Describe how a signal travels through a neuron, starting at the dendrite.
A chemical signal is detected by receptors on the dendrite. This is then translated into an electrical signal. This signal travels down the cell body to the axon. The axon then releases a chemical signal across the synapse to be detected by the dendrites of the next neuron.
Describe three different types of sensory receptors and how they work.
Chemoreceptors detect chemical signals from either inside the body (interoceptors) or the environment (exteroceptors). Thermoreceptors detect changes in temperature. While most are located on the external parts of the body, such as the skin, some thermoreceptors are found deep within the body. Mechanoreceptors detect deformation of the cell membrane. These receptors facilitate the senses of touch and hearing. Photoreceptors detect light by means of light-sensitive pigments.
What type of receptor is used for each of the five senses (touch, smell, taste, hearing, vision)?
The sense of touch uses mechanoreceptors, which detect changes in the shape of cells. Hearing also uses these receptors, usually associated with small hairs to detect movement caused by sound waves. Smell and taste both use chemoreceptors to detect different chemicals. Vision uses photoreceptors to detect different types of light.
What would the difference in appearance be when an object is viewed with and without lateral inhibition?
When viewed with lateral inhibition, the edges of the object will be well defined. Without lateral inhibition, the edges will be fuzzy and indistinct.
Explain how a simple ear detects sounds.
A simple ear consists of a tympanic membrane accompanied by mechanoreceptors. The membrane moves in response to incoming sound waves. This movement is detected by the mechanoreceptors, which fire an impulse to the brain, where it can be interpreted as sound.