Taste/Gustation & Smell/Olfaction By: Jordan, Dalton, Miranda, and Tyler

Sense Organs Nose: Smells things! Tongue: Taste things!

Gustatory They are clustered in the taste buds of the mouth and throat They react to food or drink when mixed with saliva Small bumps on the tongue contain taste buds which send taste info to nerve fibers which send messages to the brain

Olfactory Stimulated by odors These nerves cells are found in a tiny patch of tissue high up in the nose. They are connected directly to the brain

Papillae Four sets of Papillae: fillform, fungiform, vallate, follate Purpose is to: flush materials from the base of the circular depression to help taste buds respond to over changing stimuli. It is located on the upper surface of the tongue.

Taste Buds -Taste buds contain receptors for taste. -They are small structures located on the tongue, soft palate and upper esophagus. -There are 5 known elements of taste: -Salty -Sweet -Bitter -Sour -Umami (a savory taste) -The bud is formed by the supportive and gustatory cells. -The average life of a taste bud is 10 days.

Other Expectations influence your brains response to taste, as well as with other senses. If someone tells you something is gross then your brain is going to focus more on negative tastes. The brain regions that detect more pleasant tastes will be less active. To savor a taste, we breath the aroma through our nose, (things have less flavor when eating with a cold). This is an example of sensory interaction

Role of Smell in Determining Taste Smell and taste belong to our chemical sensing system (chemosensation) smelling and tasting occur when molecules released by the substances stimulate nerve cells in the nose, throat, and mouth.

Parts of Nose Cilia: nose hairs Olfactory bulb: two bulbs at the base of the brain that receive smell messages and send them to the brain Olfactory receptor cells: nucleated cells of the mucous membrane that serve as receptors for smells

How Smell Works We smell things when 5 million or more receptor cells at the top of each nasal cavity detect molecules of a substance in the air. Axon fibers alert the brain of the cell. Odor molecules come in different shapes and sizes, which takes many different receptors to detect them. Olfactory cortex decode receptor combinations to detect the smell. Scent is often associated with memories. -Smell neurons are scattered randomly rather than grouped in the nose, once the axons reach the olfactory bulbs they are highly organized. -neuron patterns are symmetrical in each nostril -all mice have the same pattern of axons in the olfactory bulb -size of olfactory bulbs directly relates to how strong sense of smell is

Pheromones A pheromone is a chemical that triggers a social response in beings of them same species. Some examples are: -Alarm Pheromones -Food Trail Pheromones -Sex Pheromones

How Smell Differs -Smells bypass the thalamus and go directly to the first and fifth cranial nerves. All of the other senses are sorted in the thalamus between what needs our attention and what does not. -The first nerve tells the difference between two things, such as a lily and an orange -The fifth nerve detects things like sweetness or spicyness -Smell is the only sense that connects our brain directly with the outside world. This is why smells are able to conjure strong memories and other senses cannot.