-
Pimary receptors (1 degree)
recetpres ARE sepcialized ends (generally dendrites) of sensory neurons
-
Secondary (2nd degree)
consist of seperate receptor cell (often an epithelial cell) which synapses with afferent neuron
-
rectpro potentials
electronically spread to the spike initiating zone where if the depolariztion reaches threshold (generator potential) an AP is generated
-
What affects the amount of neurotransmitter released
The size of the graded receptor potential
-
How does the brain determine stimulas intensity
- Varioaton in the frequencing of APs delviered to the CNS by a given sonsory receptor
- Variation in the # of receptors activated
-
Adaptation
when some sensory cells respond less when stimulation is held constant and/or repeated
-
gustation
- the sense of taste
- most taste sensors are 2 degree type sensory cells
-
What are the five tastes
sweet, bitter, sour, salty, umami
-
Olfaction
- the sense of smell
- First degree sensors
-
glomeruli
convergance of axons from the nuerons with the same receptors for olfaction
-
vomeronasal organ (VNO)
- in amphibians reptiles and many mammals
- specilized for pheromones and goes to an accesory olfactory bulb
-
how do mechanoreceptors work?
- physical distortion of a mechanorecptor's plasma membrane causes ion channels to open, which leads to the generation of APs
- Density of tactile receptors influence how finely stimulation can be resolved
-
muscle spindles
- where stretch receptors are embedded in vertebrate skeletal muscles
- they are modified msucle fibers that are innvervated in the center with extenstion of sensory neurons
- The CNS uses information from msucle spindles to maintain a certain level of contraction or muscle tone
-
gray matter
the tissue rich in neuronal cell bodies part of the spinal cord
-
white matter
contains the axons of the spinal cord
-
spinal nerves
leave the spinal cord at regular intervals; each one ahs two roots, one connecting it ot the dorals horn of the gray matter and the other connecting with the ventral horn
-
monosynaptic reflex
the simplest spinal reflex involving only two neurons and one synapse (no brain involvement)
-
Golgi tendon organ
- stretch receptor found in tendons and ligaments
- when a msucle contraction becomes too forceful, the golgi tendon organ sends signals to the CNS that inhibit motor neurons and the msucle relaxes
-
Pinnaue
collect sound waves and direct them into the auditory canal, which leads to the middle inner ear
-
tympanic membrane
the eardrum
-
rhodopsins
molecules used for photosensitivity
-
rod cell
- modified neuron that releases neurotransmitters that influence other neurons
- the outer segment has a stack of discs of plasma membrane densely packed with rhodopsin. this discs function to capture photons
-
What is the difference between vertebrates and invertebrates response to light?
- Vertebrates hyperpolarize photoreceptors
- invertebrates depolarize photoreceptors
|
|
