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.