A&P 1-Chapter 12/ Nervous Tissue Flashcards
bundle of nerve fibers (axons) wrapped in fibrous connective tissue
Nerve
About 90% of the neurons in the nervous system are __________ neurons.
sensory
A)motor
B)afferent
C)efferent
D)association
D)association
When an electrical signal reaches the end of nerve fiber, the cell secretes a chemical neurotransmitter that influences the next cell
Secretion
If threshold is reached, neuron fires fully.
If threshold is not reached, it does not fire.
This follows an________
All-or-none-law
Regeneration of damaged nerve fibers in the CNS can occur but is significantly slower than PNS.
True or False
False
Explanation: CNS regeneration cannot occur at all.
What cell provide electrical insulation around the neurosoma?
A) Satellite cells
B) Ependymal cells
C) Schwann cells
D) Schwann cells and Satellite cells
A) Satellite cells
The ____ ____ system consists of nerves and ganglia
Peripheral nervous
Myelinated fibers conduct signals with
______ ______
—(signal seems to jump from node to node)
saltatory conduction
_____ _____division carries signals to glands, cardiac and smooth muscle
Visceral motor division (autonomic nervous system)
The most abundant glial cell in CNS, covering brain surface and most nonsynaptic regions of neurons in the gray matter are _____
A)Ependymal cells
B)Astrocytes
C)Microglia
D)Oligodendrocytes
B) Astrocytes
Supportive cells that bind neurons together and form framework for nervous tissue are called
Neuroglia or glial cells
If a neuron is prevented from sending a neurotransmitter across a synapse to another cell, which neuron property is being inhibited?
A) Secretion
B) Excitability
C)Conductivity
D)Permeability
A) Secretion
Line internal cavities of the brain; secrete and circulate cerebrospinal fluid (CSF).
A)Ependymal cells
B)Astrocytes
C)Microglia
D)Oligodendrocytes
A) Ependymal cells
some neurotransmitters make the membrane potential more negative—hyperpolarize it—so it becomes less likely to produce an action potential. This is known as being ____.
A) Nondecremental or decremental
B) Irreversible or reversible
C)Inhibitory or excitatory
D) Reversible
C) Inhibitory
or excitatory
________ releases neurotransmitter and
________ responds to this neurotransmitter.
A) Postsynaptic neuron; Presynaptic neuron
B)Presynaptic neuron; Postsynaptic neuron
Presynaptic neuron; Postsynaptic neuron
_____ _____ division carries signals from the viscera (heart, lungs, stomach, and urinary bladder)
Visceral sensory
What system communicates by means of chemical messengers (hormones) secreted into the blood?
Endocrine system
Speed at which a nerve signal travels along surface of nerve fiber depends on two factors. What are the two factors?
A) Length of Fiber and Presence of myelin
B) Diameter of fiber and presence or absence of myelin
C) Diameter of fiber and absence of myelin
D) Length of fiber and presence of absence of myelin
B) Diameter of fiber and presence or absence of myelin
If excitatory local potential reaches____ _____ and is still strong enough, it can open these gates and generate an action potential
trigger zone
The _____ ______ division carries signals from receptors in the skin, muscles, bones, and joints
Somatic sensory
A cholinergic synapse uses __________ as its neurotransmitter.
A) monoamine
B) acetylcholine
C) epinephrine
D) norepinephrine
E)catecholamine
B) acetylcholine
In the brain, neurons are more abundant than neuroglia.
A)True
B) Fasle
B) False
Lie entirely within CNS connecting motor and sensory pathways (About 90% of our neurons) are ____
Interneurons
____ _____division carries signals to skeletal muscles
Somatic motor
Which neural disease causes loss of motor function and slurred speech due to degeneration of dopamine - releasing neurons?
Parkinson Disease
Regeneration of damaged peripheral nerve fiber can occur if its neurosoma is intact and at least some neurilemma remains.
True or False
True
when neuron is damaged, astrocytes form hardened scar tissue and fill in space. This is called____
A) Astrocytosis
B)Sclerosis
C) All of the above
C) All of the above
In a neuron, the opening of sodium gates typically leads to __________.
A) repolarization of the plasma membrane
B) hyperpolarization of the plasma membrane
C) depolarization of the plasma membrane
D) drifting of plasma membrane voltage toward a more negative value
E) plasma membrane voltage returning to the resting membrane potential
C) depolarization of the plasma membrane
An inhibitory local potential causes which of the following?
A)Depolarization of the plasma membrane
B)Hyperpolarization of the plasma membrane
C)Repolarization of the plasma membrane
D)Neutralization of the plasma membrane
E)Drifting of the membrane potential towards the resting membrane potential
B)Hyperpolarization of the plasma membrane
Supportive cells that protect neurons and help them function are called
Neuroglia or glial cells
A difference in concentration of charged particles between one point and another
Electrical potential
Ependymal cells line the inner cavities of the CNS.
A)True
B)False
A)True
What has the greatest influence on Resting membrane potential?
A) GABA
B)Sodium
C)Acetylcholine
D)potassium
D)potassium
What cells envelope nerve fibers in the PNS?
A) Satellite cells
B) Ependymal cells
C) Schwann cells
D) Schwann cells and Satellite cells
C) Schwann cells
Conduction of a nerve impulse would be the fastest in which of the following?
A) A large diameter myelinated fiber
B) A small diameter myelinated fiber
C) A large unmyelinated fiber
D)A small unmyelinated fiber
E)A small fiber with multiple Schwann cells
A) A large diameter myelinated fiber
Form myelin sheaths in CNS that speed signal conduction
A)Ependymal cells
B)Astrocytes
C)Microglia
D)Oligodendrocytes
D) Oligodendrocytes
which neurotransmitter Includes the catecholamines:
Epinephrine, norepinephrine, dopamine?
A) acetylcholine
B) amino acids
C) monoamines
D) neuropeptides
C) monoamines
What are the diseases of Myelin sheath?
A) Multiple sclerosis
B) MS
C)Tay- Sachs disease
D) All the above
D) All the above
A neuron can receive thousands of EPSPs from different neurons, and responds by triggering or not triggering an action potential. This addition and response to the net effect of postsynaptic potentials is called __________.
A) temporal summation
B) neural summation
C) spatial summation
D) neuronal coding
E) recruitment
C) spatial summation
What are the three kinds of synapses?
Excitatory cholinergic synapse
Inhibitory GABA-ergic synapse
Excitatory adrenergic synapse
______ system employs electrical and chemical means to send messages from cell to cell
Nervous
One axon and one dendrite is referred to as a _____
A)Multipolar neuron
B)Bipolar neuron
C)Unipolar neuron
D)Tripolar neurom
B)Bipolar neuron
____________ exists because of unequal electrolyte distribution between extracellular fluid (ECF) and intracellular fluid (ICF)
A) Resting membrane potential
B) Electrical Potential
C) Electrical current
D) Action potential
A) Resting membrane potential (RMP)
Respond to environmental changes called stimuli
Excitability
Refractory period is the period of resistance to stimulation which happens in two phases.
What are these two phases called?
Absolute refractory period &
Relative refractory period
A Single process leading away from neurosoma is referred to as a _____
Unipolar neuron
Distal end of axon has terminal _____ which is an extensive complex of fine branches
arborization
Regarding conduction speed, what type of nerve fibers would most likely be present is skeletal muscles?
A) Small, unmyelinated fibers
B) Large,unmyelinated fibers
C)Large,myelinated fibers
D)Small, myelinated fibers
C) Large,myelinated fibers
Explanation: because these are the fastest due to larger diameter and myelin presence which further speeds signal conduction.
Detect stimuli and transmit information about them toward the CNS
Sensory (afferent) neurons
Contains synaptic vesicles full of neurotransmitter
Axon terminal
What is the name of the glial cell that Monitors neuron activity, regulates blood flow to match metabolic need,
Secretes nerve growth factors, and
Communicates electrically with neurons ?
A) Schwann cells
B)Satelite cells
C)Astrocytes
D)Myelin sheath
C) Astrocytes
Most common neurons in CNS are ___ ____ which contain one axon and multiple dendrites.
A) Bipolar neuron
B)Unipolar neuron
C)Multipolar neuron
D)Anaxonic neuron
C)Multipolar neuron
Responds to stimuli by producing electrical signals that are quickly conducted to other cells at distant locations
Conductivity
Tends to arouse body for action
A)Sympathetic division
B) Parasympathetic division
A)Sympathetic division
Anterograde transport is movement
A) up the axon toward the neurosoma
B)down the axon toward the neurosoma
C) down the axon away from the neurosoma
D)up the axon away from the neurosoma
C) down the axon away from the neurosoma
100 neurotransmitters have been identified but most fall into four major chemical categories. What are they ?
acetylcholine,
amino acids,
monoamines,
and neuropeptides
Send signals out to muscles and gland cells (the effectors)
Motor (efferent) neuron
In an action potential, which event directly follows repolarization?
A) Threshold is reached
B) Hyperpolarization of the membrane
C) Depolarization of the membrane
D)Hypopolarization of the membrane
E)The resting membrane potential is reinstated
B) Hyperpolarization of the membrane
Energy is needed to create the resting potential.
True or False
True
Many CNS and PNS fibers are unmyelinated
A) True
B) False
A) True
Put the following action potential steps in order from beginning to end:
(note that some steps are missing, there is a total of 7 steps)
1) Depolarization reaches threshold at about 55mV which opens voltage -regulated gates
2)As membrane potential rises above 0 mV, Na+ channels are inactivated and close.
3)Arrival of current at axon hillock depolarizes membrane.
4) Slow K+ channels open and outflow of K+ repolarizes the cell.
A) 4,3,2,1
B) 3,2,1,4
C) 3,1,2,4
D)1,2,3,4
C) 3,1,2,4
study of cellular mechanisms for producing electrical potentials and currents
Electrophysiology
Primary site for receiving signals from other neurons
Dendrites
chemicals secreted by neurons that have long term effects on groups of neurons are called
_______
neuromodulators
Local potentials get weaker the farther they spread from the point of stimulation. This makes Local potentials _____
A)Graded
B)Reversible
C)Decremental
D)Irreversible
C) Decremental
originates from a mound on the neurosoma called the axon hillock.
Axon (nerve fiber)
Tends to have calming effect
A)Sympathetic division
B) Parasympathetic division
B) Parasympathetic division
A knotlike swelling in a nerve where the cell bodies of peripheral neurons are concentrated.
Ganglion (plural, ganglia)
If stimulation ceases, the cell quickly returns to its normal resting potential. This is a property or local potentials referred to as _____
Reversible
control center of neuron and is also called neurosoma or cell body
Neurosoma
What is the most common inhibitory neutrotransmitter in the brain?
y-aminobutyric acid
What kind of neuron has many dendrites but no axon and can be found in retina, brain, and adrenal gland?
Anaxonic neuron
What cells produce a myelin sheath similar to the ones produced by oligodendrocytes in CNS?
A) Satellite cells
B) Ependymal cells
C) Schwann cells
D) Schwann cells and Satellite cells
C) Schwann cells
____ _____ division carries signals from receptors in the skin, muscles, bones, and joints
Somatic sensory division
What are the two types of cells that occur only in the PNS?
A) Microglia and Astrocytes
B) Satellite cells and Ependymal cells
C) Ependymal cells and Schwann cells
D) Schwann cells and Satellite cells
D) Schwann cells and Satellite cells
Retrograde transport is movement
A) up the axon toward the neurosoma
B)down the axon toward the neurosoma
C) down the axon away from the neurosoma
D)up the axon away from the neurosoma
A) up the axon toward the neurosoma
Adrenergic synapse employs the neurotransmitter norepinephrine (NE), also called ________
noradrenaline
Wander through CNS looking for debris and damage
A)Ependymal cells
B)Astrocytes
C)Microglia
D)Oligodendrocytes
C)Microglia
What are the gaps between segments within the myelin sheath called
A)Trigger zone
B)Initial segment
C)Internodes
D) Nodes of Ranvier
D) Nodes of Ranvier
carries signals from CNS to effectors (glands and muscles that carry out the body’s response)
A) Motor (efferent) division
B) Somatic sensory division
C) Visceral sensory division
D)Sympathetic division
A) Motor (efferent) division
What is the thick, outermost coil of myelin sheath called?
Neurilemma
the ability to process, store, and recall information and use it to make decisions is called ______
Neural integration
Which neurotansmitter includesInclude glycine, glutamate, aspartate, and y-aminobutyric acid (GABA)?
A) acetylcholine
B) amino acids
C) monoamines
D) neuropeptides
A) acetylcholine
One axon and multiple dendrites is a _____ neuron
multipolar
mostly found in brain and spinal cord
A neuron containing one axon and on dendrite is
Bipolar
ex:olfactory cells of the nose, some neurons of retina
a neuron with one single process leading away from soma is called
unipolar
A neuron with multiple dendrites, but not axon is called
anaxonic neurons
Anterograde transport employs a motor protein called
kinesin
Retrograde uses a motor protein called
dynein