanded to show how the theories and insights from the. The Varieties of Religious Experience: A Study in Human Nature is a book by the Harvard psychologist and philosopher William James comprising 20 lectures given at the University of Edinburgh in timberdesignmag.com lectures concerned the nature of religion and the neglect of science, in James' view, in the academic study of religion.