Sensory nervous system detecting the environment Flashcards
why is it important for animals to detect there environment
in context of homeostasis
how can sensory receptors function in terms of the kind of cell it is
can function as single cell or with accessory cells
what is an example of how sensory receptors can be grouped in a complex sensory organ
the eyes of an insect
mechanoreceptors
respond to mechanical deformation
thermoreceptors
respond to cold and heat
nocioreceptors
respond to pain (tissue damage)
electromagnetic receptors
respond to electrical and magnetic fields; infrared and ultra violet light
photoreceptors
respond to visible light
chemoreceptors
respond to various chemicals
how does a sensory respond work with a change in AP firing rate
-stimuli alter ion movements across membranes
-produce a graded receptor potential
-alters rate at which AP is generated in axon hillock
-change in firing rate interpreted by CNS
what are stretch receptors
-common in invertebrates and vertebrates
-detect relative position of body structures
-membrane has a mechanically-gated Na+ channels
-deforming stimulus depolarization membrane
-preform a variety of roles in animals
what are mechanoreceptor examples
stretch receptors
hair cells
what are stretch receptors
-common in both (in)vertebrates
-detect relative positions of body structure
-membrane has mechanically gated Na+ channels
-deforming stimulus depolarizes the membrane
(hitting your knee reflex)
what are hair cells
-receptor cells with sterocillia to detect fluid currents
how do hair cells work
-they have mechanically gated ion channels in membrane
-can depolarize or hyperpolarize hair cells
-voltage regulated ca+ channels regulate neurotransmitters
-hair cells synapses with the sensory neuron that projects to CNS
what is the function of hair cells
-in organs of balance
-provides into on gravity, acceleration and water currents
-provide about sound frequency, amplitude, and loaction
where are hair cells found
in organs of sound