Character and classification of Aschelminthes,
These are the group of the animal in which the space inside the body is pseudocoel. It is not a true coelom and is represented a persistent embryonic blastocoel. these are mostly aquatic ,comprises of sense organ, the digestive system is complete with mouth and these group of animal is known as pseudocoelomates.These animal are classified into one large group and three small groups.
Summary
These are the group of the animal in which the space inside the body is pseudocoel. It is not a true coelom and is represented a persistent embryonic blastocoel. these are mostly aquatic ,comprises of sense organ, the digestive system is complete with mouth and these group of animal is known as pseudocoelomates.These animal are classified into one large group and three small groups.
Things to Remember
- The term Aschelminthes was first proposed by Grobben (1910) in place of older name Nemathelminthes.
- They are considered most hardly created by Nasa.
- According to zoologist Hyman (1951), Aschelminthes is regarded phylum
- General characteristics of Aschelminthes.
- Classification of large group Nematoda, and small group Rotifera Gastrotrich kinorhynchs,and Nematomorpha and with a suitable example of each.
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Q1:
Define urinalysis.
Type: Short Difficulty: Easy
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Answer: <p> Urinalysis is a test that evaluates a sample of your urine. Urinalysis is used to detect and assess a wide range of disorders, such as urinary tract infection, kidney disease and diabetes. Urinalysis is the physical, chemical, and microscopic examination of urine. It involves a number of tests to detect and measure various compounds that pass through the urine.</p>
Q2:
List the macroscopic tests of urinalysis. Explain.
Type: Long Difficulty: Easy
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Answer: <p> </p>
<p>MACROSCOPIC URINALYSIS</p>
<p>The first part of a urinalysis is direct visual observation. Normal, fresh urine is pale to dark yellow or amber in color and clear. Normal urine volume is 750 to 2000 ml/24hr.</p>
<p>Turbidity or cloudiness may be caused by excessive cellular material or protein in the urine or may develop from crystallization or precipitation of salts upon standing at room temperature or in the refrigerator. Clearing of the specimen after addition of a small amount of acid indicates that precipitation of salts is the probable cause of tubidity.</p>
<p>A red or red-brown (abnormal) color could be from a food dye, eating fresh beets, a drug, or the presence of either hemoglobin or myoglobin. If the sample contained many red blood cells, it would be cloudy as well as red.</p>
<h3><strong>pH</strong></h3>
<p>The glomerular filtrate of blood plasma is usually acidified by renal tubules and collecting ducts from a pH of 7.4 to about 6 in the final urine. However, depending on the acid-base status, urinary pH may range from as low as 4.5 to as high as 8.0. The change to the acid side of 7.4 is accomplished in the distal convoluted tubule and the collecting duct.</p>
<p><strong>Specific</strong> <strong>Gravity (sp gr)</strong></p>
<p>Specific gravity of urine is determined by the presence of solutes represented by particles of varying sizes, from small ions to larger proteins. Urine osmolality measures the total number of dissolved particles, regardless of their size. The most common method of measurement is freezing point depression. A refractometer measures the change in di irection of a light path (refraction) based upon particle concentration and size in a fluid. Larger particles such as glucose and albumin will alter refraction to a greater degree. The urine dipstick measurement of specific gravity is an approximation that is most sensitive to cationic concentration in urine.</p>
<p><strong>Protein</strong></p>
<p>Dipstick screening for protein is done on whole urine, but semi-quantitative tests for urine protein should be performed on the supernatant of centrifuged urine since the cells suspended in normal urine can produce a falsely high estimation of protein. Normally, only small plasma proteins filtered at the glomerulus are reabsorbed by the renal tubule. However, a small amount of filtered plasma proteins and protein secreted by the nephron (Tamm-Horsfall protein) can be found in normal urine. Normal total protein excretion does not usually exceed 150 mg/24 hours or 10 mg/100 ml in any single specimen. More than 150 mg/day is defined as proteinuria. Proteinuria > 3.5 gm/24 hours is severe and known as nephrotic syndrome.</p>
<p><strong>Glucose</strong></p>
<p>Glucosuria which is excess of sugar in urine generally means Diabetes mellitus.</p>
<h3>Ketones</h3>
<p>Ketones (acetone, aceotacetic acid, beta-hydroxybutyric acid) resulting from either diabetic ketosis or some other form of calorie deprivation (starvation), are easily detected using either dipsticks or test tablets containing sodium nitroprusside.</p>
<p><strong>Nitrite</strong></p>
<p>A positive nitrite test indicates that bacteria may be present in significant numbers in urine. Gram negative rods such as E. coli are more likely to give a positive test.</p>
<p><strong>Leukocyte</strong> <strong>Esterase</strong></p>
<p>A positive leukocyte esterase test results from the presence of white blood cells either as whole cells or as lysed cells. Pyuria can be detected even if the urine sample contains damaged or lysed WBC's. A negative leukocyte esterase test means that an infection is unlikely and that, without additional evidence of urinary tract infection, microscopic exam and/or urine culture need not be done to rule out significant bacteriuria.</p>
<p>MACROSCOPIC URINALYSIS</p>
<p>The first part of a urinalysis is direct visual observation. Normal, fresh urine is pale to dark yellow or amber in color and clear. Normal urine volume is 750 to 2000 ml/24hr.</p>
<p>Turbidity or cloudiness may be caused by excessive cellular material or protein in the urine or may develop from crystallization or precipitation of salts upon standing at room temperature or in the refrigerator. Clearing of the specimen after addition of a small amount of acid indicates that precipitation of salts is the probable cause of tubidity.</p>
<p>A red or red-brown (abnormal) color could be from a food dye, eating fresh beets, a drug, or the presence of either hemoglobin or myoglobin. If the sample contained many red blood cells, it would be cloudy as well as red.</p>
<h3><strong>pH</strong></h3>
<p>The glomerular filtrate of blood plasma is usually acidified by renal tubules and collecting ducts from a pH of 7.4 to about 6 in the final urine. However, depending on the acid-base status, urinary pH may range from as low as 4.5 to as high as 8.0. The change to the acid side of 7.4 is accomplished in the distal convoluted tubule and the collecting duct.</p>
<p><strong>Specific</strong> <strong>Gravity (sp gr)</strong></p>
<p>Specific gravity of urine is determined by the presence of solutes represented by particles of varying sizes, from small ions to larger proteins. Urine osmolality measures the total number of dissolved particles, regardless of their size. The most common method of measurement is freezing point depression. A refractometer measures the change in di irection of a light path (refraction) based upon particle concentration and size in a fluid. Larger particles such as glucose and albumin will alter refraction to a greater degree. The urine dipstick measurement of specific gravity is an approximation that is most sensitive to cationic concentration in urine.</p>
<p><strong>Protein</strong></p>
<p>Dipstick screening for protein is done on whole urine, but semi-quantitative tests for urine protein should be performed on the supernatant of centrifuged urine since the cells suspended in normal urine can produce a falsely high estimation of protein. Normally, only small plasma proteins filtered at the glomerulus are reabsorbed by the renal tubule. However, a small amount of filtered plasma proteins and protein secreted by the nephron (Tamm-Horsfall protein) can be found in normal urine. Normal total protein excretion does not usually exceed 150 mg/24 hours or 10 mg/100 ml in any single specimen. More than 150 mg/day is defined as proteinuria. Proteinuria > 3.5 gm/24 hours is severe and known as nephrotic syndrome.</p>
<p><strong>Glucose</strong></p>
<p>Glucosuria which is excess of sugar in urine generally means Diabetes mellitus.</p>
<h3>Ketones</h3>
<p>Ketones (acetone, aceotacetic acid, beta-hydroxybutyric acid) resulting from either diabetic ketosis or some other form of calorie deprivation (starvation), are easily detected using either dipsticks or test tablets containing sodium nitroprusside.</p>
<p><strong>Nitrite</strong></p>
<p>A positive nitrite test indicates that bacteria may be present in significant numbers in urine. Gram negative rods such as E. coli are more likely to give a positive test.</p>
<p><strong>Leukocyte</strong> <strong>Esterase</strong></p>
<p>A positive leukocyte esterase test results from the presence of white blood cells either as whole cells or as lysed cells. Pyuria can be detected even if the urine sample contains damaged or lysed WBC's. A negative leukocyte esterase test means that an infection is unlikely and that, without additional evidence of urinary tract infection, microscopic exam and/or urine culture need not be done to rule out significant bacteriuria.</p>
Q3:
What are the microscopic tests of urinalysis ? Explain.
Type: Long Difficulty: Easy
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Answer: <p> </p>
<p><strong>Microscopic urinalysis</strong></p>
<p><strong>RBC (Red Blood Cells)</strong></p>
<p>Hematuria is the presence of abnormal numbers of red cells in urine due to: glomerular damage, tumors which erode the urinary tract anywhere along its length, kidney trauma, urinary tract stones, renal infarcts, acute tubular necrosis, upper and lower uri urinary tract infections, nephrotoxins, and physical stress. Red cells may also contaminate the urine from the vagina in menstruating women or from trauma produced by bladder catherization. Theoretically, no red cells should be found, but some find their way into the urine even in very healthy individuals. However, if one or more red cells can be found in every high power field, and if contamination can be ruled out, the specimen is probably abnormal.</p>
<p><strong>White Blood Cell</strong></p>
<p>Pyuria refers to the presence of abnormal numbers of leukocytes that may appear with infection in either the upper or lower urinary tract or with acute glomerulonephritis. Usually, the WBC's are granulocytes. White cells from the vagina, especially in the presence of vaginal and cervical infections, or the external urethral meatus in men and women may contaminate the urine. If two or more leukocytes per each high power field appear in non-contaminated urine, the specimen is probably abnormal. Leukocytes have lobed nuclei and granular cytoplasm.</p>
<p><strong>Epithelial cell</strong></p>
<p>Renal tubular epithelial cells, usually larger than granulocytes, contain a large round or oval nucleus and normally slough into the urine in small numbers. However, with nephrotic syndrome and in conditions leading to tubular degeneration, the number sloughed isincreased.</p>
<p><strong>Casts</strong></p>
<p>Urinary casts are formed only in the distal convoluted tubule (DCT) or the collecting duct (distal nephron). The proximal convoluted tubule (PCT) and loop of Henle are not locations for cast formation. Hyaline casts are composed primarily of a mucoprotein (Tamm-Horsfall protein) secreted by tubule cells.</p>
<h3><strong>Bacteria</strong></h3>
<p>Bacteria are common in urine specimens because of the abundant normal microbial flora of the vagina or external urethral meatus and because of their ability to rapidly multiply in urine standing at room temperature. Therefore, microbial organisms found in all but the most scrupulously collected urines should be interpreted in view of clinical symptoms.</p>
<p>Diagnosis of bacteriuria in a case of suspected urinary tract infection requires culture. A colony count may also be done to see if significant numbers of bacteria are present. Generally, more than 100,000/ml of one organism reflects significant bacteriuria. Multiple organisms reflect contamination. However, the presence of any organism in catheterized or suprapubic tapspecimens should be considered significant.</p>
<h3><strong>Yeast</strong></h3>
<p>Yeast cells may be contaminants or represent a true yeast infection. They are often difficult to distinguish from red cells and amorphous crystals but are distinguished by their tendency to bud. Most often they are Candida, which may colonize bladder, urethra or vagina.</p>
<h3><strong>Crystals</strong></h3>
<p>Common crystals seen even in healthy patients include calcium oxalate, triple phosphate crystals and amorphous phosphates. Very uncommon crystals include: cystine crystals in urine of neonates with congenital cystinuria or severe liver disease, tyrosine crystals with congenital tyrosinosis or marked liver impairment, or leucine crystals in patients with severe liver disease or with maple syrup urine disease</p>
<p><strong>Microscopic urinalysis</strong></p>
<p><strong>RBC (Red Blood Cells)</strong></p>
<p>Hematuria is the presence of abnormal numbers of red cells in urine due to: glomerular damage, tumors which erode the urinary tract anywhere along its length, kidney trauma, urinary tract stones, renal infarcts, acute tubular necrosis, upper and lower uri urinary tract infections, nephrotoxins, and physical stress. Red cells may also contaminate the urine from the vagina in menstruating women or from trauma produced by bladder catherization. Theoretically, no red cells should be found, but some find their way into the urine even in very healthy individuals. However, if one or more red cells can be found in every high power field, and if contamination can be ruled out, the specimen is probably abnormal.</p>
<p><strong>White Blood Cell</strong></p>
<p>Pyuria refers to the presence of abnormal numbers of leukocytes that may appear with infection in either the upper or lower urinary tract or with acute glomerulonephritis. Usually, the WBC's are granulocytes. White cells from the vagina, especially in the presence of vaginal and cervical infections, or the external urethral meatus in men and women may contaminate the urine. If two or more leukocytes per each high power field appear in non-contaminated urine, the specimen is probably abnormal. Leukocytes have lobed nuclei and granular cytoplasm.</p>
<p><strong>Epithelial cell</strong></p>
<p>Renal tubular epithelial cells, usually larger than granulocytes, contain a large round or oval nucleus and normally slough into the urine in small numbers. However, with nephrotic syndrome and in conditions leading to tubular degeneration, the number sloughed isincreased.</p>
<p><strong>Casts</strong></p>
<p>Urinary casts are formed only in the distal convoluted tubule (DCT) or the collecting duct (distal nephron). The proximal convoluted tubule (PCT) and loop of Henle are not locations for cast formation. Hyaline casts are composed primarily of a mucoprotein (Tamm-Horsfall protein) secreted by tubule cells.</p>
<h3><strong>Bacteria</strong></h3>
<p>Bacteria are common in urine specimens because of the abundant normal microbial flora of the vagina or external urethral meatus and because of their ability to rapidly multiply in urine standing at room temperature. Therefore, microbial organisms found in all but the most scrupulously collected urines should be interpreted in view of clinical symptoms.</p>
<p>Diagnosis of bacteriuria in a case of suspected urinary tract infection requires culture. A colony count may also be done to see if significant numbers of bacteria are present. Generally, more than 100,000/ml of one organism reflects significant bacteriuria. Multiple organisms reflect contamination. However, the presence of any organism in catheterized or suprapubic tapspecimens should be considered significant.</p>
<h3><strong>Yeast</strong></h3>
<p>Yeast cells may be contaminants or represent a true yeast infection. They are often difficult to distinguish from red cells and amorphous crystals but are distinguished by their tendency to bud. Most often they are Candida, which may colonize bladder, urethra or vagina.</p>
<h3><strong>Crystals</strong></h3>
<p>Common crystals seen even in healthy patients include calcium oxalate, triple phosphate crystals and amorphous phosphates. Very uncommon crystals include: cystine crystals in urine of neonates with congenital cystinuria or severe liver disease, tyrosine crystals with congenital tyrosinosis or marked liver impairment, or leucine crystals in patients with severe liver disease or with maple syrup urine disease</p>
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Character and classification of Aschelminthes,
General characters
The characteristic of Aschelminthes is listed by following points.
- Mostly aquatic, free-living or parasitic.
- Usually small, even microscopic, Some are a meter or more in length.
- Body cylinder, vermiform, unsegmented, and triploblastic.
- Organ system grade of body organization.
- Head not distinctly formed with well-defined sense organ.
- Body wall with a syncytial or cellular epidermis externally covered with thick cuticle of scleroprotein.
- Cilia absent except anterior cilia of rotifers.
- Musculature includes mostly longitudinal fibers,
- Body cavity a pseudocoel not lined by mesoderm.
- Digestive system complete with mouth, specialized pharynx, non-muscular intestine, and posterior anus
- No circulatory and respiratory systems.
- Excretory system of protonephridia (in some) and canals.
- Cloaca present in some.
- The nervous system of cerebral , ganglia or of circumcenter nerve ring with the anterior and posterior end.
- Mostly dioecious, Male usually smaller than female, Gonads, and ducts single or double.Eggs with the chitinous shell .Cleavage determinate and spiral.
- Development usually direct with no larval stages, or indirect with a complicated life history.
Classification or major groups
Aschelminthes includes one very large group (Nematoda) and smaller groups. (Rotifera, Gastrotricha,Kinorhyncha, and Nematomorpha). According to some zoologist such as Hyman (1951), Aschelminthesis regarded as a distinct phylum, and the various groups included in it as classes. However, other treat different groups as separate and the name of Aschelminthes as a superphylum or without any taxonomic rank. The general scheme of classification of a large group and a smaller group with character and example is listed below.
Phylum Rotifera
(G., rota, wheel + ferry, to bear)
- Microscopic animal found in ponds, lakes and stream. Rarely in the ocean.
- Body wall thickened into stiff plates or lorica into which head may retreat.
- Anterior end with ciliary disc or corona (wheel organ), used for feeding and locomotion.
- Poat- anal tailor with or with toes and adhesive glands for attachment.
- Body musculature includes longitudinal and transverse muscle bands and strands.
- A digestive system with a grinding organ, mastax, lined internally by the strong cuticle.
- Excretory system of protonephridia and two protonephridia tubes with empty into a bladder.
- The nervous system of three major ganglia and nerve.
- Sensory organ antennae and eye spots.
- Male smaller than female. Parthenogenesis common. No larva stage.
Example: Philodina,Asplanchna, Rotary, Epiphanes.
2. Phylum Gastrotricha
(L., gaster, stomach + trochus,hair)
- Microscopic, marine or freshwater.
- Body wall with cuticle bearing short, curved dorsal spines.
- Corona absent cilia on ventral surface for locomation.
- Posterior end forked and with adhesive tubes and glands for attachment.
- Body musculature includes six parts of a longitudinal muscle.
- Mouth surrounded by bristle. Pharynx trihydrate and muscular.
- An excretory system with two protonephridia.
- Nervous system with a saddle-shaped ganglion and two lateral nerve.
- Dioecious or monoecious. Freshwater female pathogenetic.
- Development direct. Young and adult alike.
Example: Chaetonotus,Macrodasys.
3.Phylum Kinorhyncha(=Echinodera)
Dr, kind,to move+ rhinos, break
- Marine, microscopic,animals.
- Superficial segmentation of body into 13 to 14 overlapping ring (zones)
- Body surface with spiny cuticle but cilia is absent.
- Mouth cone or head protrusible and covered with scales.
- A pair of adhesive tubes in the front part of the ventral surfaces.
- Pseudocoel with a fluid containing amoebocytes.
- A nerve rings with ventral code with a ganglion in each zone.Eyespots in some.
- The digestive system completes , with salivary glands.
- Dioecious. Gonads as a pair of the tubular sac.
- Fertilization internal . Metamorphosis with several larval stages.
Example: Echinoderms, Pycnophyes.
4. phylum Nematomorpha(=Gordiacea)
(Gr., name, thread+ morphe, shape
- Hairwormsfound in fresh water.
- Body long, cylindrical , and slender.
- Cuticle thick bearing small papillae.
- Epidermis cellular, single layered.
- Digestive system complete in larva but degenerates in non-feeding adults.Cloaca present.
- Pseudocoel mostly filled with a circumcentre nerve ring and a mid-ventral nerve code.
- No circulatory, respiratory, and excretory system.
- Nervous system with a circumcentre nerve ring and a mid-ventral nerve code.
- Dioecious. Gonads and gonaduct paired.
- Juveniles parasitic in grasshopper, crickets, and other insects.
Example: Gordius paracords, Nectonema.
5.Phylum Nematoda
(Gr., name, thread +eidos, form)
- Aquatic, terrestrial or parasitic roundworms.
- Body elongated, cylindrical and unsegmented.
- Body wall with a thick cuticle , cellular or syncytial epidermis and longitudinal muscle cells in four bands.
- No cilia, circulatory and respiratory system.
- The digestive system completes with muscular pharynx and glands.
- Excretory system of glandular organ, canal or both.
- Nervous system circumcenter ring and anterior and posterior ring.Sense organ simple.
- Dioecious. Male with penal spicules and smaller than female . Gonads one or two.
- Male genital ducts lead into the cloaca, female genital duct with a separate opening.
- Fertilization internal. Development usually direct. No asexual reproduction or regeneration.
Example:Ascaris Necator, Wucheria, Enterobius.
Reference:
Agrawal Sarita. A Text Book of Biology,New Delhi.: Madhuban Educational Books, 2011.
Bhamrah, H.S., and Kavita, Juneja. A Text Book of Invertebrates, New Delhi: Anmol Publications Pvt Ltd, 2011.
Jordan E.L. and P. S., Verma. Invertebrate Zoology, New Delhi,: S. Chand and Company Pvt. Ltd., 2011.
Kotpal, R. L.,Modern Text Book of Zoology: Invertebrates, New Delhi, India: Rastogi Publications,2011.
http://www.parasitesinhumans.org/
https://web.stanford.edu/class/
https://en.m.wikipedia.org/wiki/Nematoda
http://www.earthlife.net/inverts/nematoda.html
Lesson
Aschelminthes
Subject
Zoology
Grade
Bachelor of Science
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