Introduction to the Nervous System Flashcards
What are ganglia?
Groups of neuronal cell bodies in the PNS
What are nuclei?
Groups of neuronal cell bodies in the CNS
What is the laminae?
Layers of neuronal cell bodies
What are nerves?
Axons bundled together in the PNS
What are tracts?
Axons that are bundled together in the CNS
What are the different types of glial cells? What is each function?
Astrocytes: maintain chemical environment, only in the CNS, form BBB
Oligodendrocytes: make myelin in the CNS
Schwann Cells: make myelin in the PNS
Microglia: macrophages
What kind of neurons are efferent? Afferent?
Motor neurons are efferent and information flows away from the brain.
Somatosensory neurons are afferent that take information towards the brain.
What are the motor components of the nervous system? What does each do?
Somatic motor system: conscious control of muscles
Autonomic nervous system: controls visceral functions, usually unconscious
Enteric Nervous System: brain of the gut
How many neurons does a somatic efferent neuron have? Autonomic efferent?
Somatic Efferent: 1 neuron
Autonomic Efferent: 2 neurons
Which branch of the ANS has a long preganglionic neuron? Short? Where is the ganglia located in each?
Parasympathetic: Long, ganglia located near organ
Sympathetic: Short, ganglia located near spinal cord
What is the sequence of events involved in transmission at a typical chemical synapse?
- -> an action potential arrives
- -> depolarization of presynaptic terminal causes opening of voltage-gated Ca2+ channels
- -> Ca2+ causes vesicles to fuse with presynaptic membrane
- -> NT is released into synaptic cleft via exocytosis
- -> NT binds to postsynaptic receptors
- -> Removal of NT by glial uptake of degradation
What are the classes of Small-molecule NT?
Small Molecule: Ach, Amino Acids, Amines, Purines
What are the classes of Amino acid NT?
Glutamate, Aspartate, GABA, Glycine
What are the classes of amines? What are examples of each?
Catecholamines: dopamine, norepinephren, epinephrin
Indoleamine: Serotonin
What is a difference between small molecule NT and peptide NT?
Peptide NT are encoded in the genome and much bigger, while small molecule NT have enzymes that make them encoded in the genome
What are the 2 types of post-synaptic receptors?
Ionotrophic & Metabotrophic
What are examples of retrograde NT?
Endocannabinoids and NO gas
What are the 3 types of cell signaling molecules?
Cell-impermeant, cell-permeant, and cell-associated
What are the steps for activation of G-proteins?
- Signal binds to receptor
- Conformational change in receptor
- GDP is exchanged for GTP
- a-subunit dissociated from B and goes off to do work in the cell
- GTP on the a-subunit is hydrolyzed to GTP (“turning off”)
- GDP bound a-subunit associated with B subunit and binds to receptor
What is the regulation of GPCRs?
GAP: turns off G-protein
GEF: turns on G-protein
What is the Gs pathway? Gi?
Gs= Norepinephrin binds --> stimulates adenylyl cyclase --> produces cAMP --> produces PKA Gi= inhibits
What is the Gq pathway?
Glutamate binds –> stimulates phospholipase C –> with IP3, PKC and Ca2+ are released
How is a G-protein signal terminated?
Signal can dissociate from receptor,
Receptors are removed from cell,
GTP hydrolysis to GDP,
pDE converts cAMP to AMP
What is epigenetic inheritance?
Modification of a nuclear gene changes the expression of the gene in an organism. Examples: methylation, X-inactivation
What significant parts of mRNA? Where are they located?
5’ UTR in front start codon
3’ UTR after stop codon
PolyA tail after 3’UTR
