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The distal nephron in the kidney of fishes. The females depart and territories may change hands. Electrophysiological evidence for Cl secretion in shark renal proximal tubules. Intracellular microelectrode measurements in the diluting segment of the amphibian nephron [Abstract]. The term adolescent and young people are often used interchangeably, as are the terms Adolescent Health and Youth Health.

What Is a Reptile?

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In primitive marine animals the blood is almost identical with seawater in composition; in typical freshwater animals the concentration of the blood is about half that of seawater. The earliest fossil vertebrates are found in marine deposits, but the fossil record shows clearly that the early evolution of fishes took place in fresh water. It is assumed that the blood of early freshwater fishes, like that of other freshwater animals, was osmotically equivalent to half-strength seawater.

The sharks and rays returned to the sea during the Carboniferous Period , and no doubt at that time they evolved the device of urea retention. The bony fishes returned to the sea later, in the Mesozoic Era , and solved their problem by swallowing seawater and rejecting excess salt at the gills.

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Evolution of the vertebrate excretory system Studies of the embryonic development of primitive vertebrates, such as the dogfish shark, clearly show that the excretory system arises from a series of tubules, one pair in every segment of the body between the heart and the tail. Page 11 of Learn More in these related Britannica articles: The biosphere is a global ecosystem composed of living organisms biota and the abiotic nonliving factors from which they derive energy and nutrients.

An organism can minimize the potential damage of absorbed toxins by excreting the chemical or by changing the chemical into a different chemical biotransformation , or by both methods.

The body can excrete exogenous chemicals in the urine, bile, sweat, or milk; the lungs can…. The blood carries the waste products of cellular metabolism to the excretory organs. The removal of carbon dioxide via the lungs has been described above. Water produced by the oxidation of foods or available from other sources in excess of needs is excreted by…. The muscular structure of the diaphragm in the Crocodilians species resembles that of various mammals.

However, there are some differences in their diaphragmatic setup. They also have two aortas playing a major role in their systemic circulation. The oxygenated and deoxygenated blood may get mixed with each other in their three-chambered heart with the level of mixing depending on the species and the physiological state of the animal.

Their circulatory system is capable of shunting back the deoxygenated blood to the body and the oxygenated blood to the lungs if necessary. Unlike other Reptiles, animals in the crocodilian subgroup have four-chambered hearts. But, their two systemic aortas are only capable of bypassing their pulmonary circulation. On the other hand, the three-chambered hearts in various lizard and snake species can function as the four-chambered ones during contraction. Majority of these animals have short digestive tracts because their diet mainly consists of meat, which is very simple to digest.

Their digestion process is slower than that in mammals due to their inability of mastication and their low metabolism rate while resting. The energy requirements for their poikilotherm metabolism are very low which allows large animals from this class such as various constrictors and crocodiles to survive for months from one large meal, digesting it slowly.

Herbivorous reptiles are also unable to masticate their food, which slows down the digestive process. Some species are known to swallow pebbles and rocks that help in grinding up plant matters within the stomach, assisting their digestion.

The basic nervous system in the Reptiles is similar to that in the Amphibians. But, Reptiles have slightly larger cerebrum and cerebellum. Most of the important sensory organs are properly developed in these creatures. However, there are certain exceptions such as the absence of external ears in snakes they have the inner and middle ears. Reptiles have twelve cranial nerve pairs. They have to use electrical tuning for expanding the range of their audible frequencies because they have short cochlea.

These animals are believed to be less intelligent compared to mammals and birds because the relative size of their brain and body is much smaller than that of the latter. However, the brain development can be more complex in some larger Reptiles. Modern species also have pineal glands in their brains. Most of these animals are tetrapods, meaning they have four legs. Snakes are examples of legless Reptiles. Their skeletal system is similar to other tetrapods with a spinal column supporting their bodies.

Their excretory system consists of two small kidneys. The diapsid species excrete uric acid as the principal nitrogenous waste product. But, turtles excrete mainly urea. Some of these species use their colons for reabsorbing water, while some are able to absorb the water stored in their bladders.

Certain Reptiles excrete the excess salts in their bodies through the lingual and nasal salt glands. Reptiles have certain characteristic features that help in distinguishing them from Amphibians, Mammals and Aves:. They are capable of adapting to almost all kinds of habitats and environmental conditions, except for extremely cold regions. These animals can inhabit dry deserts, forests, grasslands, wet meadows, shrub lands and even marine habitats.

Reptiles are capable of adapting to extremely high temperatures because they are cold blooded. Various snakes including the Rattle Snakes and King Snakes as well as different lizards like the Gila Monsters live in desert habitats. Grassland is another common type of habitat for various snakes and lizards e.

Garter Snakes, Fox Snakes. The vegetation in this habitat attracts many insects and rodents, making it easier for the Reptiles to catch prey. Swamps and large water bodies are inhabited by different Reptiles such as crocodiles, alligators, certain turtles and snakes. Animals like the Saltwater Crocodile and Marine Iguana inhabit seaside, travelling in and out of ocean as necessary. Some species, such as the Sea Snakes and Sea Turtles, live in the ocean. They leave the waters only during the breeding season for laying eggs.

These animals typically practice sexual reproduction with some specific species using asexual reproduction. Majority of these animals are amniotes, laying eggs covered with calcareous or leathery shells. The eggs are generally laid in underground burrows dug by the females. The viviparity and ovoviviparity modes of reproduction are used by many species such as all boas and many vipers. However, the level of viviparity may vary with some species retaining their eggs until shortly before hatching while others nourish the eggs for supplementing the yolks.

In some Reptile species, the eggs do not have any yolk with the adults providing all the necessary nourishment through a structure resembling the mammalian placenta.

Six lizard families and one snake family from the Squamata sub-group are known to be capable of agamogenesis or asexual reproduction. In some squamate species, the females are capable of giving birth to unisexual diploid clones of themselves. This type of asexual reproduction is known as parthenogenesis, occurring in various teiid lizards, geckos and lacertid lizards. Komodo dragons have reproduced through parthenogeny in captivitiy. Like many mammals, birds and Amphibians, their embryonic life consists of an amnion, chorion, as well as an allantois.

The incubation period may vary depending on the species and other factors like the temperature of the surroundings. Usually, hatchlings are able to take care of themselves almost immediately after coming out of the eggs. But, the females of some species are known to protect their eggs and hatchlings.

For example, female Pythons coil themselves around the eggs in order to protect them and regulate their temperature. Similarly, crocodiles are known to guard their young after the eggs hatch. TDSD or temperature-dependent sex determination can be observed in many Reptiles. In TDSD, the incubation temperature determines the sex of the offspring. This characteristic is most commonly seen in crocodiles and turtles, but can also occur in tuataras and lizards.

Different food habits can be observed between the four sub-groups. Baseline Medical History is information gained by a physician by asking specific questions , either of the patient or of other people who know the person and can give suitable information in this case, it is sometimes called heteroanamnesis , with the aim of obtaining information useful in formulating a diagnosis and providing medical care to the patient.

The medically relevant complaints reported by the patient or others familiar with the patient are referred to as symptoms, in contrast with clinical signs, which are ascertained by direct examination on the part of medical personnel.

Most health encounters will result in some form of history being taken Diagnostic Test or Medical Test is a kind of medical procedure performed to detect, diagnose, or monitor diseases, disease processes, susceptibility, and determine a course of treatment. It is related to clinical chemistry and molecular diagnostics, and the procedures are typically performed in a medical laboratory. Vitals are body functions essential for life.

Diagnosis is the identification of the nature and cause of a certain phenomenon. Medical Diagnosis is the process of determining which disease or condition explains a person's symptoms and signs. Testing and Examinations - Software Testing Assessment Errors observation flaws Monitoring medicine is the observation of a disease, condition or one or several medical parameters over time.

Transmitting data from a monitor to a distant monitoring station is known as telemetry or biotelemetry. Bioinformatics are methods and software tools for understanding biological data. Body Burden Test Triage is the process of determining the priority of patients' treatments based on the severity of their condition.

Endopat non-invasive assessment of Endothelial Dysfunction arterial health , is a functional test for early detection of underlying disease progression. Problem solving is a skill that everyone should master. Biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist involving extraction of sample cells or tissues for examination to determine the presence or extent of a disease.

Pathology is a significant component of the causal study of disease and a major field in modern medicine and diagnosis. Autopsy is a highly specialized surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause and manner of death and to evaluate any disease or injury that may be present.

It is usually performed by a specialized medical doctor called a pathologist. Also known as a post-mortem examination, obduction, necropsy, or autopsia cadaverum. Diagnostic Tests - Advanced Sensors Biomarker is a measurable indicator of the severity or presence of some disease state.

More generally a biomarker is anything that can be used as an indicator of a particular disease state or some other physiological state of an organism. Lab on a Chip is a device that integrates one or several laboratory functions on a single integrated circuit commonly called a "chip" of only millimeters to a few square centimeters to achieve automation and high-throughput screening.

LOCs can handle extremely small fluid volumes down to less than pico liters. LOCs may use microfluidics, the physics, manipulation and study of minute amounts of fluids.

Jack Andraka video and text Body Parts on a Chip video and text Microfluidics deals with the behaviour, precise control and manipulation of fluids that are geometrically constrained to a small, typically sub-millimeter, scale. Lego Organ on a Chip is a multi-channel 3-D microfluidic cell culture chip that simulates the activities, mechanics and physiological response of entire organs and organ systems, a type of artificial organ. The versatile use of exhaled volatile organic compounds in human health and disease.

Exhaled breath contains thousands of volatile organic compounds VOCs of which the composition varies depending on health status. Various metabolic processes within the body produce volatile products that are released into the blood and will be passed on to the airway once the blood reaches the lungs.

Consequently, measuring the total amount of VOCs in exhaled air, a kind of metabolomics also referred to as breathomics. Scientists have found a potentially useful link between the presence of exhaled acinetobacter baumannii derived volatile organic compounds VOCs and patients diagnosed with bacterial pneumonia. Lab Testing Facilities - Heart Diagnostics Flexible Electronics Capturing Brain Signals with Soft Electronics using long-term stable neural recording based on a novel elastic material composite, which is biocompatible and retains high electrical conductivity even when stretched to double its original length.

A team of engineers has developed stretchable fuel cells that extract energy from sweat and are capable of powering electronics, such as LEDs and Bluetooth radios. The biofuel cells generate 10 times more power per surface area than any existing wearable biofuel cells.

The devices could be used to power a range of wearable devices. A new medical-diagnostic device made out of paper detects biomarkers and identifies diseases by performing electrochemical analyses -- powered only by the user's touch -- and reads out the color-coded test results, making it easy for non-experts to understand.

The top layer of the SPED is fabricated using untreated cellulose paper with patterned hydrophobic "domains" that define channels that wick up blood samples for testing. These "microfluidic channels" allow for accurate assays that change color to indicate specific testing results.

A machine-vision diagnostic application also was created to automatically identify and quantify each of these "colorimetric" tests from a digital image of the SPED, perhaps taken with a cellphone, to provide fast diagnostic results to the user and to facilitate remote-expert consultation. The bottom layer of the SPED is a " triboelectric generator ," or TEG, which generates the electric current necessary to run the diagnostic test simply by rubbing or pressing it.

The researchers also designed an inexpensive handheld device called a potentiostat, which is easily plugged into the SPED to automate the diagnostic tests so that they can be performed by untrained users.

The SPEDs were used to detect biomarkers such as glucose, uric acid and L-lactate, ketones, and white blood cells, which indicate factors related to liver and kidney function, malnutrition and anemia.

Future versions of the technology will contain several additional layers for more complex assays to detect diseases such as dengue fever, yellow fever, malaria, HIV and hepatitis.

Laboratory is a facility that provides controlled conditions in which scientific or technological research , experiments , and measurement may be performed. Medical Laboratory is a laboratory where tests are usually done on clinical specimens in order to obtain information about the health of a patient as pertaining to the diagnosis , treatment, and prevention of disease.

Clinical laboratories are thus focused on applied science mainly on a production-like basis, as opposed to research laboratories that focus on basic science on an academic basis.

A synthetic, injectable hydrogel developed to deliver drugs and encourage tissue growth turns out to have therapeutic properties all its own.

Food Sensors - Sensors ai Surgery Surgeon is a doctor who performs operations, which is a medical procedure involving an incision with instruments; performed to repair damage or arrest disease in a living body. Incision is cutting of or into body tissues or organs.

Surgeons may be physicians, podiatrists, dentists, or veterinarians. Surgery Encyclopedia Universal Anesthesia Machine Onebreath low-cost Ventilator Surgery Simulator Color Coded Surgery video Ultrasound Surgery video Web Robotic Surgery Invasive Surgical Procedure refers to surgical techniques that limit the size of incisions needed and so lessens wound healing time, associated pain and risk of infection.

An endovascular aneurysm repair as an example of minimally invasive surgery is much less invasive in that it involves much smaller incisions, than the corresponding open surgery procedure of open aortic surgery.

A new type of implant scaffold to provide localised drug treatment and prevent infection. Battling bacterial infection with hexamethylene diisocyanate cross-linked and Cefaclor-loaded collagen scaffolds. Organ Transplants Organ Transplantation is a medical procedure in which an organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ.

The donor and recipient may be at the same location, or organs may be transported from a donor site to another location. Transplants that are recently performed between two subjects of the same species are called allografts.

Allografts can either be from a living or cadaveric source. T-Cells Organ Donation is when a person allows to be removed, legally, either by consent while the donor is alive or after death with the assent of the next of kin. Donation may be for research, or, more commonly healthy transplantable organs and tissues may be donated to be transplanted into another person.

Some organs and tissues can be donated by living donors , such as a kidney or part of the liver, but most donations occur after the donor has died.

As of August 1, , there are , people waiting for life-saving organ transplants in the US. Of these, 96, await kidney transplants. While views of organ donation are positive there is a large gap between the numbers of registered donors compared to those awaiting organ donations on a global level. Presumed consent is alternatively known as an 'opt-out' system and means that unless the deceased has expressed a wish in life not to be an organ donor then consent will be assumed.

In opt-out systems , organ donation will occur automatically unless a specific request is made before death for organs not to be taken. Every day, over 75 people in the United States get an organ transplant.

Vertebrate Renal System