2fitb Flashcards
3 parts of hindbrain
pons, cerebellum, medulla oblongata
4 main sections of cerebral cortex
the frontal lobe, the
parietal lobe, the occipital lobe, and the temporal lobe.
Overall the nervous system is __
a vast biological computing
device formed by a network of gray matter regions
interconnected by white matter tracts.
Somatic nerves in the __
region are related to __; those in
the __ region serve the __; and those in the
__ regions interact with the __
Somatic nerves in the cervical
region are related to the neck and arms; those in
the thoracic region serve the chest; and those in the
lumbar and sacral regions interact with the legs
In the __, the glia
that make the __ are called __, and in the
__, they are known as __.
In the brain, the glia
that make the sheath are called oligodendrocytes, and in the
peripheral nervous system, they are known as Schwann cells.
Nerve impulses involve __. The flow of
ions creates __.
The ability of a neuron to generate an
electrical impulse depends on __
Nerve impulses involve the opening and
closing of ion channels. The flow of
ions creates an electrical current that produces
tiny voltage changes across the neuron’s cell
membrane.
The ability of a neuron to generate an
electrical impulse depends on a difference in
charge between the inside and outside of the
cell.
When a nerve impulse begins, __ occurs on the
cell’s membrane, as the neuron switches from __.
The change, called __, then __. In this way, a neuron
may be able to __.
When these voltage changes reach
the end of an axon, they trigger __
When a nerve impulse begins, a dramatic
reversal in the electrical potential occurs on the
cell’s membrane, as the neuron switches from an
internal negative charge to a positive charge state.
The change, called an action potential, then passes
along the axon’s membrane at speeds up to several
hundred miles per hour. In this way, a neuron
may be able to fire impulses multiple times every
second.
When these voltage changes reach
the end of an axon, they trigger the release
of neurotransmitters
When
the neurotransmitter is in place (in receptor), this interaction __ and __, such as (3)
When
the transmitter is in place, this interaction alters the target
cell’s membrane potential and triggers a response from the
target cell, such as the generation of an action potential, the
contraction of a muscle, the stimulation of enzyme activity,
or the inhibition of neurotransmitter release.
Much less is known about ACh in the
brain. Recent discoveries suggest that it may be
critical for __
normal attention, memory, and sleep.
ACh is synthesized in __.
When an action potential arrives at the nerve
terminal, __, and __. On __, this action __.
ACh is then broken down by the enzyme
__ and resynthesized in the
nerve terminal.
ACh is synthesized in axon terminals.
When an action potential arrives at the nerve
terminal, electrically charged calcium ions
rush in, and ACh is released into the synapse,
where it attaches to ACh receptors on the target
cells. On voluntary muscles, this action opens
sodium channels and causes muscles to contract.
ACh is then broken down by the enzyme
acetylcholinesterase and resynthesized in the
nerve terminal.
__ and __ act as
__ signals, activating, among others, __ (NMDA) receptors which, in developing animals,
have been implicated in activities ranging from __.
Glutamate and aspartate act as
excitatory signals, activating, among others, N-methyl-d-aspartate (NMDA) receptors which, in developing animals,
have been implicated in activities ranging from learning
and memory to development and specification of nerve
contacts.
In the brain, serotonin has been
identified as an important factor in __
sleep quality, mood,
depression, and anxiety.
Researchers also have identified
genes that code for receptors and are involved in the signaling
mechanisms of trophic factors. These findings are expected to
result in a greater understanding of how trophic factors work
in the brain. This information should also prove useful for
the
design of new therapies for brain disorders of development and
for degenerative diseases, including Alzheimer’s disease and
Parkinson’s disease.
6 classes of steroid hormones
androgens, estrogens, progestins, glucocorticoids,
mineralocorticoids, and vitamin D
The brain contains receptors for __ hormones and the six classes of
__ hormones, which are synthesized from __. The receptors are found
in __.
The brain contains receptors for thyroid hormones
(those produced by the thyroid) and the six classes of
steroid hormones, which are synthesized from cholesterol. The receptors are found
in selected populations of neurons in the brain and relevant
organs in the body.
__ and __ hormones bind to
__ that in turn __. This can result in __.
Thyroid and steroid hormones bind to
receptor proteins that in turn bind to DNA and regulate the
action of genes. This can result in long-lasting changes in
cellular structure and function.
The brain has receptors for many hormones; for
example, the __ hormones (4). These hormones are taken
up from __ and act to affect __.
The brain has receptors for many hormones; for
example, the metabolic hormones insulin, insulin-like
growth factor, ghrelin, and leptin. These hormones are taken
up from the blood and act to affect neuronal activity and
certain aspects of neuronal structure.
In response to stress and changes in our biological
clocks, such as day and night cycles and jet lag, hormones
__. In
the brain, hormones __ as well as
__. As a result, the circuitry of
the brain and its capacity for neurotransmission are changed
over a course of hours to days.
hormones
enter the blood and travel to the brain and other organs. In
the brain, hormones alter the production of gene products
that participate in synaptic neurotransmission as well as
affect the structure of brain cells.
Reproduction in females is a good example of a regular,
cyclic process driven by circulating hormones and involving
a feedback loop: The __ in the __ produce
__, a __ that
acts on cells in the __. In both males and females,
this causes two hormones — __ — to be __.
The neurons in the hypothalamus produce
gonadotropin-releasing hormone (GnRH), a peptide that
acts on cells in the pituitary. In both males and females,
this causes two hormones — the follicle-stimulating hormone
(FSH) and the luteinizing hormone (LH) — to be released
into the bloodstream.
The endocrine system works in large part by acting on
__, which controls __. __. This is referred to as __.
The endocrine system works in large part by acting on
neurons in the brain, which controls the pituitary gland. The
pituitary gland secretes factors into the blood that act on
the endocrine glands to either increase or decrease hormone
production. This is referred to as a feedback loop.
Sexual differentiation of the brain is caused by sex
hormones acting in fetal and early postnatal life, although
recent evidence suggests __. Scientists
have found statistically and biologically significant
differences between the brains of men and women that are
similar to sex differences found in experimental animals.
These include differences in __ and__.
Sexual differentiation of the brain is caused by sex
hormones acting in fetal and early postnatal life, although
recent evidence suggests genes on either the X or Y
chromosome may also contribute to this process. Scientists
have found statistically and biologically significant
differences between the brains of men and women that are
similar to sex differences found in experimental animals.
These include differences in the size and shape of brain
structures in the hypothalamus and the arrangement of
neurons in the cortex and hippocampus.
Scientists have identified a new class of neurotransmitters
that are gases. These molecules — __ — do not act like other neurotransmitters. Being
gases, they are not __. Instead,
they are __.
Scientists have identified a new class of neurotransmitters
that are gases. These molecules — nitric oxide and carbon
monoxide — do not act like other neurotransmitters. Being
gases, they are not stored in any structure, certainly not in
storage structures for classical and peptide transmitters. Instead,
they are made by enzymes as they are needed and released
from neurons by diffusion.
Rather than __,
these gas neurotransmiters simply __.
Rather than acting at receptor sites,
these gases simply diffuse into adjacent neurons and act upon
chemical targets, which may be enzymes.Rather than acting at receptor sites,
these gases simply diffuse into adjacent neurons and act upon
chemical targets, which may be enzymes.
several diseases that most scientists
once thought were purely disorders of adult function,
such as __, are now being considered in
developmental terms; that is, such disorders may occur
because __
several diseases that most scientists
once thought were purely disorders of adult function,
such as schizophrenia, are now being considered in
developmental terms; that is, such disorders may occur
because pathways and connections to the brain did
not form correctly early in life.
by applying knowledge about __, __ is now viewed as a future possibility
by applying knowledge about how connections
form during development, regeneration following injury
to the brain is now viewed as a future possibility
common associated symptoms of ASD?
include intellectual
disabilities, seizures, and gastrointestinal problems.
Based mainly on __, ASDs are thought to
be __; already, more than __ genes have been
linked to increased risk for autism. ASD is typically diagnosed based on
behavioral symptoms detected in children about __ years
of age.
Based mainly on twin studies, ASDs are thought to
be highly genetic; already, more than 100 genes have been
linked to increased risk for autism; three
__ can detect differences in children between __
and __ years old, a time when many affected children exhibit
__.
very sensitive measures of social engagement and interaction; 1, 2; abnormal, accelerated growth of the brain
In
addition, recent evidence indicates that some forms of autism
may be due to __, either __
In
addition, recent evidence indicates that some forms of autism
may be due to dysregulation of the immune system, either in
the mother or the child.
Brain alterations in autism are subtle; there is no obvious
change such as in Down syndrome or Alzheimer’s disease.
There is speculation that abnormal development of certain
regions of the brain involved in __ leads to __
There is speculation that abnormal development of certain
regions of the brain involved in language, cognition, and
social communication leads to abnormal connections with
other parts of the brain
Although no cure exists and no drugs for the major
symptoms of autism have been developed, many affected
children respond very well to __, with earlier interventions leading
to better outcomes.
specialized behavioral therapies
based on learning theory
ADHD is characterized by
excessively inattentive, hyperactive, or impulsive behaviors
Neuroscientists have found that
almost all abused drugs produce pleasure by
activating a specific network of neurons called the brain reward system.
The circuit is normally involved in an important type of
learning that helps us stay alive. It evolved to mediate the
pleasurable and motivating effects of natural rewards, such as
eating when we are hungry or drinking when we are thirsty.
Indeed, when a reward produces feelings of pleasure, we
learn to repeat the actions that got us the reward in the first
place. Drugs can activate this same system, thus promoting
continued drug use.
In
addition to the brain reward system, brain regions that
are changed by drugs include those involved in __. These latter brain systems are
important in __.
In
addition to the brain reward system, brain regions that
are changed by drugs include those involved in executive
functions and judgment. These latter brain systems are
important in inhibiting behavior and in decision-making.
__
are standard responses of the brain and body to drugs.
Tolerance and dependence
are standard responses of the brain and body to drugs.
(4) are
equally effective in treating the more than __
people addicted to nicotine.
Nicotine
gum, the transdermal patch, nasal spray, and inhalers are
equally effective in treating the more than one million
people addicted to nicotine.
In addition, animal research has shown that alcohol
works by __
activating the endogenous opioid system. This
means that susceptible individuals may feel an opioid-like
euphoria from their own endorphins when they drink.
Opiates create effects like those elicited by the naturally
occurring opioid peptides. They __ —
important medical uses.
relieve pain, depress
breathing, cause nausea and vomiting, and stop diarrhea
opiate addiction medication
methadone, naloxone, naltrexone, buprenorphine
methadone
helps opiate addicts rehabilitate themselves by preventing
withdrawal symptoms that can motivate continued drug
use.
naloxone
available medications
that act as antagonists at opioid receptors; that is, they can
curb the allure of opiates by blocking the opiate receptors
so that opiates produce no pleasurable effects when they are taken. The blockers alone are sometimes useful for addicts
who are highly motivated to quit.
naltrexone
available medications
that act as antagonists at opioid receptors; that is, they can
curb the allure of opiates by blocking the opiate receptors
so that opiates produce no pleasurable effects when they are taken. The blockers alone are sometimes useful for addicts
who are highly motivated to quit. In addition, scientists are
developing a long-lasting version of naltrexone that needs to
be taken only once a month.
buprenorphine
Another medication used to treat heroin addiction,
buprenorphine, causes a weaker effect on the receptors than
methadone and creates only a limited high, which deters an
addict from abusing the medication itself.
__ users often go on binges, consuming a large
amount of the drug in just a few days. A __ occurs
after this period of intense drug-taking, resulting in such
symptoms as __. These symptoms may come from __. __ are in clinical trials.
Cocaine users often go on binges, consuming a large
amount of the drug in just a few days. A crash occurs
after this period of intense drug-taking, resulting in such
symptoms as emotional and physical exhaustion and
depression. These symptoms may come from an actual
shutdown, or crash, in dopamine and serotonin function, as
well as an increased response of the brain systems that react
to stress. Vaccines to produce antibodies to cocaine in the
bloodstream are in clinical trials.
Alzheimer’s patients usually die from
pneumonia or some other complication of
immobility
In the earliest stages, the clinical diagnosis of
possible or probable Alzheimer’s can be made with greater
than __ percent accuracy. As the course of the disease
progresses, the accuracy of diagnosis at Alzheimer’s research
centers exceeds __ percent. final confirmation of the
diagnosis requires __
80; 90; final confirmation of the
diagnosis requires examination of brain tissue, usually
obtained at autopsy.
what causes the clinical symptoms of Alzheimer’s?
damage to neural systems that transmit acetylcholine, somatostatin, monoamines, and glutamate; these systems are critical for attention, memory, learning, higher cognitive abilities
Microscopic examination of brain tissue from people
who died from Alzheimer’s shows (2) and where?
amyloid plaques and tau tangles (also called fibrillary tanges); in brain regions important for
memory and intellectual functions
how do genes cause Alzheimer’s?
Genes that cause dominant Alzheimer’s
appear to do so by causing beta amyloid plaques to
accumulate.
Experimental therapies in models of other
neurodegenerative diseases — __,
for example — have been effective in mice with the disease
but not in humans.
amyotrophic lateral sclerosis
Over the past several decades, scientists have shown
that in primate models of Parkinson’s,
there are specific
regions in the basal ganglia, the group of cellular structures
deep in the brain, that are abnormally overactive. Most
important, they found that surgical deactivation or
destruction of these overactive structures — the pallidum
and subthalamic nucleus — can greatly reduce symptoms of
Parkinson’s disease (pallidotomy)
what does MPTP stand for
(1-methyl-4-phenyl-1, 2, 3, 6
tetrahydropyridine
2 phobias mentioned
- acrophobia, fear of heights
- agoraphobia, fear of open spaces
anxiety disorders include
OCD; panic disorder; phobias;
social anxiety disorder; generalized anxiety disorder; PTSD
New therapies for brain tumors are being developed
in clinical trials. Many of these trials focus on
targeted
therapy — treatment aimed at the biologic characteristics
of tumors.
brain tumor targeted therapies (6)
- vaccines
- monoclonal antibodies
- anti-angiogenic therapy
- immunotherapy
- gene therapy
- target delivery of substances
Researchers are exploring the role of __ in the
origin of brain tumors
stem cells
MS: While many medications and therapies
are available to control symptoms such as __, no treatments
are available for __.
While many medications and therapies
are available to control symptoms such as muscle stiffness
(spasticity), pain, fatigue, and mood swings, as well as
bladder, bowel, or sexual dysfunction, no treatments
are available for the nerve degeneration that causes the
progression of the disease.
how long have steroids been used to treat MS?
3 decades
MS: Because the (3) are
commonly affected, symptoms such as (3) often occur.
Because the spinal cord, cerebellum, and optic nerve are
commonly affected, symptoms such as numbness, clumsiness,
and blurred vision often occur.
However MS can affect many
other brain areas, including __ and __, so
symptoms may also include __.
However MS can affect many
other brain areas, including bundles of myelinated nerve fibers
(white matter) and areas rich in neurons (gray matter), so
symptoms may also include slurred speech, weakness, loss of
coordination, pain, uncontrollable tremors, loss of bladder
control, memory loss and other cognitive problems, depression,
and fatigue.
HIV: In developing
countries, however, only about __ percent of the people
who need therapy are receiving such treatment.
36
HAND also affects those __,
though __.
HAND also affects those receiving the
modern combination antiretroviral treatment (CART),
though not to the same degree.
Each year, about
__ new __ injuries are reported, caused mostly by __.
Each year, about
12,000 new spinal cord injuries are reported, caused mostly by motor
vehicle accidents, sports injuries, violence, and falls.
The leading causes
of traumatic brain injury are
falls and motor-vehicle related
events.
No magic bullet has yet been found, but doctors have
discovered methods to stave off severe neurological damage
caused by head and spinal cord injuries and to improve
neurological function. This is accomplished by
working to
prevent secondary pathogenesis, or damage that occurs after
the initial insult; support regeneration and repair; and refine
and optimize rehabilitation techniques.
In general, patients who arrive
in the emergency room and are diagnosed with a severe
head injury are
monitored for pressure on the brain from
bleeding or swelling.
A recent pilot clinical trial for
patients with moderate to severe closed-head injury found
that __. Those in the
moderately injured group had __.
A recent pilot clinical trial for
patients with moderate to severe closed-head injury found
that the hormone progesterone cut the number of deaths
in severely injured patients by 50 percent. Those in the
moderately injured group had improved functional recovery
30 days after injury.
Often moderate pain
is treated by combining
a mild opioid, such as codeine,
with aspirin or an NSAID.
how do NSAIDs work?
NSAIDs work by inhibiting the cyclo-oxygenase
(COX) enzymes that make the inflammatory and painproducing
chemical prostaglandin.
b/c NSAIDs are __, they also are effective for treating
injuries or conditions such as __
b/c NSAIDs are anti-inflammatory, they also are effective for treating
injuries or conditions such as arthritis and postoperative
pain.
4 types of neuropathic pain
- diabetic neuropathy
- neuralgia
- phantom limb pain
- post-stroke pain
For some neuropathic pain
conditions in which a light touch
to the skin can produce severe pain,
topical lidocaine may be effective.
The finding that \_\_ receptors are concentrated in the \_\_ led to the use of injections of \_\_ into \_\_, without causing \_\_
The finding that opioid receptors are concentrated in the spinal cord led to the use of injections of morphine and other opioids into the cerebrospinal fluid in which the spinal cord is bathed, without causing paralysis, numbness, or other severe side effects.
Because
adverse side effects of drugs arise from __ — for
example, __ — new analgesics that target only
the __ may have fewer side effects.
Because
adverse side effects of drugs arise from the widespread
location of the molecules targeted by analgesics — for
example, constipation results from morphine’s action on
opioid receptors in the gut — new analgesics that target only
the nociceptor may have fewer side effects.
Among the many
nociceptor targets are __— one
of which is activated by __, the pungent ingredient
in hot peppers, and another by __ — as well as a
variety of __ and __
Among the many
nociceptor targets are specialized receptor channels — one
of which is activated by capsaicin, the pungent ingredient
in hot peppers, and another by mustard oil — as well as a
variety of acid-sensing sodium and calcium ion channels.
idiopathic
arising
from an uncertain cause
Seizures occur because of
sudden, disorderly discharges
of interconnected neurons in the brain that temporarily
alter one or more brain functions.
epilepsy types
idiopathic and symptomatic,
generalized and partial
Many antiepileptic drugs are available. Their principal
targets are
either ion channels or neurotransmitter receptors.
