Studies In Cell Culture:
Investigation of the distribution of NOS in the rat vagina in response to ovariectomy and estrogen replacement was recently performed using immunohistochemical analyses with n-NOS and e-NOS antibodies. In intact cycling animals, e-NOS and n-NOS expression were found to be highest during proestrous and lowest during metestrous while in ovariectomized animals n-NOS and e-NOS expression declined substantially. Estrogen replacement resulted in significant increase in e-NOS and n-NOS expression, when compared with NOS in intact animals. It was suggested that estrogen plays a critical role in regulating vaginal NOS expression of the rat vagina and that NO may modulate both vaginal blood supply and vaginal smooth musculature. More recent studies have shown the opposite observation. They found that rabbit vaginal NOS activity was considerably reduced by treatment with estradiol or estradiol and progesterone. They also noted that progesterone treatment alone up-regulated vaginal NOS. NOS-containing nerves could be demonstrated in vagina by immunohistochemistry. Vaginal smooth muscle responded with relaxation after EFS, which was inhibited by NG-nitro-L-arginine. A tissue specific role for NOS in vagina was suggested based on NO-dependent response of vaginal smooth muscle, expression of relatively high NOS, which is down-regulation by estradiol and up-regulation by progesterone.
Sex Differences In Erogenous Zones
This table shows the sex differences in erogenous zones and includes the top ten most arousing areas for both sexes. Each body part was rated out of ten for how arousing it is when touched. Apart from body parts exclusive to one gender such as the penis or clitoris, many of the erogenous zones are similar and contain many nerve endings.
Patient Discussion About Stimulation
Q. How does a Transcutaneous electrical nerve stimulation unit help fibromyalgia. My aunt was suggested to go through TENS. Will that really help? How does a Transcutaneous electrical nerve stimulation unit help fibromyalgia?
Q. Can some depression be treated with stimulantes in adults?? I was treated with dextroamphetimins in the 1970’s. Why arent they used anymore? I know all of the things about addiction, so I dont need those answers. When the medication was used by me, it worked. My husband is suffereing from depression he has been given all of the “wonder” drugs No results. I hope someone can answer this for me, and for my husbands sakeThank YouShirley
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As A Cytosolic Dna Sensor
Cyclic dinucleotides-second-messenger signaling molecules produced by diverse bacterial species were detected in the cytosol of mammalian cells during intracellular pathogen infection this leads to activation of TBK1–IRF3 and the downstream production of type I interferon.STING has been shown to bind directly to cyclic di-GMP, and this recognition leads to the production of cytokines, such as type I interferon, that are essential for successful pathogen elimination.
Ras Activation At The Plasma Membrane
Fig. 1. Schematic showing the activation of the Ras to ERK pathway by growth factor binding to a receptor tyrosine kinase. Ligand binding induces receptor dimerization and autophosphorylation. The Grb2 adapter protein binds to activated receptors and increases association of the guanine nucleotide exchange factor Sos to Ras, resulting in Ras loading of GTP and activation. Ras enhances membrane recruitment and activation of the Raf protein kinases, which activate MEKs, leading to ERK activation. Once activated, ERKs phosphorylate cytoplasmic substrates and translocate to the nucleus to phosphorylate nuclear targets.
Haichao Wang, … Kevin J. Tracey, in, 2003
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Skeletal Muscles Are Stimulated To Contract By Nerves And Act As Effectors
Muscles act in antagonistic pairs against an incompressible skeleton.
Gross and microscopic structure of skeletal muscle. The ultrastructure of a myofibril.
The roles of actin, myosin, calcium ions and ATP in myofibril contraction.
The roles of calcium ions and tropomyosin in the cycle of actinomyosin bridge formation.
The roles of ATP and phosphocreatine in muscle contraction.
The structure, location and general properties of slow and fast skeletal muscle fibres.
Students could examine prepared slides of skeletal muscle using an optical microscope.
Students could investigate the effect of repeated muscular contraction on the rate of muscle fatigue in human vounteers.
Heart Action: Initiation & Control
- Control of the basic heartbeat is myogenic, which means the heart will beat without any external stimulus
- This intrinsic rhythm means the heart beats at around 60 times per minute
- The sinoatrial node is a group of cells in the wall of the right atrium. The SAN initiates a wave of depolarisation that causes the atria to contract
- The Annulus fibrosus is a region of non-conducting tissue which prevents the depolarisation spreading straight to the ventricles
- Instead, the depolarisation is carried to the atrioventricular node
- This is a region of conducting tissue between atria and ventricles
Stages in the cardiac cycle table
The wave of depolarisation spreads across the heart in a coordinated manner
Explain the roles of the sinoatrial node, the atrioventricular node and the Purkyne fibres in a heartbeat.
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Where Does Stimulus Come From
The first records of stimulus come from the 1600s. It comes from the Latin word stimulus, meaning cattle proda sharp stick used to poke cattle to get them to keep moving. In a general sense, thats what a stimulus doesit prods something into action. What that action is varies depending on the context.
Scientifically speaking, a stimulus is anything that produces a response in an organism or in a cell or tissue of an organism. Such stimuli can be internal or external. Internal stimuli come from inside an organismpain and hunger are internal stimuli. In humans, an external stimulus is anything thats detected by the senseslight, noises, things we feel on our skin. Parents are often told to avoid having newborn babies around too many stimuli at once so that they dont become overstimulated . In psychology, the term stimulus is often used in the context of conditioned responseslike the famous example of Pavlovs dogs salivating at the sound of a bell. In this case, one stimulus became associated with another .
Not all stimulus measures involve sending money directly. The phrase stimulus package typically refers to a whole bundle of government policies meant to stimulate the economy in some way, including tax breaks, interest limits, and other actions, perhaps in addition to payments. During the recession in 2008, the U.S. government issued temporary tax cuts to certain households and businesses with the goal of economic stimulus.
Control Of Blood Glucose Concentration
The factors that influence blood glucose concentration.
The role of the liver in glycogenesis, glycogenolysis and gluconeogenesis.
The action of insulin by:
The action of glucagon by:
The role of adrenaline by:
The second messenger model of adrenaline and glucagon action, involving adenylate cyclase, cyclic AMP and protein kinase.
The causes of types I and II diabetes and their control by insulin and/or manipulation of the diet.
Students should be able to evaluate the positions of health advisers and the food industry in relation to the increased incidence of type II diabetes.
Required practical 11: Production of a dilution series of a glucose solution and use of colorimetric techniques to produce a calibration curve with which to identify the concentration of glucose in an unknown âurineâ sample.
AT b and c
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What Is Latent In Biology
Being in a condition of biological rest or inactivity characterized by cessation of growth or development and the suspension of many metabolic processes. A latent bud. adjective. 1. Present but invisible or inactive lying hidden and undeveloped within a person or thing, as a quality, power, or talent.
What Is Latency Medical Term
Medical Definition of latency 1 or latency period or latent period. a : the quality or state of being latent especially : the state or period of living or developing in a host without producing symptoms The cellular mechanisms by which viral latency is maintained or viral replication is induced is not known.
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What Is Electrical Stimulation
Electrical stimulation or neuromuscular electrical stimulation is a technique used to elicit a muscle contraction using electrical impulses. Electrodes, controlled by a unit, are placed on the skin over a predetermined area. Electrical current is then sent from the unit to the electrodes and delivered into the muscle causing a contraction.
Numerous forms of electrotherapy are used to serve many purposes ranging from decreasing pain and inflammation to improving function and strength.
Role In Host Immunity
Although type I IFN is absolutely critical for resistance to viruses, there is growing literature about the negative role of type I interferon in host immunity mediated by STING. AT-rich stem-loop DNA motif in the Plasmodium falciparum and Plasmodium berghei genome and extracellular DNA from Mycobacterium tuberculosis have been shown to activate type I interferon through STING. Perforation of the phagosome membrane mediated by ESX1 secretion system allows extracellular mycobacterial DNA to access host cytosolic DNA sensors, thus inducing the production of type I interferon in macrophages. High type I interferon signature leads to the M. tuberculosis pathogenesis and prolonged infection. STING-TBK1-IRF mediated type I interferon response is central to the pathogenesis of experimental cerebral malaria in laboratory animals infected with Plasmodium berghei. Laboratory mice deficient in type I interferon response are resistant to experimental cerebral malaria.
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Epidemiology Of Female Sexual Dysfunction
Well-designed, random-sample, community-based epidemiologic investigations of women with sexual dysfunction are limited. Current data reveals that up to 76% of women have some type of sexual dysfuntion. U.S. population census data suggest that approximately 10 million American women ages 50-74 self-report complaints of diminished vaginal lubrication, pain and discomfort with intercourse, decreased arousal, and difficulty achieving orgasm. Recently, Laumann and Rosen found that sexual dysfunction is more prevalent in women than in men and is associated with various psychodemographic characteristics such as age, education, and poor physical and emotional health. More importantly, female sexual dysfunction is associated with negative sexual relationship experiences.
Experimental Models For Investigation Of Female Sexual Genital Arousal
Park et al., also reported that estrogen replacement normalized genital hemodynamics to control levels. In our studies, treatment of ovariectomized animals with estradiol significantly increased pelvic nerve-stimulated genital blood flow above control levels . Interestingly, treatment with testosterone did not restore blood flow to that observed in control animals. Park et al., also noted marked thinning of the vaginal epithelial layers, decreased vaginal submucosal microvasculature, and diffuse clitoral cavernosal fibrosis in ovariectomized animals. In addition, the percentage of clitoral cavernosal smooth muscle was significantly decreased in ovariectomized animals. These studies suggest that estrogens modulate genital hemodynamics and are critical for maintaining tissue structural integrity.
Vaginal lubrication, an estrogen-dependent physiological process, is one of the indicators of genital arousal and tissue integrity. Min et al., showed that vaginal lubrication in ovariectomized animals under basal conditions and after pelvic nerve stimulation was reduced and normalized with estrogen treatment . In contrast, androgen treatment of ovariectomized animals with testosterone alone or in combination with estradiol did not restore vaginal lubrication to that observed in control animals. Finally, it was noted that ovariectomy caused vaginal atrophy and reduced vaginal epithelial cell maturation, which was normalized by estrogen but not androgen treatment.
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Biology Of Female Sexual Function
Ricardo Munarriz, MD, Noel N. Kim, PhD, Irwin Goldstein, MD and Abdul M. Traish, PhD
Excerpt from North American Clinics
Female sexual dysfunction is defined as disorders of sexual desire, arousal, orgasm and/or sexual pain, which results in significant personal distress and may have an impact on the quality of life and interpersonal relationships. Although each specific condition can be separately defined in medical terms, clinically there is significant overlap in afflicted patients. The limited available data on female anatomy, physiology, biochemistry and molecular biology of the female sexual response makes this field particularly challenging to clinicians, psychologists and basic science researchers alike.
Temporal Modulation Of Dendrodendritic Inhibition
In slices, paired-pulse mitral cell stimulation experiments show that self-inhibition elicited by the second pulse was markedly reduced and recovered with a time constant of 6 s . This finding may, in part, account for the decrement in GABAergic synaptic input to mitral cells across respiratory cycles during odor stimulation . The observation that GC odor responses subside across sniffs may also lead to reduced dendrodendritic inhibition during respiration. Thus, the strength of dendrodendritic inhibition is likely to be temporally modulated with respect to respiration. Other studies indicate that higher frequency local -oscillatory activity generated by mitral cellGC interactions may also modulate GABAergic inhibition. Local -frequency stimulation in the GCL or ELP can facilitate mitral cell feedback and lateral inhibition by relieving the Mg2+ block of NMDA receptors on GCs .
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Research Methods And Techniques
Intracellular measurements of electrical potential across the membrane can be obtained by microelectrode recording. Patch clamp techniques allow for the manipulation of the intracellular or extracellular ionic or lipid concentration while still recording potential. In this way, the effect of various conditions on threshold and propagation can be assessed.
As A Signaling Adaptor
DDX41, a member of the DEXDc family of helicases, in myeloid dendritic cells recognizes intracellular DNA and mediates innate immune response through direct association with STING. Other DNA sensors- DAI, RNA polymerase III, IFI16, have also been shown to activate STING through direct or indirect interactions.
Cyclic GMP-AMP synthase , which belongs to the nucleotidyltransferase family, is able to recognize cytosolic DNA contents and induce STING-dependent interferon response by producing secondary messenger cyclic guanosine monophosphateâadenosine monophosphate . After cyclic GMP-AMP bound STING is activated, it enhances TBK1‘s activity to phosphorylate IRF3 and STAT6 for downstream type I interferon response.
It has been proposed that intracellular calcium plays an important role in the response of the STING pathway.
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Stimulator Of Interferon Genes
|Ortholog search: PDBeRCSB|
|List of PDB id codes|
Stimulator of interferon genes , also known as transmembrane protein 173 and MPYS/MITA/ERIS is a protein that in humans is encoded by the STING1 gene.
STING plays an important role in innate immunity. STING induces type I interferon production when cells are infected with intracellular pathogens, such as viruses, mycobacteria and intracellular parasites.Type I interferon, mediated by STING, protects infected cells and nearby cells from local infection by binding to the same cell that secretes it and nearby cells It thus plays an important role, for instance, in controlling norovirus infection.
STING works as both a direct cytosolic DNA sensor and an adaptor protein in Type I interferon signaling through different molecular mechanisms. It has been shown to activate downstream transcription factors STAT6 and IRF3 through TBK1, which are responsible for antiviral response and innate immune response against intracellular pathogen.
Discover Biology With Biology Simulations
Biology Simulations helps students to learn about biology and practice data analysis skills. These simulations allow students to experiment with concepts that may take too much time or too many resources to complete in a traditional science lab setting. While simulations cannot replace real-world experiences, they are a useful tool in both scientific research and education.
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Encoding And Transmission Of Sensory Information
Four aspects of sensory information are encoded by sensory systems: the type of stimulus, the location of the stimulus in the receptive field, the duration of the stimulus, and the relative intensity of the stimulus. Thus, action potentials transmitted over a sensory receptors afferent axons encode one type of stimulus. This segregation of the senses is preserved in other sensory circuits. For example, auditory receptors transmit signals over their own dedicated system. The electrical activity in the axons of the auditory receptors will be interpreted by the brain as an auditory stimulus: a sound.
The intensity of a stimulus is often encoded in the rate of action potentials produced by the sensory receptor. Thus, an intense stimulus will produce a more rapid train of action potentials. Reducing the stimulus will likewise slow the rate of production of action potentials. A second way in which intensity is encoded is by the number of receptors activated. An intense stimulus might initiate action potentials in a large number of adjacent receptors, while a less intense stimulus might stimulate fewer receptors. Integration of sensory information begins as soon as the information is received in the central nervous system.