I feel like the content, passages, and questions are really spcific
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Is Berkeley review good? i'm studying for 2015 mcat.
- Thread starter RSK25
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Be careful not to mistake several examples where multiple topics are being mixed together and applications of the concepts as being really specific. Those are the things that make BR standout. And the detailed explanations that discuss the concepts and extremely useful shortcuts you won't find anywhere else make the books look thicker, but again, that's a strength. Doing well on this test requires that you learn to thinking quicker and in a more organized fashion. That's what the books aim to teach.
The 2015 physical sciences section is not changing all that much. There are a few new topics being added and a few being removed. It will likely involve more applications to biological systems, but you will be fine in that section. Just omit some of the topics that are being removed and be aware that organic chemistry is now moving to the physical sciences section. For BS, biochemistry is being added and the level of difficulty is going up. That is a perfect fit for BR. Using the current BR books for the 2015 science sections should be fine, because they have been slowly changing and incorporating more passages aimed at the new MCAT. Obviously for the sociology/psychology section, you'll need to study with new books.
The 2015 physical sciences section is not changing all that much. There are a few new topics being added and a few being removed. It will likely involve more applications to biological systems, but you will be fine in that section. Just omit some of the topics that are being removed and be aware that organic chemistry is now moving to the physical sciences section. For BS, biochemistry is being added and the level of difficulty is going up. That is a perfect fit for BR. Using the current BR books for the 2015 science sections should be fine, because they have been slowly changing and incorporating more passages aimed at the new MCAT. Obviously for the sociology/psychology section, you'll need to study with new books.
Acetylcholine is one of the body's most important
neurotransmitters, responsible for the transmission of
nerve impulses across synaptic junctions. There are two
main classes of acetylcholine receptors. The nicotinic
acetylcholine receptor responds to nicotine as an agonist
and to curare as an antagonist. The muscarinic
acetylcholine receptor responds to muscarine as an
agonist and to scopolamine as an antagonist.
Nicotine is a psychoactive alkaloid extracted from
tobacco plants. It is a toxic substance, one that places a
stress on the heart and the entire cardiovascular system.
Because this drug is quite addictive, several techniques
have been designed to cure nicotine dependence.
In a novel nicotine replacement therapy, a
combination of physostigmine and scopolamine is
administered. Physostigmine is an acetylcholinesterase
inhibitor at both muscarinic and nicotinic acetylcholine
receptors. It must be noted that scopolamine is functional
in the central nervous system, but receptors in heart tissue
are insensitive to scopolamine. Figure 1 schematically
depicts the action of these substances in the autonomic
nervous system.
C is correct, a net nicotinic and parasympathetic nervous system excitation. We want to offer the person who is
addicted to nicotine the "high." without the cardiovascular risks associated with nicotine. Therefore, we will want to
stimulate the nicotinic receptors in the central nervous system to achieve this sensation. The problem is that
nicotinic receptors arc located in the pre-ganglionic synapse of both the sympathetic and parasympathetic nervous
systems. We might think that since both are stimulated, they simply cancel each other out. However, we know that
nicotine causes stress on the heart, so the nicotinic receptor in the sympathetic nervous system must be dominant.
With this in mind, let us look at the two drugs added. The first is physostigmine (eserine). This acetylcholinesterase
inhibitor will cause increased levels of acetylcholine in both nicotinic and muscarinic receptors. This will give us
the nicotine "high" that we want. Yet wc do not want to stimulate all the muscarinic receptors, so we add
scopolamine. This acts to block all muscarinic receptors. This is what we want. We get the familiar feeling caused
by nicotine and have blocked all muscarinic receptors. We are not done, though. We are still left to deal with the
cardiovascular stress. The physostigmine will increase acetylcholine (ACh) levels at the first synapse in the
sympathetic nervous system. But in the parasympathetic system, it increases ACh levels at both the nicotinic and
the muscarinic receptors (remember that scopolamine does not work directly upon heart tissue). Therefore, we have
two stimulations in the parasympathetic system while we only have one in the sympathetic system. Therefore, we
are left with a net nicotinic stimulation with a parasympathetic excitation. The correct choice is C.
I'm really not getting this question and the answer
neurotransmitters, responsible for the transmission of
nerve impulses across synaptic junctions. There are two
main classes of acetylcholine receptors. The nicotinic
acetylcholine receptor responds to nicotine as an agonist
and to curare as an antagonist. The muscarinic
acetylcholine receptor responds to muscarine as an
agonist and to scopolamine as an antagonist.
Nicotine is a psychoactive alkaloid extracted from
tobacco plants. It is a toxic substance, one that places a
stress on the heart and the entire cardiovascular system.
Because this drug is quite addictive, several techniques
have been designed to cure nicotine dependence.
In a novel nicotine replacement therapy, a
combination of physostigmine and scopolamine is
administered. Physostigmine is an acetylcholinesterase
inhibitor at both muscarinic and nicotinic acetylcholine
receptors. It must be noted that scopolamine is functional
in the central nervous system, but receptors in heart tissue
are insensitive to scopolamine. Figure 1 schematically
depicts the action of these substances in the autonomic
nervous system.
C is correct, a net nicotinic and parasympathetic nervous system excitation. We want to offer the person who is
addicted to nicotine the "high." without the cardiovascular risks associated with nicotine. Therefore, we will want to
stimulate the nicotinic receptors in the central nervous system to achieve this sensation. The problem is that
nicotinic receptors arc located in the pre-ganglionic synapse of both the sympathetic and parasympathetic nervous
systems. We might think that since both are stimulated, they simply cancel each other out. However, we know that
nicotine causes stress on the heart, so the nicotinic receptor in the sympathetic nervous system must be dominant.
With this in mind, let us look at the two drugs added. The first is physostigmine (eserine). This acetylcholinesterase
inhibitor will cause increased levels of acetylcholine in both nicotinic and muscarinic receptors. This will give us
the nicotine "high" that we want. Yet wc do not want to stimulate all the muscarinic receptors, so we add
scopolamine. This acts to block all muscarinic receptors. This is what we want. We get the familiar feeling caused
by nicotine and have blocked all muscarinic receptors. We are not done, though. We are still left to deal with the
cardiovascular stress. The physostigmine will increase acetylcholine (ACh) levels at the first synapse in the
sympathetic nervous system. But in the parasympathetic system, it increases ACh levels at both the nicotinic and
the muscarinic receptors (remember that scopolamine does not work directly upon heart tissue). Therefore, we have
two stimulations in the parasympathetic system while we only have one in the sympathetic system. Therefore, we
are left with a net nicotinic stimulation with a parasympathetic excitation. The correct choice is C.
I'm really not getting this question and the answer
