The senses Flashcards
What is objective testing?
Measures attributes of products evaluated by a panel
What is subjective testing?
Measures preference by a representative of customers
What is taste controlled by?
Gustatory system
What occurs on the tongue when food is consumed?
Sapid molecules dissolve into saliva and enter pore of the taste bud
Where are the taste buds located on the tongue?
Circumvallate papillae (back)
Foliate papillae (side)
Fungiform papillae (front)
From tongue to brain what are the 5 stages of taste?
Facial nerve
Glossopharyngeal nerve
Vagus nerve
Gustatory nucleus
Primary gustatory cortex
What is the role of G protein coupled receptors for taste?
Detect sweet, bitter and umami
What controls smell?
Olfactory system
How do we smell?
Compounds become volatile and travel up the nose through 2 routes
What are the 2 routes for smell?
Orthonasal and retronasal
What is the orthonasal route?
Sniffing up the nasal cavity
What is the retronasal route?
Consumption causes compounds to be delivered via the nasopharynx
Where do compounds go once they are in the nasal cavity?
Olfactory nerves in the olfactory epithelium containing small cells called cilia
Once in the celia where do compounds travel?
To the brain via olfactory bulb
How many volatiles are there in food?
17000
What is mouthfeel controlled by?
Somatosensory system
What is the role of tactile receptors?
Detect force, particle size, heat and chemical stimulus
Where are tactile receptors found?
Lips, tongue, face and hands
How is muscle tension and relaxation detected?
Nerve fibres in muscles, tendons and joints
What are the 3 elements of texture?
Mechanical
Geometric
Mouthfeel
What is hearing controlled by?
Auditory system
How do sound waves cause the eardrum to vibrate?
By entering the outer ear and travelling down the canal
What do the eardrum vibrations cause?
Millions of hair cells are activated in the cochlea and signals are sent to the brain
How are signals sent to the brain for hearing?
Auditory nerves
What is sight controlled by?
Visual system
What happens to light waves when they enter the eye?
Through the lens onto the retina
What does the retina contain?
Millions of photoreceptors
What is the role of photoreceptors?
Visual pigments trigger nerve impulses
How do the nerve impulses get passed on to the brain?
Optic nerve
What do the 3 different types of photoreceptor cones detect?
Red
Blue
Green
What is the role of photoreceptor rods?
Detect shape and movement
Where are cones and rods found?
Cones=centre of retina
Rods=edge of retina
How many cones and rods are there?
Cones=7 million
Rods=120 million
What is anosmia?
Loss of smell
What do trigeminal receptors detect?
Burns from capsaicin
Tingling from CO2 in drinks
Cooling from menthol
Astringency from tannins
What are additive effects?
Sum of individual compound effects
What is synergistic interactions?
When sensory is greater than additive effects
What is antagonistic interactions?
Supressing or masking effect
What is the detection threshold?
Lowest stimulus capable of producing sensation
What is recognition threshold?
Level of stimulus which can be recognised and identified
What are just noticeable differences?
Change in stimulus needed to produce a noticeable difference
What is terminal threshold?
Level of stimulus above which there is no increase in intensity
