Misplaced Pages

#532467

34-457: Bactrodinae Centrocnemidinae Cetherinae Chryxinae Ectrichodiinae Elasmodeminae Emesinae Microtominae (=Hammacerinae) Harpactorinae Holoptilinae Manangocorinae Peiratinae Phimophorinae Phymatinae Physoderinae Pseudocetherinae Reduviinae Saicinae Salyavatinae Sphaeridopinae Stenopodainae Triatominae Tribelocephalinae Vesciinae Visayanocorinae The Reduviidae

68-416: A bad, metallic taste at all times). A rare condition identified to affect taste is that of 'Saliva Hypernatrium' , or excessive amounts of sodium in saliva that is not caused by any other condition (e.g., Sjögren syndrome ), causing everything to taste 'salty'. The production of saliva is stimulated both by the sympathetic nervous system and the parasympathetic . Sympathetic stimulation of saliva

102-407: A large role in fat digestion in newborn infants as their pancreatic lipase still needs some time to develop. Saliva is very important in the sense of taste . It is the liquid medium in which chemicals are carried to taste receptor cells (mostly associated with lingual papillae ). People with little saliva often complain of dysgeusia (i.e. disordered taste, e.g. reduced ability to taste, or having

136-456: A role in breaking down food particles entrapped within dental crevices, thus protecting teeth from bacterial decay. Saliva also performs a lubricating function, wetting food and permitting the initiation of swallowing , and protecting the oral mucosa from drying out . Saliva has specialized purposes for a variety of animal species beyond predigestion. Certain swifts construct nests with their sticky saliva. The foundation of bird's nest soup

170-534: A small subfamily of the reduviid (assassin bugs). Only one genus and five species have been described to date, all from the Neotropical Region (South America). These bugs are slender and long-legged, the first antennal segment is long and the eyes jut out. They also have ocelli placed on raised protrusions. Saliva The enzymes found in saliva are essential in beginning the process of digestion of dietary starches and fats. These enzymes also play

204-450: Is Reduvius personatus , known as the masked hunter because of its habit of camouflaging itself with dust. Some species tend to feed on pests such as cockroaches or bedbugs and are accordingly popular in regions where people regard their hunting as beneficial. Reduvius personatus is an example, and some people breed them as pets and for pest control. Some assassin bug subfamilies are adapted to hunting certain types of prey; for example,

238-420: Is a health hazard to the public. Many birds in the swift family, Apodidae, produce a viscous saliva during nesting season to glue together materials to construct a nest. Two species of swifts in the genus Aerodramus build their nests using only their saliva , the base for bird's nest soup . A common belief is that saliva contained in the mouth has natural disinfectants , which leads people to believe it

272-630: Is a large cosmopolitan family of the suborder Heteroptera of the order Hemiptera (true bugs). Among the Hemiptera and together with the Nabidae almost all species are terrestrial ambush predators ; most other predatory Hemiptera are aquatic. The main examples of non-predatory Reduviidae are some blood-sucking ectoparasites in the subfamily Triatominae , with a few species from South America noted for their ability to transmit Chagas disease . Though spectacular exceptions are known, most members of

306-599: Is an aerodramus nest. Venomous saliva injected by fangs is used by cobras, vipers, and certain other members of the venom clade to hunt. Some caterpillars use modified salivary glands to store silk proteins, which they then use to make silk fiber. Produced in salivary glands , human saliva comprises 99.5% water, but also contains many important substances, including electrolytes , mucus , antibacterial compounds and various enzymes . Medically, constituents of saliva can noninvasively provide important diagnostic information related to oral and systemic diseases. Experts debate

340-607: Is beneficial to " lick their wounds ". Researchers at the University of Florida at Gainesville have discovered a protein called nerve growth factor (NGF) in the saliva of mice . Wounds doused with NGF healed twice as fast as untreated and unlicked wounds; therefore, saliva can help to heal wounds in some species. NGF has been found in human saliva, as well as antibacterial agents as secretory mucin , IgA , lactoferrin , lysozyme and peroxidase . It has not been shown that human licking of wounds disinfects them, but licking

374-402: Is likely to help clean the wound by removing larger contaminants such as dirt and may help to directly remove infective bodies by brushing them away. Therefore, licking would be a way of wiping off pathogens, useful if clean water is not available to the animal or person. In Pavlov's experiment, dogs were conditioned to salivate in response to a ringing bell; this stimulus is associated with

SECTION 10

#1732775722533

408-435: Is more socially acceptable (even if officially disapproved of or illegal), and spittoons are still a common appearance in some cultures. Some animals, even humans in some cases, use spitting as an automatic defensive maneuver. Camels are well known for doing this, though most domestic camels are trained not to. Spitting by an infected person (for example, one with SARS-CoV-2 ) whose saliva contains large amounts of virus ,

442-458: Is to facilitate respiration , whereas parasympathetic stimulation is to facilitate digestion . Parasympathetic stimulation leads to acetylcholine (ACh) release onto the salivary acinar cells. ACh binds to muscarinic receptors , specifically M 3 , and causes an increased intracellular calcium ion concentration (through the IP 3 /DAG second messenger system). Increased calcium causes vesicles within

476-469: The Ectrichodiinae eat millipedes , and feather-legged bugs eat ants. A spectacular example of the latter is Ptilocnemus lemur , an Australian species in which the adult attacks and eats ants, but the nymph waits until the ant bites the feathery tufts on its hind legs, upon which it whips around and pierces the ant's head with its proboscis, and proceeds to feed. Some research on the nature of

510-418: The oral mucosa mechanically protecting it from trauma during eating, swallowing, and speaking. Mouth soreness is very common in people with reduced saliva ( xerostomia ) and food (especially dry food) sticks to the inside of the mouth. The digestive functions of saliva include moistening food and helping to create a food bolus . The lubricative function of saliva allows the food bolus to be passed easily from

544-478: The prosternum , where it can be used to produce sound by stridulation . Sound is made by rasping the proboscis against ridges in this groove or stridulitrum (stridulatory organ). These sounds are often used to discourage predators. When harassed, many species can deliver a painful stab with the proboscis, injecting venom or digestive juices. The effects can be intensely painful and the injection from some species may be medically significant. Predatory Reduviidae use

578-500: The Gram-positive ( Streptococcus pyogenes ). Some species are bloodsuckers rather than predators, and they are accordingly far less welcome to humans. The blood-feeding habit is thought to have evolved from species that lived in the nests of mammalian hosts. Several species are known to live among bat roosts, including Cavernicola pilosa , Triatoma dimidiata and Eratyrus mucronatus . Triatoma species and other members of

612-427: The amount of saliva that a healthy person produces. Production is estimated at 1500ml per day and researchers generally accept that during sleep the amount drops significantly. In humans, the submandibular gland contributes around 70 to 75% of secretions, while the parotid gland secretes about 20 to 25%; small amounts are secreted from the other salivary glands. Saliva contributes to the digestion of food and to

646-405: The cells to fuse with the apical cell membrane leading to secretion. ACh also causes the salivary gland to release kallikrein , an enzyme that converts kininogen to lysyl-bradykinin . Lysyl-bradykinin acts upon blood vessels and capillaries of the salivary gland to generate vasodilation and increased capillary permeability , respectively. The resulting increased blood flow to the acini allows

680-485: The death of 12,000 people a year. The Emesinae live among spider webs. Current taxonomy is based on morphological characteristics. The first cladistic analysis based on molecular data (mitochondrial and nuclear ribosomal DNA) was published in 2009 and called into question the monophyly of some current groups, such as the Emesinae . Reduviidae are monophyletic, and the "Phymatine Complex" is consistently recovered as

714-535: The family are fairly easily recognizable: they have a relatively narrow neck, sturdy build, and formidable curved proboscis (sometimes called a rostrum ). Large specimens should be handled with caution, if at all, because they sometimes defend themselves with a very painful stab from the proboscis. The family members are almost all predatory, except for a few blood-sucking species, some of which are important as disease vectors. About 7000 species have been described, in more than 20 recognized subfamilies, making it one of

SECTION 20

#1732775722533

748-596: The largest families in the Hemiptera. The name Reduviidae is derived from the type genus , Reduvius . That name, in turn, comes from the Latin reduvia , meaning " hangnail " or "remnant". Possibly this name was inspired by the lateral flanges on the abdomen of many species. Common genera include: While members of most subfamilies have no common names other than assassin bugs , some subfamilies have their own common names such as: Adult insects range from roughly 12 to 36 mm (0.47 to 1.42 in), depending on

782-467: The long rostrum to inject a lethal saliva that liquefies the insides of the prey, which are then sucked out. The saliva contains enzymes that digest the tissues they swallow. This process is generally referred to as extraoral digestion . The saliva is commonly effective at killing prey substantially larger than the bug itself. The legs of some Reduviidae have areas covered in tiny hairs that aid in holding onto their prey while they feed. Others, members of

816-423: The maintenance of oral hygiene. Without normal salivary function the frequency of dental caries , gum disease ( gingivitis and periodontitis ), and other oral problems increases significantly. Saliva limits the growth of bacterial pathogens and is a major factor in sustaining systemic and oral health through the prevention of tooth decay and the removal of sugars and other food sources for microbes. Saliva coats

850-422: The mouth into the esophagus. Saliva contains the enzyme amylase, also called ptyalin, which is capable of breaking down starch into simpler sugars such as maltose and dextrin that can be further broken down in the small intestine. About 30% of starch digestion takes place in the mouth cavity. Salivary glands also secrete salivary lipase (a more potent form of lipase) to begin fat digestion. Salivary lipase plays

884-421: The oral cavity. Sympathetic stimulation results in the release of norepinephrine . Norepinephrine binding to α-adrenergic receptors will cause an increase in intracellular calcium levels leading to more fluid vs. protein secretion. If norepinephrine binds β-adrenergic receptors, it will result in more protein or enzyme secretion vs. fluid secretion. Stimulation by norepinephrine initially decreases blood flow to

918-456: The production of more saliva. In addition, Substance P can bind to Tachykinin NK-1 receptors leading to increased intracellular calcium concentrations and subsequently increased saliva secretion. Lastly, both parasympathetic and sympathetic nervous stimulation can lead to myoepithelium contraction which causes the expulsion of secretions from the secretory acinus into the ducts and eventually to

952-399: The salivary glands due to constriction of blood vessels but this effect is overtaken by vasodilation caused by various local vasodilators. Saliva production may also be pharmacologically stimulated by the so-called sialagogues . It can also be suppressed by the so-called antisialagogues . Spitting is the act of forcibly ejecting saliva or other substances from the mouth. In many parts of

986-575: The sister to the higher Reduviidae, which includes 90 percent of the reduviid species diversity. Reduviidae is suggested to have split from other Cimicomorphs during the Jurassic, based on molecular clock. The oldest fossils of the family are from the Late Cretaceous ( Cenomanian ) aged Burmese amber , represented by nymphs and the genus Paleotriatoma , belonging to the subfamily Triatominae . Bactrodinae The Bactrodinae are

1020-405: The species. They most commonly have an elongated head with a distinct narrowed 'neck', long legs, and prominent, segmented, tubular mouthparts, most commonly called the proboscis, but some authors use the term "rostrum". Most species are bright in colour with hues of brown, black, red, or orange. The most distinctive feature of the family is that the tip of the proboscis fits into a ridged groove in

1054-572: The subfamily Phymatinae in particular, have forelegs that resemble those of the praying mantis , and they catch and hold their prey in a similar way to mantises. As nymphs , some species cover and camouflage themselves effectively with debris or the remains of dead prey insects. The nymphal instars of the species Acanthaspis pedestris present one good example of this behaviour where they occur in Tamil Nadu in India. Another well-known species

Reduviidae - Misplaced Pages Continue

1088-479: The subfamily Triatominae , such as Rhodnius species, Panstrongylus megistus , and Paratriatoma hirsuta , are known as kissing bugs, because they tend to bite sleeping humans in the soft tissue around the lips and eyes. A more serious problem than their bites is the fact that several of these haematophagous Central and South American species transmit the potentially fatal trypanosomal Chagas disease , sometimes called American trypanosomiasis. This results in

1122-710: The venom from certain Reduviidae is under way. The saliva of Rhynocoris marginatus showed some insecticidal activity in vitro , in tests on lepidopteran pests. The effects included reduction of food consumption, assimilation, and use. Its antiaggregation factors also affected the aggregation and mobility of haemocytes. The saliva of the species Rhynocoris marginatus (Fab.) and Catamirus brevipennis (Servile) have been studied because of their activity against human pathogenic Gram-negative bacteria (including strains of Escherichia coli , Pseudomonas aeruginosa , Proteus vulgaris , and Salmonella typhimurium ) and

1156-462: The world, it is considered rude and a social taboo , and has sometimes been outlawed. In some countries, for example, it has been outlawed for reasons of public decency and attempting to reduce the spread of disease. These laws may not strictly enforced, but in Singapore , the fine for spitting may be as high as SGD$ 2,000 for multiple offenses, and one can even be arrested. In China , expectoration

#532467