What types of nerve system exist
central nervous system
peripheral nervous system
What are sensors?
Sensors respond to stimuli with changes of their membrane potential
Afferent neurons
relay signals as a series of action potentials towards integration centers
Interneurons
within integration center
compute incoming information
Efferent neurons
send signals as a series of action potentials towards effectors as muscles
What part in bilateral body plans carries the most sensors
anterior end (first contact with novel stimuli)
What is the subdivision of the vertebrate brain?
telencephalon-> diencephalon -> mesencephalon -> thombencephalon -> spinal cord
In which parts can the nervous system tissue be differentiated
ganglia (cell mass with many cell bodies outside ns)
laminae (layered arrangement of cell bodies)
neuropil structures (composed of axonal and dendritic structures without cell bodies)
What are nuceleus?
concentration of cell bodies in the CNS, often wirh a clear boundary to the surrounding tissue
Which part of the brain is differentially organized in mammals?
forebrain
Cerebellum
Kleinhirn
Which two sorts of wings/horns are in the spinal cord?
ventral = towards belly
dorsal = towards back
contain cell bodies
How does functions work in dorsal horns
receive afferents from sensors in muscle & joints
afferent fibers enter spinal cord via dorsal root
have their cell bodies in dorsal root ganglia
How does functions work in ventral horns
contain motor neurons
make axonal connections via ventral roots towars muscle targets
How is the vertebrate midbrain called (except mamals)
and how is it called in mammals?
Optic tectum
superior colliculus
How does the midbrain work?
receives input from all spatially organized sensory organs & forms an orderly representation of these inputs - neuronal maps of the outer world
gray area
cortex with somata
white matter
axonal connections
How many layers do the mammals cortex consist of?
6
Why does cortex fold?
if area of cortex increases
In which lobes can the human cortex be differntiated?
frontal lobe
pariental lobe
temporal lobe
occipital lobe
Name 3 ways to differentiate the cortex?
overlying bones
functional regions
fine histological details
gyri & sulcus
folds & grooves
Where is the primary motor cortex located
gyrus in front of the central sulcus
How are the hemispheres seperated?
sagittal groove
How are the hemispheres connected
corpus callosum
When does gray and white matter peak in human
gray matter -> late childhood
white matter -> yound adulthood
How many layers does the cortex has
Which cell types form the cortical circuits?
pyramidal neurons
stellate neurons with/without dendritic knobs
What are the second characteristic cell type in brain and which types exist (+function)
gilal cells:
astrocytes (mechanical)
oligodendrocytes (insulation)
microglia (repair and immune function)
ependymal cells (fluid compostition)
What is the basic structure of neurons?
cell body, dendrites, long axon with several to many synaptic endings
Whate are spines
prostrusions at dendrites
What do you know about spines?
are small computational modules where changes in synaptic strength can take place
functions in area of memroy formation and learning
What is a sense
well-adapted transduction device (computation along the brain nuclei connected to the sense organ determines what we see)
What are the three steps of hearing
converting airborne sounds to fluid movement
Converting fluid movement to frequency-specific excitation
Computing input patterns to determine sound position and to classify sounds
How does the brain determine sound direction
compute various parameters (time & amplitude)
Converting airborne sound to fluid movement
human middle ear = 3 small bones
transfer movement of tympanum to oval window of cohela
small mucles at ossicles can contract and dampen the transfer
How does the cochlea separate sound frequencies?
Movement of the last ossicle creates pressure waves in the cochlea.
Specific frequencies move specific parts of the basilar membrane.
Hair cells at those locations fire action potentials.
The auditory nerve transmits frequency, timing, and intensity to the brain.
Human vision in 3 steps
sensory transduction
retinal computation
networks in the brain
the human retina is …
inverse (light enters the retina from the ganglion cell layer)
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