Neurons Flashcards
The peripheral nervous system (PNS) is made up of..
cranial nerves and spinal nerves
Central Nervous (CNS) is made up of
brain and spinal cord
The Autonomic nervous system (ANS) is made up of
the sympathetic and parasympathetic nerves
How many neurons are in the brain?
100 billion
Each neuron has between _____ and _____ synapses
1,000 and 10,000
The gut contains some ______ neurons
100 million
The diameter of a neuron is in between __ and ___ microns (or __ millimeters)
Between 4 and 100, .1 mm.
Velocity of a signal transmitted through a neuron is between __ and ___ mph
1.2 and 250
A neuron is an ______ cell that processes and transmits information by _____ and _____ signaling
electrically excitable; electrical/chemical
The fundamental task of a nerve cell is to ____, ______, and ______ signals
receive, conduct, transmit signals
Neurons connect via ____ to each other to form neural networks
synapses
Dendrites transmit electrical impulses to the ______
cell body
The axon transmits information away from the _____
cell body
The myelin sheath is made up of _________ (type of glial cells)
oligodendrocytes
Nodes of Ranvier are ______ in between myelin sheath that allow for ____
Permeable gaps; the exchange of ions
Pre-synaptic terminal is located at the end of the ____
axon
The glia of the brain and spinal chord are called ____
astrocytes
Astrocytes support the _______, provide _______ to the nervous tissue, maintain _______, and repair of the brain and spinal cord following traumatic injuries.
blood-brain barrier; nutrients to the nervous tissue; extracellular ion balance
Action potential is the _______ conducted along neuronal axons
electrical signal
Action potentials are generated by special types of _______ embedded in a cell’s ______
voltage-gated ion channels; plasma membrane
What are the two types of action potentials?
One type is generated by the voltage-gated sodium channels in the axon and the other by voltage-gated calcium channels in the pre-synaptic terminal
Sodium-based action potentials last for________
less than one millisecond
Calcium based action potentials last for _____
100 milliseconds or longer
The resting membrane potential in neurons is ____
-70mV
The sodium potassium pump is activated during _____ and sends 3 ____ ions out for every 2 ____ ions in
hyperpolarization; sodium, potassium
During the depolarization of the axon ____ enter through the ____
sodium ions; Nodes of Ranvier
During the repolarization of the cell, _____ leave the cell
Potassium ions
Salutatory conduction is the propagation of an _______ along _____ from one _____ to the next
action potential; myelinated axons; node of ranvier
The myelin sheath creates an express train that goes ___ times faster than unmyelinated neurons
50 times faster
In the central nervous system, myelinated axons form ____ matter
white
What makes up the gray matter of the CNS?
Dendrites and cell bodies
Most common disease that affects the myelin sheath?
Multiple Sclerosis - MS lesions cause inflammation that destroys the myelin sheath around the axons
In the sodium potassium pump, ions move ____ the concentration gradient, thus it requires ______
against; ATP to provide energy
Neurotransmitters are stored in ____
Vesicles in the presynaptic terminals
SYNAPSE: When an action potential invades the presynaptic terminal, this causes _______ and the opening of ________. The influx of the _____ causes ______ containing _____ to _____ with the _______. The _____ is then released into the _______ via _____, where it then binds to _______ in the _______. The ______ then causes _____ or _____ ____ ___ that changes the excitability of the ______ cell.
depolarization of presynaptic terminal and the opening of voltage-gated Calcium channels. The influx of calcium ions causes vesicles containing neurotransmitters to fuse with the presynaptic membrane. The neurotransmitter is then released into the synaptic cleft via exocytosis, where in then binds to receptor molecules in the postsynaptic membrane. The postsynaptic current then causes excitatory or inhibitory postsynaptic potential that changes of the excitability of the postsynaptic cell.
Reuptake is the _____ of a neurotransmitter by a _____ _____ of a ________
Reuptake is the reabsorption of a neurotransmitter by a neurotransmitter transporter of a pre-synaptic neuron
The EFFICIENT NEURON: Myelin ____ the conductance of a signal along the _____. Myelin also reduces the amount of energy it takes to ________. Reuptake makes sure that neurotransitters _______.
Myelin speeds up the conductace of a signal along the axon. Myelin also reduces the amount of energy it takes to restore resting potential. Reuptake makes sure that neurotransmitters do not to go waste.
Excitatory postsynaptic potentials (EPSP) ______ the postsynpatic neuron
depolarize
Inhibitory postsynaptic potential (IPSP) _______ the postsynaptic neuron.
hyperpolarize
Glutamate is involved with _______
the regulation of muscle tone in humans
GABA and Glycine are _____ neurotransmitters
inhibitory neurotransmitters
Norepinephrine helps ________
awaken us from deep sleep
Epinephrine increases ____
heart rate
dopamine is involved with _____ ____and ____
movement, reward, and learning
serotonin is involved with ____, _____, _____, and _____
sensory perception, temp regulation, mood, and sleep
Nitric oxide may play a role in ____ and _____
memory and learning
Substance P is a neurotransmitter known to _______
enhance the perception of pain
Dopamine is a monoamine transmitters in the ______ family
catecholamine
How many types of dopamine receptors are there?
Five
Dopamine is mostly produced in the ____ ______ and the ____ ____ ___.
Substantia Nigra and Ventral Tegmental Area
The three main dopamine pathways are: ___, ____, and ______.
Mesolimbic, mesocortical, and nigrostriatal
Dopamine: The mesolimbic pathway transmits DA from the ______ (in the midbrain) to the ______ (in the limbic system).
The mesolimbic pathway transmits DA from the ventral tegmental area (in the midbrain) to the nucleus accumbens (in the limbic system)
Dopamine: the Mesocortical pathway transmits dopamine from the ______ to the _________
The Mesocortical Pathway transmits dopamine from the VTA to the frontal cortex.
Which two dopamine pathways are implicated in schizophrenia?
Mesolimbic and mesocortical
Dopamine: The Nigrostriatal pathway transmits dopamine from the ____ to the _____
From the substantia nigra to the striatum
The Nigrostriatal Pathway is associated with _____ - and this disease
motor control - Parkinson’s disease
Which neurotransmitter is implicated in laughter and schandenfreude?
Dopamine
Parkinson’s disease is caused by loss of ____ in the _____
Dopamine-secreting neurons in the substantia nigra
Schizophrenia has been shown to involve elevated levels of dopamine activity in the _____ and decreased levels of dopamine in the _______
Mesolimbic pathway; prefrontal cortex
Serotonin is a ____ amine also known as
biogenic; 5-Hydroxytryptamine
5-HT neurons are found in the _____
midbrain raphe
Serotonin projects: Regions receiving MRN (median raphe nuclei) projections include the _____
hippocampus
Serotonin Projection: DRN projections include
frontal cortex, dorsal striatum, and globus pallidus
What gene has been implicated in depression
Serotonin transporter gene 5-HTT - short allele (SS)
What neurotransmitter is the primary inhibitory regulator of aggressive behavior?
Serotonin
What neurotransmitter influences moral judgement and behavior and unfairness behavior? (Crocket, 2008 & 2010)
Serotonin
