Integrative system (Part 1) Flashcards
refers to processes—such a
summation and coordination— that produce coherency and result in harmonious function.
Integration
refers to the selective combination and processing
of sensory, endocrine, and central nervous system (CNS) information in ways that promote the harmonious functioning of the whole.
Whole-animal integration
The ___ sets the level of a variable (temperature, blood pressure, muscle force, and so on) that is being controlled.
control system
____is a cell that is specially adapted to generate an electrical signal—most often in the form of a brief, self-propagating impulse called an ____—that travels from place to place in the cell.
neuron; action potential
A neuron receives input—signals from other neurons or sensory cells—at specialized cell–cell contact points called ___
synapses.
____ – nucleus and metabolic center of the cell
Cell body
____ – fibers that extend from the cell body (dendrites and axons)
Processes
___ – relay sensory signals to integrative centers of the CNS
Afferent Neuron
____ – relay control signals (instructions) from the CNS to target cells that are under nervous control, such as muscle cells or secretory cells
Efferent Neuron
release hormones into the blood
Endocrine cells
Endocrine control has two essential features:
slow; broadcast.
______ such as neurons, muscle fibers, and a few others can generate electrical signals.
Excitable cells
are one of the most important kinds of electrical signals underlying the integrative activity of nervous systems.
Action potentials
_____result from voltage-dependent changes in membrane
permeabilities to ions
Action potentials
An ____ is initiated by a change in the resting membrane potential, specifically by a ____ sufficiently strong to open the voltage-gated channels.
action potential; depolarization
results from intense, localized increases in permeabilities to specific ions
action potential
Action potentials are propagated along the axons of neurones via ___
local currents
____ induce depolarisation of the adjacent axonal membrane.
Local currents
areas of the membrane that have recently depolarised will not depolarise again due to the ____
refractory period
The ability to store charge
Membrane Capacitance
The lower capacitance results in a ___ before the threshold is no longer reached.
greater distance
This depends on the number of ion channels open.
Membrane Resistance
The ___ the number of channels open, the ___ membrane resistance is
lower; greater
The ___ controls predominantly the fine, rapid movements of discrete muscles, the ____ typically controls more widespread, prolonged activities such as metabolic changes.
nervous system; endocrine system
is a specialized site of contact of a neuron with another neuron.
Synapse
Neurons are typically separated by a ___ (nm) space called the ___
20- to 30-nanometer; synaptic cleft.
a presynaptic signal—usually an action potential— affects a postsynaptic cell.
Synaptic transmission
Refers to the ability to change the functional properties of synapses.
Synapse Transmission
can change the synapse itself to make it stronger or weaker, and they can also produce long-lasting changes
in postsynaptic cell
Synaptic actions
A___can work chemically or electrically.
synapse
can act immediately and directly on the membrane potential of the postsynaptic cell, or they can have indirect and longer-lasting effects
Synapses
electric currents from one cell flow directly into the next cell, changing its membrane potential
Electrical Synapse
electrical synapses are found in ____ where speed is most important, and where synchronous activity of several cells is an advantage
nervous systems
The major structural specialization for electrical transmission is the
gap junction
is a specialized locus where protein channels bridge the gap between two cells, directly connecting their cytoplasm.
Gap Junction
provide a low-resistance path for current flow, electrically coupling the cells that they join.
Gap junctions
These receptors produce fast changes in membrane potential (depolarization or hyperpolarization) by directly increasing permeability to ions
Ionotropic receptors
These receptors have relatively slow, long-lasting modulatory effects on synaptic processes
Metabotropic receptors
These receptors trigger a signaling cascade of second messengers in the postsynaptic cell
Metabotropic receptors
is an increase in the probability that a cell will generate an impulse
Excitation
____causes an increase in the impulse frequency.
Excitation
is a decrease in the probability of impulse generation or a decrease in impulse frequency.
Inhibition
are chemical messengers that carry, boost, and balance signals between neurons
Neurotransmitters
Small-molecule transmitters, like ___ and _____, typically act directly on neighboring cells.
dopamine; glutamate
The _____, small molecules like ___ and ___, work more subtly, modulating, or adjusting, how cells communicate at the synapse
neuropeptides; insulin, oxytocin
Criteria Neurotransmitter (4)
-Presence of the chemical within cell
-Stimulus-dependent release
-Action on the postsynaptic cell
-mechanism for removal
The chemical must be released by the ___, and the ____ must contain receptors that the chemical will bind to
presynaptic neuron; postsynaptic neuron
Classification of Neurotransmitter (3)
-Excitatory Neurotransmitters
-Inhibitory Neurotransmitters
-Modulatory Neurotransmitters
These types of neurotransmitters increase the likelihood that the neuron will fire an action potential.
Excitatory Neurotransmitters
major excitatory neurotransmitters include ___ and ___
epinephrine; norepinephrine
These types of neurotransmitters decrease the likelihood that the neuron will fire an action potential
Inhibitory Neurotransmitters
major inhibitory neurotransmitters include ___ and ___
serotonin; gammaaminobutyric acid (GABA)
these types of neurotransmitters are capable of affecting a larger number of neurons at the same time
Modulatory Neurotransmitters/ neuromodulators
these types of neurotransmitters influence the effects of other chemical messengers
Modulatory Neurotransmitters
These types of neurotransmitters diffuse across a larger area and are more slow-acting.
Modulatory Neurotransmitters/ Neuromodulators
Neurotransmitters that act as neuromodulators include (5)
acetylcholine, dopamine, serotonin, histamine,cannabinoids
Categories of Neurotransmitter (6)
-Amino Acids
-Peptides
-Monoamines
-Purines
-Gasotransmitter
-Acetylcholine
Categories of neurotransmitters: amino acids (2)
Gamma-aminobutyric acid (GABA)
Glutamate
This naturally occurring amino acid acts as the body’s main inhibitory chemical messenger.
Gamma-aminobutyric acid (GABA)
contributes to vision and motor control, also playing a role in the regulation of anxiety.
GABA
are used to help treat anxiety, function by increasing the efficiency of GABA neurotransmitters, which can increase feelings of relaxation and calm.
Benzodiazepines
The most plentiful neurotransmitter found in the nervous system; plays a role in cognitive functions such as memory and learning.
Glutamate
Excessive amounts of glutamate can cause ___ resulting in cellular death.
excitotoxicity
This excitotoxicity caused by glutamate build-up is associated with some diseases and brain injuries including ___ , ___, and ___
Alzheimer’s disease, stroke, epileptic seizures
Categories of neurotransmitters: Peptides (2)
Oxytocin
Endorphins
This powerful hormone acts as a neurotransmitter in the brain.
Oxytocin
It is produced by the hypothalamus and plays a role in social recognition, bonding, and sexual reproduction
Oxytocin
Synthetic oxytocin such as ___ is often used as an aid in labor and delivery.
Pitocin
Both ___ cause the uterus to contract during labor
oxytocin and Pitocin
These neurotransmitters inhibit the transmission of pain signals and promote feelings of euphoria.
Endorphins
These chemical messengers are produced naturally by the body in response to pain, but they can also be triggered by other activities such as aerobic exercise.
Endorphins
Categories of neurotransmitters: Monoamines (5)
-Epinephrine
-Norepinephrine
-Histamine
-Dopamine
-Serotonin
Also known as adrenaline, it is considered both a hormone and a neurotransmitter.
Epinephrine
Generally, ____ is a stress hormone that is released by the adrenal system; However, it functions as a neurotransmitter in the brain.
epinephrine
This naturally occurring chemical is a neurotransmitter that plays an important role in alertness and is involved in the body’s fight-or-flight response.
Norepinephrine
Its role is to help mobilize the body and brain to take action in times of danger or stress
Norepinephrine
Levels of this neurotransmitter are typically lowest during sleep and highest during times of stress.
Norepinephrine
This organic compound acts as a neurotransmitter in the brain and spinal.
Histamine
It plays a role in allergic reactions and is produced as part of the immune system’s response to pathogens.
Histamine
Commonly known as the feel-good neurotransmitter; involved in reward, motivation, and additions.
Dopamine
This chemical messenger also plays an important role in the coordination of body movements.
Dopamine
is a degenerative disease that results in tremors and motor movement impairments, is caused by the loss of dopamine-generating neurons in the brain.
Parkinson’s disease
A hormone and neurotransmitter, ____ plays an important role in regulating and modulating mood, sleep, anxiety, sexuality, and appetite
serotonin
are a type of antidepressant medication commonly prescribed to treat depression, anxiety, panic disorder, and panic attacks.
Selective serotonin reuptake inhibitors (SSRIs)
__ work to balance serotonin levels by blocking the reuptake of serotonin in the brain, which can help improve mood and reduce feelings of anxiety.
SSRIs
Categories of neurotransmitters: Purines (2)
Adenosine
Adenosine triphosphate (ATP)
This naturally occurring chemical acts as a neuromodulator in the brain and is involved in suppressing arousing and improving sleep.
Adenosine
Considered to be the energy currency of life, ___ acts as a neurotransmitter in the central and peripheral nervous systems
ATP
plays a role in autonomic control, sensory transduction, and communication with glial cells.
Adenosine triphosphate (ATP)
Research suggests it may also have a part in some neurological problems including pain, trauma, and neurodegenerative disorders.
Adenosine triphosphate (ATP)
Categories of neurotransmitters: Gasotransmitter (2)
Nitric oxide
Carbon monoxide
This compound plays a role in affecting smooth muscles, relaxing them to allow blood vessels to dilate and increase blood flow to certain areas of the body.
Nitric oxide
This colorless, odorless gas can have toxic and potentially fatal effects when people are exposed to high levels of the substance
Carbon monoxide
it is also produced naturally by the body where it acts as a neurotransmitter that helps modulate the body’s inflammatory response
Carbon monoxide
This is the only neurotransmitter in its class. Found in both the central and peripheral nervous systems, it is the primary neurotransmitter associated with motor neurons.
Acetylcholine
It plays a role in muscle movements as well as memory and learning
Acetylcholine
