Chapter 10 Sensory Physiology Flashcards
What type of information do receptors recieve
Sensory
What do receptors do
Transduce different energy forms into graded potentials which initiate action potentials
Where do receptors send information
To the CNS through Afferent sensory
Name the 5 different receptors and what do they respond to
- Mechanoreceptors = touch/pressure
- Thermoreceptors = temperature
- Photoreceptors = light
- Chemoreceptors = chemicals
- Nociceptors = pain
What is a Receptor potential
Graded potential in sensory receptor in response to environmental stimulus
What does the transduction process involve
opening and closing of ion channels
What is adaptation and what does it lead to
Decrease in receptor sensitivity during maintained stimulation
Leads to… decrease in AP frequency in afferent neuron
What are the two types of adaptation
Phasic (fast adapting receptor) = AP very quickly cease
e.g Pressure when seating
Tonic (slow adapting receptors) = persistent or slow decay of the firing APs
e.g. joint and muscle receptors that maintain posture
What is somatic sensation
Touch Pressure Pain Temperature Proprioception - posture and movement
What is chemosensation
Taste = Gustation Smell = Olfaction
Where are taste cells located
Taste buds on the surface of the tongue
Taste buds are located on
lingual papillae
Papilla = small bump
Name the 5 taste categories and where they are localised on the tongue
Bitter = back Sweet = tip Sour = sides Salty = tip Umami = pharynx
What taste category is related to H+
Sour
What taste category is related to Na+
Salty
What does GPCR stand for
Gene protein couple receptors
What steps allow us to smell
Odorants bind to the proteins in the membrane of cilia attached to dendrites of olfactory receptor neurons
- GPCR
- Axons of receptor neurons synapse onto olfactory bulb of brain
- Unique pattern of activity that brain interprets to percieve an odor
How many odors are coded and how many receptor proteins
10,000
380
What does the Vestibular system do and where is it located
Senses:
Head position
Head movement = angular acceleration in 3 dimensions
Linear acceleration
Structures are in the inner ear
What are the two otolith organs and what do they do
- Saccule
- Utricle
Sense linear acceleration with respect to gravity
Each sensor has a mass of Otoliths on top of a gelatinous substance
Where do Olfactory receptor cells synapse
In the 2 olfactory bulbs
What are Otoliths and what do they cover
Calcium carbonate crystals
Utricle and saccule
Makes them heavier
What are semicircular canals and what do they do
Fluid filled endolymph
They sense ANGULAR ACCELERATION of the head in three Dimensions (X-Y-Z)
What do each semicircular canal have
Crista (sensory organ)
