PARTS AND FUNCTIONS OF A COMPOUND MICROSCOPE

Written by Tuesday, 25 July 2017 15:42
The microscope is the most important piece of equipment in the clinic laboratory. The microscope is used to review fecal, urine, blood, and cytology samples on a daily basis (see Figure). Understanding how the microscope functions, how it operates, and how to care for it will improve the reliability of your results and prolong the life of this valuable piece of equipment.

Parts and functions of a compound microscope

Compound Microscope(A) Arm: Used to carry the microscope.
 
(B) Base: Supports the microscope and houses the light source.
 
(C) Oculars (or eyepieces): The lens of the microscope you look through. The ocular also magnifies the image. The total magnification can be calculated by multiplying the objective power by the ocular power. Oculars come in different magnifications, but 10× magnification is common.
 
(D) Diopter adjustment: The purpose of the diopter adjustment is to correct the differences in vision an individual may have between their left and right eyes.
 
(E) Interpupillary adjustment: This allows the oculars to move closer or further away from one another to match the width of an individual’s eyes. When looking through the microscope, one should see only a single field of view. When viewing a sample, always use both eyes. Using one eye can cause eye strain over a period of time.
 
(F) Nosepiece: The nosepiece holds the objective lenses. The objectives are mounted on a rotating turret so they can be moved into place as needed. Most nosepieces can hold up to five objectives.
 
(G) Objective lenses: The objective lens is the lens closest to the object being viewed, and its function is to magnify it. Objective lenses are available in many powers, but 4×, 10×, 40×, and 100× are standard. 4× objective is used mainly for scanning. 10× objective is considered “low power,” 40× is “high power” and 100× objective is referred to as “oil immersion.” Once magnified by the objective lens, the image is viewed through the oculars, which magnify it further. Total magnification can be calculated by multiplying the objective power by the ocular lens power.
 
For example: 100× objective lens with 10× oculars = 1000× total magnification.
 
(H) Stage: The platform on which the slide or object is placed for viewing.
 
(I) Stage brackets: Spring-loaded brackets, or clips, hold the slide or specimen in place on the stage.
 
(J) Stage control knobs: Located just below the stage are the stage control knobs. These knobs move the slide or specimen either horizontally (x-axis) or vertically (y-axis) when it is being viewed.
 
(K) Condenser: The condenser is located under the stage. As light travels from the illuminator, it passes through the condenser, where it is focused and directed at the specimen.
 
(L) Condenser control knob: Allows the condenser to be raised or lowered.
 
(M) Condenser centering screws: These crews center the condenser, and therefore the beam of light. Generally, they do not need much adjustment unless the microscope is moved or transported frequently.
 
(N) Iris diaphragm: This structure controls the amount of light that reaches the specimen. Opening and closing the iris diaphragm adjusts the diameter of the light beam.
 
(O) Coarse and fine focus adjustment knobs: These knobs bring the object into focus by raising and lowering the stage. Care should be taken when adjusting the stage height. When a higher power objective is in place (100× objective for example), there is a risk of raising the stage and slide and hitting the objective lens. This can break the slide and scratch the lens surface. Coarse adjustment is used for finding focus under low power and adjusting the stage height. Fine adjustment is used for more delicate, high power adjustment that would require fine tuning.
 
(P) Illuminator: The illuminator is the light source for the microscope, usually situated in the base. The brightness of the light from the illuminator can be adjusted to suit your preference and the object you are viewing.

KOHLER ILLUMINATION

Written by Tuesday, 25 July 2017 13:43
What is Kohler illumination?

Kohler illumination is a method of adjusting a microscope in order to provide optimal illumination by focusing the light on the specimen. When a microscope is in Kohler, specimens will appear clearer, and in more detail.

Process of setting Kohler
 
Materials required
 
  • Specimen slide (will need tofocus under 10× power)
  • Compound microscope.
 
Kohler illumination
 
  1. Mount the specimen slide onthe stage and focus under 10×.
  2. Close the iris diaphragm completely.
  3. If the ball of light is not in the center, use the condenser centering screws to move it so that it is centered.
  4. Using the condenser adjustment knobs, raise or lower the condenser until the edges of the field becomes sharp (see Figure 797.1 and Figure 797.2).
  5. Open the iris diaphragm until the entire field is illuminated.
 
Note the blurry edges of the unfocused light
Figure 797.1 Note the blurry edges of the unfocused light
 
Adjusting the condenser height sharpens the edges of the ball of light
Figure 797.2 Adjusting the condenser height sharpens the edges of the “ball of light.”
 
When should you set/check Kohler?
 
  • During regular microscope maintenance
  • After the microscope is moved/transported
  • Whenever you suspect objects do not appear as sharp as they could be.
 
Further Reading:
 

CELLS OF THE IMMUNE SYSTEM

Written by Saturday, 15 July 2017 16:00
The major cells of the immune system are lymphocytes. Lymphocytes that are critical for immune reactions are of two types namely B-cells and T-cells. Both cells develop from stem cells located in the liver of the foetus and in bone marrow cells of adults.
 
The lymphocytes which are differentiated in the bone marrow are B-cells. The lymphocytes that migrate to thymus and differentiate under its influence are called T-cells. The young lymphocytes migrate to lymphoid tissues such as spleen, lymph nodes and tonsils where they undergo final maturation. Matured lymphocytes circulate in the body fluids. T-cells are responsible for cellular immunity and B-cells produce antibodies about 20 trillion per day.
 
Both components require antigens to trigger them into action but they respond differently.
 
Antigens
 
An antigen is a substance when introduce into an individual, stimulates the production of an antibody with which it reacts. Antigens are large molecules of proteins or polysaccharides. Some of the antigens are the parts of microorganisms others include pollen, egg white, certain fruits, vegetables, chicken, feathers etc.

Antibodies
 
Antibodies are protein molecules called immunoglobulin (Ig). They are produced by lymphocytes. The antibodies inactivate antigens. An antibody  consists of four amino acid chains bounded together by disulphide bonds. Of the four chains two are long, heavy chains and two are short, light chains. All of them are arranged in the shape of the letter ‘Y’. The tail portion of antibody having two heavy chains is called constant fragment (Fc). On the tip of each short arm, an antigen- binding fragment (Fab) is present which specifically hold antigen.
 
Antibody immunity10
 
Based upon the five types of heavy chains, the immunoglobulin's are classified into five major types. Light chains are similar in all types of Immunoglobulin's.
 
TYPES OF IMMUNOGLOBULIN'S
 
lgG is the most important long acting antibody representing about 80% of the antibodies. The second important antibody is IgM. IgA is called secretory antibody, found in tears, saliva and colostrum, (the first milk secreted by mother). IgD serves as a receptor site at the surface of B cells to secrete other antibodies. IgE plays an important role in allergic reactions by sensitizing cells to certain antigens.
 
iimmunoglobulin types12
Lizard, bird and rabbit all these three animals come under the group amniota. The taking away of nitrogenous un wanted waste products from the body is called excretion. If excretion takes place not  properly in the body they become poisonous. Vertebrates main excretory organs are called as kidneys. Skin, gills, lungs, liver and intestine are also acts as accessory excretory organs.
 
The kidneys are made up with numerous uriniferous tubules.kidneys are located in dorsal side of coelom.
 
A typical uriniferous tubule having three parts.
 
  1. Ciliated peritoneal funnel
  2. Malpighian body
  3. Ciliated convoluted tube
 
EXCRETORY SYSTEM - GARDEN LIZARD EXCRETORY SYSTEM - PIGEON EXCRETORY SYSTEM - RABBIT
1. Paired kidneys are dark red and irregular in shape. These are flattened organs. 1. Kidneys are dark red and some what rectangular and flattened organs. 1. Kidneys are dark red and bean shaped organs.
2. Kidneys are located in the posterior region of the abdominal cavity and attached to the dorsal wall by a fold of peritoneum. 2. Kidneys are situated in the anterior part of the abdomen. 2. Kidneys are located in the posterior part of the abdominal cavity.
3. Right and left kidneys are opposite to each other. 3. Same as in calotes. 3. The two kidneys are distinct. The right kidney lies much ahead than the left kidney.
4. They are attached to the dorsal muscles. 4. They are fitted in the hollows of the pelvic girdle. 4. Same as in calotes.
5. They are very near to the median line kidneys are Metanephros type. 5. They are a little away from the median line. Kidneys are Meta nephros type. 5. They are well away from the median line. Kidneys are meta ne phros type.
6. Each kidney has two lobes Anterior lobe is broad and posterior lobe is broad Hilus is absent. 6. Each kidney has three lobes They are anterior, median and posterior lobes. Hilus is absent. 6. Each kidney is a single-lobed structure. Inner side of the kidney has a concave depression is known as the 'hilus'.
7. The two kidneys are united posteriorly forming a V-shaped structure. 7. The two kidneys are separate and do not fuse with each other. 7. The two kidneys are distinct.
8. The two ureters are narrow, thin-walled ducts extending behind from the kidneys to the cloaca, where these open into the urodaeum. 8. Same as in Calotes. 8. The ureters open into the urinary bladder. Ureters arise from the hilus of each kidney.
9. There is no pelvis. 9. There is no pelvis. 9. Each ureter is expanded in its kidney into a funnel like pelvis.
10. In males the ureters join at its posterior end with its corresponding vas deferens and both open by a common urino-genital aperture. 10. The ureters do not join with the vas deferens and both open separately into the cloaca. 10. Ureters open separately into the urinary bladder.
11. A thin walled urinary bladder opens on the ventral side of cloaca. 11. Urinary bladder is absent. 11. Urinary bladder is a large, median, pear, shaped, thin walled transparent sac.
12. Urinary bladder communicates with urodaeum thrumph its ventral wall. 12. __ 12. Urinary bladder opens into the urethra or unnogenital canal.
13. Calotes is uricotelic animal Urine consists n.ainly of uric acid. 13. Urine consists mainly of uric acid cotelic animal. 13. Urine consists mainly of urea - ureotelic animal.
14. Urine is excreted in a semi solid state. 14. Urine is excreted in a semisolid state (Bird droppinos). 14. Urine is passed out in a fluid state.
Kidneys are the major excretory organs in all vertebrates. Some other organs such as lungs, gills, liver, intestine and skin also remove certain waste materials besides their normal functions. These are also known as the accessory excretory organs. Both shark and frog are anamniotic animals.
 
The kidneys lie dorsal to the coelom and are composed of large number of renal or uriniferous tubules. A uriniferous tubule typically con­sists of three regions - a ciliated peritoneal funnel, a malpighian body and a ciliated convoluted tube. The malpighian body is a two layered cup, the 'Bowman's capsule' containing a mass of capillaries the 'glomerulus'. The convoluted tube opens into a Longitudinal duct which extends backwards and opens into the cloaca. The excretory organs remove the nitrogenous waste products formed during the metabolic activities from time to time. If these products are not removed from the body, they are changed to toxic substances.
 
EXCRETORY SYSTEM OF FISH EXCRETORY SYSTEM OF FROG
1. Paired kidneys are very long and ribbon like. 1. Paired kidneys are short and roughly oval in shape.
2. Each kidney is differentiated into a small non-renal part (genital part) and a long posterior renal part. The two parts exhibit morphological difference. 2. Each kidney possesses genital as well as renal region. But these are not morphologically differentiat­ed.
3. The kidneys are uriniferous 'Opisthonephros' but functional Mesonephros. 3. The kidneys are mesonephros.
4. Some uriniferous tubules retain peritoneal funnel. 4. The peritoneal funnels are absent.
5. The uriniferous tubules have a specialised urea - absorbing seg­ment. 5. The urea-absorbing segment is absent.
6. Uriniferous tubules lead into special tubes - the urinary ducts (ureters). These are distinct from wolffian ducts. 6. Uriniferous tubules lead into the wolffian ducts.
7. Ureters run back ward over the ventral surface of the kidneys. 7. Wolffian ducts leave outer border of kidneys and run backward.
8. Ureters are independent ducts to carry urine from the kidneys to the Urinogenital sinus'. 8. The ureters serve for the passage of genital elements as well as urine. So they are known as urino-genital ducts.Urino genital sinus is absent.
9. The urinary bladder is absent. 9. A large bilobed urinary bladder is present. It opens into the cloaca opposite the openings of the ureters.
10. The urine is hypotonic to blood. 10. The urine is hypertonic to blood.
11. Scoliodon is an ureotelic animal. The endproduct of nitrogen metabolism is urea. A large Quantity of urea is retained in the body as an adaptation to marine life.Excess of urea is excreted chiefly through its gills. 11. Frog is also ureotelic animal. It excretes urine from the cloaca in the form of urea.
Calotes is a cold blooded (poikilothermic) and terrestrial garden lizard. Pigeon is a ward blooded bird adapted for aerial mode of life. Rabbit is warm blooded and a herbivorous mammal which is also known as Oryctolagus. The circulation of blood in vertebrates is of closed type(circulation occurs is blood vessels. The blood vessels which collect blood from different parts of the body are called as veins. The walls of veins are thick and possess valves.Thier lumen is wide. They collect deoxygenated blood from different parts of the body and carry to the heart. The veins are formed by means of capillaries in the respective tissues or organs. The deoxygenated blood is received by the sinus venosus or the right auricle. The portal veins are having capillaries at their both ends. The pulmonary veins possess oxygenated blood.
 
VENOUS SYSTEM OF CALOTES (GARDEN LIZARD) VENOUS SYSTEM OF COLUMBA (PIGEON) VENOUS SYSTEM OF ORYCTOLAGUS (RABBIT)
1. The venous system consists of common pulmonary vein, two precaval and one post caval veins. These collect blood from the various parts of the body. 1. The venous system con­sists of three large veins-teeo precavak and one post caval along with four large pulmonary veins. 1. The venous system con­sists of four distinct divisions. i) System of venae carae ii) Hepatic portal system iii) Pulmonary system iv) Coronary system
2. The two precaval veins collect blood from the anterior part of the body. Each precaval is formed by the union of the internal and external jugular veins from head and the sub clavian vein from the arm. Transverse jugular vein is absent. Azygous vein is also absent. 2. The two precaval veins collect blood from the anterior part of the body. Each precaval vein is formed by the union of Jugular (head), brachial (arm) and pectoral (Pectoral muscfes) veins. Transverse jugular vessel is present in between the jugular veins. Azygous vein is absent. 2. The two precaval veins collect blood from the anterior part of the body. Each precaval vein is formed by the union of the external jugular vein (head) and subclavian vein (fore limb). The right precaval vein receives the azygous (unpaired) and intercostal veins (intercostal muscles and dorsal wall of theory). Left azygous vein is absent.
3. The post canal vein joins the posterior angle of the sinus venous. It forms by the union right and left efferent renal veins and brings blood from the posterior side. 3. The post caval vein is formed by the union of two large itac veins a tittle behind the liver. 3. The post caval vein is a large median vein. It stands at the cauda region (icaudal vein) and runs forward and receives blood in its course. The veins which join the posl caval vein are pairec ilio himbars, iliacs gonadial renal, anc hepatic.
4. The renal portal system collects blood from the posterior side of the body. Caudal vein bifurcates into two pelvic veins which . unite in front and form into the median anterior abdominal vein enters into the liver. Each pelvic vein joined by femoral, sciatic veins of that side. From the pelvic arise the renal portal veins which branch into capillaries in the substance of the kidneys coccygeo-mesenteric vein is absent. 4. Renal portal system is not well developed in pigeon caudal vein bifurcates into right and left renal portal veins (Hypo gastric veins) each of which enters the kidney. The hypogastric vein receives the Internal iliac vein abng with femoral & sciatic veins. At the bifurcation of the caudal vein into the two renal portal veins arise a median 'coccygeome-senteric vein'. It is characteristic of birds. The coccygeo- mesenteric vein joins the hepatic portal vein. 4. Renal portal system is completely absent in Rabbit.
5. The Hepatic portal vein collects blood from the alimentary canal and enters the liver and breaks upto capillaries. 5. The Hepatic portal vein collects bbod from the alimentary canal and emptied into the liver. From the Ever the blood is carried by the post caval vein through hepatic veins. 5. Same as in pigeon.
6. Epi gastric vein is absent. 6. Epi gastric vein returns the blood from the mesenteries and joins the hepatic veins. This vein corresponds to the abdominal vein of the frog. 6. Epi gastric vein is absent.
7. The right and left pulmonary veins bring pure blood from the right and left lungs and united into a common branch. Common pulmonary vein opens into the left auricle. 7. Four large pulmonary veins return blood from the posterior part of the left auricle. 7. A pair of pulmonary veins bring oxygenated blood from the lungs They unite by a common arch and open into the dorsal wall of the left auricle.
8. The right auricle receives deoxygenated blood through sinus venosus and left auricle possess oxygenated blood. In the partially divided ventricle the blood mixes to some extent. 8. The right side of the heart (right auricle & ventricle) receives de-oxygenated blood and left side folded with (left auricle & ventricle) oxygenated blood. 8. Same as in pigeon. Coronary veins collect deoxygenated blood from the wall of the heart. The coronary sinus opens into the right auricle through an aperture guarded by the Valve of The besius'. The opening is called as the 'formina of the The besius'.

COMPARATIVE ANATOMY: VENOUS SYSTEM OF FROG AND FISH

Written by Wednesday, 15 July 2009 02:54
Scoliodon commonly called as shark fish is a poikilothermic (cold blooded) animal. It is cartilaginous fish. Rana (frog) is also poikilothermic and amphibious animal. The circulation of blood in vertebrates is of closed type. The blood vessels which collect blood from various parts of the body are known as veins. The walls of the veins are thin and possess valves. Their lumen is wide. They collect deoxygenated blood from different parts of the body and carry to the heart. The veins are formed by means of capillaries in the respective tissues or organs. The deoxygenated blood first enter into the sinus venosus which is the part of the heart. The portal veins are having capillaries at their both ends. The pulmonary veins possess oxygenated blood.
 
 
FISH (SHARK) - VENOUS SYSTEM FROG (RANA) - VENOUS SYSTEM
1. The venous system comprises a system of large thin walled sinuses which collect blood from the different body organs 1. The venous system comprises of thin walled tubular veins.
2. It consists of the following systems i) Anterior cardinal system ii) Posterior cardinal system iii) Hepatic porta! system iv) Ventral veins vi) Cutanecious system 2. It is divided into i) Anterior system of veins ii) Posterior system of veins iii) Portal systems.
3. The anterior cardinal system and the interior jugular sinuses collect blood from the head region through a number of sinuses. 3. The blood from the head region is collected by a pair of precoval veins. Each precaval vein is formed by External jugular, innominate and subclavian veins.
4. The blood from gills is collected by five pairs of dorsal nutrient sinuses and five pairs of ventral nutrient sinuses. 4.The blood from the lungs is collected by a pair of pulmonary veins.
5. The nutrient sinuses carry deoxygenated blood. 5. The pulmonary veins carry oxygenated blood.
6. The nutrient sinuses empty into anterior cardinal and interior jugular sinuses which inturn open into the ductus cuvieri. Thus the blood finally carried to the sinus venosus. 6. The pulmonary veins open into the left auricle.
7. From the posterior part of the body the blood is collected by i) a pair of posterior cardinal sinuses ii) a pair of lateral abdominal veins iii) a pair of brachial veins. 7. The blood from the posterior part of the body is collected by i) renal portal system and ii) Post caval vein.
8. The renal portal system includes the caudal vein and the renal postal veins & Iliac veins. The blood from the pelvic fins is not carried to the kidneys. 8. The renal portal system consists of veins hind limbs i.e. femoral, sciatic and renal portal veins. The caudal vein is absent.
9. It is absent. 9. A part of the blood from the hind-body is transported to the liyer by an anterior abdominal vein.
10. The blood from the kidneys is collected by renal veins which open into posterior cardinals, opening into the cuvierian sinus. 10. The blood from kidneys is collected by four pairs of renal veins which open into the post caval vein.
11. The brachial veins join the lateral abdominals to form sub clavian veins which open into the ductus cuvieri. 11. The brachial veins open into the precaval veins particularly into the subclavian veins.
12. Three pairs cutaneous veins collect blood from the muscles of skin and open into the cardinal sinuses, lateral abdominals and brachial veins. 12. The cutaneous veins are only one pair which join with muscular & brachial and finally open into the subclavian veins.
13. The venus blood does not enter the sinus venosus directly. But it is collected first by the cuvierian sinus present transversely. 13. The blood collected by the two precavals and one post caval veins directly enters into the sinus venosus.
14. The blood from the parts of the alimentary canal is collected by the Hepatic portal vein and empties into the liver and from there it is transported by Hepatic sinuses into the sinus venosus. 14. The Hepatic portal vein collects blood from the different parts of the alimentary canal and empties into the liver. From the blood is transported into the sinus venosus through the hepatic veins and post caval vein.
Calotes is  called as garden lizard. It is a poikilothermic terrestrial reptile. Columba is commonly called as pigeon, being a bird it is  adapted for aerial mode of life. Oryctolagus (rabbit) is an herbivorous mammal. The blood circulation in these vertebrates is of closed type. The blood vessels which carry blood from the heart to the various parts of the body are known as arteries The walls of the arteries are thick and do not possess valves. The pure blood flows in the arteries. However the arteries which carry blood from the heart to the respiratory organs possess deoxygenated blood. The blood has high pressure in the arteries. Arteries ends by means of blood capillaries in the tissues. The different arteries associated in the circulation of blood form a system which is called as Arterial System.
 
In the above three vertebrates, the arteries arise differently but carry blood from the heart to the various parts of the body.
 
 
Calotes (Garden Lizard) Columba (Pigeon) Oryctolagus (Rabbit)
1. Arterial system consists of a pair of systemic arches and a pulmonary arch. 1. Arterial system consists of two arches-Right sys­temic arch and pulmonary arch. The right systemic arch is called Right Aortic arch. 1. Aiterial system con­sists of two arches, left systemic arch and pulmonary arch. The left systemic arch is known as Left aortic arch
2. The systemic arches and the pulmonary arch arise from the dorsal and ventral parts of the single ventricle. All the three arches are connected by connective tissue. 2. Right aortic arch arises from the left ventricle and pulmonary arch arises from the right ventricle. 2. Left aortic arch airses from the left ventricle and the pulmonary arch arises from the right ventricle.
3. The carotid branch of each side is connected with systemic arch by a vessel, 'Ductus caroticus'. 3. Ductus caroticus is absent. 3. Same is absent.
4. The subclavian arteries arise from the right systemic arch. 4.The right & left carotid and sub clavian arteries originate from the respective innominate arteries, ises. 4. The right carotid and sub clavian arteries arise from the innominate artery. But the left carotid and sub calvian arteries originate directly from the right aortic arch
5. Inter cestal arteries are present. 5. Same are present. 5. Same are present.
6. It is absent. 6. Pectoral artery supplies blood to the muscles of the wings. 6. It is absent.
7. Coeliac artery and anterior mesenteric artery arise separately from the dorsal from the dorsal aorta. 7. Same in pigeon. 7. Same in rabbit.
8. It is absent. 8. It is absent. 8. Phronic artery supplies blood to the muscles of the Diaphragm.
9. A pair of gonadial arteries are present. 9. From the anterior renal arteries the gonadial arteries are formed. 9. Paired Gonadial arteries arise directly from the dorsal arch.
10. Unpaired posterior mesenteric artery is present. 10. Same is present in pigeon. 10. Same is present in rabbit.
11. Three pairs of renal arteries arise from the dorsal aorta. 11. The anterior renal arteries develop from the dorsal aorta. But middle & posterior renal arteries arise from the sciatic artery of each side. 11. A pair of renal arteries arise from the dorsal aorta.
12. Common Iliac ar­teries are formed from the dorsal aor­ta. 12. The internal iliac arteries are formed from the dorsal aorta. 12. Iliolumbar arteries arise from the dorsal aorta.
13. The caudal artery is the terminal portion of the dorsal aorta to the tail. 13. The caudal artery the terminal portion of the dorsal aorta to the tail. 13. The caudal artery is the continuation of the dorsal aorta to the tail.
14. The pulmonary arteries carry blood from right part of the single ventricle to theright and left lungs. 14. Each pulmonary artery carries deoxygenated blood to the respective lung for purification. 14. The pulmonary artery which arises from the right ventricle divides into two branches and carry deoxygenated blood to the respective lungs.
15. Coronary arteries supply blood to the walls of the heart. 15. Coronary arteries supply blood to the walls of the heart of bird. 15. Coronary arteries supply blood to the walls of the heart.
Scoliodon ( Shark) is a poikilothermic animal. It is a cartilaginous fish. Frog ( Rana) is a cold blooded and amphibious animal. The circulation of blood is carried by closed vessels. The vessels which supply blood to the various organs of the body are known as arteries as the net work of arteries form the Arterial system. The walls of arteries are thick and lumen is narrow. The blood pressure is high in the arteries. Arteries do not possess valves. The arteries end in capillaries. Arteries deeply seated in the body. Mostly arteries contain oxygenated blood. A few arteries also carry deoxygenated blood to the respiratory organs (either gills or lungs) for purification.
 
 
Scoliodon (Fish) Rana (Frog)
1. The arterial system consists of a ventral aorta, afferent and efferent branchials, dorsal aorta, and its branches and hypobranchials. 1. The arterial system consists of a truncus arteriosus, three pairs of aortic arches and the dorsal aorta & its branches.
2. Five pairs afferent branchial arteries are present. 2. Absent.
3. Efferent branchial system is associated with gill-slits along with the respective arteries. 3. Absent.
4. The arteries to the head are given off from the first pair of epibranchials and by the branches of dorsal aorta carotid labyrinth is absent. 4.The head is supplied blood by the branches. Carotid arteries arising from the truncus arteriosus. Carotid labyrinth is present.
5. Parietal arteries are present. 5. Parietal arteries are absent.
6. Hypobranchial plexus is present. 6. It is absent.
7. Dorsal aorta is formed by the union of epibranchial arteries of both the right and left sides. 7. The second branches of turncus, the systemic arches of the left and right sides unite to form the dorsal aorta.
8. Subclavian arteries arise from the dorsal aorta. 8. Sub clavian artery arises from each systemic arch.
9. Absent. 9. Occipito-vertebral artery arises from the systemic arch of each side.
10. Coeliaco-mesenteric artery aris­es from behind the union of the four pairs of epibranchials. 10. Coeliaco-mesenteric artery arises from the junction of the two system¬ic arches.
11. Just below the Coeliaco-mesen­teric artery, lienogastric artery arises. 11. Lie no gastric artery is absent.
12. The parietal artery gives off four pairs renal arteries. 12. Four pairs of renal arteries arise directly from the dorsal aorta.
13. Gonadial (Spermatic or ovari­an) artery arises from the lieno ­gastric artery. 13. Gonadial arteries arise directly from the first pair of renal arteries.
14. Dorsal aorta terminates into caudal artery. 14. C-iudal artery is absent.
15. Pulmo cutaneous arch is absent. 15. The third branch of truncus is the pulmo-cutaneous arch which is divided into pulmonary and cutanecious arteries.
 
The heart of fish possess venous blood and blood passes through the heart only once in a complete circuit. But in frog the heart receives both oxygenated and venous blood and the circulation is bi circuit.
 
The fish is an aquatic animal and possesses five pairs of gills. The blood is supplied by pairs of afferent bronchial arteries and is collected by nine pairs of efferent bronchial arteries. In frog however, the respiratory organs are a pair of lungs (skin & buccal cavity also help in respiration) which are supplied by a pair of pulmonary arteries.
Calotes is a poikilothermic terrestrial lizard. Columba is pigeon adapted for aerial mode of life. Oryctolagus is an herbivorous mammal.
 
Both pigeon and Rabbit are warm blooded animals. Heart, arteries, veins and blood capillaries are included in the circulatory system. The blood circulation is controlled by an important organ Heart. Normally the blood flows in the closed vessels. So blood circulation is of closed type in verte­brates. The heart possesses auricles and ventricles. The pericardium is at­tached to the heart by gubernaculum cordis'.
 
The number of chambers of heart varies from calotes and other two vertebrates (Pigeon & Rabbit). The heart contracts and relaxes rhythmi­cally. This is called heart beat.
 
The detailed comparison of the heart of the above three animals is mentioned below.
 
Calotes (Lizard) Columba (Pigeon) Oryctolagus (Rabbit)
1. Heart is situated mid ventrally in the an­terior part of the body cavity in the pleuro peritoneal cavity be­hind the sternum. 1. Same way the heart is located. 1. Heart is situated in the thoracic cavity, between the lungs of two sides (Mediastinum). It is present slightly towards the left side.
2. Heart is comparatively smaller in size. 2. Heart is comparatively larger in size. 2. Heart is comparatively larger in size.
3. It is enclosed by double walled pericardium. 3. It is also enclosed in the double walled pericardium. 3. Same.
4. Heart includes a dorsal sinusvenusus aright auricle, a left auricle and a single incom-pletely divided ventricle. 4. Heart is four chambered, sinus venosus is absent in the adult. Completed divided two auricles and two ventricles by inter auricular septum and inter ventricular septum respectively. 4. Same as in columba.
5. The three vena cavae or two precavals and a post caval vein open into the sinus venosus. 5. The three vena cavae or two precavals and a post caval empty the blood directly into the right auricle. 5. Same as in pigeon.
6. The left auricle receives two pulmonary veins from the lungs. 6. The left auricle receives four pulmonary veins from the lungs. 6. Left auricle receives two pulmonary veins from the lungs.
7. The right auricle pos­sess sinu auricular aperture guarded by valve. 7. Absent. 7. Absent.
8. The two auricles are completely separated by inter auricular sep­tum. But the inter ven­tricular septum in the ventricle is incomplete. Hence oxygenated and deoxygenated types of blood is mixed to some extent in the ventricle. 8. Complete inter auricular and inter ventricular septa are present. There is no possibility of mixing the oxygenated blood with deoxygenated blood. 8. Same as in pigeon.
9. The heart of lizard is in a transitional stage approcarhing the double circuit stage But it has not reached it completely due to incomplete division of the encircle. 9. The heart is a double circuit heart because of complete division of ventricle into right and left chambers. 9. Same as in pigeon.
10. The auriculo ventricular aperture is guarded by two flap like semilumar valves. 10. The right auriculo ventricular aperture is guarded by two large muscular flap like valve and the left by three valves. 10. The right auriculo-uentricular aperture is guarded by tricuspid valve and the left by bicuspid valve (mytral valve).

11. There are three aortic arches arising from the ventricle.

  1. Pulmonary trunk (ventral most)
  2. Right systemic trunk (arise from left side of ventricle)

11. Only two aortic arches originate from the ventricles.

  1. Pulmonary trunk (from right ventricle)
  2. Right systemic trunk (from left ventricle)

i.e. Right aortic arch is characteristic of birds.

11. Only two aortic arches arise from the ventricles.

  1. Pulmonary arch (right ventricle)
  2. Left systemic aorta (Left aortic arch from the left ventricle). Right aortic arch is absent.
12. Ductus caroticus is present (connection between carotid & systemic arches) 12. Absent 12. Absent
13. Lizard's heart presents a transitional heart, since it approaches the double circuit heart but has not yet completely attained. So the heart is less efficient. 13. Avian heart has at tained maximum com olexity and is a double circuit heart, i.e. venous blood is com pletely separated frorr oxygenated blood. 13. Same as in Pigeon.
14. Absent. 14. Sinu-Auricular Node and Auriculo ventricular node are present. 14. SA - node and A.V. node are present. In addition bundle of His muscles are also develop.
Advertisement
Advertisement

Featured

CHOLERA: CAUSES, SYMPTOMS, DIAGNOSIS AND TREATMENT

CHOLERA: CAUSES, SYMPTOMS, DIAGNOSIS AND TREATMENT

CHOLERA is a specific infectious disease that affects the lower portion of the intestine and is char...

Useful Sites

  • NCBI

    National Center for Biotechnology Information
  • LTO

    Lab Tests Online® by AACC
  • ASCP

    American Society for Clinical Pathology
  • ASM

    American Society for Microbiology
  • The Medical Library®

    Project of BioScience.pk
Advertisement

Connect With Us

Contact Us

All comments and suggestions about this web site are very welcome and a valuable source of information for us. Thanks!

Tel: +(92) 302 970 8985-6

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Website: https://www.bioscience.pk


This website is certified by Health On the Net Foundation. Click to verify. This site complies with the HONcode standard for trustworthy health information:
verify here.

Our Sponsors

InsightGadgets.comPathLabStudyTheMedicalLibrary.orgThe Physio Club

By using BioScience.pk you agree to our use of cookies to enhance your experience on this website.