__________ cells aid the functions of neurons and are about five times more abundant than neurons.
In the CNS, supporting cells are collectively called _____________
glial cells OR neuroglia
A multipolar neuron located entirely within the CNS. It integrates functions of the Nervous System.
Association neuron (interneuron)
A neuron that transmits impulses from a sensory receptor into the CNS
Sensory (afferent) neuron
A neuron that transmits impulses from the CNS to an effector organ (i.e. a muscle).
Motor (efferent) neuron
Consists of brain and spinal cord
Nerves, ganglia, and nerve plexuses (outside CNS)
Cablelike collection of many axons in the PNS; may be "mixed" (contain sensory and motor neurons).
Nerve hat stimulates contractions of skeletal muscles
Somatic motor nerve
Nerve that stimulates (OR inhibits) contractions of smooth muscle and cardiac muscle and stimulates glandular secretion
Autonomic motor nerve
Grouping of neuron cell bodies located outside the CNS
grouping of neuron cell bodies within the CNS
Grouping of axons that interconnect regions of the CNS
______________ is energy-dependent and is often divided into a fast component and two slow components.
transport from the cell body to the axon and dendrites. This is called ________ (uses kinesin protein).
transport along the axon and dendrites toward the cell body is known as __________ (uses dynein protein).
2 types of motor neurons:
these neurons innervate involuntary effectors
autonomic motor neurons
neuron responsible for both reflex and voluntary control of skeletal muscles
somatic motor neuron
_____ have two processes, one at either end; this type is found in the retina of the eye
the most common type of neuron. have several dendrites and one axon. (i.e. motor neurons)
_________ (also called neurolemmocytes), form myelin sheaths around PNS axons
____________ (or ganglionic gliocytes) support neuron cell bodies within the ganglia of the PNS
form myelin sheaths around axons of the CNS
___________ migrate through the CNS and phagocytose foreign and degenerated material
___________ help to regulate the external environment of neurons in the CNS
___________ cells line the ventricles (cavities) of the brain and the central canal of the spinal cord
All axons in the PNS (myelinated and unmyelinated) are surrounded by a continuous living sheath of Schwann cells, known as the _______________, or sheath of Schwann
gaps in the myelin sheath exposed to produce nerve impulses
nodes of ranvier
white matter = ________
gray matter = _________
cells lacking myelination
An autoimmune disease leading to degeneration of oligodendrocytes and myelin sheaths, which can develop hardened scars in the brain
Multiple Sclerosis (MS)
_____________ promote neuron growth (in fetal development)
Because K+ diffuse out of neurons, ______ take up this excess (maintains proper ion environment)
Astrocytes take up neurotransmitters to transform them to _________ and release back to the neruons (recycling)
____________ support synapse function and creation
astrocytes help stem cells form glial cells and neurons. this is called ______________
The blood brain barrier is supported by ___________
molecules within brain capillaries must be moved through the endothelial cells by diffusion and active transport, as well as by endocytosis and exocytosis. This feature of brain capillaries imposes a very selective ___________
Blood brain barrier!
All cells in the body maintain a potential difference (voltage) across the membrane, or ___________, in which the inside of the cell is negatively charged in comparison to the outside of the cell
Resting membrane potential
resting membrane potential for a neuron is
-70 mV (compared to heart muscles @ -85mV)
If appropriate stimulation causes positive charges to flow into the cell, this change is ______________
A return to resting membrane potential is called _______________
stimulation causes the inside of the cell to become more negative than the resting membrane potential, this change is called _____________
(- charge enters cell OR + charge leaves cell)
What medication acts by increasing the action of nitric oxide as a treatment for erectile dysfunction?
Excitatory postsynaptic potentials are produced by
A nerve is a bundle of axons in the CNS T/F?
What portion of the neuron is NOT involved in integration?
A lack of extracellular Ca2+ would cause increased release of neurotransmitters T/F?
Destruction of astrocytes would decrease the rate at which action potentials are transmitted T/F?
Neurotransmitter release can be inhibited by damaging the SNARE complex T/F?
True; snare binds vesicle with terminal bouton to release NT, etc.
The normal effect of b-endorphin can be blocked by
Axons originate at the ___________
Which of the following affect(s) acetylcholine synaptic transmission? curare, strychnine, botulinum toxin
Curare & botulinum toxin
Which ion's outward diffusion movement is responsible for repolarization?
Which poison inhibits glycine receptors?
which type of synapse has a "delayed" impulse?
The varied strength of synaptic transmission is called
The membrane of resting nerve cells is more permeable to ____________ ions than ____________ ions.
Fetal neuron growth requires the actions of a group of chemicals known as ________
What process is needed to return a membrane to its resting membrane potential with all ions in the correct locations?
___________________ are pseudounipolar and carry impulses toward the CNS
Conduction of an action potential in a (myelinated) axon is called ___________
Sensory nerves regulate muscle contraction T/F?
False; motor nerves
the opening of Cl- channels into the neuron produces a(n) __________ on the postsynpatic membrane
IPSP (inhibitory post synaptic potential)
muscarinic receptors are a type of glutamate receptor T/F?
False; muscarine is involved with Acetylcholine
conduction through dendrites and cell bodies of neurons are NOT action potentials T/F?
true, action potentials are in the Axon
Do all cells have a membrane potential?
myelinated axons in the CNS: ____________
increased __________ of stimuli: this is the coding system used for neurons to get a greater response.
Postsynaptic inhibition is caused by ____________ & _____________
GABA (gamma-aminobutyric acid) and glycine
astrocytes phagocytose foreign material in the CNS T/F?
False; microglial cells are responsible for phagocytosis
_____ which is secreted as a hormone from the small intestine, is also released from neurons and used as a neurotransmitter in the brain. Promotes satiety (i.e. after eating).
Cholinergic fibers use ____ as the neurotransmitter
Cells become more negative during ______________________.
The capacity of synapses for alteration at the molecular level is termed ___________
What type of neuron is found entirely in the CNS?
interneurons / association neurons
Regeneration of CNS axons may be prevented in part by inhibitory proteins in the membranes of the ____________
If the binding of muscarine to its receptor (in the heart) causes the beta-gamma complex (of the G-protein) to bind to a K+ channel... then the K+ channel will _____, leading to _____polarization and inhibition.
Glutamate opens ion channels through ________ receptors binding to glycine, releasing ____ to open them. (in partially depolarized membrane).
**NO Cl- is involved**
Hyperpolarization in the postsynaptic cell is caused by _______ and movement of _____ out of the cell
IPSP's(inhibitory post synaptic potential);
The period of time when Na+ channels are recovering from their inactive state, AND K+ channels are still open are ________ and ____________ periods
__________ axonal transport may be responsible for movement of herpes virus, rabies virus, and tetanus toxin from nerve terminals to the cell body
Synaptic plasticity involves structural changes in neurons such as formation of ___________
What channels are present at the axon hillock that allows the production of action potentials?
Atropine is an antagonist to nicotine T/F?
_________ can bind to nicotine receptors.
moves TOWARD the cell body, uses molecular motor proteins of DYNEIN, & moves membranes, vesicles, and VIRUSES
saltatory conduction is condution of a(n) ______________ in a myelinated axon
enkephalins, dynorphins, endorphins are examples of natural ___________
An inhibitory postsynaptic potential (IPSP) would be produced by a neurotransmitter opening ________ channels
Electrical synapses are functionally linked by ______ junctions
cell adhesion molecules (CAMs)-- proteins that are present at ________ synapses to ensure ____ of the presynaptic and postsynaptic membranes?
Axonal transport is NOT passive T/F?
true; it is active
Both long-term potentiation and long-term depression requires release of ___ from the postsynaptic neuron membrane
Neurotransmitter release would be inhibited by blocking _________ influx in the axon terminal.
The greater the number of depolarization regions on an axon, the faster the action potential will be conducted T/F?
________ are pseudounipolar and carry impulses toward the CNS
alpha subunits bind to K+ channels, and close them... leading to depolarization-- This is the action of binding ________ to its receptors in the ________ system.
_________ is found around PNS axons, which are NOT found around CNS axons.
MAO inhibitors may cause hypertensive crisis by a person eating foods rich in __________
The disease ______________ is characterized by destruction of CNS myelin sheaths and the formation of hardened scars
multiple sclerosis (MS)
The __________ dopamine system may be involved in emotional reward and drug addiction.
Chemicals that stimulate action potentials in postsynaptic cells are called __________
Axonal _________ is inhibited by myelin-associated inhibitory protein
________ blocks the reUPTAKE of dopamine, norepinephrine, and serotonin.
What portion of the neuron is NOT involved in integration?
the axon (involved in conduction!)
Endogenous opioids transmit impulses of pain T/F?
False; reduce impulses of pain
What type of autonomic fibers release ACh at effectors?
neurons that use ACh (acetylcholine) as a NT (neurotransmitter) are called _________ neurons