Special Senses- olfactory Flashcards
Modality
Type of stimulus that receptor respond to - taste,smell
Chemoreceptors
Chemical receptor- smell/taste
Photoreceptors
Light intensity- vision
Electroreceptor
Electrical fields
Magnetoreceptor
Magnetic field
Thermoreceptor
Temperature
Mechanoreceptor
Pressure and movement- touch, hearing, balance, BP
Modality
Based on type of stimuli/ receptor detected - modality=stimuli
Labeled line- sensory receptors- modality of sensation (pathway)
Principal type of sensation- pain, touch, sound. Despite fact that we experience different modalities of sensation, nerve fibers transmit only impulse
How do different nerve fibers transmit different modalities of sensation
Each nerve tract terminates at a specific point in CNS. Type of sensation depends on point in NS to which fiber leads
Transduction
Convert stimulus (energy) to electrical impulse. Cannot maintain homeostasis without transduction
Labeled line
Stimuli- specific electrical current-specific receptor- specific part of the brain
Sensory receptor
Specialized cell or cell monitoring processes monitoring conditions in/out of body. Specific for receptor “ receptor specificity”
Are all transducers changing incoming stimulus into impulse
Homeostasis
Not keeping conditions static , keeping conditions in tightly regulated physiological tolerance limits
Components of a sensation
- Stimulus- change in environment ( think receptor)
- Transduction receptor carries this out. Converts to electrical energy
- Conduction- carried out by sensory neuron
- Translation- brain carries this out. Translate impulse to sensation- brain detects
Electrical energy travels
Sultatory conduction- myelinated axon
Continuous conduction-unmyelinated axon
Translation
Conversion of impulse to a registration of the stimulus in the brain. Result is a sensation
Sensation
Generally subconscious level. Touch, taste, sight, sound, smell
Perception
When sensation becomes conscious, sensation interpreted. How we make sense of things around us
Reflex arc
Can’t react to stimulus not detected properly
Arc— (sensory portion) receptor- sensory neuron- cns (brain)- ( activates) motor neuron- effector (organ)
Olfactory (smell)
-Sensitive.
-Depends on sensory receptors responding to airborne chemical
- cavity lined with epithelium, small patch of olfactory epithelium.
- modality- chemoreceptors- located in olfactory epithelium
-Sensory neurons- each with primary cilium
-
Olfactory epithelium
Lots of bipolar neurons ( 2 extensions),
Chemicals we smell are water soluble
Transport is thru cranial nerve #1- olfactory nerve
Olfactory tract carries impulse to brain
Olfactory pathway
Receptor- nerve tract- thalamus- temporal lobe- (olfactory center)
Primary cell sensations
Camphoraceous ( sulfur) Musky Floral Peppermint Ethereal Pugnet (sweet) Putrid ( decay)
100 primary sensations of smell
