Exam 1

Question 1

The historical surgical practice of drilling a hole in the skull is called ______

Answer 1

trepanation

Question 2

During the Middle Ages, scholars and physicians believed that sense information from the five external senses (touch, taste, smell, hearing and sight) was transferred to the _______. This is called the ventricular theory.

Answer 2

ventricles of the brain

Question 3

Spinal nerves divide into the ventral and dorsal roots before they attach to the spinal cord. Charles Bell (1774-1842) found that cutting only the ventral root caused muscular paralysis. Later, François Magendie (1783-1855) showed that the dorsal roots carry sensory information into the spinal cord. Is the following statement correct as a conclusion drawn from those experiments?

“These results suggested that each axon in a spinal nerve conveys information only in one direction; either from the periphery to the spinal cord (sensory information) or from the spinal cord to the periphery (motor information)”.

Answer 3

correct

Question 4

Broca’s area is a cortical area identified by Paul Broca (1824-1880). What is the main function of this area?

Answer 4

speech production

Question 5

Camillo Golgi (1843-1926) proposed that the neurites of different cells are fused

together to form a continuous network (which later turned out not to be true). This theory is called the ________.

Answer 5

reticular theory

Question 6

Which of the following is NOT a typical feature of neurons?

Answer 6

Insulate axons by forming a myeline sheath.

Question 7

Nissl bodies are discrete granular structures in a neuron that are strongly stained by basic dyes (e.g., Nissl stain). Which organelles constitute Nissl bodies?

Answer 7

Free ribosomes and rough endoplasmic reticulum

Question 8

Which of the following molecules does NOT exist on the cell membrane of a typical neuron?

Answer 8

myelin

Question 9

Action potentials usually arise in the ________ of the neuron.

Answer 9

initial segment

Question 10

What type of molecules exists inside of synaptic vesicles?

Answer 10

neurotransmitters

Question 11

The space between the presynaptic and postsynaptic membranes is called the ______.

Answer 11

synaptic cleft

Question 12

A researcher injected a special type of dye (axon tracer dye) into the retina. Several days later, she found that the dye stained the target areas of retinal axons (e.g., lateral geniculate nucleus, superior colliculus). What is the mechanism that transported the dye from the retina to the brain targets?

Answer 12

Anterograde axoplasmic flow

Question 13

Dendrites of some neurons have small protrusions called ________, which form synapses with axon terminals.

Answer 13

dendritic spines

Question 14

Neurons that convey information from the periphery to the central nervous system are called _____.

Answer 14

afferent neurons

Question 15

Gaps in the myelin sheath are called _________.

Answer 15

nodes of Ranvier

Question 16

Which type of glial cells forms the myelin sheath in the central nervous system?

Answer 16

oligodendrocytes

Question 17

Which glial cells function as phagocytes in the central nervous system and remove debris of dead or degenerating cells?

Answer 17

microglia

Question 18

The difference in electrical charges across the cell membrane of an unstimulated neuron is called _____.

Answer 18

resting membrane potential

Question 19

Which of the following is NOT a feature of action potential?

Answer 19

Their size increases if a stronger stimulus is applied to the neuron.

Question 20

Individual ions exist at different concentrations in the extracellular fluid and in the cytoplasm. Which ion exists at a higher concentration in the cytoplasm than in the extracellular fluid?

Answer 20

Potassium ion

Question 21

Which of the following is NOT a feature of ion channels?

Answer 21

Actively transport ions by using energy produced from ATP.

Question 22

___________ channels open and close in response to a change in the membrane potential.

Answer 22

Voltage-gated

Question 23

Is the statement below true or false?

“Ionic movements through channels are influenced by the concentration gradient of the ion and the electrical gradient across the cell membrane”

Answer 23

True

Question 24

The membrane potential at which there is no net movement of a particular ion across the cell membrane is called __________.

Answer 24

equilibrium potential

Question 25

In Ohm’s law (I=gV), “g” is the conductance. In the neuronal cell membrane, the conductance (“g”) for a particular type of ion is proportional to __________.

Answer 25

the number of ion channels that are open in the neuronal cell membrane

Question 26

Is the following statement true or false?

“The equilibrium potential for an ion can be calculated by using the Nernst equation, if the concentrations of the ion in the extracellular fluid and in the cytoplasm are known.”

Answer 26

True

Question 27

The resting membrane potential can be calculated using the Goldman equation. The equation shows that K+ is a key determinant of resting membrane potential, because __________.

Answer 27

the neuronal cell membrane is more permeable for K+ than other ions

Question 28

Which of the following is a feature of the Na+-K+ pump?

Answer 28

-Pumps Na+ and K+ against concentration gradients.
-Has an ATPase activity.
-Expels three Na+ from the neuron and imports two K+ into the neuron in each cycle of action.

Question 29

In the neuron, the magnitude of the depolarizing current is reflected in _______.

Answer 29

the frequency of action potential

Question 30

The concentration gradients of Na+ and K+ across the neuronal membrane are maintained by ________.

Answer 30

Na+/K+ pumps

Question 31

In the repolarizing phase of action potential, ___________ are open and allow _____.

Answer 31

K+ channels; efflux of Ka+ ions

Question 32

Tetrodotoxin is a potent neurotoxin found in the liver and ovary of pufferfish. Tetrodotoxin blocks ___________ thus inhibits action potentials.

Answer 32

Na+ channels

Question 33

Is the following statement true or false?

“When the membrane is depolarized above the threshold, Na+ channels open before K+ channels”.

Answer 33

True

Question 34

The period of time after an action potential when a neuron cannot generate another action potential (even if a stronger stimulus is applied to the neuron) is called the __________.

Answer 34

absolute refractory period

Question 35

Action potentials propagate only in one direction, from the soma to the axon terminal. This feature is called _________.

Answer 35

orthodromic conduction

Question 36

Which of the following does NOT usually affect the speed of axon potential propagation?

Answer 36

Strength of stimulus

Question 37

The saltatory conduction of axon potential occurs only in __________.

Answer 37

myelinated axons