Practive Questions - CH 1 Flashcards
two basic kinds of cells in the nervous system are
neurons and glia.
Santiago Ramon y Cajal demonstrated that
neurons are separate from one another.
Both _____ and ______ shared the nobel prize in 1996.
Golji and Cajal
_____ allow in important things like water, oxygen, sodium, etc.
protein channels.
neurons differ most strongly from other body cells in their ____
shape.
what do neurons have that other cells do not?
large, branching extensions
Dr.McLaughlin’s lab studies how newly formed proteins are folded inside neurons. They would be most interested in studying the _______
ribosomes.
water, oxygen, and _______ freely flow across a cell membrane.
carbon dioxide
The structure that contains a cell’s chromosomes is called the
nucleus.
small charged molecules can cross cell membrane through
protein channels.
Professor Lopez studies the specialized _______ in the eye that detect light.
sensory neurons
Ribosomes are the part of the cell that
synthesizes new proteins.
The endoplasmic recticulum is a
network of thin tubes that transport newly synthesized proteins.
Dendrites are ______
branching fibres that get narrower near their ends.
The branching fibers that form the information receiving pole of the nerve cells are called _____
dendrites.
Prof Xi studies the _________ located on the _______ of neurons in order to between understand how messages are received by the neuron.
synaptic receptors; dendrites.
The tree like branches of a neuron that receive info from other neurons are called ____
dendrites.
many dendrites contain short outgrowths called spines that _________
increase the surface area available for synapses.
as compared to dendrites, axons usually _______.
are covered in myelin.
the insulating material that covers many vertebrate axons is called the ________.
myelin sheath.
Jasmine is in her physiology lab practising labelling a neuron. When she gets to the nodes of Ranvier, she will be labelling __________
the gaps in the myelin sheath along the axon.
gaps in the insulating material that surrounds axons are known as
nodes of ranvier.
a presynaptic terminal is also known as
an end bulb.
an axon has many brances, each of which swells at its tip, these are known as _______
presynaptic terminals.
Prof Case studies how drugs of abuse change the amount of chemical that neurons release from the presynaptic terminal into to _________
junction between neurons.
neurons typically have on ________, but many _______.
axon; dendrites.
as a general rule, axons convey info __________.
away from their own cell body.
If you were to accidentally touch a hot stove with your hand, you would quickly pull your hand away. The information carried o the muscles in you arm to make them contract was carried by _____
efferent neurons.
if all of a neurons dendrites or axons were contained within the spinal cord, it would be considered an ________ neuron.
intrinsic.
what type of neuron in the pons receives information only from other cells in the pons and sends info only to other cells in the pons?
intrinsic.
Prof Peach is teaching about glial cells. She will tell her class that glial cells ___________
are not as well studies as neurons but have been shown to perform many important function in the nervous system.
what type of glia helps to synchronize the activity of axons?
astrocytes.
which type of glia remove waste material in the nervous system?
astrocytes.
what type of glial cells myelinate axons in the brain and spinal cord?
oligodendrocytes.
which type of glia release chemicals that modify the activity of neighbouring neurons?
astrocytes.
which type of glia builds myelin sheaths around axons in the periphery of the body?
Schwann cells.
Radial glia ____________.
guide the migration of neuron during embryonic development.
what mechanisms prevents or slows some chemicals from entering the brain, while allowing others to enter?
blood brain barrier.
Molecules that can cross the BBB are usually __________
molecules that can dissolve in the fats of the capillary walls.
major disadvantage of a BBB is that ________
certain required chemicals must be actively transported.
Glucose is the main source of fuel for the nervous system and enter the brain via _______
active transport.
what is the main source of nutrition for vertebrate neurons?
glucose
glucose is so important to the brain because
it can cross the BBB to be used by neurons.
why does the brain need thiamine?
to enable it to metabolize glucose
Dalton has been diagnosed with Korsakoff’s syndrome, what likely caused his disorder?
he doesn’t have enough thiamine probably as a result of chronic alcoholism.
Korsakoff’s syndrome is
marked by severe memory impairments.
The membrane of a neuron is composed of _______ with _______ embedded in them.
phosphilipids; proteins
What term describes the difference in voltage that typically exists between the inside and the outside of a neuron?
resting potential.
in order to change the amount of polarization of a neuron, Prof Alley would need to change the difference in voltage between __________
inside the cell and outside the cell.
The resting potential is mainly the result of
a negatively charged proteins inside the cell.
Prof Durrant explained to his student that the resting potential of neuron is the ________.
total amount of negative charge inside the neuron relative to the outside.
Pok is in the lab and is measuring the resting potential of neurons. Approximately what should she measure as the resting potential?
-70 mV.
when the neuronal membrane is at rest, the potassium channels _________
permit potassium ions to pass slowly.
Before the action potential when the neuron is at rest, sodium channels __________
are closed and dont allow sodium to pass through.
Prod Rhodus is lecturing about selective permeability of neurons. What would he tell the class?
only certain molecules can cross the membrane freely.
when a neurons membrane is at rest, the concentration gradient tends to move sodium ________ the cell and the electrical gradient tends to move it _________ the cell.
into; into
when a neurons membrane is at rest, the concentration gradient tends to move potassium _____ the cell and the electrical gradient tends to move it ________ the cell.
out of; into
electrical gradients lead to the ________
movement of ions to areas having opposite electrical charges.
under which conditions would the sodium-potassium pump likely be far less effective in creating a concentration gradient?
if selective permeability of the membrane did not exist.
the net effect of each cycle of the sodium-potassium pump is to _______
decrease the number of positively charged ions within the cell.
___________ is the main reason the neuron is able to maintain the resting potential.
the sodium-potassium pump.
concentration gradient refers to the ________
difference in distribution for various ions between the inside and outside of the membrane.
which event will increase the concentration gradient of sodium?
increasing activity of the sodium potassium pump.
the concentration gradient for potassium tend to _______.
push potassium out of the cell.
when the neuron is at rest ___________, is mostly responsible for the movement of potassium ions out of the cell.
potassium’s concentration gradient.
when a neuron is at rest, what primarily responsible for moving potassium ions into the cell?
both the sodium-potassium pump and electrical gradient.
when a membrane is at rest, what attracts potassium ions to the inside of the cell?
an electrical gradient
when a membrane is at rest, what attracts sodium ions to the inside of the cell?
both electrical gradient & concentration gradient.
resting potential is advantageous because ______
the cell is ready to produce an action potential quickly following a stimulus.
stimulation of a neuron takes place ______
at the synapse.
what occurs when a stimulus shifts the potential inside an neuron from the resting potential to a more negative potential?
hyperpolarization.
Dr. Smith is trying to produce hyperpolarization in the neurons in her lab, what should she do?
use a microelectrode to apply a negative charge.
in order to produce an action potential, the collective amount of depolarization must exceed the ______
threshold of excitation.
a membrane produces an action potential whenever the potential across it reaches what level?
the threshold of excitation.
what occurs when depolarization is less than the cell’s threshold?
sodium cross the membrane only slightly more than usual.
what action would depolarize a neuron?
increasing membrane permeability to sodium.
the action potential of a neuron depends mostly on what movement of ions?
sodium ions entering the cell.
voltage activated channels are channels for which a change in the voltage across the membrane alters their ______
permeability
at the peak of the action potential, the electrical gradient of potassium ___________
pushes potassium out of the cell.
when the potential across a membrane reaches the threshold, the sodium channels
open to let sodium enter the cell rapidly.
a drug that blocks the sodium gates of a neurons membrane will
block the action potential.
after the peak of an action potential, what prevents sodium ions from continuing to enter the cell?
the sodium gates in the membrane close.
the sodium channel closes after _________
the neuron reaches threshold.
what causes potassium ions to leave the axon just after the peak of the action potential?
a continuing concentration gradient and the opening of potassium gates.
a drug will prevent action potential if it
blocks the movement of sodium ions across the membrane.
Dr.Blanchard is giving a lecture about the propagation of the action potential. What would she tell the class?
that the process of an action potential repeats itself over and over down the length of the axon thanks to the diffusion of sodium ions.
Dr. Ruggs is giving a lecture about the all or non law. What would she tell the class?
that after reaching threshold, the amplitude and velocity of the action potential is the same each time.
the primary feature of a neuron that prevents the action potential from travelling back from where it just passed is the ______
refractory period.
during the refractory period, the
sodium gates are reverting to their usual state.
what will most affect the speed of an action potential?
the resistance of the membrane.
the speed of an action potential down an unmyelinated axon is best describes as
faster in thick axons than in thin ones.
in what direction does a local neuron transmit information?
equally well in any direction
which of the following describes the transmission of information in a local neuron?
the signal decreases in strength as it travels.
