INTEGRATIVE SYSTEM 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
sets the level of a variable
(temperature, blood pressure, muscle force, and
so on) that is being controlled
The control system
The nervous and endocrine systems are also often
described as control systems because ____
nerve cells
and endocrine cells control how other cells
function.
a cell that is specially adapted to
generate an electrical signal
neuron
an electrical signal—most often in the form of a brief, self-propagating impulse that travels from place to place in
the cell.
action potential
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
Signals of the neurons in nervous systems—
____—the signals produced by
the endocrine system are broadly distributed
throughout the animal’s body
precisely targeted
Endocrine cells release hormones into the
____ (or sometimes just into other
extracellular fluids)
blood
Endocrine control has two essential features:
slow and broadcast
neurons, muscle fibers, and a few others can generate electrical signals are known as
Excitable cells
action potentials which neurons may
also be called?
nerve impulses
one of the most important kinds of electrical
signals underlying the integrative activity
of nervous systems
Action potentials/
nerve impulses
Action potentials result from ____ changes in membrane
permeabilities to ions because the ion
channels that produce action potentials are
voltage-gated—that is, their opening depends
on the membrane potential
voltage dependent
An action potential is initiated by a change in
the resting membrane potential, specifically
by a ____ sufficiently strong to open
the voltage-gated channels
depolarization
An action potential results from intense,
localized ____—increases that are both
voltage- and time-dependent.
increases in permeabilities to
specific ions
Action potentials are propagated along the axons of neurones via
local currents
Local currents induce depolarisation of the
____.
Where this reaches a threshold, further action
potentials are generated
adjacent axonal membrane
The areas of the membrane that have recently
depolarised will not depolarise again due to the
____ – meaning that the action
potential will only travel in one direction.
refractory period
These local currents would eventually
decrease in charge until a threshold is ____
no
longer reached
distance that it would take depends
on the membrane are?
membrane capacitance and
membrane resistance
ability to store charge. The lower capacitance results in a ____ is no longer reached
Membrane Capacitance
greater distance before the threshold
_the number of ion channels open.
The lower the number of channels open, the ____ membrane resistance is.
A higher membrane resistance results in a ____ before
the threshold is no longer reached.
Membrane Resistance
greater
greater distance
The nervous system controls predominantly the ________, the endocrine system typically controls more ____ activities such as metabolic changes.
fine,
rapid movements of discrete muscles
widespread,
prolonged
specialized site of contact of a
neuron with another neuron
Synapse
Neurons (except in the special case of
those having electrical synapses) are
discontinuous with each other; even at
synapses, they 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
The effect is rapid and transient, and it
can be ____
* This ____is the simplest kind of
synaptic action
excitatory or inhibitory.
transmission of a signal across
the synapse
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 the
postsynaptic cell
Synaptic actions
can result from a permeability increase or a
permeability decrease
synaptic potential
electric currents from one cell flow directly into the next cell,
changing its membrane potential
Electrical Synapse
Because of their instantaneous transmission of signals and their
synchronizing ability, 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
a specialized locus where protein
channels bridge the gap between two
cells, directly connecting their cytoplasm
Gap Junction
Gap junctions provide a ____
path for current flow, electrically coupling
the cells that they join.
Thus any electrical change in one cell is
recorded in the other, with some
weakening but with negligible delay
low-resistance
chemical synapses have a discontinuity between the cells
because the ____________ of a chemical synapse is
a barrier to direct electrical communication
20- to 30-nm synaptic cleft
first transduced into a
chemical signal: the release of neurotransmitter molecules from
the presynaptic terminals
presynaptic electrical signal
molecules of neurotransmitter rapidly diffuse to the
____, where they bind to receptor molecules
that are specialized to generate an electrical or chemical change
in response to the neurotransmitter binding
postsynaptic membrane
Ways of How Neurotransmitter Works
produce fast changes in membrane
potential (depolarization or hyperpolarization) by directly increasing permeability to ions
Ionotropic receptors
Ways of How Neurotransmitter Works
have relatively slow, long-lasting modulatory effects on synaptic processes; trigger a signaling cascade of second messengers in the postsynaptic cell
Metabotropic receptors
Synaptic Potentials Control Neuronal
Excitability
an increase in the probability that a cell will
generate an impulse (an action potential), or if the cell is already generating impulses, ____ causes an increase in the impulse frequency.
excitation
Synaptic Potentials Control Neuronal
Excitability
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 (also known as nerve cells) and target cells throughout the body.
* These target cells may be in glands, muscles, or other
neurons
Neurotransmitters
Neurotransmitter like dopamine and
glutamate, typically act directly on neighboring cells
Small-molecule transmitters
Neurotransmitter, small molecules like insulin and
oxytocin, work more subtly, modulating, or adjusting, how cells communicate at the synapse
neuropeptides
4 Criteria Neurotransmitter
- Presence of the chemical within the cell.
- Stimulus-dependent release
- Action on the postsynaptic cell
- A mechanism for removal.
Classification of
Neurotransmitter
Excitatory Neurotransmitter
Inhibitory Neurotransmitter
Modulatory Neurotransmitters
they increase the likelihood that the neuron will fire an action potential.
Excitatory Neurotransmitters
examples of Excitatory Neurotransmitters
epinephrine and
norepinephrine
they decrease the likelihood that the neuron will fire an action potential
Inhibitory Neurotransmitters
examples of Inhibitory Neurotransmitters
serotonin and gamma-aminobutyric acid (GABA)
- often referred to as neuromodulators, are capable of affecting a larger number of neurons at the same time
- also influence the effects of other chemical messengers.
- diffuse across a larger area and are more slow-acting
Modulatory Neurotransmitters
examples of Modulatory Neurotransmitters
acetylcholine, dopamine, serotonin, histamine, and
cannabinoids.
6 categories of NT
amino acids
peptides
monoamines
purines
gasotransmitter
acetylcholine
types of amino acids
GABA
glutamate
types of peptides
oxytocin
endorphins
types of monoamines
epinephrine
norepinephrine
histamine
dopamine
serotonin
type of purines
adenosine
types of gasotransmitter
nitric oxide
carbon monoxide
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
which are used to help treat anxiety, function by increasing the efficiency of GABA neurotransmitters, which can increase feelings of relaxation and calm
Benzodiazepines
- most plentiful neurotransmitter found in the nervous system
glutamate
plays a role in cognitive
functions such as memory and learning
glutamate
Excessive amounts of glutamate can cause ____
resulting in cellular death
excitotoxicity
diseases associated with glutamate build-up
Alzheimer’s disease
stroke
and
epileptic seizures
powerful hormone acts as a neurotransmitter in the brain
Oxytocin
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
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
Also known as adrenaline
Epinephrine
is considered both a hormone and a neurotransmitter (functions as NT in the brain)
Epinephrine
a stress hormone that is released
by the adrenal system
epinephrine
plays an important role in alertness and is involved in the body’s fight-or-flight response
Norepinephrine
to help mobilize the body and brain to take action in times of
danger or stress.
norepinephrine
norepinephrine levels of this neurotransmitter are typically ____ during sleep and ____ during times of stress
lowest
highest
organic compound acts as a
neurotransmitter in the brain and spinal
Histamine
plays a role in allergic reactions and is produced as part of
the immune system’s response to pathogens.
histamine
aka feel-good neurotransmitter, involved in reward, motivation, and addictions
Dopamine
Several types of addictive drugs increase dopamine levels in the
brain.
This chemical messenger also plays an important role in the
coordination of body movements.
dopamine
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
- hormone and neurotransmitter
- plays an important role in regulating and modulating mood, sleep, anxiety, sexuality, and appetite.
serotonin
a type of antidepressant medication commonly prescribed to treat depression, anxiety, panic disorder, and panic attacks
Selective serotonin reuptake inhibitors (SSRIs)
SSRIs work to balance serotonin levels by ____ the reuptake of serotonin in the brain, which can help improve mood and reduce feelings of anxiety.
blocking
acts as a neuromodulator in the brain and is involved in suppressing arousing and improving sleep
adenosine
acts as a neurotransmitter in the central and peripheral nervous systems (CNS and PNS). It plays a role in autonomic control, sensory transduction, and communication with glial cells.
ATP
ATP associated neurological problems
pain, trauma, and neurodegenerative disorders
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
colorless, odorless gas can have toxic and potentially fatal effects when people are exposed to high levels of the substance. However, it is also produced naturally by the body where it acts as a neurotransmitter that helps modulate the body’s inflammatory response
carbon monoxide
Found in both the central and peripheral nervous systems, it is the primary neurotransmitter associated with motor neurons, as well as memory and learning
acetylcholine
Problems of Neurotransmitters
- Neurons might not manufacture enough of a particular
neurotransmitter - Neurotransmitters may be reabsorbed too quickly
- Too many neurotransmitters may be deactivated by
enzymes - Too much of a particular neurotransmitter may be released
5 important NT
dopamine
oxytocin
norepinephrine
endorphins
serotonin
a chemical substance produced and released by
nonneural endocrine cells or by neurons
hormone
hormone exerts regulatory influences on the function of other, distant cells reached via the blood; and it is effective at _____
very low concentrations
Hormones released by neurons
neurohormones
neurons and hormones
neuroendocrine or
neurosecretory cells
Secretory cells may be organized into discrete organs
endocrine glands
Classification of Hormones
steroid hormones
peptide and protein hormones
amine hormones
hormones that are synthesized from cholesterol
with examples
steroid hormones
steroids, cortisol, aldosterone
are structured from chains of amino
acids
with examples
Peptide and protein hormones
antidiuretic hormone (ADH), atrial-natriuretic peptide, FSH,
insulin and growth hormone
modified amino acids; synthesized
from tryptophan or tyrosine
with examples
amine hormones
Melatonin, thyroid, catecholamines
– epinephrine, norepinephrine, and dopamine
Types of Endocrine Cells
Epithelial endocrine cells -> hormone
Neurosecretory cells -> neurohormones
The hypothalamus–posterior pituitary connection illustrates one form of control of endocrine function: neural control of neurosecretory cells
stores and releases hormones (oxytocin, ADH) produced by hypothalamus
neurohypophysis
In mammalian hypothalamus, the ____, produce oxytocin and
vasopressin and are released into the blood in the
pars nervosa
neurohypophysis
paraventricular
nuclei and supraoptic nuclei
Anterior pituitary hormones
secretes hormone (ACTH, prolactin, somatotropin) independently
adenohypophysis
adenohypophysis are categorized into two main
groups according to their target tissues
1st group: principal effects on nonendocrine
tissues
2nd group: hormones that control other
endocrine glands
adenohypophysis first group example
Growth hormone (GH), prolactin, and melanocyte-stimulating hormone (MS)
adenohypophysis second group example
Thyroid-stimulating hormone (TSH)/
thyrotropin
The ____ is a neurohemal organ in which the axons of several populations of hypothalamic neurosecretory cells terminate. These cells produce neurohormones that control the secretions
of specific groups of anterior pituitary cells.
Hypothalamo–hypophysial portal
system.
median eminence
Some hypothalamic neurohormones stimulate secretion of hormones and are called
Hypothalamo–hypophysial portal
system.
releasing hormones (RHs).
inhibit secretion of anterior pituitary hormones
Hypothalamo–hypophysial portal
system.
inhibiting hormones (IHs),
as providing an interface between the brain and much of the endocrine system.
Hypothalamo–hypophysial portal system
The posterior pituitary is an ____ of the brain.
The anterior pituitary—although not part of the brain—is under
the ____ of the brain and regulates the functions of many
other tissues, including several endocrine glands
extension
control
“Neural control of the endocrine system
____, but endocrine control
of the nervous system is also _____”
“Neural control of the endocrine system
deserves emphasis, but endocrine control
of the nervous system is also important”
