Flashcards in Unit 1 Deck (16):
What are the four types of synaptic connections, and which one has "the last say"?
-Axoaxonic: axon to axon (has the last say)
-Axodendritic: axon to dendrite
-Axosomatic: axon to soma
-motor end plate/neuromuscular plate: axon to muscle cell
What characteristics of neurons allow for communication?
1) Irritability: reaction towards physical/chemical stimuli to create action potential
2) conductivity: propagation of electrical signal
3) transmission: of signal to other cells
Describe the four anatomical neuron shapes and give examples of each.
1) Unipolar Cell: one axon, one soma, no dendrities. Ex: rods and cones
2) Bipolar Cell: one dendrite/soma/axon Ex: olfactory receptor neurons
3) Pseudounipolar: only in peripheral ganglia
4) Multipolar: majority of neurons, many dendritic projections
Name the three functional classification of neurons.
1) sensory neuron: afferent, into CNS, dendrites
3) motor neuron: efferent, our from CNS, axons
Name and describe the function of all the types of glial cells.
1) astrocytes (CNS) blood vessel connection to neurons for nourishment
2) Oligodendrocytes: CNS myelination
3) Ependymal Cells: CNS epithelial cells
4) Microglia: CNS clean up crew, potential for stem cell actions?
5) Schwann Cells: PNS myelination
6) Satellite Cells: PNS specific to dorsal root ganglia.
Breakdown CNS divisions
-medulla (inferior), pons, midbrain
-hemispheres plus diencephalon
Describe gray vs white matter.
Gray matter includes soma/dendrites, in the center of spinal cord but on outer cortex in brain
White matter in myelinated/unmyelinated axons
Explain organization from neuronal cell to nerve including an important note about the CNS
-individual axons are called fibers when encased by myelin, fibers bundle to form a nerve BUT there are no nerves in the CNS. Instead fibers form tracts which carry info from one area to another within CNS
Describe anatomy positional terminology as it refers to the nervous system.
BELOW diencephalon: Dorsal=posterior, Ventral=anterior, Caudal=inferior, Rostral=superior
ABOVE diencephalon: Dorsal=superior, Ventral=inferior, Caudal=posterior, Rostral=anterior
Explain the difference between pathway and tract.
Pathway: direct route, may or may not be same as tract
Tract: subdivisons of the travel plan as a whole
What is the main differentiation between us and other species that allows for complex NS functions?
We have more interconnections/interneurons
Explain reflex arcs.
Direct: just a sensory and a motor
Indirect: sensory/motor and interneuron: knee reflex
In development of NS, what are the three primary layers?
endoderm, mesoderm, ectoderm
Describe the process of early NS development.
Start: primitive pit and primitive streak form the notochord, which defines the midline and is vital for development to progress. Above the notochord is the neuroectoderm, which will give rise to the rest of the NS. The notochord itself disappears after early development. Neurulation begins and the neural plate forms. The plate ivaginates forming neural groove/folds which fuse to form the neural tube. Failure to close can result in spina bifida/ anencephaly. Neural crest develops which becomes the PNS. Neural tube walls thicken to form brain/spinal cord. Neural tube lumen forms ventricular system of brain and central canal of spinal cord.
Further Explain spinal cord development.
A longitudinal groove, the sulcus limitans separates the (dorsal) alar plate and (ventral) basal plate. Alar=afferent, Basal=Efferent