Comparative account of Heart
Comparative account of Heart
Heart in the vertebrate organisms is sac like muscular pumping organ of circulatory system. Heart is built on same basic plan comprising a series of chambers that receives blood from veins & pumps it towards respiratory surfaces & body circulation through the arteries. Basically heart differs in number of chamber, they bear in different group of vertebrates viz. single chambered heart, Two-chambered heart(fishes from cyclostomes & telosts). Three-chambered heart (from Dipnoi, Amphibians, Reptiles), four chambered C Birds & Mammals).
⚫Two-chambered heart in Fishes. e.g.- Scoliodon(Single circuit venous heart)
(1) Two chambered heart is typically found in most of the fishes & heart of acartilaginous fish. e.g.-Scoliodon is typical & generalized for most fishes.
(2) The heart is muscular dorso-ventrally bent, s-shaped tube consisting of total four chambers arranged in a linear sequence. But as there are two accessory chambers namely sinus vensous & conus arteriosus among these four, hence in true sense there are only two chambers viz. auricle & ventricle in most of fishes.
(3) Sinus vensous is posterior most elastic, thin, walled accessory chamber & receives venous blood of body through large paired veins namely ductus cuvirius & hepatic sinus. It serves as a reservoir that opens into the auricle through sina-auricular aperture guarded by value to prevent back flow of blood.
(4) Auricle is muscular, elastic chamber lies in front of sinus venosus dorsally upon the ventricle.
(5) Auricle opens into ventricle through an aurico ventricular aperture guarded by values.
(6) Heart of fishes enclosed in a small pericardial cavity separated from general coelom by a transverse septum.
⚫Three-chambered heart in amphibians e.g. Frog[Transitional heart]
(1) Amphibian has progressive heart over the piscine heart & consists of total three chamber. i.e. two auricle & single ventricle. It also two accessory chambers namely sinus venosus & trunchus arteriosus.
(2) Sinus venosus is dark coloured thin walled chamber attached dorsally to heart & is made up of three large caval veins .i.e. two precavals anteriorly & singles postcaval posteriorly.
(3) Two auricle right & left are thin walled & completely separated by inner-auricular septum that separates the oxygenated and deoxygenated blood.
(4) A twisting result in shifting of auricle toward anterior side of ventricle.
(5) There is single ventricle which is receives the blood from right & left auricle separated through auriculo-ventricular aperture guarded with values.
(6) Ventricle is undivided but it's thick muscular wall raised into trabeculae permitting only little mixing of the oxygenated & deoxygenated bloods.
(7) The truncus arteriosus is prominant & divided by a spiral value which directs deoxygenated blood into pulmonary vessels & oxygenated blood into systemic vessels.
Fig. Three chambered heart in amphibians
e.g.Frog(Dorsal view, ventral view)
⚫Three chambered heart in reptiles. e.g. Calotes[Incompletely four chambered heart]
(1) Heart of the reptiles shows further improvement over that of the amphibian heart.
(2) It shows two auricle & ventricle, but ventricle is partially divided by an incomplete interventricular septum.
(3) A truncus arteriosus is lacking. The thin walled sinus venosus reduced & unequally bilobed by a consistriction lies transversely & dorsally upon the auricle.
(4) Sinus venosus opens into right auricle by larger sinu-auricular aperture guarded by valves while pulmonary vein is opens into thin walled left auricle.
(5) Ventricle has thick, spongy muscular walls internally projecting ridges called columnae cornae. Two auricle opens into ventricle through auriculo-ventricular aperture guarded by valves.
(6) The right & left systemic aortae carrying & arterial & venosus blood respectively, joints to form the dorsal aorta in which the two blood get mixed before distribution.
(7) Ventral aorta of embryo becomes split in the adult into three distinct trunks-pulmonary, right & left systemic.
⚫Four chambered heart in birds & mammals
e.g.-Pigeon [double circuit pulmonary heart]
(1) Birds & mammals have a completely divided ventricle, so that their heart is completely four chambered.(2 auricle & 2 ventricles).
(2) Left auricle receives aerated blood from lungs, pours to left ventricle which pumps it to entire body through systemic circulation.
(3) Right auricle receives deoxygenated blood returning from body passes it to the right ventricle, which pumps it to lungs for re-orygenation.
(4) Thus, there is a double circulation in which there is no mixing of oxygenated & deoxygenated blood at all such a heart is as pulmonary heart.
(5) Sinus venosus is absent, being completely incorporated into right auricle which directly receives 2 precaval & a post caval.
(6) Primitive conus arteriosus is completely replace by a pulmonary aorta leaving the right ventricle for lungs & a single systemic aorta leaving the left ventricle for body.
(7) All major vessels have value basally at the point of exit from or entry into the heart.
Comparative account of Heart
Heart in the vertebrate organisms is sac like muscular pumping organ of circulatory system. Heart is built on same basic plan comprising a series of chambers that receives blood from veins & pumps it towards respiratory surfaces & body circulation through the arteries. Basically heart differs in number of chamber, they bear in different group of vertebrates viz. single chambered heart, Two-chambered heart(fishes from cyclostomes & telosts). Three-chambered heart (from Dipnoi, Amphibians, Reptiles), four chambered C Birds & Mammals).
⚫Two-chambered heart in Fishes. e.g.- Scoliodon(Single circuit venous heart)
(1) Two chambered heart is typically found in most of the fishes & heart of acartilaginous fish. e.g.-Scoliodon is typical & generalized for most fishes.
(2) The heart is muscular dorso-ventrally bent, s-shaped tube consisting of total four chambers arranged in a linear sequence. But as there are two accessory chambers namely sinus vensous & conus arteriosus among these four, hence in true sense there are only two chambers viz. auricle & ventricle in most of fishes.
(3) Sinus vensous is posterior most elastic, thin, walled accessory chamber & receives venous blood of body through large paired veins namely ductus cuvirius & hepatic sinus. It serves as a reservoir that opens into the auricle through sina-auricular aperture guarded by value to prevent back flow of blood.
(4) Auricle is muscular, elastic chamber lies in front of sinus venosus dorsally upon the ventricle.
(5) Auricle opens into ventricle through an aurico ventricular aperture guarded by values.
(6) Heart of fishes enclosed in a small pericardial cavity separated from general coelom by a transverse septum.
⚫Three-chambered heart in amphibians e.g. Frog[Transitional heart]
(1) Amphibian has progressive heart over the piscine heart & consists of total three chamber. i.e. two auricle & single ventricle. It also two accessory chambers namely sinus venosus & trunchus arteriosus.
(2) Sinus venosus is dark coloured thin walled chamber attached dorsally to heart & is made up of three large caval veins .i.e. two precavals anteriorly & singles postcaval posteriorly.
(3) Two auricle right & left are thin walled & completely separated by inner-auricular septum that separates the oxygenated and deoxygenated blood.
(4) A twisting result in shifting of auricle toward anterior side of ventricle.
(5) There is single ventricle which is receives the blood from right & left auricle separated through auriculo-ventricular aperture guarded with values.
(6) Ventricle is undivided but it's thick muscular wall raised into trabeculae permitting only little mixing of the oxygenated & deoxygenated bloods.
(7) The truncus arteriosus is prominant & divided by a spiral value which directs deoxygenated blood into pulmonary vessels & oxygenated blood into systemic vessels.
Fig. Three chambered heart in amphibians
e.g.Frog(Dorsal view, ventral view)
⚫Three chambered heart in reptiles. e.g. Calotes[Incompletely four chambered heart]
(1) Heart of the reptiles shows further improvement over that of the amphibian heart.
(2) It shows two auricle & ventricle, but ventricle is partially divided by an incomplete interventricular septum.
(3) A truncus arteriosus is lacking. The thin walled sinus venosus reduced & unequally bilobed by a consistriction lies transversely & dorsally upon the auricle.
(4) Sinus venosus opens into right auricle by larger sinu-auricular aperture guarded by valves while pulmonary vein is opens into thin walled left auricle.
(5) Ventricle has thick, spongy muscular walls internally projecting ridges called columnae cornae. Two auricle opens into ventricle through auriculo-ventricular aperture guarded by valves.
(6) The right & left systemic aortae carrying & arterial & venosus blood respectively, joints to form the dorsal aorta in which the two blood get mixed before distribution.
(7) Ventral aorta of embryo becomes split in the adult into three distinct trunks-pulmonary, right & left systemic.
⚫Four chambered heart in birds & mammals
e.g.-Pigeon [double circuit pulmonary heart]
(1) Birds & mammals have a completely divided ventricle, so that their heart is completely four chambered.(2 auricle & 2 ventricles).
(2) Left auricle receives aerated blood from lungs, pours to left ventricle which pumps it to entire body through systemic circulation.
(3) Right auricle receives deoxygenated blood returning from body passes it to the right ventricle, which pumps it to lungs for re-orygenation.
(4) Thus, there is a double circulation in which there is no mixing of oxygenated & deoxygenated blood at all such a heart is as pulmonary heart.
(5) Sinus venosus is absent, being completely incorporated into right auricle which directly receives 2 precaval & a post caval.
(6) Primitive conus arteriosus is completely replace by a pulmonary aorta leaving the right ventricle for lungs & a single systemic aorta leaving the left ventricle for body.
(7) All major vessels have value basally at the point of exit from or entry into the heart.
Comparative account of Heart
Heart in the vertebrate organisms is sac like muscular pumping organ of circulatory system. Heart is built on same basic plan comprising a series of chambers that receives blood from veins & pumps it towards respiratory surfaces & body circulation through the arteries. Basically heart differs in number of chamber, they bear in different group of vertebrates viz. single chambered heart, Two-chambered heart(fishes from cyclostomes & telosts). Three-chambered heart (from Dipnoi, Amphibians, Reptiles), four chambered C Birds & Mammals).
⚫Two-chambered heart in Fishes. e.g.- Scoliodon(Single circuit venous heart)
(1) Two chambered heart is typically found in most of the fishes & heart of acartilaginous fish. e.g.-Scoliodon is typical & generalized for most fishes.
(2) The heart is muscular dorso-ventrally bent, s-shaped tube consisting of total four chambers arranged in a linear sequence. But as there are two accessory chambers namely sinus vensous & conus arteriosus among these four, hence in true sense there are only two chambers viz. auricle & ventricle in most of fishes.
(3) Sinus vensous is posterior most elastic, thin, walled accessory chamber & receives venous blood of body through large paired veins namely ductus cuvirius & hepatic sinus. It serves as a reservoir that opens into the auricle through sina-auricular aperture guarded by value to prevent back flow of blood.
(4) Auricle is muscular, elastic chamber lies in front of sinus venosus dorsally upon the ventricle.
(5) Auricle opens into ventricle through an aurico ventricular aperture guarded by values.
(6) Heart of fishes enclosed in a small pericardial cavity separated from general coelom by a transverse septum.
⚫Three-chambered heart in amphibians e.g. Frog[Transitional heart]
(1) Amphibian has progressive heart over the piscine heart & consists of total three chamber. i.e. two auricle & single ventricle. It also two accessory chambers namely sinus venosus & trunchus arteriosus.
(2) Sinus venosus is dark coloured thin walled chamber attached dorsally to heart & is made up of three large caval veins .i.e. two precavals anteriorly & singles postcaval posteriorly.
(3) Two auricle right & left are thin walled & completely separated by inner-auricular septum that separates the oxygenated and deoxygenated blood.
(4) A twisting result in shifting of auricle toward anterior side of ventricle.
(5) There is single ventricle which is receives the blood from right & left auricle separated through auriculo-ventricular aperture guarded with values.
(6) Ventricle is undivided but it's thick muscular wall raised into trabeculae permitting only little mixing of the oxygenated & deoxygenated bloods.
(7) The truncus arteriosus is prominant & divided by a spiral value which directs deoxygenated blood into pulmonary vessels & oxygenated blood into systemic vessels.
Fig. Three chambered heart in amphibians
e.g.Frog(Dorsal view, ventral view)
⚫Three chambered heart in reptiles. e.g. Calotes[Incompletely four chambered heart]
(1) Heart of the reptiles shows further improvement over that of the amphibian heart.
(2) It shows two auricle & ventricle, but ventricle is partially divided by an incomplete interventricular septum.
(3) A truncus arteriosus is lacking. The thin walled sinus venosus reduced & unequally bilobed by a consistriction lies transversely & dorsally upon the auricle.
(4) Sinus venosus opens into right auricle by larger sinu-auricular aperture guarded by valves while pulmonary vein is opens into thin walled left auricle.
(5) Ventricle has thick, spongy muscular walls internally projecting ridges called columnae cornae. Two auricle opens into ventricle through auriculo-ventricular aperture guarded by valves.
(6) The right & left systemic aortae carrying & arterial & venosus blood respectively, joints to form the dorsal aorta in which the two blood get mixed before distribution.
(7) Ventral aorta of embryo becomes split in the adult into three distinct trunks-pulmonary, right & left systemic.
⚫Four chambered heart in birds & mammals
e.g.-Pigeon [double circuit pulmonary heart]
(1) Birds & mammals have a completely divided ventricle, so that their heart is completely four chambered.(2 auricle & 2 ventricles).
(2) Left auricle receives aerated blood from lungs, pours to left ventricle which pumps it to entire body through systemic circulation.
(3) Right auricle receives deoxygenated blood returning from body passes it to the right ventricle, which pumps it to lungs for re-orygenation.
(4) Thus, there is a double circulation in which there is no mixing of oxygenated & deoxygenated blood at all such a heart is as pulmonary heart.
(5) Sinus venosus is absent, being completely incorporated into right auricle which directly receives 2 precaval & a post caval.
(6) Primitive conus arteriosus is completely replace by a pulmonary aorta leaving the right ventricle for lungs & a single systemic aorta leaving the left ventricle for body.
(7) All major vessels have value basally at the point of exit from or entry into the heart.
Comparative account of Heart
Heart in the vertebrate organisms is sac like muscular pumping organ of circulatory system. Heart is built on same basic plan comprising a series of chambers that receives blood from veins & pumps it towards respiratory surfaces & body circulation through the arteries. Basically heart differs in number of chamber, they bear in different group of vertebrates viz. single chambered heart, Two-chambered heart(fishes from cyclostomes & telosts). Three-chambered heart (from Dipnoi, Amphibians, Reptiles), four chambered C Birds & Mammals).
⚫Two-chambered heart in Fishes. e.g.- Scoliodon(Single circuit venous heart)
(1) Two chambered heart is typically found in most of the fishes & heart of acartilaginous fish. e.g.-Scoliodon is typical & generalized for most fishes.
(2) The heart is muscular dorso-ventrally bent, s-shaped tube consisting of total four chambers arranged in a linear sequence. But as there are two accessory chambers namely sinus vensous & conus arteriosus among these four, hence in true sense there are only two chambers viz. auricle & ventricle in most of fishes.
(3) Sinus vensous is posterior most elastic, thin, walled accessory chamber & receives venous blood of body through large paired veins namely ductus cuvirius & hepatic sinus. It serves as a reservoir that opens into the auricle through sina-auricular aperture guarded by value to prevent back flow of blood.
(4) Auricle is muscular, elastic chamber lies in front of sinus venosus dorsally upon the ventricle.
(5) Auricle opens into ventricle through an aurico ventricular aperture guarded by values.
(6) Heart of fishes enclosed in a small pericardial cavity separated from general coelom by a transverse septum.
⚫Three-chambered heart in amphibians e.g. Frog[Transitional heart]
(1) Amphibian has progressive heart over the piscine heart & consists of total three chamber. i.e. two auricle & single ventricle. It also two accessory chambers namely sinus venosus & trunchus arteriosus.
(2) Sinus venosus is dark coloured thin walled chamber attached dorsally to heart & is made up of three large caval veins .i.e. two precavals anteriorly & singles postcaval posteriorly.
(3) Two auricle right & left are thin walled & completely separated by inner-auricular septum that separates the oxygenated and deoxygenated blood.
(4) A twisting result in shifting of auricle toward anterior side of ventricle.
(5) There is single ventricle which is receives the blood from right & left auricle separated through auriculo-ventricular aperture guarded with values.
(6) Ventricle is undivided but it's thick muscular wall raised into trabeculae permitting only little mixing of the oxygenated & deoxygenated bloods.
(7) The truncus arteriosus is prominant & divided by a spiral value which directs deoxygenated blood into pulmonary vessels & oxygenated blood into systemic vessels.
Fig. Three chambered heart in amphibians
e.g.Frog(Dorsal view, ventral view)
⚫Three chambered heart in reptiles. e.g. Calotes[Incompletely four chambered heart]
(1) Heart of the reptiles shows further improvement over that of the amphibian heart.
(2) It shows two auricle & ventricle, but ventricle is partially divided by an incomplete interventricular septum.
(3) A truncus arteriosus is lacking. The thin walled sinus venosus reduced & unequally bilobed by a consistriction lies transversely & dorsally upon the auricle.
(4) Sinus venosus opens into right auricle by larger sinu-auricular aperture guarded by valves while pulmonary vein is opens into thin walled left auricle.
(5) Ventricle has thick, spongy muscular walls internally projecting ridges called columnae cornae. Two auricle opens into ventricle through auriculo-ventricular aperture guarded by valves.
(6) The right & left systemic aortae carrying & arterial & venosus blood respectively, joints to form the dorsal aorta in which the two blood get mixed before distribution.
(7) Ventral aorta of embryo becomes split in the adult into three distinct trunks-pulmonary, right & left systemic.
⚫Four chambered heart in birds & mammals
e.g.-Pigeon [double circuit pulmonary heart]
(1) Birds & mammals have a completely divided ventricle, so that their heart is completely four chambered.(2 auricle & 2 ventricles).
(2) Left auricle receives aerated blood from lungs, pours to left ventricle which pumps it to entire body through systemic circulation.
(3) Right auricle receives deoxygenated blood returning from body passes it to the right ventricle, which pumps it to lungs for re-orygenation.
(4) Thus, there is a double circulation in which there is no mixing of oxygenated & deoxygenated blood at all such a heart is as pulmonary heart.
(5) Sinus venosus is absent, being completely incorporated into right auricle which directly receives 2 precaval & a post caval.
(6) Primitive conus arteriosus is completely replace by a pulmonary aorta leaving the right ventricle for lungs & a single systemic aorta leaving the left ventricle for body.
(7) All major vessels have value basally at the point of exit from or entry into the heart.
Post a Comment