Miscellany

Jai Ganesh · 2025-09-28 17:40:16

2401) Duck-billed platypus

Gist

Along with echidnas, Platypuses are grouped in a separate order of mammals known as monotremes, which are distinguished from all other mammals because they lay eggs.

They outdo all waterfowl by having a bill that can detect electrical signals created by the muscular activity of animals swimming underwater. Using the special organs on their bill to detect electrical impulses created by prey, platypuses can locate worms and insect larvae in dark, murky waters.

Sometimes known as a duck-billed platypus, this curious mammal combines the characteristics of many different species in one. The platypus is a duck-billed, beaver-tailed, otter-footed, egg-laying aquatic creature native to Australia.

Summary

Duck-billed platypuses are small, shy animals. They have a flattened head and body to help them glide through the water. Their fur, dark brown on top and tan on their bellies, is thick and repels water to keep them warm and dry even after hours of swimming.

The duck-billed platypus's head and body grow to about 15 inches (38 centimeters) and its tail grows to about 5 inches long (13 centimeters). Their most remarkable feature is their amazing snout. It looks like a duck's bill, but is actually quite soft and covered with thousands of receptors that help the platypus detect prey.

Males are also venomous. They have sharp stingers on the heels of their rear feet and can use them to deliver a strong toxic blow to any foe.

Platypuses spend most of their time alone, sleeping or eating.

These mammals are bottom feeders. They scoop up insects and larvae, shellfish, and worms in their bill along with bits of gravel and mud from the bottom. All this material is stored in cheek pouches and, at the surface, mashed for consumption. Platypuses do not have teeth, so the bits of gravel help them to "chew" their meal.

Platypuses are long-lived, surviving 20 years or more in captivity and up to 12 years in the wild. Scientists think these fascinating creatures are the earliest relatives of modern mammals. Recent studies show that they first evolved more than 112 million years ago, well before the extinction of the dinosaurs.

Details

The platypus (Ornithorhynchus anatinus), sometimes referred to as the duck-billed platypus, is a semiaquatic, egg-laying mammal endemic to eastern Australia, including Tasmania. The platypus is the sole living representative of its family Ornithorhynchidae and genus Ornithorhynchus, though a number of related species appear in the fossil record. Together with the four species of echidna, it is one of the five extant species of monotremes, mammals that lay eggs instead of giving birth to live young. Like other monotremes, the platypus has a sense of electrolocation, which it uses to detect prey in water while its eyes, ears and nostrils are closed. It is one of the few species of venomous mammals, as the male platypus has a spur on each hind foot that delivers an extremely painful venom.

The unusual appearance of this egg-laying, duck-billed, beaver-tailed mammal at first baffled European naturalists. In 1799, the first scientists to examine a preserved platypus body judged it a fake made of several animals sewn together. The unique features of the platypus make it important in the study of evolutionary biology, and a recognisable and iconic symbol of Australia. It is culturally significant to several Aboriginal peoples, who also used to hunt it for food, and has appeared on stamps and currency.

The platypus was hunted for its fur, but it has been a legally protected species in all states where it occurs since 1912. Captive breeding programs have had slight success, and it is vulnerable to pollution, bycatching and climate change. It is classified as a near-threatened species by the IUCN, but a November 2020 report has recommended that it be upgraded to threatened species under the federal EPBC Act, due to habitat destruction and declining numbers in all states.

Description

Most of the platypus' small streamlined body is covered with short, dense, brown, fur that traps a layer of insulating air to keep the animal warm, both in and out of water. The fur coat is waterproof and consists of flattened guard hairs and curvy underfur hairs. It is one of the most densely furred mammals, behind only otters. It is also biofluorescent and glows cyan and green when under ultraviolet light; this may serve to camouflage it in low lighting from UV-sensitive predators. The duck-like bill consists of a long snout and lower jaw which is covered in soft skin. The nostrils are located near the tip of the snout's dorsal surface, while the eyes and ears are just behind the snout in a groove which closes underwater. Its has cheek pouches for storing food. The platypus's wide, flat tail is compared to a beaver's but is furry rather than scaly; it stores fat reserves and can act as a rudder during swimming. The legs are short and have a sprawling stance. Webbing is more significant on the front feet. While walking on land, the feet are folded up in knuckle-walking to protect the webbing.

The platypus has an interclavicle in the shoulder girdle, a trait which they share in common with reptiles. As in many other aquatic and semiaquatic vertebrates, the bones show osteosclerosis, increasing their density to reduce buoyancy. Adult platypuses lack teeth and instead have heavily keratinised food-grinding pads. Young platypuses have one premolar tooth and two molars on each maxillae, and three molars on the dentaries. The first upper and third lower cheek teeth have only one major cusp, while the rest have two. They lose their teeth around the time they leave their natal burrow.

Male platypuses have an average length of 50 cm (20 in) and weight of 1,700 g (3.7 lb), while females are smaller with an average length of 43 cm (17 in) and weight of 900 g (2.0 lb). The species follows Bergmann's rule, with individuals being larger the farther south they are, due to colder climates; there are local variations, however. The platypus has an average body temperature of about 32 °C (90 °F), lower than the 37 °C (99 °F) typical of placental mammals. Research suggests this has been a gradual adaptation to harsh environmental conditions among the few marginal surviving monotreme species, rather than a general characteristic of past monotremes.

The platypus has a single opening, called a cloaca, for both the reproductive and waste systems.

Senses

Monotremes are the only mammals (apart from the Guiana dolphin) known to have a sense of electroreception. The playtpus relies on electrolocation when feeding, as the eyes, ears, and nose are closed while underwater. Digging in the bottom of streams with its bill, its electroreceptors detect tiny electric currents generated by the muscular contractions of its prey. Experiments have shown the platypus will even react to an "artificial shrimp" if a small electric current is passed through it.

The 40,000 electroreceptors are arranged in rows in the skin of the bill from front to back, while mechanoreceptors for touch are uniformly distributed across the bill. The electrosensory area of the cerebral cortex is in the tactile somatosensory area, and some cortical cells receive input from both electroreceptors and mechanoreceptors, suggesting the platypus feels electric fields as touches. These receptors in the bill dominate the somatotopic map of the platypus brain, in the same way human hands dominate the Penfield homunculus map. The platypus can feel the direction of an electric source, perhaps by comparing differences in signal strength across the array of electroreceptors, enhanced by the characteristic side-to-side motion of the animal's head while hunting. It may also be able to determine the distance of moving prey via the timing difference between electrical and mechanical pressure sensations. Monotreme electrolocation for hunting in murky waters may be tied to their tooth loss. The extinct Obdurodon was electroreceptive, but unlike the modern platypus it foraged in open water.

The eyes of the platypus have basal traits also found in lungfish and amphibians, such as scleral cartilage, double cones, and droplets. The platypus's eyes are small and shut under water, though several features indicate its ancestors relied on vision. As with other aquatic mammals, the eye has a flattened cornea and surrounding lens, while the posterior surface of the lens is sharply inclined. A temporal (ear side) concentration of retinal ganglion cells, important for binocular vision, indicates a vestigial role in predation, though the actual visual acuity is insufficient for such activities. Limited acuity is matched by low cortical magnification, a small lateral geniculate nucleus, and a large optic tectum, suggesting that the visual midbrain plays a more important role than the visual cortex, as in some rodents. These features suggest that the platypus has adapted to an aquatic and nocturnal lifestyle, developing its electrosensory system at the cost of its visual system. This contrasts with the small number of electroreceptors in the short-beaked echidna, which dwells in dry environments, while the long-beaked echidna, which lives in wetter habitats is intermediate between the other two monotremes.

The ears of the platypus are adapted for hearing while out of water. As in all true mammals, it has three middle ear bones, though the cochlea lacks spirals, but is described as "well organised". Within the cochlea, there are rows of inner and outer hair cells. As in placental mammals, the outer hair cells of the platypus are adapted for hearing high frequencies, suggesting it is an ancestral mammalian trait. However it also possesses more rows of inner hair cells. The olfactory (smelling) systems of the platypus and the echidna independently evolved from an ancestor with less advanced smelling. The main olfactory bulb of the platypus lacks the complex layers of the echidna, while both the piriform cortex and flaps (lamella) are simpler. Monotremes differ from placental mammals in that their mitral cells are distributed throughout the outer plexiform layer of the olfactory bulb rather than packed as a monolayer.

Venom

While both male and female platypuses are born with back ankle spurs, only the males retain them into adulthood. Similar spurs are found on many archaic mammal groups, indicating that this was an ancient general characteristic among mammals. The spurs of the male injects venom, which is powerful enough to inflict pain in humans. Starting from the wounded area, the affect limb develops edema (swelling via fluid buildup) which can lead to an excruciating hyperalgesia (heightened sensitivity to pain) that can last as long as months.

The venom is composed largely of defensin-like proteins (DLPs) produced by the immune system, some of which are unique to the species. It is produced in kidney-shaped alveolar glands located in each of the thighs of the hind limbs and connected to the spur. The venomous spurs of male platypuses serve as weapons in battles with other males for breeding.

Distribution and habitat

The platypus is native to the freshwaters of eastern Australia, from Queenland to Tasmania (including King Island but not the Furneaux Group). It was believed to be extinct on the South Australian mainland, with the last sighting recorded at Renmark in 1975. Platypuses were captively bred at Warrawong Sanctuary in 1990-91. In October 2020 a nesting platypus was filmed in the wild after the previously abandoned Sanctuary reopened. There is a population on Kangaroo Island introduced in the 1920s, said to stand at 150 individuals in the Rocky River region of Flinders Chase National Park. In the 2019–20 Australian bushfire season, large portions of the island burned, decimating wildlife. However, SA Department for Environment and Water recovery teams worked to restore their habitat, with a number of sightings reported by April 2020. The platypus has almost disappeared from the Murray–Darling Basin, possibly due to poor water management. Platypuses can be found in a variety of freshwater habitats including rivers, streams, lakes and lagoon-like pools. The surrounding terrestrial environment includes tropical rainforests and colder alpine areas.

Additional Information

A platypus, (Ornithorhynchus anatinus) is a a small amphibious Australian mammal noted for its odd combination of primitive features and special adaptations, especially the flat, almost comical bill that early observers thought was that of a duck sewn onto the body of a mammal. Adding to its distinctive appearance are conspicuous white patches of fur under the eyes. The fur on the rest of the body is dark to light brown above, with lighter fur on the underside.

The platypus is common in waterways of eastern Australia, where it generally feeds on bottom-dwelling invertebrates but also takes an occasional frog, fish, or insect at the water’s surface. This shy creature forages most actively from dusk to dawn, sheltering during the day in burrows dug into stream banks. It is exquisitely adapted for its aquatic lifestyle, having a flattened torpedo-like body, dense waterproof fur, and strong front limbs used for swimming as well as digging. Even the head is streamlined, each ear being housed in a groove together with a small eye. The senses of sight, smell, and hearing are essentially shut down while the platypus is submerged to feed, but it possesses a unique electromechanical system of electroreceptors and touch receptors that allow it to navigate perfectly underwater. Similar electroreceptors are also present in echidnas, which, together with the platypus, make up the mammalian order Monotremata, a unique group with an exceptionally ancient history.

Natural history

Platypuses are generally solitary, spending their lives either feeding along the bottoms of rivers, streams, and lakes or resting in burrows dug into the banks. They are extremely energetic, feeding almost continuously while in the water, shoveling through streambed debris with their flat bills as they hunt for larval insects and freshwater crustaceans (a favourite food). The platypus uses its sophisticated electromechanical system to detect minute electrical signals given off by the muscles of its prey. After feeding, it retires to its burrow, the entrance of which is large enough to admit only the platypus and serves to squeeze excess moisture from the fur.

The platypus is found in terrain ranging from the high country of Tasmania and the Australian Alps to lowland areas close to the sea. Although it has on occasion been seen swimming in salt water, the platypus must feed in fresh water, where its electrical navigation system is operative. The platypus is present in all eastern Australian states in both eastward- and westward-flowing river systems, but it is absent from far northern Queensland and, unlike its relatives, the echidnas, does not appear to have colonized the island of New Guinea.

Generally most active around dawn and dusk (crepuscular), platypuses can also be active during the day depending on the season, cloud cover, stream productivity, and even individual preference. Platypuses are not known to hibernate. However, they have an unusually low body temperature for mammals (about 32 °C [90 °F]). Studies have shown that they can maintain a constant body temperature even after extended periods in water with temperatures as low as 4 °C (39 °F), a fact that puts to rest the belief that monotremes cannot regulate their body temperature.

Form and function

Platypuses range in length from 38 to 60 cm (15 to 24 inches); males are generally larger than females. Aquatic adaptations include the flat streamlined body, dorsally placed eyes and nostrils, and dense waterproof fur that keeps the platypus well insulated. Long guard hairs protect the soft underfur, which remains dry even after hours in the water. The extensive webbing on the front feet extends well past the claws and is essential in propelling the animal through the water. The paddlelike tail acts as a stabilizer during swimming, while the back feet act as rudders and brakes.

Odd skeletal features of platypuses include an archaic robust shoulder girdle and a short, wide humerus providing extensive muscle attachment areas for the exceptionally strong front limbs. The outside of the bill is covered by soft, sensitive skin. Inside the bill, adult platypuses do not have true teeth but instead have developed flat pads of hardened gum tissue. Male platypuses have a spur on the inner side of each ankle that is connected to a venom gland located over the thighs. The spurs can be wielded in defense, and the venom is potent enough to kill small animals and cause intense pain in humans if the spur penetrates the skin.

Life cycle and reproduction

Despite their abundance, little is known about the life cycle of the platypus in the wild, and few of them have been kept successfully in captivity. The sexes avoid each other except to mate, and they do not mate until they are at least four years old. Males often fight during the breeding season, inflicting wounds on each other with their sharp ankle spurs. Courtship and mating take place in the water from late winter through spring; timing varies with latitude, mating occurring earlier in the more northern parts of the range and later in the more southerly regions. Mating is a strenuous affair; in one recorded session the male was seen tightly grasping the tail of the female with his bill as she led him on an exhaustive chase.

Males take no part in rearing the young. Females construct specially built nursery burrows, where they usually lay two small leathery eggs. Gestation is at least two weeks (possibly up to a month), and incubation of the eggs takes perhaps another 6 to 10 days. The female incubates the eggs by curling around them with her tail touching her bill. Each tiny platypus hatches from the egg with the aid of an egg tooth and fleshy nub (caruncle), structural holdovers from a reptilian past. The young drag milk from special mammary hairs and remain protected in the burrow, suckling for three to four months before becoming independent. Hatchlings, whose weight often increases by a factor of 20 during their first 14 weeks of life, possess vestigial teeth that are shed shortly after the young platypus leaves the burrow to feed on its own.

Males and females become fully grown between ages 12 and 18 months, and they become sexually mature at about age 18 months. They are long-lived for small mammals. Some studies have documented individuals living more than 20 years in the wild. The platypus can survive for nearly 23 years in captivity.

Evolution, paleontology, and classification

Aquatically adapted platypus-like monotremes probably evolved from a more-generalized terrestrial monotreme. The first occurrence in the fossil record of a platypus-like monotreme is from about 110 million years ago, in the early Cretaceous Period, when Australia was still connected to South America by Antarctica. Until recently this Cretaceous monotreme (Steropodon galmani, known by a stunning opalized jaw) was placed within the platypus family, but, partly on the basis of molecular studies and partly on dental structure, it is now classified in its own family, Steropodontidae.

The living platypus family (Ornithorhynchidae) includes the extinct genera Monotrematum (which dates to the Paleocene Epoch some 61 million years ago) and Obdurodon (which may have first emerged near the boundary of the Oligocene and Miocene epochs some 23 million years ago) and the living Ornithorhychus. The discovery of M. sudamericanum in 62-million-year-old Patagonian sediments confirmed that platypuses were once distributed through the southern continents that were once linked geographically (Gondwana). Species of Monotrematum and Obdurodon retained functional teeth and were more robust than the living platypus, Obdurodon measuring up to 60 cm (24 inches) long.

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Jai Ganesh · 2025-09-29 19:05:00

2402) Gypsum

Gist

Gypsum is a soft, white-to-grey sulfate mineral, chemically known as calcium sulfate dihydrate (CaSO4·2H2O), which is commonly used in construction for drywall, as a soil conditioner in agriculture, and as a food additive. Found in naturally occurring sedimentary deposits, gypsum releases its water when heated, allowing it to be mixed with water to form a hard, durable material suitable for building and art.

Gypsum is a mineral primarily used for construction, especially in making drywall/wallboard and cement. It's also used in agriculture to condition soil by providing calcium and sulfur and improving water movement. Other uses include creating plaster of Paris for decorative elements, as a filler in paper and textiles, and in the production of some foods like tofu.

Summary

Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk. Gypsum also crystallizes as translucent crystals of selenite. It forms as an evaporite mineral and as a hydration product of anhydrite.[citation needed] The Mohs scale of mineral hardness defines gypsum as hardness value 2 based on scratch hardness comparison.

Fine-grained white or lightly tinted forms of gypsum known as alabaster have been used for sculpture by many cultures including Ancient Egypt, Mesopotamia, Ancient Rome, the Byzantine Empire, and the Nottingham alabasters of Medieval England.

Physical properties

Gypsum is moderately water-soluble (~2.0–2.5 g/L at 25 °C) and, in contrast to most other salts, it exhibits retrograde solubility, becoming less soluble at higher temperatures. When gypsum is heated in air it loses water and converts first to calcium sulfate hemihydrate (bassanite, often simply called "plaster") and, if heated further, to anhydrous calcium sulfate (anhydrite). As with anhydrite, the solubility of gypsum in saline solutions and in brines is also strongly dependent on sodium chloride (common table salt) concentration.

The structure of gypsum consists of layers of calcium (Ca2+) and sulfate ions tightly bound together. These layers are bonded by sheets of anion water molecules via weaker hydrogen bonding, which gives the crystal perfect cleavage along the sheets (in the {010} plane).

Crystal varieties

Gypsum occurs in nature as flattened and often twinned crystals, and transparent, cleavable masses called selenite. In the form of selenite, gypsum forms some of the largest crystals found in nature, up to 12 m (39 ft) long. Selenite contains no significant selenium; rather, both substances were named for the ancient Greek word for the Moon.

Selenite may also occur in a silky, fibrous form, in which case it is commonly called "satin spar".

It may also be granular or quite compact. In hand-sized samples, it can be anywhere from transparent to opaque.

A very fine-grained white or lightly tinted variety of gypsum, called alabaster, is prized for ornamental work of various sorts.

In arid areas, gypsum can occur in a flower-like form, typically opaque, with embedded sand grains called desert rose.

Details

Gypsum is common sulfate mineral of great commercial importance, composed of hydrated calcium sulfate (CaSO4·2H2O). In well-developed crystals the mineral commonly has been called selenite. The fibrous massive variety has a silky lustre and is called satin spar; it is translucent and opalescent and is valued for ornaments and jewelry. The fine-grained massive variety called alabaster is carved and polished for statuary and ornamental use when pure and translucent. Gypsite is the earthy pulverulent variety.

Gypsum occurs in extensive beds associated with other evaporite minerals (e.g., anhydrite and halite), particularly in Permian and Triassic sedimentary formations; it is deposited from ocean brine, followed by anhydrite and halite. It also occurs in considerable quantity in saline lakes and salt pans and is an important constituent of cap rock, an anhydrite-gypsum rock forming a covering on salt domes, as in Texas and Louisiana. Very commonly it is formed from the hydration of anhydrite by surface waters and groundwaters, and, thus, many gypsiferous strata grade downward into anhydrite rocks. This replacement causes a 30 percent to 50 percent volume increase and results in intense, tight folding of the remaining anhydrite layers. Gypsum also occurs disseminated in limestones, dolomitic limestones, and some shales.

Gypsum deposits occur in many countries, but Spain, Thailand, the United States, Turkey, and Russia are among the leading producers. The largest gypsum crystal was found in the Braden mine in Chile and exceeds 3 metres (about 10 feet) in length and 0.4 metre (about 1.5 feet) in diameter. In the U.S., commercial sedimentary gypsum deposits occur in New York and Michigan; others of economic importance occur in Virginia, Ohio, Iowa, Kansas, Texas, Nevada, and southern California. In Canada, gypsum is produced for export in Nova Scotia and New Brunswick. In France, gypsum is common in the marls and clays of the Paris Basin (hence the name plaster of paris), especially in Montmartre.

Crude gypsum is used as a fluxing agent, fertilizer, filler in paper and textiles, and retarder in portland cement. About three-fourths of the total production is calcined for use as plaster of paris and as building materials in plaster, Keene’s cement, board products, and tiles and blocks. Gypsum plaster is a white cementing material made by partial or complete dehydration of the mineral gypsum, commonly with special retarders or hardeners added. Applied in a plastic state (with water), it sets and hardens by chemical recombination of the gypsum with water.

For an especially hard-finish plaster, the gypsum is completely dehydrated at a high temperature, and such chemicals as alkali sulfate, alum, or borax are added. Hair or fibre and lime or clay may be added to plasters during manufacture. The plaster coats, except for some finish coats, are sanded.

Additional Information

Gypsum is a common mineral. It is found in layers that were formed under salt water millions of years ago. When water evaporated, it left the mineral behind.

Gypsum is mined from sedimentary rock formations around the world. It takes the form of crystals which can at times be found projecting from rock – leading to its old English name of the Spear Stone. The largest gypsum quarries in Europe are found in France, Germany, Italy, Poland, Spain, and the UK. There is also evidence of gypsum dunes on Mars.

Gypsum is composed of calcium sulphate (CaSO4) and water (H2O). Its chemical name is calcium sulphate dihydrate (CaSO4.2H2O).

Gypsum can be milled mixed with water and then resume its original rock-like state. This means it can be shaped and hardened. Gypsum also has a “closed recycling loop”, meaning it can be endlessly recycled while maintaining a high quality.

One alternative to natural gypsum is Flue Gas Desulphurisation Gypsum, or FGD Gypsum. This is a by-product of coal-fired power stations.

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Jai Ganesh · 2025-09-30 22:36:39

2403) Bronchospasm

Gist

Bronchospasm is the sudden tightening of muscles in the airways of the lungs, which constricts the air passages and makes breathing difficult. It is often a symptom of asthma, but can also be triggered by allergens, infections, exercise, or irritants, causing wheezing, coughing, and shortness of breath. While it can be a mild inconvenience, it can also become a severe, life-threatening condition, so proper diagnosis and treatment are crucial.

Bronchospasm is caused by irritants, allergens, infections, and underlying conditions like asthma. Common triggers include cigarette smoke, dust mites, pollen, pet dander, cold air, chemical fumes, and viral infections. Exercise, certain medications (beta-blockers, NSAIDs), and general anesthesia can also induce bronchospasm. (Non-Steroidal Anti-inflammatory Drug).

Summary

Bronchospasm or a bronchial spasm is a sudden constriction of the muscles in the walls of the bronchioles. It is caused by the release (degranulation) of substances from mast cells or basophils under the influence of anaphylatoxins. It causes difficulty in breathing which ranges from mild to severe.

Bronchospasms occur in asthma, chronic bronchitis and anaphylaxis. Bronchospasms are a possible side effect of some drugs: pilocarpine, beta blockers (used to treat hypertension), a paradoxical result of using LABA drugs (to treat COPD), and other drugs. Bronchospasms can present as a sign of giardiasis.

Some factors that contribute to bronchospasm include consuming certain foods, taking certain medicines, allergic responses to insects, and fluctuating hormone levels, particularly in women. Bronchospasms are one of several conditions associated with cold housing.

The overactivity of the bronchioles' muscle is a result of exposure to a stimulus which under normal circumstances would cause little or no response. The resulting constriction and inflammation causes a narrowing of the airways and an increase in mucus production; this reduces the amount of oxygen that is available to the individual causing breathlessness, coughing and hypoxia.

Bronchospasms are a serious potential complication of placing a breathing tube during general anesthesia. When the airways spasm or constrict in response to the irritating stimulus of the breathing tube, it is difficult to maintain the airway and the patient can become apneic. During general anesthesia, signs of bronchospasm include wheezing, high peak inspiratory pressures, increased intrinsic PEEP, decreased expiratory tidal volumes, and an upsloping capnograph (obstructive pattern). In severe cases, there may be complete inability to ventilate and loss of ETCO2 as well as hypoxia and desaturation.

LABA: Long-acting beta-adrenoceptor agonist.
COPD: Chronic obstructive pulmonary disease.
PEEP: Positive end-expiratory pressure.
ETCO2: ETCO2, or end-tidal carbon dioxide, is the concentration of carbon dioxide in the last part of an exhaled breath.

Details

Bronchospasms happen when the muscles that line the airways in your lungs tighten. It causes wheezing, coughing and other symptoms. Many things cause bronchospasm, including asthma. Medications can usually manage bronchospasm.

What Is a Bronchospasm?:

With bronchospasm, the muscles that line your bronchi tighten and make it harder for air to pass through your airways.

A bronchospasm (pronounced “BRONG-kuh-spaz-uhm”) is when the muscles that line your bronchi tighten. Your bronchi are the tubes that air travels through to get to your lungs. They connect your windpipe (trachea) to your lungs. If the muscles in your bronchi tighten or squeeze, your airways narrow. This limits how much oxygen your body receives. Bronchospasms can occur alongside many different lung conditions, including:

* Asthma
* Chronic obstructive pulmonary disease (COPD)
* Emphysema
* Lung infections
* Allergic reactions, including anaphylaxis

They can be scary because it feels like you can’t get enough air to breathe. Go to the nearest emergency room if you have sudden or severe breathing problems.

Symptoms and Causes:

What are the symptoms of bronchospasm?

The main symptom of bronchospasm is the feeling that you can’t catch your breath. Other bronchospasm symptoms include:

* Wheezing
* Chest pain or chest tightness
* Coughing
* Shortness of breath
* Dizziness
* Fatigue

What is the cause of bronchospasm?

Asthma is the most common cause of bronchospasm. But many other things can also cause irritation and swelling in your airways. Irritation and swelling can cause bronchospasm. These include:

* Allergens, like dust, pollen and pet dander
* Bacterial, fungal or viral infections in your lungs or airways
* Chemical fumes or other irritants, like perfume or cologne
* Cold or hot/humid temperatures
* Exercise (exercise-induced bronchospasm)
* General anesthesia
* Smoking or vaping
* Poor air quality

Just because you have a condition or are around a trigger, it doesn’t mean you’ll have a bronchospasm. In rare cases, bronchospasm medications like albuterol can actually make your symptoms worse. This is a paradoxical bronchospasm. If this happens, stop using your bronchodilator immediately and tell your healthcare provider. They’ll work with you to find a different treatment.

Is it contagious?

No, bronchospasms aren’t contagious. But some bronchospasm causes are contagious, like bacterial or viral infections.

Diagnosis and Tests:

How doctors diagnose bronchospasm

A healthcare provider can diagnose bronchospasm. They’ll review your medical history, ask about your symptoms and perform a physical exam. During the exam, they may listen to your lungs with a stethoscope. If they think you’re having bronchospasms, they may refer you to a pulmonologist or allergist.

What does it sound like?

Healthcare providers listen to your lungs with a stethoscope. Stethoscopes pick up very quiet sounds. When they use one, they listen for high-pitched whistling sounds.

Tests that are used

Your healthcare provider may recommend pulmonary (lung) function tests to see how well your lungs work. These may include:

* Spirometry: You use a spirometer that measures the force of air as you breathe in and out.
* Lung diffusion capacity: You breathe into a tube to determine how well oxygen transfers or diffuses between your lungs and blood.
* Lung volume assessment: This tells your provider how much air your lungs can hold.
* Pulse oximetry: Your provider places a device on your finger or ear to measure how much oxygen is in your blood.

Depending on your history, your provider may also recommend:

* Methacholine challenge or provocation tests: These test for the presence of asthma. They measure how your lungs respond to methacholine. Methacholine is a medication that can induce bronchospasm.
* Imaging tests: Chest X-rays and CT scans can help your provider see infections or other lung problems.
* Arterial blood gas: This test measures the amount of oxygen and carbon dioxide in your blood. It also measures the levels of acids and bases (alkaline) in your blood (pH level).
* Eucapnic voluntary hyperventilation: This test checks for exercise-induced bronchospasm. You breathe in a mixture of oxygen and carbon dioxide. The mixture mimics breathing during exercise.
You likely have exercise-induced bronchospasm if the mixture negatively affects your lungs.

Additional Information:

Definition

Bronchospasm is an abnormal contraction of the smooth muscle of the bronchi, resulting in an acute narrowing and obstruction of the respiratory airway. A cough with generalized wheezing usually indicates this condition.

Bronchospasm is a chief characteristic of asthma and bronchitis.

Description

Bronchospasm is a temporary narrowing of the bronchi (airways into the lungs) caused by contraction of the muscles in the lung walls, by inflammation of the lung lining, or by a combination of both.

This contraction and relaxation is controlled by the autonomic nervous system. Contraction may also be caused by the release of substances during an allergic reaction.

The most common cause of bronchospasm is asthma, though other causes include respiratory infection, chronic lung disease (including emphysema and chronic bronchitis), anaphylactic shock, or an allergic reaction to chemicals.

The bronchial muscle goes into a state of tight contraction (bronchospasm), which narrows the diameter of the bronchus. The mucosa becomes swollen and inflamed which further reduces the bronchial diameter.

In addition, bronchial glands produce excessive amounts of very sticky mucus which is difficult to cough out and which may form plugs in the bronchus, further obstructing the flow of air.

When bronchi become obstructed, greater pressures are needed to push air through them in order to meet the body's requirement for oxygen. This requires greatly increased muscular effort. Breathing during bronchospasm requires more effort than normal breathing.

The excessive amounts of sticky mucus caught in the bronchi are highly irritating, and often trigger coughing.

Causes

Excessive bronchial irritability is the root of asthma. Asthmatic attacks in children can be caused by a number of triggers:

* Allergy

When foreign substances such as bacteria, viruses or toxic substances enter the body, one of the natural defenses is the formation of antibodies - molecules which combine with the foreign substances so as to render them harmless. This process is called immunity. Allergic children form protective antibodies just as do normal children. However, the allergic child forms other kinds of antibodies - which, rather than being protective, may actually do harm.

The ones that commonly cause problems are animal dander, pollen, dusts, molds and foods. Inhalation of an allergen triggers bronchoconstriction.

* Exercise

This is a very common trigger for the symptoms in asthmatic children. This may take the form of obvious wheezing after exercise, or simply coughing.

* Emotions

Psychological stress may trigger symptoms but asthma is not a psychosomatic disease.

* Upper Respiratory Infections

When an asthmatic child has an upper respiratory infection, asthma may be triggered. Viral respiratory infections can provoke and alter asthmatic responses. Viral respiratory illnesses may produce their effect by causing epithelial damage, producing specific Immunoglobulin E (IgE) antibodies directed against respiratory viral antigens and enhancing mediator release. Antibiotics are not usually helpful -- either in clearing up the infection or in preventing bronchospasm. The best treatment of a cold is prevention through frequent handwashing.

* Irritants

There is a wide variety of substances which irritate the nose, throat or bronchi. Cigarette smoke is one of the most common, but dust, aerosol sprays, and strong odors may serve as irritants.

Symptoms

Cough is a major symptom, and may be a more important symptom than wheezing in some asthmatic children, especially infants and toddlers. Wheezing and tightness in the chest are also very common.

Diagnosis

Diagnosis is based upon the clinical exam in which wheezing, poor air flow and generalized signs of an asthma attack may be found. Chest x-ray may show little if any change from normal.

Treatment

Beta2-agonists relax airway smooth muscle and may modulate mediator release from mast cells and basophils. Beta-agonist inhalers (bronchodilators) act to ease symptoms of asthma by relaxing muscles surrounding the walls of the bronchial tubes. Most beta-agonist drugs are prescription medications. Those sold in the U.S. include albuterol (Proventil, Ventolin), bitolterol (Tornalate), isoetharine (Bronkometer), metaproterenol (Alupent), pirbuterol (Maxair), and terbutaline (Brethaire).

While anti-inflammatory drugs, such as inhaled corticosteroids or cromolyn sodium, treat the underlying inflammation that causes the airways to react and narrow, beta-agonists only treat symptoms.

Jai Ganesh · Yesterday 16:41:50

2404) Cerebral Atrophy

Gist

Cerebral atrophy is the progressive loss of neurons (brain cells) and their connections, resulting in a reduced brain volume or shrinkage. While some atrophy is normal with aging, it can also be a symptom of serious neurological conditions like dementia, stroke, or Huntington's disease, leading to cognitive, motor, and functional impairments. Diagnosis involves imaging tests like MRI, and treatment focuses on managing the underlying condition.

Symptoms of brain atrophy include memory problems, difficulty with problem-solving and decision-making, changes in mood and personality, speech and language difficulties, and impaired motor skills such as coordination and balance. The specific symptoms depend on the affected areas of the brain, and some symptoms like sudden confusion or severe memory loss warrant immediate medical attention.

Summary

Cerebral atrophy is a common feature of many of the diseases that affect the brain. Atrophy of any tissue means a decrement in the size of the cell, which can be due to progressive loss of cytoplasmic proteins. In brain tissue, atrophy describes a loss of neurons and the connections between them. Brain atrophy can be classified into two main categories: generalized and focal atrophy. Generalized atrophy occurs across the entire brain whereas focal atrophy affects cells in a specific location. If the cerebral hemispheres (the two lobes of the brain that form the cerebrum) are affected, conscious thought and voluntary processes may be impaired.

Some degree of cerebral shrinkage occurs naturally with the dynamic process of aging. Structural changes continue during adulthood as brain shrinkage commences after the age of 35, at a rate of 0.2% per year. The rate of decline is accelerated when individuals reach 70 years old. By the age of 90, the human brain will have experienced a 15% loss of its initial peak weight. Besides brain atrophy, aging has also been associated with cerebral microbleeds.

Details

Brain atrophy refers to a loss of brain cells, or a loss in the number of connections between brain cells. It can occur as a result of the natural aging process, injury, infection, or certain health conditions.

There are two main types of brain atrophy: focal atrophy, which occurs in specific brain regions, and generalized atrophy, which occurs across the brain.

People who experience brain atrophy typically develop lower cognitive functioning as a result of this type of brain damage.

This article describes the symptoms and causes of brain atrophy.

Symptoms of brain atrophy

The symptoms of brain atrophy will vary depending on the location of the atrophy and its severity. They may include:

Seizures

A seizure is a sudden spike of electrical activity in the brain. There are two main types of seizure: partial seizures, which affects just one part of the brain, and generalized seizures, which affects both sides of the brain.

The symptoms of a seizure depend on which part of the brain it affects. Some people may not experience any noticeable symptoms, whereas others may experience one or more of the following:

* behavioral changes
* jerking eye movements
* a bitter or metallic taste in the mouth
* drooling or frothing at the mouth
* teeth clenching
* grunting and snorting
* muscle spasms
* convulsions
* loss of consciousness

Aphasia

Aphasia refers to a group of symptoms that affect a person’s ability to communicate. Some types of aphasia can affect a person’s ability to produce or understand speech. Others can affect a person’s ability to read or write.

According to the National Aphasia Association, there are eight different types of aphasia. The type of aphasia a person experiences depends on the part or parts of the brain that sustain damage.

Some cases of aphasia are relatively mild, whereas others may severely impair a person’s ability to communicate.

Dementia

Dementia refers to a continuing decline in brain function. The symptoms may include:

* memory loss
* difficulty with reasoning or judgment
* difficulty with language or communication
* problems with movement and coordination
* mood or personality changes
* hallucinations
* difficulty carrying out daily activities

There are several different types of dementia. Alzheimer’s disease is the most common.

A person’s risk of dementia increases with age. However, it is not a natural part of the aging process.

Causes of brain atrophy

Brain atrophy can occur as a result of injury, either from a traumatic brain injury (TBI) or a stroke. It may also occur as a result of one of infections, such as HIV or those that cause brain inflammation (encephalitis).

In some cases, brain atrophy may occur as a result of a chronic condition, such as:

* multiple sclerosis (MS)
* Huntington’s disease
* Alzheimer’s disease
* Parkinson’s disease
* cerebral palsy
* leukodystrophies, which are a group of rare genetic conditions affecting the nervous system

Diagnosis

When diagnosing brain atrophy, a doctor may begin by taking a full medical history and asking about a person’s symptoms. This may include asking questions about when the symptoms began and if there was an event that triggered them.

The doctor may also carry out language or memory tests or other specific tests of brain function.

If they suspect that a person has brain atrophy, they will need to locate the brain damage and assess its severity. This will require an MRI or CT scan.

Additional Information

Brain atrophy (cerebral atrophy) is a loss of neurons and connections between neurons. Different conditions cause brain atrophy, including cerebral palsy, dementia and infectious diseases. Symptoms and severity of brain atrophy depend on the specific disease and location of damage. Treatment involves managing the underlying disorder.

What is brain atrophy?

People with brain atrophy, also called cerebral atrophy, lose brain cells (neurons), and connections between their brain cells and brain volume often decreases. This loss can lead to problems with thinking, memory and performing everyday tasks. The greater the loss, the more impairment someone has.

There are two types of brain atrophy:

* Focal: Damage occurs in one area of your brain.
* Generalized: Damage expands to your entire brain.

Is brain atrophy a normal part of aging?

People lose some brain cells as they get older, and brain volume decreases as well, but healthcare providers use the term “brain atrophy” when a person has more brain changes than expected for age. Here, the damage happens faster than the typical aging process.

Who is at risk for brain atrophy?

Some factors may increase your chances of developing brain atrophy, such as:

* Advanced age.
* Family history of genetic disorders, such as Huntington’s disease.
* Family history of neurological disorders, such as Alzheimer’s disease.
* Head or brain injury.
* Heavy drinking (alcohol use disorder).
* Smoking.

Does brain atrophy lead to dementia?

There’s a connection between brain atrophy and dementia. Specifically, dementia causes extreme brain atrophy. Dementia is a general term that describes severe thinking problems that interfere with daily life.

The most common type of dementia is Alzheimer’s disease.

Does brain atrophy cause aphasia?

People with aphasia (speaking and language problems) as part of an underlying neurodegenerative disease like Alzheimer’s disease often have brain atrophy as well. Here, damage occurs in areas responsible for producing and processing language. This disorder ranges in severity. Some people have trouble recalling the correct name for people, places and things. Others are completely unable to communicate.

Symptoms and Causes:

What causes brain atrophy?

Many different disorders, neurodegenerative diseases, infectious diseases and severe injuries can cause brain atrophy, including:

* Cerebral palsy.
* Encephalitis.
* HIV and AIDS.
* Huntington’s disease.
* Leukodystrophies.
* Multiple sclerosis.
* Stroke.
* Syphilis.
* Traumatic brain injury.
* Alzheimer’s disease.

What are the symptoms of brain atrophy?

Symptoms of brain atrophy vary depending on which specific part of your brain is damaged. Symptoms also range from mild to severe.

In general, brain atrophy happens with various conditions, and symptoms can vary to include:

Aphasia

* Difficulty speaking.
* Difficulty writing.
* Inability to understand the meaning of words.

Dementia

* Hallucinations.
* Loss of language.
* Memory problems.
* Mood and personality changes.
* Poor judgment.

Seizures

* Bitter or metallic taste.
* Convulsions.
* Loss of consciousness.
* Spasms.
* Teeth clenching.

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Math Is Fun Forum

#2601 2025-09-28 17:40:16

Re: Miscellany

#2602 2025-09-29 19:05:00

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#2603 2025-09-30 22:36:39

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#2604 Yesterday 16:41:50

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