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Sensory Organs - Coggle Diagram
Sensory Organs
Gustation:
Definition:
- Begins with chemical stimulation of sensory cells
Location:
- Tongue, inside the cheeks, on the palate, pharynx and epiglottis
Structure:
- ovoid clusters, banana-shaped taste cells, nonsensory supporting cells and unspecialised basal cells
Taste cells:
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- taste hairs project into taste pore (apex of taste bud)
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Olfaction:
Definition:
- the sense of smell, in response to airborne chemicals
Structure:
- patch of sensory epithelium (olfactory mucosa)
Olfactory cells:
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- swollen tip bearing 10-20 cilia (olfactory hairs)
- bulbous body containing the nucleus
- basal end tapers to thin axon leading to the brain
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Further structures:
- olfactory nerve = multiple olfactory cells converged to form little bundles
- cranial nerve penetrate through pores in cribriform plate in ethmoid plate
- nerve fibers end in a pair of olfactory bulbs of the brain
- olfactory tracts = neurons form bundles of fibers. relay signals to multiple locations in the cerebrum and brainstem, especially primary olfactory cortex
Pain:
Definition
- discomfort induced by tissue injury or noxious stimulation
Receptors
- nociceptors = respond to chemicals released by injured tissues
- location = skin, mucous membranes and nearly all organs (except brain)
General types
- somatic pain = skin, muscles, joints
- visceral = internal organs of body cavity
Specific types
- Referred pain = where viscera pain is mistaken to come from skin
- Phantom pain = pain coming from a limb that has been amputated
- Spinal gating = absence or minimal sense of pain