CHAPTER 3: FUNCTIONAL UNITS OF THE NERVOUS SYSTEM Flashcards
______ is the technique that allows researchers to label different neurons by highlighting them with
distinct colors.
brainbow
The Golgi stain made use of ______ to stain neurons so they could be viewed under a microscope.
silver nitrate
Based on their observations of stained neurons, Golgi put forward the ______ hypothesis.
nerve net
Cajal proposed the ______ hypothesis.
neuron
In the central nervous system there are approximately:
100 billion neurons
how many axons do neurons have?
have only one axon
The ______ is the core region of the cell that contains the nucleus and other organelles.
soma
______ are branches extending out of a neuron’s cell membrane that allow it to collect information
from other cells.
dendrites
______ are single fibres that carry messages to other neurons.
axons
what are parts of a neuron’s function?
A) encoding memories
B) production of thoughts and memories
C) production of behavior
what is not part of a neuron’s function?
producing myelin
The action potential typically originates at the:
axon hillock.
The part of the axon that conveys information to other neurons is the:
terminal button.
Which of the following defines a synapse?
end foot, space, dendrite
What is the most common sequence of information flow through a neuron?
dendrite, nucleus, axon hillock, axon
- What is the best analogy for a neuron?
a multi-input computational device with one output wire
______ carry information from receptors to the brain.
sensory neurons
which cells are examples of different types of interneurons.
A) Purkinje; stellate
B) Purkinje; pyramidal
C) Pyramidal; stellate
_____ are also called association cells because they link up sensory and motor neurons.
interneurons
______ are known for having the largest cell bodies and the longest axons.
motor neurons
______ are a special type of interneuron found in the cerebellum.
Purkinje cells
The simplest neuron is a(n):
bipolar neuron
Which of the following is characteristic of a pyramidal cell?
A) long axon
B) pyramid-shaped body
C) two sets of dendrites
Which of the following is not characteristic of a pyramidal cell?
one set of dendrites
what do interneurons do?
interneurons are involved in processing sensory information and sending information to the motor neurons.
Stellate cells are:
interneurons
what is not an interneuron?
schwann cell
what are Glial cells are primarily responsible for?
the support of neurons
______ act as “glue” that helps bind neurons together.
glia
what is formed throughout life?
Both some new neurons and many new glial cells are formed throughout life.
what glial cells are responsible for producing cerebrospinal fluid (CSF)?
ependymal cells
what are Ependymal cells are associated with?
the production of CSF.
Hydrocephalus is usually caused by blockage at:
the fourth ventricle
what are the ventricles in the brain?
The ventricular system is a set of four interconnected cavities (ventricles) in the brain, where the cerebrospinal fluid (CSF) is produced. Within each ventricle is a region of choroid plexus, a network of ependymal cells involved in the production of CSF.
______ are glial cells that have nutritive and supportive functions.
astrocytes
Brain tumours often result from the unregulated growth of:
glial cells
______ are tumours that begin in one part of the body and spread to another part of the body.
metastatic tumours
The blood–brain barrier is made up of ______ attached to neurons and blood vessels.
astrocytes
Chris has been feeling very ill lately. He has had a severe headache for a week now and has been
vomiting, has had trouble concentrating, and has started losing some of his vision. This morning he
had a seizure. You tell Chris he should go to the hospital immediately because he probably has:
a brain tumour
The fluid in which the cell’s internal structures are suspended is called:
intracellular fluid
Astroglia (astrocytes) are associated with:
A) expansion of blood vessels.
B) the blood–brain barrier.
C) formation of scar tissue.
Astroglia (astrocytes) are not associated with:
removal of dead tissue.
Which glial cells operate as part of the brain’s immune system?
microglia
what is the blood-brain barrier?
a protective partition between blood vessels and the brain
Which glial cells operate as part of the brain’s immune system?
microglial cells
what percentage do microglial cells make up of glial cells and where do they originate from?
microglial cells make up 20% of all glial cells and originate in the blood as an offshoot of the immune system. they then migrate throughout the nervous system.
Greg accidentally cuts his fingertip with a knife. The next day he notices that his fingertip seems
numb to the touch. Greg is very concerned about this, but you tell him not to worry because:
nerves in the PNS (periphery nervous system, since it was his finger that got cut) regenerate thanks to Schwann cells.
______ help generate myelin in the CNS.
oligodendroglial cells
______ help generate myelin in the PNS.
Schwann cells
Myelin is produced by what cells?
oligodendroglia and Schwann cells
what does Myelin around axons do?
speeds up transmission of information.
Multiple sclerosis symptoms are caused by:
loss of myelin on axons
Melissa, a 23-year-old female living in Alaska, has been having tingling sensations in her right arm
and leg for a few weeks. Today when she woke up she realized that she could barely move her
right arm. She had a similar set of symptoms a couple of years ago, but they went away, so she
thought everything was fine. Your advice to Melissa is to go to the doctor because:
she may have multiple sclerosis.
what do Schwann cells do in the PNS?
In the peripheral nervous system Schwann cells serve as guideposts to show axons where to
terminate when regeneration occurs. axons can get lost, as sometimes happens after a surgeon reattach a severed limb. if axons destined to innervate one finger end up innervating another finger instead, the wrong finger will move when a message is sent along that neuron.
Which three elements constitute more than 90% of a cell?
oxygen, hydrogen, carbon
The smallest quantity of an element that retains the properties of an element is a(n):
atom
______ is a structure that gathers, stores, and releases energy.
the mitochondrion
The ______ contain(s) the chromosomes and genes of a cell.
nucleus
The place where protein packages are wrapped and shipped in a cell is called:
Golgi body
Mitochondria and lysosomes are analogous to:
power and transportation.
______ are involved in transporting molecules and help give the cell its shape.
tubules
Cell wastes are handled by:
lysosomes (also transportation)
The cell membrane is important because:
it controls the amount of water in the cell and regulates the concentration of salts on two sides
of the membrane.
In the CNS, what is the extracellular fluid?
cerebrospinal fluid
The ______ help(s) regulate the concentration of different ions inside and outside of the neuron.
cell membrane
All of the cells in our body are made from a book of blueprints contained in:
chromosomes of each individual cell.
The code for the synthesis of proteins is contained in:
in genes
Membranes of a cell are made of special molecules called:
phospholipids
DNA is composed of four nucleotide bases. Which one of the following is not a nucleotide base?
histamine
how many chromosomes do Human cells contain:
46 chromosomes
what is the order of arising structures starting with chromosomes?
chromosomes, genes, proteins, enzymes
A chain of amino acids forms a:
protein
where are Proteins are assembled in:
endoplasmic reticulum
Which of the following is part of the cells’ membranes?
endoplasmic reticulum
A series of amino acids is called a:
polypeptide chain
Humans require _______ amino acids for the synthesis of proteins.
20
Any one neuron may use as many as _____ protein molecules.
10,000
Golgi bodies package ______ and ship them to other parts of the neuron via ______.
proteins; microtubules
Golgi bodies essentially act as ______ for neurons.
an internal postal service
An analogous term for receptor is:
keyhole
Protein molecules can:
A) act as a gate.
B) act as a pump.
C) change shape.
Membrane channels are made up of:
proteins
Some membrane channels can selectively allow in one type of ion (e.g., K+
) but not others. The
ability to restrict the passage of only certain ions largely depends on:
the size and shape of the channel.
Humans have approximately how many genes?
20,000 genes
Expressed genetic traits of an individual are referred to as their:
phenotype
The gene that is most common in a population is called a:
wild-type gene
The ______ chromosome pair determines our sexual characteristics.
twenty-third chromosome pair
______ is a term that means having two different alleles for the same trait.
heterozygous
________, caused by a genetic mutation, can help prevent malaria.
Sickle-cell anemia
In ______, an allele’s own trait and that of the other allele in the gene pair are expressed
completely.
codominance
A child who has seizures, blindness, and degenerating motor and mental ability and who dies at an
early age most likely has:
Tay-Sachs disease
Since the mutation that leads to Tay-Sachs disease is recessive, the probability that a child of two
parents who both carry the recessive Tay-Sachs allele will later develop Tay-Sachs disease is:
25%
Because the gene that leads to Huntington’s disease is dominant, a child who has one parent with
Huntington’s disease has a _____ chance of developing the disorder
50%
Huntington’s chorea leads to the death of cells in the:
basal ganglia and cortex.
A patient who, previous to death, showed abnormal involuntary movements and loss of memory
most likely suffered from:
Huntington’s disease
Ashley, a 36-year-old female, has recently had trouble controlling the movement of her arms. For
example, sometimes her arms will flail about as if they are reaching for something even though she
does not want them to. She has also started having memory problems and changes in her
personality. Her father had similar symptoms in his thirties but died before he turned 40. You tell
Ashley to go to the doctor because she might have:
Huntington’s disease
Down syndrome is caused by (an) extra ______ chromosome(s).
twenty-first
Characteristic facial features, short stature, heart defects, and mental retardation are signs of:
Down syndrome.
The simplest way to select for specific genetic traits in animals (e.g., dogs) is through the use of:
selective breeding
One genetic technique that could be used to produce new tissue or organs for transplant to the
original genetic donor is:
cloning
Transgenic animals are:
produced by adding a gene to the genome.
If you are interested in testing the role that a specific gene plays in a disorder, you can eliminate the
gene and observe the effects using:
knockout technology
If you want to study the role of a specific gene on a particular behavior, you could take the gene
from one species and insert it into the genome of another species. This is referred to as:
knock-in technology
Chimeric animals are the result of:
combining the genes from two different species
The notion that two individuals with the exact same genes could end up developing differently is
explained by:
phenotypic plasticity
______ is the study of how the environment can influence the expression of different genes.
epigenetics
how epigenetic mechanisms can influence the
expression of a particular gene?
B) histone modification
C) DNA modification
D) mRNA modification
what can epigenetic mechanisms not influence the
expression of a particular gene?
ribosome modification
