Dendrite
... to merely convey stimulation passively, without
action potentials and without activation of ... excitatory synaptic stimulation whether or not an
action potential is present. This propagation is ... such dendrites.
Scientists have shown that
action potentials do propagate back into the dendrites ...
Electrophysiology
... used to study cell excitability by analyzing the
action potentials produced by a cell.
The most common ... medium and field-potentials contributed by the
action potentials of many neurons are recorded. Some ... recordings allow the detection and measurement of
action potentials in excitable cells such as neurons and ...
Insulin
... on cellular and metabolic level
4 Regulatory
action on blood glucose
5 Signal transduction
... that is later transformed by proteolytic
action into the active hormone.
The remaining part is ... excrete it into the blood. This is the clinical
action of insulin which is useful in reducing high blood ...
Neuron
... of signalling
5 Adaptations to carrying
action potentials
6 Histology and internal ... will spread to the axon hillock generating an
action potential which then travels as a wave of electrical excitation along the axon. Arrival of an
action potential at the tip of an axon triggers the ...
Neurotransmitter
... 1 Types of neurotransmitters
2 Mechanism of
action
3 Post-synaptic effect
4 Specific ... the neurotransmitter's effect.
Mechanism of
action
Within the cells , small-molecule ... molecules are packaged in vesicles . When an
action potential travels to the synapse, the rapid ...
Synapse
... triggered by the arrival of a nerve impulse (or
action potential ) and occurs through an unusually rapid ... and ready at the synaptic membrane. The arriving
action potential produces an influx of calcium ions ... the simple coincidence sensory stimuli and
action potentials in the synaptically linked cells.
...
Andrew Huxley
... Medicine for his work with Alan Lloyd Hodgkin on the basis of nerve "
action potentials ," the electrical impulses that enable the activity of an ... later.
The experimental measurements on which the pair based their
action potential theory represent one of the earliest applications of a technique ...
Brain
... The neurons carry information in the form of electrical pulses known as
action potentials . They communicate with other neurons in the brain and ... in bioelectricity and to the discovery of the membrane potential ,
action potential , etc., by researchers such as Emil du Bois-Reymond .
The ...
Homeostasis
... equilibrium
They are unpredictable (the resulting effect of a precise
action often has the opposite effect to what was expected).
Main examples of ... a threshold electric potential triggers the generation of a much larger
action potential . (See also leverage points .)
Ecological homeostasis ...
Operator
... is an operator which is fundamentally used in Calculus to denote the
action of taking a derivative. Common notations are such d/dx , y'(x) to denote ... notation we have been using, that is, using D f to represent the
action of taking the derivative of f.
Integral operators
Given that ...
Prion
... self-reproducing protein structures. Though their exact mechanisms of
action and reproduction are still unknown, it is now commonly accepted that ... An alternative idea is that prion propagation does not require direct
action of a prion protein on a normal protein, but rather results from a positive ...
Antibiotic
... Chloramphenicol
Clindamycin
Fusidic acid
Trimethoprim
Another such classification is by their mechanism of
action (that is, the mechanism by which they selectively poison bacterial cells):
Antibiotics which interfere with cell-wall synthesis
...
Antibiotic resistance
...
4 See also
5 External links
Causes
Antibiotic resistance is a consequence of evolution via natural selection . The antibiotic
action is an environmental pressure; those bacteria which have a mutation allowing them to survive will live on to reproduce. They will then pass this ...
Apoptosis
... but, in the absence of Shh, one of the ends of this same Ptc1 receptor (the carboxyl-terminal, inside the membrane) is cleaved by caspase-3, an
action that exposes an apoptosis-producing domain (see the Perspective by Isabel Guerrero and Ariel Ruiz i Altaba and the research report by Chantal Thibert ...
Arabidopsis
... root organs is the predominant tropic effect in these organs, specimens treated with mutagens and then selected for the absence of gravitropic
action have shown both negative phototropic response to blue or white light, and positive phototropic response to red light. The photosensitive pigments ...
Axon
... Hodgkin and Andrew Huxley also employed the squid axon (1939) and by 1952 they had obtained a full quantitative description of the ionic basis of the
action potential.
Hodgkin and Huxley were awarded jointly the Nobel Prize for this work in 1963.
See also
Dendrite
Medial longitudinal ...
Cell growth
... motor unit that is controlled by the motoneuron. Invertebrates often have giant neurons and axons that provide special functions such as rapid
action potential propagation. Mammals also use this trick for increasing the speed of signals in the nervous system, but they can also use myelin to ...
Charles Darwin
... of Flowers on Plants of the Same Species
1880 – The Power of Movement in Plants
1881 – Formation of vegetable Mould Through the
action of Worms
1887 – Autobiography of Charles Darwin (Edited by his Son Francis Darwin)
Letters
Life and Letters of Charles ...
Competitive inhibitor
... In biochemistry one distinguishes two ways in which a molecule may block the
action of an enzymes : competitive and noncompetitive inhibition.
In competitive inhibition , the molecule acts on the same active site as the normal ...
Diabetes mellitus
... the principal hormone that regulates uptake of glucose into cells (primarily muscle and fat cells) from the blood, deficiency of insulin or its
action plays a central role in all forms of diabetes.
Most of the carbohydrates in food are rapidly digested to glucose , the principal sugar in ...
Depolarization
... of membrane potentials is important for other cell types, particularly muscle cells.
Related topics
membrane potential
action potential
...
Disulfide bond
... peroxide ( H 2 O 2 ) in particular can severely damage DNA and kill the bacterium at low concentrations if it weren't for the protective
action of the SS-bond.
In rubber
Disulfide bonds also play a significant role in the vulcanization of rubber .
In eukaryotes
In ...
Edward Jenner
... the location of the "Air Balloon" public house .
Jenner was a keen observer of nature and he was one of the first to write about the baby cuckoo's
action of pushing the eggs and the young of its host out of the nest so that the baby cuckoo was the only one to receive food from its foster parents. It ...
Enzyme
... of oxygen. Most of our cells (an exception being erythrocytes ), would literally starve for oxygen even with an abundance of oxygen without the
action of the enzyme, cytochrome oxidase. Enzymes are also necessary for muscle contraction and relaxation. The fact is, without both of these classes of ...
Fermentation
... fermentation processes include the making of yogurt . The science of fermentation is known as zymology .
Fermentation usually implies that the
action of the microoganisms is desirable.
Brewing is the production of alcoholic beverages through fermentation . This is the method used in beer ...
Flagellum
... some components of archaeal flagella share sequence and morphological similarity with components of type IV pili , which are assembled through the
action of type II secretion systems (the nomenclature of pili and protein secretion systems is not consistent).
These differences mean that the ...
Gene therapy
... are currently used as vectors in gene therapy: retroviruses , adenoviruses and adeno-associated viruses . They differ in their mechanisms of
action and results.
Retroviruses
The genetic material in retroviruses is in the form of RNA molecules, while the genetic material of their hosts is ...
Photosynthesis
... In plants, there are two photosystems involved, which are most active at 700 and 680 nm . However, other wavelengths are also peaks in the
action spectrum for photosynthesis.
Photosynthesis begins when light ionizes a chlorophyll molecule, releasing two electrons , which are transferred ...
Hormone
... action) in the same tissue or cells of a distant organ of the body. The function of hormones is to serve as a signal to the target cells; the
action of hormones is determined by the pattern of secretion and the signal transduction of the receiving tissue.
Hormone actions vary widely, but can ...
Immune system
... sections:
The humoral immune system , which acts against bacteria and viruses in the body liquids (such as blood ). Its primary means of
action are proteins called immunoglobulins , also called antibodies , which are produced by B cells
The cellular immune system , which (among ...
Ion channel
... a more detailed understanding of how these enzymes work.
See also
transmembrane receptor
passive transport
active transport
action potential
External links
The Voltage Sensor in Voltage-Dependent Ion Channels
X-ray crystal structure of a potassium channel
Ion ...
Konrad Lorenz
... Behaviour . Lorenz and Tinbergen developed the idea of the "Innate Releasing Mechanism" to explain the occurrence of instinctive behaviours ("Fixed
action Patterns"), and under the influence of the ideas about instinct of William McDougall , Lorenz further developed this into a "Psychohydraulic" model ...
Leaf
... of light. The slight separation of the cells provides maximal absorption of carbon dioxide. This separation must be minimal to afford capillary
action for water distribution. In order to adapt to their different environment (such as sun or shade), plants had to adapt this structure to obtain ...
Lyon hypothesis
... profile reveals extensive variability in X-linked gene expression in females. . Nature 2005;434:400-404. PMID 15772666 .
Lyon MF. Gene
action in the X chromosome of the mouse (Mus musculus L). Nature 1961;190:372-373. PMID 13764598 .
...
Memory
... are intentions triggered by cues, such as remembering to post a letter (action) after seeing a mailbox (cue). Cues do not need to be related to the
action (as the mailbox example is), and lists, sticky-notes, knotted hankerchiefs, or string around the finger (see box) are all examples of cues that are ...
Modern evolutionary synthesis
... Between Relatives on the Supposition of Mendelian Inheritance ", which showed using a model how continuous variation could be the result of the
action of many discrete loci . This is generally regarded as the starting point of the synthesis.
Tenets of the modern synthesis
According to the ...
Antibiotic resistance
...
4 See also
5 External links
Causes
Antibiotic resistance is a consequence of evolution via natural selection . The antibiotic
action is an environmental pressure; those bacteria which have a mutation allowing them to survive will live on to reproduce. They will then pass this ...
Nervous system
... structural support.
Rapid signalling within the nervous system occurs by two primary mechanisms:
Within neuronal nerve fibers by way of
action potentials
Between neurons by way of neurotransmitter diffusion across synapses .
Vertebrate nervous systems
The nervous systems of ...
Neuroscience
... - These two fields are interested in explaining the link between the mind and the brain. Common methods involve functional imaging, recording of
action potentials, and careful analysis of behavior.
Neurobiology of disease - This field, directly aligned with medical research, is interested in ...
Osmoregulation
... a contractile vacuole to collect excretory waste, such as ammonia , from the intracellular fluid by both diffusion and active transport. As osmotic
action pushes water from the environment into the cytoplasm, the vacuole moves to the surface and disposes the contents into the environment.
Kidneys ...