Touch
- The sense of 'Touch", is part of the Somatosensory System.
- It's made up of a number of different receptors; thermoreceptors, photoreceptors, mechanoreceptors and chemoreceptors
- But, the skin contains more than 4 million sensory receptors and is mostly concentrated in the fingers, tongue, and lips, that gather information related to touch, pressure, temperature, and pain and send it to the brain for processing and reaction.
- "Touch" is considered one of the five traditional senses, the impression of touch is formed as a part of several "modalities" including pressure, skin stretch, vibration and temperature.
- That information is sent from the receptors of the sensory nerves, through tracts in the spinal cord and then into the brain.
- The somatosensory system is spread through all major parts of a body.
- The Somatosensory path has three long neurons ; in the root of the spinal nerves, in the spinal cord or the brainstem, and in the VPN of the thalamus.
- In the periphery, the somatosensory system detects various stimuli by sensory receptors,for tactile sensation and nociceptors for pain sensation.
- In the spinal cord, the system includes ascending pathways from the body to the brain.T
- The brain is the primary somatosensory area in the human cortex that is located in the postcentral gyrus of the parietal lobe and makes up four distinct fields or regions known as Brodmann areas 3a, 3b, 1, and 2.
Fine & Crude Touch
- Fine touch is a sensory modality which allows a subject to sense and localize touch.
- Crude touch is a sensory modality which allows the subject to know that something has touched them, without being able to understand or figure out where they were touched
Taste
Taste is the sense that recognizes the sweet, sour, salty, and bitter qualities with the taste buds on the tongue. Taste is important as well as smell because they prepare our bodies to digest the food and provide us with information about the food and how things smell and taste. The primary organ for tasting is the mouth.Their are tastes, like spicy and creamy fatty taste that aren't considered in the general form of taste but are widely recognize. Their is 5 types of taste sweet, sour, salty, bitter, and umami. Umami is a pleasant savory meaty taste, umami is in meat, fish, vegetable, and dairy products.
Smell
Our sense of smell, like our sense of taste, is part of our chemosensory system, or the chemical senses. Specialized sensory cells, called olfactory sensory neurons, are found in a small patch of tissue high inside the nose. These cells connect directly to the brain. Each olfactory neuron expresses one odor receptor.
- hearing is the ability to perceive sound by detecting vibrations.
- sound information from each ear is distributed to both sides of the brain.
- in humans and other vertebrates, hearing is performed primarily by the auditory system: mechanical waves, known as vibrations are determined
- there are three main components of the human ear: the outer ear, the middle ear, and the inner ear.
Hearing Mechanism
Outer Ear
- the outer ear includes the pinna, the outer part of the ear
- it also includes the ear canal which terminates at the eardrum, also called the tympanic membrane
- the pinna serves to focus sound waves through the ear canal toward
Middle Ear
- the middle ear consists of a small air - filled chamber that is located medial to the eardrum
- within this chamber are the smallest bones in the body, known collectively as the ossicles
- the ossicles include the malleus, incus and stapes
they aid in the transmission of the vibrations from the eardrum to the inner ear
Inner Ear
- the inner ear consists of the cochlea, which is a spiraled - shaped, fluid - filled tube
- it is divided lengthwise by the organ of corti, which is the main organ of mechanical to nueral transduction
Neuronal
- the sound information from the cochlea travels via the auditory nerve to the cochlea nucleus in the brain stem
- from there, the signals are projected to the inferior colliculus in the mid brain tectum
- disturbances (such as a stroke or trauma) can cause hearing problems
- sound information from each ear is distributed to both sides of the brain.
- in humans and other vertebrates, hearing is performed primarily by the auditory system: mechanical waves, known as vibrations are determined
- there are three main components of the human ear: the outer ear, the middle ear, and the inner ear.
Hearing Mechanism
Outer Ear
- the outer ear includes the pinna, the outer part of the ear
- it also includes the ear canal which terminates at the eardrum, also called the tympanic membrane
- the pinna serves to focus sound waves through the ear canal toward
Middle Ear
- the middle ear consists of a small air - filled chamber that is located medial to the eardrum
- within this chamber are the smallest bones in the body, known collectively as the ossicles
- the ossicles include the malleus, incus and stapes
they aid in the transmission of the vibrations from the eardrum to the inner ear
Inner Ear
- the inner ear consists of the cochlea, which is a spiraled - shaped, fluid - filled tube
- it is divided lengthwise by the organ of corti, which is the main organ of mechanical to nueral transduction
Neuronal
- the sound information from the cochlea travels via the auditory nerve to the cochlea nucleus in the brain stem
- from there, the signals are projected to the inferior colliculus in the mid brain tectum
- disturbances (such as a stroke or trauma) can cause hearing problems
Sight is a sense that we humans have, and not only use but most animals as well. sight occurs when ever colored light from an object reflects and our eye's then absorb the light. From there our eye's send the information to our brains to flip the image our eye's see and create what were looking at.
Eye Facts:
Eye Facts:
- Senses are a collection of sensory organs or cells in the body that respond to particular physical occurrences. Senses send information collected to various parts of the brain where the data is interpreted and an appropriate response signal returned.
- The exact number of senses humans have is disputed due to the various definitions of what a 'sense' is. However, it is widely agreed that there are five main human senses: sight, hearing, taste, touch and smell.
- The five main sense organs are your eyes, ears, nose, tongue and skin.
- Sight or vision is the ability of the eye to detect and focus on images of visible light with photoreceptors found in the retina of the eye. Electrical nerve impulses are generated for different colors, hues and brightness.
- The two types of photoreceptors are rods and cones. Rods are sensitive to light, while cones identify different colors. It is generally agreed that these two receptors are two senses, one sense for color and one for brightness, which together make up the overall sense of sight.
- Hearing is a sense that detects the vibrations of sound. Mechanoreceptors in the inner ear in the form of tiny bones and hair-like fibers, turn motion or sound waves from the air into electrical nerve pulses that the brain can then interpret.
- The sense of touch is activated by neural receptors such as hair follicles found in the skin, but also pressure receptors on the tongue and throat.
- The taste of food, is detected by sensory cells called taste buds located on top of the tongue. There are five basic tastes: sweet, bitter, sour, salty and savoury.
- Smell, like taste, is deemed to be a chemical sense. There are hundreds of olfactory receptors or sensory cells in our nasal passage, each of which will bind itself to a different molecular smell feature.
- Around 80% of what we think is taste is actually smell. Flavor, is a combination of taste and smell perception. Test this yourself by holding your nose closed the next time you eat something, can you taste it very well? Chances are you can't.
- Other perceived human senses are debatable but generally include, the ability to detect temperature, pain, balance and kinesthetic (which is the relative positions of our body parts - test this sense by closing your eyes and touching your nose with a finger).
- There are many internal body stimuli that may be perceived as senses too. For example, chemoreceptors for detecting salt and carbon dioxide concentrations in the blood and stretch receptors in the lungs which control our breathing rate.
- Compared to animals, humans have a quite weak sense of smell.
- Animals have differences in how their receptors sense the world around them, for example dogs and sharks have a terrific sense of smell. While cats can see very well in dim light.
- Some animals have receptors in places that seem very unusual to us. Flies and butterflies, for example have taste organs on their feet, so they can taste anything they land on and catfish have taste organs across their entire bodies.
- Other animals have sense receptors we can only dream off. Some snakes have sensory organs that can detect infrared light, birds and bees can see ultraviolet light. While bats and dolphines use sonar sounds to interpret their surroundings.
- Certain fish and rays can detect changes in nearby electrical fields and many bird species use the Earth's magnetic fields to determine the direction they are flying.