Lepidotrichia are bony, bilaterally-paired, segmented fin rays found in bony fishes. July 28, at 4: Systemic enzymes help other processes in the body and control swelling, reduce fibrin a blood-clotting factor levels, thin mucus, support cardiovascular and joint health, and more. Publication Policies and Ethics. The Journal is using Editorial Manager System for online manuscript submission, review and tracking. At first the waste is in a liquid state, but as it moves through the colon, the water is removed and it becomes the solid form of stool. It is thought that the original selective advantage garnered by the jaw was not related to feeding, but to increased respiration efficiency.
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Fins located in different places on the fish serve different purposes, such as moving forward, turning, and keeping an upright position. For every fin, there are a number of fish species in which this particular fin has been lost during evolution.
In bony fish, most fins may have spines or rays. A fin may contain only spiny rays, only soft rays, or a combination of both. If both are present, the spiny rays are always anterior. Spines are generally stiff, sharp and unsegmented.
Rays are generally soft, flexible, segmented, and may be branched. This segmentation of rays is the main difference that distinguishes them from spines; spines may be flexible in certain species, but never segmented.
Spines have a variety of uses. In catfish , they are used as a form of defense; many catfish have the ability to lock their spines outwards. Triggerfish also use spines to lock themselves in crevices to prevent them being pulled out. Lepidotrichia are bony, bilaterally-paired, segmented fin rays found in bony fishes.
They develop around actinotrichia as part of the dermal exoskeleton. Lepidotrichia may have some cartilage or bone in them as well. They are actually segmented and appear as a series of disks stacked one on top of another. The genetic basis for the formation of the fin rays is thought to be genes coding for the proteins actinodin 1 and actinodin 2.
As with other vertebrates, the intestines of fish consist of two segments, the small intestine and the large intestine. In most higher vertebrates, the small intestine is further divided into the duodenum and other parts. In fish, the divisions of the small intestine are not as clear, and the terms anterior intestine or proximal intestine may be used instead of duodenum.
It commonly has a number of pyloric caeca , small pouch-like structures along its length that help to increase the overall surface area of the organ for digesting food. There is no ileocaecal valve in teleosts, with the boundary between the small intestine and the rectum being marked only by the end of the digestive epithelium.
Instead, the digestive part of the gut forms a spiral intestine , connecting the stomach to the rectum. In this type of gut, the intestine itself is relatively straight, but has a long fold running along the inner surface in a spiral fashion, sometimes for dozens of turns.
This fold creates a valve-like structure that greatly increases both the surface area and the effective length of the intestine. The lining of the spiral intestine is similar to that of the small intestine in teleosts and non-mammalian tetrapods.
Hagfish have no spiral valve at all, with digestion occurring for almost the entire length of the intestine, which is not subdivided into different regions. The pyloric caecum is a pouch, usually peritoneal , at the beginning of the large intestine. It receives faecal material from the ileum , and connects to the ascending colon of the large intestine.
It is present in most amniotes , and also in lungfish. Their purpose is to increase the overall surface area of the digestive epithelium, therefore optimizing the absorption of sugars, amino acids, and dipeptides, among other nutrients.
As with other vertebrates, the relative positions of the esophageal and duodenal openings to the stomach remain relatively constant. As a result, the stomach always curves somewhat to the left before curving back to meet the pyloric sphincter. However, lampreys , hagfishes , chimaeras , lungfishes , and some teleost fish have no stomach at all, with the esophagus opening directly into the intestine.
These fish consume diets that either require little storage of food, or no pre-digestion with gastric juices, or both. The kidneys of fish are typically narrow, elongated organs, occupying a significant portion of the trunk. They are similar to the mesonephros of higher vertebrates reptiles, birds and mammals. The kidneys contain clusters of nephrons , serviced by collecting ducts which usually drain into a mesonephric duct.
However, the situation is not always so simple. In cartilaginous fish there is also a shorter duct which drains the posterior metanephric parts of the kidney, and joins with the mesonephric duct at the bladder or cloaca.
Indeed, in many cartilaginous fish, the anterior portion of the kidney may degenerate or cease to function altogether in the adult. They consist of a row of nephrons, each emptying directly into the mesonephric duct. The spleen is found in nearly all vertebrates. It is a non-vital organ, similar in structure to a large lymph node. It acts primarily as a blood filter, and plays important roles in regard to red blood cells and the immune system.
Even in these animals, there is a diffuse layer of haematopoeitic tissue within the gut wall, which has a similar structure to red pulp, and is presumed to be homologous with the spleen of higher vertebrates. The liver is a large vital organ present in all fish. It has a wide range of functions, including detoxification , protein synthesis , and production of biochemicals necessary for digestion. It is very susceptible to contamination by organic and inorganic compounds because they can accumulate over time and cause potentially life-threatening conditions.
Because of the liver's capacity for detoxification and storage of harmful components, it is often used as an environmental biomarker. Fish have what is often described as a two-chambered heart ,  consisting of one atrium to receive blood and one ventricle to pump it,  in contrast to three chambers two atria, one ventricle of amphibian and most reptile hearts and four chambers two atria, two ventricles of mammal and bird hearts.
Ostial valves, consisting of flap-like connective tissues, prevent blood from flowing backward through the compartments. The ventral aorta delivers blood to the gills where it is oxygenated and flows, through the dorsal aorta , into the rest of the body. In tetrapods , the ventral aorta has divided in two; one half forms the ascending aorta , while the other forms the pulmonary artery.
The circulatory systems of all vertebrates , are closed. Fish have the simplest circulatory system, consisting of only one circuit, with the blood being pumped through the capillaries of the gills and on to the capillaries of the body tissues. This is known as single cycle circulation. In the adult fish, the four compartments are not arranged in a straight row but, instead form an S-shape with the latter two compartments lying above the former two.
This relatively simpler pattern is found in cartilaginous fish and in the ray-finned fish. In teleosts , the conus arteriosus is very small and can more accurately be described as part of the aorta rather than of the heart proper.
The conus arteriosus is not present in any amniotes , presumably having been absorbed into the ventricles over the course of evolution. Similarly, while the sinus venosus is present as a vestigial structure in some reptiles and birds, it is otherwise absorbed into the right atrium and is no longer distinguishable. The swim bladder or gas bladder is an internal organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth, ascend, or descend without having to waste energy in swimming.
The bladder is found only in the bony fishes. In the more primitive groups like some minnows , bichirs and lungfish , the bladder is open to the esophagus and doubles as a lung. It is often absent in fast swimming fishes such as the tuna and mackerel families. The condition of a bladder open to the esophagus is called physostome , the closed condition physoclist. In the latter, the gas content of the bladder is controlled through a rete mirabilis , a network of blood vessels effecting gas exchange between the bladder and the blood.
Fishes of the superorder Ostariophysi possess a structure called the Weberian apparatus , a modification which allow them to hear better. This ability which may well explain the marked success of otophysian fishes. This allows the transmission of vibrations to the inner ear. A fully functioning Weberian apparatus consists of the swim bladder, the Weberian ossicles, a portion of the anterior vertebral column, and some muscles and ligaments.
Fish reproductive organs include testes and ovaries. In most species, gonads are paired organs of similar size, which can be partially or totally fused. The genital papilla is a small, fleshy tube behind the anus in some fishes, from which the sperm or eggs are released; the sex of a fish often can be determined by the shape of its papilla. Most male fish have two testes of similar size. In the case of sharks , the testis on the right side is usually larger.
The primitive jawless fish have only a single testis, located in the midline of the body, although even this forms from the fusion of paired structures in the embryo. Under a tough membranous shell, the tunica albuginea , the testis of some teleost fish, contains very fine coiled tubes called seminiferous tubules.
The tubules are lined with a layer of cells germ cells that from puberty into old age, develop into sperm cells also known as spermatozoa or male gametes. The developing sperm travel through the seminiferous tubules to the rete testis located in the mediastinum testis , to the efferent ducts , and then to the epididymis where newly created sperm cells mature see spermatogenesis.
The sperm move into the vas deferens , and are eventually expelled through the urethra and out of the urethral orifice through muscular contractions. However, most fish do not possess seminiferous tubules. Instead, the sperm are produced in spherical structures called sperm ampullae.
These are seasonal structures, releasing their contents during the breeding season, and then being reabsorbed by the body. Before the next breeding season, new sperm ampullae begin to form and ripen. The ampullae are otherwise essentially identical to the seminiferous tubules in higher vertebrates, including the same range of cell types. In terms of spermatogonia distribution, the structure of teleosts testes has two types: Fish can present cystic or semi-cystic spermatogenesis in relation to the release phase of germ cells in cysts to the seminiferous tubules lumen.
Many of the features found in ovaries are common to all vertebrates, including the presence of follicular cells and tunica albuginea There may be hundreds or even millions of fertile eggs present in the ovary of a fish at any given time. Fresh eggs may be developing from the germinal epithelium throughout life. Corpora lutea are found only in mammals, and in some elasmobranch fish; in other species, the remnants of the follicle are quickly resorbed by the ovary. In some elasmobranchs , only the right ovary develops fully.
In the primitive jawless fish , and some teleosts, there is only one ovary, formed by the fusion of the paired organs in the embryo. Fish ovaries may be of three types: In the first type, the oocytes are released directly into the coelomic cavity and then enter the ostium , then through the oviduct and are eliminated. Secondary gymnovarian ovaries shed ova into the coelom from which they go directly into the oviduct.
In the third type, the oocytes are conveyed to the exterior through the oviduct. Cystovaries characterize most teleosts, where the ovary lumen has continuity with the oviduct. Fish typically have quite small brains relative to body size compared with other vertebrates, typically one-fifteenth the brain mass of a similarly sized bird or mammal.
Fish brains are divided into several regions. At the front are the olfactory lobes , a pair of structures that receive and process signals from the nostrils via the two olfactory nerves. The olfactory lobes are very large in fish that hunt primarily by smell, such as hagfish, sharks, and catfish. Behind the olfactory lobes is the two-lobed telencephalon , the structural equivalent to the cerebrum in higher vertebrates. In fish the telencephalon is concerned mostly with olfaction.
The forebrain is connected to the midbrain via the diencephalon in the diagram, this structure is below the optic lobes and consequently not visible. The diencephalon performs functions associated with hormones and homeostasis.
This structure detects light, maintains circadian rhythms, and controls color changes. These are very large in species that hunt by sight, such as rainbow trout and cichlids. The hindbrain or metencephalon is particularly involved in swimming and balance. The brain stem or myelencephalon is the brain's posterior.
Vertebrates are the only chordate group to exhibit a proper brain. A slight swelling of the anterior end of the dorsal nerve cord is found in the lancelet , though it lacks the eyes and other complex sense organs comparable to those of vertebrates. Other chordates do not show any trends towards cephalisation. The front end of the nerve tube is expanded by a thickening of the walls and expansion of the central canal of spinal cord into three primary brain vesicles: The prosencephalon forebrain , mesencephalon midbrain and rhombencephalon hindbrain , further differentiated in the various vertebrate groups.
Vesicles of the forebrain are usually paired, giving rise to hemispheres like the cerebral hemispheres in mammals. The circuits in the cerebellum are similar across all classes of vertebrates , including fish, reptiles, birds, and mammals.
There is considerable variation in the size and shape of the cerebellum in different vertebrate species. In amphibians , lampreys , and hagfish , the cerebellum is little developed; in the latter two groups, it is barely distinguishable from the brain-stem. Although the spinocerebellum is present in these groups, the primary structures are small paired nuclei corresponding to the vestibulocerebellum.
The cerebellum of cartilaginous and bony fishes is extraordinarily large and complex. In at least one important respect, it differs in internal structure from the mammalian cerebellum: The fish cerebellum does not contain discrete deep cerebellar nuclei.
Instead, the primary targets of Purkinje cells are a distinct type of cell distributed across the cerebellar cortex, a type not seen in mammals.
In mormyrid fish a family of weakly electrosensitive freshwater fish , the cerebellum is considerably larger than the rest of the brain put together. A digestive enzyme supplement enhances digestion to get the full nutritional value of food. As active protein molecules, enzymes do not accumulate in the body. It sets standards for ingredients.
In the case of enzymes, FCC is a standard assay used to accurately determine the activity of enzymes. Take 2 capsules twice daily. For digestive support, take enzymes at mealtime with first bite of food.
For systemic support, take at least 30 minutes before or 2 hours after a meal with a full glass of purified water. Keep out of reach of children. Consult your healthcare provider if pregnant, nursing, taking blood thinners or for any additional concerns. Digestive enzymes, such as amylase, protease and lipase break down foods into smaller components that are more easily absorbed. Enzymes are secreted throughout the digestive tract.
Beginning in the mouth, starches and fats break down as they are chewed and mixed with saliva, which contains amylase ptyalin and lingual lipase. Once swallowed, it travels to the stomach where protease pepsin begins to break down protein into smaller peptides and amino acids. This mixture is transferred to the first part of the small intestine. A number of proteases trypsinogen and chymotrypsinogen, for example are released with pancreatic lipase and amylase from the pancreas in their inactive forms into the small intestine where they are activated.
Systemic enzymes help other processes in the body and control swelling, reduce fibrin a blood-clotting factor levels, thin mucus, support cardiovascular and joint health, and more. Systemic enzymes have been used in many types of therapy and it has been suggested that enzyme supplementation is probably beneficial for most people.
This codex standardizes the activity units of enzymes for easy comparison. Historically, enzymes have been measured using different units at the discretion of the manufacturer or scientist measuring activity. There is now an attempt within the nutraceutical industry to use standardized measurements so that materials are comparable from product to product and between suppliers. Compounding this problem is the fact that there are often many grades of raw materials available from raw material suppliers, meaning that you must multiply the activity per gram of the particular enzyme by the weight of the amount that is used per serving in order to calculate the activity of the amount that you are ingesting.
This can be listed in different ways on supplement labels, so it is important to make sure you understand what you're getting. The VeganZyme label indicates the activity per serving for ease of use. If you are trying to compare a number of different products that use different units of activity, it may not be possible since they may measure completely different actions for which there is no equivalency.
Research has shown that older people and people with chronic disease have fewer enzymes in their saliva, urine, and tissue. Enzymes are essential and if your enzyme levels are dropping, supplemental digestive enzymes can help improve your health and bring your systems into balance.
In most cases, digestive enzymes can safely be taken with medications. However, discuss with your healthcare provider. Prescription blood thinning agents are one item of caution and absolutely require a consultation with your physician before beginning an enzyme regimen. Wobenzyme N is a popular enzyme formula containing 5 essential enzymes: Try it on different areas of the mouth! Are our senses really so strictly divided?
Try putting your toothpick of lemon juice where sweet should be, or your sugar where salty should be! Moving along through the digestive process, our mouth does a lot more than just taste your food!
When you take a bite of something like a crunchy apple your mouth produces saliva , a liquid containing enzymes that softens and dissolves your food. Your teeth mash together, chomping and breaking things down smaller pieces. Your tongue pushes the pieces of food together into a lump of chewed food called a bolus. When you swallow the bolus, your esophagus muscles swing into action to start pushing your food down toward your stomach.
Once your food is pushed into your stomach, the real digestive action begins! While it is called the small intestine because of its diameter just about 1 inch , this organ is actually quite large, ranging from 10 ft to 22 ft in length!
It is here where the vast majority of the nutrients are absorbed from your food! Once your food has traveled through your small intestine, it makes its way through the large intestine!
The large intestine is only 5 feet in length, but has a diameter of about 2. Your large intestine will also absorb most of the water from the slop, leaving behind a semi-solid mass of waste material. From here, it will be stored in the rectum until it can be eliminated from your body as fecal waste poop!
Set this aside for later use. Take your peanut butter sandwich and break it up into tiny pieces. Put the pieces into the sandwich bag and add your water.
This will act as the saliva, further breaking down your food. Add the acid into your bag, simulating the hydrochloric stomach acids that work to break down your food. Continue mashing your food, pretending that your hands are acting as stomach muscles!
Take your nylon tube and hold it over your shallow pan. Pour your chyme into the nylon. Start squeezing the chyme through the nylon. This would be the nutrient rich material that is absorbed through the small intestine!
If you want to get really detailed, you can roll it into a nice shape, and examine your handiwork. You should have a nice round pile of…. Now, there is a much more palatable way of appreciating our digestive system. One of our favorite projects of all time, was when I surprised my daughter and niece with making our very own digestive system anatomy cake!
It was really easy, and really fun! Cake Mix and the supplies for baking! Take your kids to the dollar store and pick out a bunch of candy! Have them make a list before you go, detailing what kind of candy they might use for each organ.
We ended up using the following candies: We used a simple box cake. I let the kids bake the cake themselves, which gave an added bonus lesson of math and measurements in the kitchen! Tape that down as well.