Nervous System Flashcards
describe the structure function of the parts of a neuron
the neuron is composed of
① a cell body which is the integrating center that processes info
② branched dendrites which bring in incoming info to the neuron from other neurons , receptors , etc.
③ axon which carries outgoing info to send to other neurons, target cells ,etc 1- carry APs
Central Nervous System
Brains & Spinal Cord
Peripheral Nervous System
All outside CNS
Sensory/Afferent Division
Signals to CNS
Motor/Efferent Division
Signals from CNS
Visceral Sensory
Internal Conditions
Somatosensory
Touch, pain, temp., etc.
Visceral Motor
Autonomic System
Somatic Motor
Skeletal Muscles
Sympathetic Nervous System
Fight or Flight
Parasympathetic Nervous system
Rest and Digest
Dendrites
Incoming information
Cell body
Integrating center
Axon
Outgoing information
Types of Neurons (Location)
Central
Cell body in central nervous system
Peripheral
Cell body in peripheral nervous system
Types of Neurons (Function)
Sensory/Afferent
Carry information to central nervous system
Interneuron
Located entirely within central nervous system
Motor/Efferent
Carry information away from central nervous system
Neuroglia
Neural support Cells
Astrocytes (CNS)
Assist in neuron growth
Help provide neurons with energy
Form blood-brain barrier
Maintain ECF homeostasis
Ependymal cells (CNS)
Line fluid-filled compartments
Microglia (CNS)
Immune cells
Oligodendrocytes (CNS)
Produce myelin
Satellite cells (PNS)
Similar to astrocytes
Schwann cells (PNS)
Produce myelin
Myelin
Phospholipid membrane wrapped around axons
Provides insulation
Increases action potential transmission speed
White matter
Covered by myelin
Axons
Gray matter
Not covered by myelin
Cell bodies, dendrites & some axons
Discuss differences in axon regeneration in the central (CNS) and peripheral nervous systems (PNS).
in the CNS , axon regeneration does not occur because of chemicals secreted by glia , damage may be permanent.
in the PNS ,
the axon area below the injury degrades while the area above regenerates
Explain the difference between electrical and chemical synapses.
electrical synapses occur when the neurons or cells are connected by gap junctions , allowing
the electrical signal to flow from one cell to the other
↳Usually found in CNS and glial cells
Chemical synapses are when cells are separated by a cleft, preventing an electrical signal from
crossing .a neurotransmitter (chemical signal) must cross the cleft to cause change
Describe the steps in chemical synaptic transmission.
an action potential spreads down axon and triggers Ca++
entry , which triggers exocytosis of
neurotransmitter . Neurotransmitter crosses synaptic cleft and binds to receptor. This can change ion
concentration. Or active 2 messenger.
Compare small-molecule neurotransmitters to neuropeptides. Give actions of the following small molecule neurotransmitters: acetylcholine, dopamine, GABA, glutamate, glycine, nitric oxide, norepinephrine, and serotonin.
small molecule neurotransmitters are generally rapidly acting and are simple to make , created in the presynaptic terminals .
They usually function as ligands to open or close ion channels
Neuropeptide (slowly acting)
Generally synthesized in cell body
Generally alter metabolism in cells
Growth factors
Hormones
Acetylcholine (Ach)
Involved in many motor signals
Usually excitatory
Glutamate
Involved in many sensory pathways
Usually excitatory
Norepinephrine (NE)
Brain stem/hypothalamus
Sympathetic system
Usually excitatory
Nitric oxide (NO)
Changes intracellular metabolism
Dopamine
Basal ganglia
Usually inhibitory
GABA (gamma-aminobutyric acid)
Spinal cord, cortex, cerebellum
Usually inhibitory
Glycine
Spinal cord synapses
Usually inhibitory
Serotonin
Brain stem
Usually inhibitory
Describe transport of materials up and down an axon.
axonal transport is the movement of things between the cell body and the axon.
Transport can be slow (
cytoplasmic flow) or
(relative]
fast, using the motor proteins dyenin and kinesin to transport .
Movement can be intergrade (Toward axon terminal
) or retrograde (Toward cell body).
Slow transport
Cytoplasmic flow
Fast transport
Motor proteins carrying vesicles along microtubules
Anterograde movement
Toward axon terminal
Retrograde movement
Toward cell body
Ionotropic receptors
receptors open or close ion channels to alter concentration.
(small molecule neurotransmitters)
Metabotropic
Change metabolism in cell
Generally GPCRs
Also enzyme-linked receptors
Describe generation of inhibitory post synaptic potentials (IPSPs) and excitatory post synaptic potentials (EPSPs) and explain how they can initiate or inhibit an action potential.
EPSPS and IPSPS are graded potentials that usually occur as input signals on dendrites or cell bodies . EPSPS depolarize ,
and when summed can lead to an AP. IPSPs lead to re/hyper - polarization and can inhibit an AP when summed .
These signals decay over time due to lack of Na++ channels.
Describe summation in a neuron.
summation is when graded potentials (ipsp or epsp) combine to either initiate or inhibit an AP.
Summation can be temporal ; several graded potentials at same time or spatial ; several graded potentials over multiple neurons
