NEUROSCIENCE MIDTERM 1 EXAM
QUESTIONS AND ANSWERS WITH
ACCURATE RATIONALES(PASSED).
"All-or-Nothing" Action Potentials - correct answer - - An
action potential is the same magnitude (it doesn't weaken
at the end).
- It occurs completely or not at all.
- Don't need any more stimulation beyond the threshold.
- *Graded potentials fizzle out*
- - Lever activated toilet analogy
1. Cytosol and Extracellular Fluid - correct answer - -
*H20*: is held together by polar covalent bonds
- *Ions*: are molecules with an electrical charge (Na+,
K+, Cl-, Ca2+)
- *Cations*: ions with a net positive charge
- *Anions*: ions with a net negative charge
- Na+ and Cl- Produce NaCl (*Ionic bond*)
- NaCl dissolves in water (it is *hydrophilic*).
1. Methods - correct answer - i. Experiments
,ii. Quasi-experiments
iii. Case Studies
iv. Correlational Research
1. Microtubules - correct answer - Run *longitudinally*
along neurites (axon, dendrites) and are composed on
strands of *tubulin braided around a core*. They are
anchored by *MAPs* (ex. *Tau Protein*. They also act as a
transport system for materials from the cell body to the
axon terminals in both directions.
1. Nerves Conduct Electrical Signals: Charles Bell and
Francois Magendie (1810) - correct answer - Found that
nerves are made of two types of fibres: *motor and
sensory*. Fibres enter or exit the spinal cord separately
(as *dorsal* or *ventral* roots)
- Found that cutting the *ventral roots* resulted in
*muscle paralysis*.
- Found that cutting the *dorsal roots* resulted in
*sensory loss*.
1. Nerves Conduct Electrical Signals: Luigi Galvani -
correct answer - *Luigi Galvani* (1731-1798) was an
Italian scientist who performed experiments on frogs in
which he stimulated the frogs leg's nerves and found that
muscles twitch. He also showed that the *brain produces
,electricity* but was not totally correct in the idea of
movement. --> The actual movement of muscles is not
solely due to impulses but is also due to chemicals
(neurotransmitters).
1. Nerves Conduct Electrical Signals: Otto Loewi - correct
answer - He won the Nobel prize in 1936 for his
*Chemical Neurotransmission Theory*. He demonstrated
this theory in two different experiments where he placed
2 beating frog hearts in a bath and stimulated the *vagus
nerve* (experiment 1) then the *accelerator nerve*
(experiment 2).
1. Observation - correct answer - Information obtained
from experiments, *introspection*, case studies, or
phenomena in the world. Neuroscience relies on
*empirical research* i.e., collecting information from
observations.
1. Resting/Equilibrium Potential - correct answer - -
Undistributed axons are *polarized*: they have a stable
difference in electrical charge across the membrane, but
there is potential for change.
- Inside the membrane is *-65mv* relative to the outside.
- The difference is due to the *unequal distribution of
Na+, Cl-, K+, and large protein anions*.
, - *K+ accumulates inside* as it can easily pass through
membrane ion channels.
- Accumulation of K+ is *limited* by the *concentration
gradient*. *K+ diffuses out* but *electrical potential pulls
it back in* until *equilibrium potential is reached*. Sodium
cannot go back in with K+ as the channels are highly
selective.
- *Total Ionic Driving Force = diffusion, electrical potential
and conductance*.
- *Cl-* ions don't contribute to potential and there is more
pressure on Na+ ions than K+
1. Sodium-Potassium Pump - correct answer - An
enzyme (protein) that uses ATP energy to actively
exchange internal Na+ for external K+. 3 Na+ ions
pumped out per 2 K+ ions pumped in. It also takes
sodium ions that have entered and must be pumped out.
2. Calcium Pump - correct answer - An enzyme that
actively transports Ca2+ out using ATP.
2. Localization of Specific Functions: Franz Joseph Gall -
correct answer - Gall (1758-1828) developed
*Phrenology* and focused on localizing functions. He
believed that the bumps on the skull reflect the brains
bumps and are used to identify *personality traits*. He
worked in the Academy of Science in Paris.
QUESTIONS AND ANSWERS WITH
ACCURATE RATIONALES(PASSED).
"All-or-Nothing" Action Potentials - correct answer - - An
action potential is the same magnitude (it doesn't weaken
at the end).
- It occurs completely or not at all.
- Don't need any more stimulation beyond the threshold.
- *Graded potentials fizzle out*
- - Lever activated toilet analogy
1. Cytosol and Extracellular Fluid - correct answer - -
*H20*: is held together by polar covalent bonds
- *Ions*: are molecules with an electrical charge (Na+,
K+, Cl-, Ca2+)
- *Cations*: ions with a net positive charge
- *Anions*: ions with a net negative charge
- Na+ and Cl- Produce NaCl (*Ionic bond*)
- NaCl dissolves in water (it is *hydrophilic*).
1. Methods - correct answer - i. Experiments
,ii. Quasi-experiments
iii. Case Studies
iv. Correlational Research
1. Microtubules - correct answer - Run *longitudinally*
along neurites (axon, dendrites) and are composed on
strands of *tubulin braided around a core*. They are
anchored by *MAPs* (ex. *Tau Protein*. They also act as a
transport system for materials from the cell body to the
axon terminals in both directions.
1. Nerves Conduct Electrical Signals: Charles Bell and
Francois Magendie (1810) - correct answer - Found that
nerves are made of two types of fibres: *motor and
sensory*. Fibres enter or exit the spinal cord separately
(as *dorsal* or *ventral* roots)
- Found that cutting the *ventral roots* resulted in
*muscle paralysis*.
- Found that cutting the *dorsal roots* resulted in
*sensory loss*.
1. Nerves Conduct Electrical Signals: Luigi Galvani -
correct answer - *Luigi Galvani* (1731-1798) was an
Italian scientist who performed experiments on frogs in
which he stimulated the frogs leg's nerves and found that
muscles twitch. He also showed that the *brain produces
,electricity* but was not totally correct in the idea of
movement. --> The actual movement of muscles is not
solely due to impulses but is also due to chemicals
(neurotransmitters).
1. Nerves Conduct Electrical Signals: Otto Loewi - correct
answer - He won the Nobel prize in 1936 for his
*Chemical Neurotransmission Theory*. He demonstrated
this theory in two different experiments where he placed
2 beating frog hearts in a bath and stimulated the *vagus
nerve* (experiment 1) then the *accelerator nerve*
(experiment 2).
1. Observation - correct answer - Information obtained
from experiments, *introspection*, case studies, or
phenomena in the world. Neuroscience relies on
*empirical research* i.e., collecting information from
observations.
1. Resting/Equilibrium Potential - correct answer - -
Undistributed axons are *polarized*: they have a stable
difference in electrical charge across the membrane, but
there is potential for change.
- Inside the membrane is *-65mv* relative to the outside.
- The difference is due to the *unequal distribution of
Na+, Cl-, K+, and large protein anions*.
, - *K+ accumulates inside* as it can easily pass through
membrane ion channels.
- Accumulation of K+ is *limited* by the *concentration
gradient*. *K+ diffuses out* but *electrical potential pulls
it back in* until *equilibrium potential is reached*. Sodium
cannot go back in with K+ as the channels are highly
selective.
- *Total Ionic Driving Force = diffusion, electrical potential
and conductance*.
- *Cl-* ions don't contribute to potential and there is more
pressure on Na+ ions than K+
1. Sodium-Potassium Pump - correct answer - An
enzyme (protein) that uses ATP energy to actively
exchange internal Na+ for external K+. 3 Na+ ions
pumped out per 2 K+ ions pumped in. It also takes
sodium ions that have entered and must be pumped out.
2. Calcium Pump - correct answer - An enzyme that
actively transports Ca2+ out using ATP.
2. Localization of Specific Functions: Franz Joseph Gall -
correct answer - Gall (1758-1828) developed
*Phrenology* and focused on localizing functions. He
believed that the bumps on the skull reflect the brains
bumps and are used to identify *personality traits*. He
worked in the Academy of Science in Paris.
