Signal Processing
what are sensory receptors?
detect specific stimuli such as light, smell, or taste
What must happen before an AP can be generated?
threshold must be met
what is hyperpolarization?
depolarization?
more negative
more positive
What is the name of the space between the pre and post synaptic cells?
Synaptic cleft
Name the two types of neuroglia of the PNS
schwann cells and satellite cells
What are the three types of receptors?
sensory, visceral, and somatic
What is the refractory period
Period during which the cell is recovering and a second AP cannot be generated
which is more prevalent on a typical neuron, Na+ channels or K+ channels?
K+
The neural cells responsible for the analysis of sensory inputs and coordination of motor outputs are
interneurons
what is the function of satellite cells?
Regulate diffusion of gases and nutrients and surround cell bodies with ganglia
What are the divisions of the autonomic nervous system?
sympathetic and parasympathetic
Explain the all or nothing principal of AP's
once the threshold is met, an action potential of the same size every time will be generated regardless of the size of the stimulus
What is temporal summation?
Spatial?
temporal summation- same neuron fires repeatedly
Spatial- different neurons fire in the same area
why can the typical neuron not replace itself
they do not contain centrioles
Name the 4 types of CNS neuroglia.
astrocytes, ependymal, oligodendrocytes, microglia
what are the three types of neurons within the CNS and their functions?
Motor neurons- coordinate motor controls
sensory neurons- transmit information between the PNS and the CNS
Interneurons- communicate between the two
Explain what happens at a typical acetylcholinic synapse.
AP reaches synapse triggering influx of Ca+2 into the synaptic cleft and triggering the release of ACh. Ach binds with the receptors on the post synaptic cell causing sodium gates to open, depolarizing the cell. Steps of original AP generation follow and Ach is degraded by AchE
What is typical resting potential?
-70 mv
what are the three types of gates and how do they function?
. ligand gated- specific molecule binds with receptor and opens gate
Mechanically gated- certain trigger such as pressure and opens gate
Voltage gated- change in the charge of the cytoplasm open the gate
which type of neurolia myelinates neurons in the CNS? In the PNS?
oligodendrocytes
schwann cells
list the steps of signal processing from receptor to effector.
1. receptors pickup stimuli
2. afferent division of the PNS delivers information to the PNS
3. information is processed in the CNS
4. Efferent division of the PNS delivers motor commands to effectors
5. effectors carry out commands
List the steps of AP generation
. 1. Graded potential stimulates membrane and causes cells to depolarize
2. if threshold is met, voltage gated sodium channels open
3. sodium floods the cell and the cell further depolarizes
4. at the peak action potential, sodium gates close and potassium gates open so potassium begins to leave the cell
5.as large amounts of potassium leaves the cell, the cell becomes hyperpolarized and enters the refractory period
6. Na+/K+ pump restores resting potential
What restores RP?
Na/K pump
what a type a type b and type c fibers
Type A- myelinated- carry AP very quickly
Type B- myelinated and small diameter, slower
Type C- unmyelinated and small diameter, very slow
what is the function of microglia?
act as lysozomes