sensory perception Flashcards
what is the function of the peripheral nervous system
a) Detect external and internal stimuli—sensory systems
b) Process and integrate different types of information and make relevant decisions—higher brain regions
c) Execute decisions—motor system
what are the two types of general senses
visceral afferent and somatic sensory
what is the visceral afferent senses
Incoming information from internal viscera
what is the somatic sensory
afferents Sensation from body surface and proprioception
what are the modalities of the sensory system
Visual system
somatosensory system
auditory system
olfactory system
gustatory system
what is a sesnory receptor
structures at peripheral endings of afferent neurons
what are vision receptors
photoreceptors
what are taste and smell receptors
chemoreceptors
what are temperature receptors
thermoreceptors
what are mechanoreceptors
touch, balance, proprioception and hearing receptors
what are pain receptors
nociceptors
what is transduction
The process of converting energy forms into electrical signals via a receptor/generator potential which triggers an action potential if it is large enough to reach threshold.
what are the stages of transduction in separate sensory receptors
- entry of Na+ through channels opens voltage gated Ca2+ channels
- triggers exocytosis of neurotransmitter
- opens chemically gated channels, permitting Na+ entry into neuron
- opens adjenct channels too
- Na+ entry initiates action potential
how do you detect the quality of stimulus
- The frequency of AP transmitted down the afferent fiber
- The number of sensory receptors activated (higher number of cells activated)
what is The receptive field of a sensory neuron
a region of space in which the presence of a stimulus will alter the firing of that neuron. This region can be a hair in the cochlea
or a piece of skin etc
what are PHASIC receptors
sensory receptors that adapt rapidly to a constant stimulus. They primarily respond to changes in stimulus intensity, such as the onset or offset of a stimulus, rather than its continuous presence.
e.g. Pressure, touch, hearing, smell
what are TONIC receptors
Tonic receptors are a type of sensory receptor that adapt slowly to a sustained stimulus. They continue to generate action potentials at a relatively constant rate for as long as the stimulus is present,
e.g. Pain, proprioception, chemicals in the blood or CSF
describe the receptor signal of phasic receptors
signals change in stimulus intensity (differential receptors)
describe the receptor signals of tonic receptors
continous flow of information about stimulus (proportional receptors)
what is a menchanical adaptation mechanism
are ways that sensory receptors adjust their sensitivity through physical or structural changes when a stimulus is constant. (specialized receptor endings in Pacinian cells of the skin)
what is a chemical adaptation mechanism
are ways that sensory receptors adjust their sensitivity over time by changing their internal chemical processes when a stimulus is constant.
what is mechanical adaptation for phasic receptors
Specialized receptor ending of concentric layers of connective tissue (onion-like).
Sustained pressure causes layers to slip, dissipating stimulus intensity
what is chemical adaptation in phasic receptors
depolarization of membrane
Ca2+ binding calmodulin decreases the activity of CNGC
what is stimulated by paina nd heat
bare nerve endings
what is meissner corpuscle
respond to touch; are thought to be responsible for fine & discriminative touch in glabrous skin
what are merkels’ disks receptors
fiber connected to an epithelium-like cell
what is pacinian corpuscle
phasic receptor detecting vibration
what is ruffini’s ending
tonic touch receptor
