Vibration
The Meissner corpuscle and the Pacinian corpuscle sense vibration. As mentioned earlier, the Meissner corpuscle is a type of mechanoreceptor, a sensory nerve ending that is sensitive to mechanical pressure or movement. When an object comes into contact with the skin, the movement or pressure of the object activates the Meissner corpuscle, which sends a signal to the brain that is interpreted as a sensation of touch or vibration. This allows the body to detect and respond to stimuli in the environment, such as the movement of an object against the skin or the pressure of a surface against the body.
The Pacinian corpuscle is also a type of mechanoreceptor, and like the Meissner corpuscle, it is sensitive to mechanical pressure or movement. When an object comes into contact with the skin, the movement or pressure of the object activates the Pacinian corpuscle, which sends a signal to the brain that is interpreted as a sensation of touch or vibration. This allows the body to detect and respond to stimuli in the environment, such as the movement of an object against the skin or the pressure of a surface against the body. Unlike the Meissner corpuscle, which is sensitive to low-frequency vibrations, the Pacinian corpuscle is most sensitive to high-frequency vibrations. This allows it to detect rapid changes in pressure or movement, such as those that occur when an object is rapidly tapped against the skin.
Nociception
Free nerve endings and nociceptors sense pain. Free nerve endings are a type of sensory nerve ending that are responsible for detecting pain. They are found throughout the body, including in the skin, muscles, and internal organs. When tissue is damaged or inflamed, free nerve endings in the area are activated and send a signal to the brain that is interpreted as a sensation of pain. This allows the body to respond to potential harm and protect itself from further injury.
Nociceptors are specialized sensory nerve cells that are responsible for detecting potentially harmful stimuli, such as extreme temperatures, damaging mechanical forces, or chemicals released by damaged cells. When a nociceptor is activated by one of these stimuli, it sends a signal to the brain that is interpreted as a sensation of pain. Nociceptors are found throughout the body, including in the skin, muscles, and internal organs. They are activated only by intense or damaging stimuli, allowing the body to respond to potential harm and protect itself from further injury.
Equilibrioception
The vestibular system, which is located in the inner ear, is responsible for maintaining balance and providing the sense of spatial orientation. It does this by detecting the acceleration and orientation of the head and sending signals to the brain that are used to coordinate movement and maintain balance. The vestibular system includes a network of channels filled with fluid, as well as tiny hairs that protrude into the fluid. When the head moves, the fluid moves along with it, causing the hairs to bend. This bending of the hairs activates sensory cells, which send signals to the brain that are used to determine the head’s acceleration and orientation. The brain then uses this information to coordinate movement and maintain balance.
Sound
The auditory system is responsible for detecting and processing sound. It includes the ears, the auditory nerves, and the brain. When sound waves enter the ear, they cause the eardrum to vibrate. This vibration is transmitted through the middle ear bones (the malleus, incus, and stapes) to the cochlea, a spiral-shaped structure in the inner ear. Inside the cochlea, the vibrations are converted into mechanical signals that travel along the auditory nerve to the brain. The brain then processes these signals and interprets them as sound.
Taste
Taste buds are sensory structures that are located on the tongue and other areas of the mouth. They are responsible for detecting the five basic tastes: sweet, sour, salty, bitter, and umami (savory). When we eat or drink something, molecules from the food or drink dissolve in saliva and come into contact with the taste buds. This activates the taste buds, which send signals to the brain that are interpreted as a sensation of taste. Each taste bud contains a number of specialized cells called gustatory cells, which are sensitive to different tastes. The brain uses the information from these cells to determine the overall taste of a food or drink.
Smell
Olfactory receptors are specialized sensory cells that are located in the nose. They are responsible for detecting and identifying different smells. When we breathe in air, molecules from the air enter the nose and dissolve in a layer of mucus that covers the olfactory receptors. This activates the olfactory receptors, which send signals to the brain that are interpreted as a sensation of smell. The brain then uses this information to identify the specific smell that we are experiencing. There are many different types of olfactory receptors, each of which is sensitive to different types of molecules. This allows us to distinguish between a wide range of different smells.
Next Up… Chemoreception