A sense organ, or one of its cells (such as those for the sense of taste or smell), that can respond to a chemical stimulus; a chemosensor. mechanoreceptor Any information about mechanical changes in its environment, such as movement, tension and pressure. photoreceptor A specialized neuron able to detect, and react to light nociceptor A sensory receptor that sends signals that cause the perception of pain in response to a potentially damaging stimulus. thermoreceptor A nerve cell that is sensitive to changes in temperature
A sensation is : A physical feeling or perception resulting from something that happens to or comes into contact with the body. A projection is: process by which the brain causes a sensation to seem to come from the region of the body being stimulated. Sensory adaptation is: The phenomenon of a sensation becoming less noticeable once it has been recognized by constant repeated stimulation. Touch utilizes sensory nerve fibers, meissner’s corpuscles, and pacinian corpuscles. The two types of temperature receptors are cold and warm thermoreceptors Somatic sense > Pain is stimulated when there is tissue damage
The special senses are; vision, hearing, smell, and taste. Stretch receptors are mechanoreceptors responsive to distention of various organs and muscles, and are neurologically linked to the medulla in the brain stem via afferent nerve fibers. Examples include stretch receptors in the arm and leg muscles and tendons, in the heart, in the colon wall, and in the lungs. Smell involves olfactory receptor cells Stretch receptors are mechanoreceptors responsive to distention of various organs and muscles, and are neurologically linked to the medulla in the brain stem via afferent nerve fibers.
Examples include stretch receptors in the arm and leg muscles and tendons, in the heart, in the colon wall, and in the lungs. Hearing involves the cochlea, stapes, incus, malleus, and auricle The Organ of Corti is internal to the cochlea, and contains about 15,000-20,000 specialized sensory cells, each with a tiny hair capable of picking up minute vibrations in the cochlear fluid. If destroyed by loud sounds, these hairs would never grow back. Various hairs are specialized to detect sounds at various frequencies, and turn them into nerve signals to be sent to the brain.
The inner ear can detect your position of the body in relation to the original pull of gravity on the body and can tell you when it is different and when it comes back to normal. If you do a dive off of a diving board, you will unknowingly realize when you are upside right or inverted to any degree other than upright Static means to be still, dynamic means there is motion. A rock has static equilibrium. A moving bicycle has dynamic equilibrium. The vestibule lies between the semicircular canals and the cochlea. It contains two bulblike sacs, the saccule and utricle, whose membranes are continuous with those of the cochlea and semicircular canals, respectively. The saccule and utricle contain receptors that help maintain equilibrium. Cornea, Sclera, Choroid, Ciliary Body, Suspensory ligament, lens, iris, pupil, retina, fovea centralis The pupil is the black part in your eye. If it is dilated, it is bigger than usual. The pupils usually constrict (get smaller) when you shine light into it, and they dilate (get bigger) when it is dark. You can check this by looking into a mirror and than shining a light at your eyes.
Both of your pupils should get smaller when the light hits the eyes (even if it only hits one eye! ), and then bigger again when the light is gone. Some drugs affect pupils. Amphetamines (speed, meth) can dilate them, for example, while opiates (heroin) can constrict them. Cornea, Sclera, Choroid, Ciliary Body, Suspensory ligament, lens, iris, pupil, retina, fovea centralis The optic nerve has to enter the confines of the eye somewhere in order to innervate the retina. Where it enters has no rods and cones (the very nerve endings of the optic nerve which allow us to see). Therefore, this is a “blind spot.
There are two types of photoreceptors in the human retina, rods and cones. Rods are responsible for vision at low light levels (scotopic vision). They do not mediate color vision, and have a low spatial acuity. Cones are active at higher light levels (photopic vision), are capable of color vision and are responsible for high spatial acuity. The central fovea is populated exclusively by cones. There are 3 types of cones which we will refer to as the short-wavelength sensitive cones, the middle-wavelength sensitive cones and the long-wavelength sensitive cones or S-cone, M-cones, and L-cones for short.