The pelvic girdle is directly attached to the vertebral column in the sacral region. The pelvic girdle consists of two similar halves which are known as ossa innominata. Each os innominatum is. formed by three bones. The dorsal bone is known as ilium, antero-Ventral bone is named as pubis and the ventral bone is called ischium. The pelvic girdle has a depression (concavity) at the junction of the three bones. It is known as acetabulum, into which the head of femur of the hind limb articulates.
 
bird pelvic girdle18
 
The same bones are present in all the pelvic girdles of the different vertebrates but have undergone modification.
 
 
rabbit pelvic girdle16
 
Calotes (Garden Lizard) Columba (Pigeon) Oryctolagus (Rabbit)
1. Pelvic girdle is stout and solid. Ifts well suited for walking habits. 1. Pelvic girdle is large and pneumatic. It is well suited for bipedal locomotion. 1. Pelvic girdle is stout and associates with the vertebral column. It is adopted for swift running.
2. Each os innominatum is formed by the ilium, ischium and pubis. 2. Same as in calotes. 2. Each os innominatum is formed by ilium, ischium, pubis and cotyloid cartilage bones.
3. The bones are structurally united. 3. The bones are compactly fused. 3. Same as in columba.
4. Ilium is strong, rod shaped and is directed upwards. 4. Ilium is long, thin and plate-like bone. It is differentiated into preacetabular and postacetabular regions. 4. Ilium is large and broad. The antero-dorsal edge is raised to form iliac crest.
5. Ilium articulates with two sacral vertebrae. 5. Ilium articulates with synsacrum. 5. Anteriorly ilium has articular surface for the sacral vertebrae.
6. Ischium is flat, slightly curved and axe-shaped. It is directed downwards and backwards. 6. Ischium a flat bone fused with the post acetabulariiium. They are separated by ilio-ischial foramen. 6. Ischium is broad and slightly curved bone lying behind ilium. It is posterodorsal in position.
7. Ilio-ischial foramen is present. 7. llio-ischial foramen is large. 7. Ilio-ischial foramen is absent.
8. Ischial tuberosity is absent. 8. It is absent is pigeon. 8. Ischium bears an ischial tuberosity.
9. Ischial symphysis is present. 9. It is absent. 9. Ischial symphysis is present.
10. Hypoischium is present between the ends of the two ischia. 10. Absent. 10. Absent.
11. On the ventral side posteriorly the pubis is formed like a flat elongated and slight ly curved bone, pubis. 11. Pubis is long, slender, curved bone. It lies ventral and parallel with ischial, Pubis. 11. Pubis is flat curved bone directed ventrally pubis symphysis is present. Epipubis is absent.
The hip or pelvic girdle' is present in the posterior side of the body to which the pelvic fins or hind limbs are attached. The pelvic girdle is connected directly to the vertebral column in the sacral region. The pelvic girdle has two equal halves which are known as 'ossa innominata'. Each as innominatum is formed by three bones. They are the dorsal bone ilium, the ventral bone-ischium and the antero-ventral bone pubis. The pelvic girdle has a depression at the junction of the three bones. It is termed as acetabulum into which the head femur of the hind limb articulates and forms a ball and socket joint.
 
frog pelvic girdle15
 
In the different vertebrates, the same bones are present in the pelvic girdle with some modifications.
 
 
Shark (Scoliodon) Frog (Rana)
1. The pelvic girdle is formed with cartilage tissues. 1. The pelvic girdle is formed chiefly with bone tissues.
2. It is embeded in the body wall muscles infront of the cloacal aperture. 2. It is present at the hind end of the trunk.
3. It is a simple transverse bar known as ischio - pubis bar. 3. It consists of two similar halves which are separated infront and fused behind to form a median vertical disc.
4. Each half of the girdle is formed by the fusion of ilium ischium and pubis. 4. Each half of the girdle consists of three bones - ilium, isclium and pubis.
5. Acetabulum is absent. 5. Each side of the vertical disc bears a cup-like depression Acetabulum. The head of femur of the thigh bone articulates with the acetabulum. So all the three bones take part in the formation of the acetabulum.
6. The ilium possess an iliac process and a foramen. 6. The ilium extends forwards in the form of an arm to articulate with the transverse process of the sacral vertebra. A vertical ridge is formed along with this arm is called iliac crest.
7. Ischium and pubis fused together and form Ischio-pubis bar. 7. The ischium forms the posterior part of the disc and acetabulum. Ischium, fuses with the other side ischium and forms ischium symphysis.
8. Pubis fuses with ischium. It is not a separate bone. 8. The pubis forms the ventral part of the disc and acetabulum. It fuses with the pubis of the other half and forms pubic symphysis. It is a separate bone.
9. Pubis is formed with cartilage tissue. 9. Pubis is formed with calcified cartilage tissue.
10. The pelvic girdle is straight in the middle but bent at the ends. These are produced dorso-lat-erally into short iliac processes. 10. The pelvic girdle V-shaped associated with a vertical disc formed with the ischium & pubis bones.
11. The pelvic fins are attached directly. 11. The hind limb bones are articulating with the pelvic girdle.
12. The pelvic girdle provides attachment to the claspers through the muscles of male. 12. Such arrangement is absent. Penis is absent.
The pectoral girdle is connected to the vertebral column through muscles and ligaments. The pectoral girdle consists of two similar halves and each half is formed by three bones namely dorsal, ventral and antero ventral. The dorsal bone is known as scapula, the antero ventral bone is called clavicle and the ventral bone is the coracoid. At the junction of tne scapula and coracoid, there is a depression (concavity) which is known as glenoid cavity into which the head humerus of the forelimb anticulates. The same bones are present in all the pectoral girdles of the different vertebrates but have undergone modification.
 
Calotes (Garden Lizard) Columba (Pigeon) Oryctolagus (Rabbit)
1. Girdle is well developed. 1. Girdle is well developed for flight. 1. Girdle is reduced.
2. The two halves of the girdle are united mid-ventrally by cartilagenous sternal plate. 2. The two halves of the girdle are broadly separated. 2. The two halves of the girdle are broadly separated.
3. Each half of the girdle is known as os innominatum. Os innominatum is formed by scapula, Suprascapula, coracoid and epicoracoid bones. 3. Each half is chiefly formed by the scapula, coracoid. The suprascapula is absent. 3. Each half is chiefly formed by the scapula. The supra scapula and coracoid bones are reduced.
4. The glenoid cavity is formed between the coracoid and scapula. 4. Same as in calotes. 4. The glenoid cavity is formed by the scapula bone alone. But the coracoid is attached to it as a process.
5. Comparatively the scapula is smaller. It is in the form of a flattened and curved articulating ventrally. 5. The scapula is long and blade-Eke. It is sabre-shaped bone extending dorsally over the ribs and articulating anteriorly with the coracoid. 5. The scapula is the largest bone. It is flat and triangular with broad base directed downwards and narrow apex upwards.
6. Spinous ridge is absent. 6. The scapula extends internally into an acromion process. 6. A spine extends along the entire surface of the scapula dorsally. It increases in height towards the apical end and divides into acromion and meta-cromion processes.
7. Cartilagenous suprascapula is a broad, flat and almost rectangular in shape. Dorsally it possess fenestrae. 7. Suprascapula is absent. 7. Suprascapula is much reduced and is in the form of thin strip of cartilage.
8. On the ventral side the coracoid bone is flat and have two perforatious coracoid fenestrae. 8. The coracoid bone is stout and pillar-like coracoid fenestrae are absent. 8. The coracoid bone is reduced and represented by a small coracoid process which is fused with the scapula.
9. The coracoid bone is differentiated into epicoracoid, mesocor-acoid and coracoid proper. 9. Epi coracoid and Meso-coracoid are absent. 9. No such parts are seen since the coracoid is highly reduced into a coracoid process.
10. The two clavicle bones are curved, flat, bony rods. These are separated mid ven-trally by a T- shaped interclavicle. 10. Clavicle bones are thin and attached dorsally to the scapula bones. These two are fused distally with the interclavicle to form furcula or Merry thought bone or wish bone. 10. The two clavicles are rod-like and attached to the sternum. Interclavicle is absent.
11. Foramen of triosseum is absent. 11. At the junction of coracoid, scapula and clavicle bones foramen of triosseum is present. 11. Foramen of triosseum is absent.
The skeletal system or skeleton includes the hard parts of the animal body. All the vertebrates possess the endoskeleton (inside the body).
 
These are the living tissues develop from the interior layers of mesoderm of the body. The term skeleton denotes the endoskeleton in vertebrates. Skeleton plays a very important role in the life of vertebrates. It forms a strong frame work and gives a definite shape to the animal body. It also protects the chief organs of the body such as brain, spinal cord, sense organs, heart and lungs. It provides hard surface for the attachment of muscles which exhibit effective movements. Blood corpuscles are produced from the narrow part of the limb bones.
 
Two main parts present in Endoskeleton. 1. Axial skeleton and  2. Appendicular.
 
Paired appendages articulate with the axial skeleton by means of girdles. The shoulder or pectoral girdle is present in the anterior side of the body to which the pelvic fins or forelimbs are attached. The pectoral girdle is connected to the vertebral column through muscles and ligaments. The pectoral girdle has two equal halves which are known as 'ossa innominata'. Each of innominatum possess the dorsal bone - Scapula, the ventral bone ‘Coracoid' and antero - ventral bone - 'clavicle'. At the junction of scapule and coracoid, a depression or concavity is formed. It is known as glenoid cavity into which head of lumerus of the forelimb articulates and forms a ball and socket joint.
 
pectoral girdle frog thumb15
 
In the different vertebrates the same bones are present in pectoral girdle with some modifications.
 
Shark (Scoliodon) - Pectoral Girdle Frog (Rana) - Pectoral Girdle
1. Pectoral girdle is present in the body wall muscles below the last branchial arch. 1. Pectoral girdle is present in the anterior part ot the trunk.
2. It is not connected to the axial skeleton and formed with cartilage tissues only. 2. It is connected to the axial skeleton (vertebral column) dorsally with muscles & ligaments and formed mostly with bone tissues.
3. Pectoral girdle has two halves. 3. Same as in shark.
4. The osinnominatum has a thin flat, ventral coracoid and a thick rod-like dorsal scapula along with clavicle bones. This type of girdle is known as scapulo-coracoid bar. Supra scapula is absent. 4. The os innominatum has the dorsal scapular part and ventral coracoid part. Stouter scapula on the lateral side and the supra scapula formed of calcified cartilage which is a* thin, broad present on the dorsal side. The clavicle membrane bone is present antero-ventral to the pectoral girdle.
5. The coracoid bone is poorly developed and present on the ventral side. It is not differentiated into pre, and epi coracoids. 5. The coracoid part possess, proper stout uralid, infront of it calcified cartilaginous pre coracoid along with another strip cartilaginous epicoracoid bones. The two epicoracoids are closely associated with each other in the mid ventral line.
6. Glenoid cavity is absent. 6. At the junction of scapular & coracoid bones on the posterior side, the depression of glenoid cavity is present.
7. Sternum is absent. 7. The sternum lies in the mid ventral line of the chest part. It has two portions. The anterior presternum attached to the anterior part of the girdle. It possess a X - shaped omosternumand at its distal end a small carlilaginous episternum. The posterior purt sternum is present behind the girdle. It consists of a stout bone mesosternum and flat plate xiphisternum at the distal end.
8. The basal cartilages of the pec-toral fin are articulating with the pectoral girdle. 8. The forelimb bones are articulating with pectoral girdle.
9. Coracoid bones bear on its part a few formina for blood vessels. 9. Coracoid fenestrae are present.
10. It helps only for the movements of the pectoral fins and also protects the heart. 10. It not only helps the movements of the fore limbs but also protects the heart and lungs.
Respiratory System in Bird
 
Respiratory System in Reptile
 
Respiratory System in Mammals
 
Comparative anatomy of respiratory systems in calotes (lizard), columba (pigeon) and oryctolagus (rabbit).
 
Calotes is a poikilothermic terrestrial lizard. It is commonly known as garden lizard. Columba and oryctolagus are homoiothermic animals. Columba is commonly known as pigeon adapted for aerial mode of life. Oryctolagus is herbivorous mammal. It is commonly called rabbit. All these three animals are grouped under Amniota.
 
reptiles respiration larynx thumb27
LARYNYX OF LIZARD
 
Living cells require energy for performing metabolic activities. This energy is provided by the oxidation of food materials present within the cells. During oxidation the oxygen is consumed and releases carbon dioxide and water. Carbon dioxide is harmful to the protoplasm. Hence to keep the oxidation continuously, there is a constant need for the supply of oxygen to the cells and the removal of carbon dioxide from them. Oxygen is obtained from the environment (water or air) and in return carbon dioxide is added to the environment. The exchange oxygen of the environment with the carbon dioxide of the body is known as 'respiration'. In all vertebrates, some organs of the body are specialised for the exchange of gases. These are called 'respiratory organs or breathing organs'. The surface of these organs at which the exchange takes place is called respiratory surface.
 
respiration mammals llungs thumb27
LUNGS OF RABBIT
 
Vertebrate respiratory organs include the gills and the lungs. Both of these organs develop from the pharynx. Lungs arise in the embryo as an endodermal diverticulum from the ventral wall of the pharynx. The diverticulum soon divides into two parts, which form right and left lungs. A windpipe or trachea connects the lungs with the pharynx. Anterior part of the trachea is modified into the larynx. The larynx communicates with the pharynx by a slit like opening the glottis. The laryrnx functions as sound producing organ in tetrapods except in birds. The birds have their sound-producing organ known as 'syrinx'. The trachea bifurcates into two branchi. Each primary branchus further divided inside the lungs as secondary bronchi, tertiary bronchi and bronchides. The bronchides are connected to the alveoli.
 
In vertebrates the blood plays a vital role in respiration. It carries oxygen from the lungs to the cells for oxidation and collect carbon dioxide for removal from the body. There are two phases of respiration. The exchange of gases takes in the lungs is called 'external respiration'. In the tissues the gaseous exchange takes place and it is termed internal respiration. The respiration performed by the lungs is called 'pulmonary respiration'.
 
Calotes (Garden lizard) Columba (Pigeon) Oryctolagus (Rabbit)
1. Paired external nostrils are small and oval apertures situated dorsally at the tip of the snout. 1. Paired external nostrils are oblique slits present far above the mouth and lie at the base of the upperbeak. 1. Paired external nostrils are oblique slits lying a little above the mouth.
2. External nostrils are uncovered and are not connected to the mouth. 2. Same as in calotes. 2. External nostrils are partly covered by fleshy tip of the snout and are connected with a cleft in the upper lip.
3. External nostrils possess valves. 3. Valves are absent. 3. Valves are absent.
4. Nasal chambers are small and do not have the conchae. 4. Nasal chambers are small and conchae are present. 4. Nasal chambers are long and have conchae.
5. Nasal chambers remain separate throughout as there are two internal nostrils. 5. Nasal chambers remain separate throughout as these are two internal nostrils. 5. Nasal chambers join posterior as there is a single internal nostril.
6. Paired internal nostrils open into the anterior part of the buccal cavity. 6. Paired internal nostrils open into the posterior part of the buccal cavity. 6. Internal nostril opens into the pharynx.
7. Glottis is without epiglottis. 7. Same as in calotes. 7. Glottis is covered by a cartilagenous plate-epiglottis.
8. Larynx is supported by a pair of arytenoids and a median single cricoids cartilaginous plates. 8. Larynx is supported by the same cartilagenous plates as in calotes. But the cricoid is sub-divided into four pieces procricoids. 8. Larynx is supported by four cartilagenous plates. Median ventro-lateral Thyroid, ring-like lower cricoid and paired arytenoid cartilages on the dorsal side. It is also lined by ciliated epithelium.
9. Laryrnx is a voice-box by possessing paired vocal cards which are functional. 9. Larynx is poorly developed and nonfunctional, ie. The sound is not produced. 9. Larynx possesses a pair of vocal cards and their vibrations produce sound.
10. Larynx has two paired muscles - innermusculus compressor laryngis and outer musculus dilater laryngis. It opens into the trachea. 10. Same as in calotes. Larynx opens into the trachea. 10. Same as in Columba and the larynx opens into the trachea.
11. Trachea is supported by complete cartilaginous rings. 11. Trachea is supported by incomplete bony rings present dorsally. 11. Trachea is long, thin walled tube, supported by incomplete cartilaginous rings present dorsally.
12. Bronchi have complete cartilagenous rings. 12. Median incomplete cartilagenous rings are present in the bronchi. 12. Bronchi have incomplete median and dorsal cartilaginous rings.
13. Bronchides are not formed. 13. Bronchides are formed in a complex manner. 13. Bronchides are formed by repeated branching of bronchi.
14. Syrinx is absent. 14. The sound producing organ Syrinx is present at the bifurcation of the trachea. 14. Syrinx is absent.
15. Lungs have orange colour. These are elongated bodies of fairly large size. 15. Lungs have pinkish colour. These are ovoid organs relatively small in size. 15. Lungs have pinkish colour. These are irregular organs of large size.
16. Lungs are hollow sacs with thin elastic wall. These are having low septa and shallow alveoli on the inner surface. 16. Lungs are compact spongy organs. They are slightly distensible. 16. Lungs are soft, spongy and elastic organs.
17. Lungs are not differentiated into lobes. 17. Same as in calotes. 17. Lungs are divisible into lobes. The right lung has four lobes Anterior azygos, anterior, posterior and posterior azygos. The left is divisible into two lobes-anterior & posterior.
18. Lungs are enclosed by peritoneum. 18. Lungs don't have peritoneum on the dorsal side. 18. The lungs are completely covered by peritoneum. The space between the lungs is called mediastinum where heart is present.
19. Air sacs are absent. 19. Lungs are associated with thin, transparent air sacs. There are nine air sacs. These are, median interclavicle, paired cervical, paired anterior thorasic, paired posterior thorasic and paired abdominal air sacs. 19. Air sacs are absent.
20. The inter costal muscles help during the processes of inspiration and expiration. 20. The inter costal and abdominal muscles help during the processes of inspiration and expiration. 20. The inter costal muscles and peripheral muscles of diaphragm help during the processes of inspiration and expiration.
21. Gaseous exchange occurs through the entire inner surface of the lungs. 21. Gaseous exchange occurs in the blood capillaries present in the lungs. Double respiration takes place since the air is preserved in the air sacs. 21. Gaseous exchange takes place in the alveoli present within the lungs.
22. Some deoxygenated residual air is left over in the lungs. Hence aeration of blood is not very efficient. 22. Residual air is not left over in the lungs.Hence aeration of blood is very efficient. 22. Some deoxygenated residual air is always left over in the lungs. Hence aeration of blood is not so efficient.
Scoliodon (fish) is a poikilothermic cartilaginous fish. It is commonly known as shark. Rana (frog) is an amphibian and poikilothermic animal. It is commonly called as frog.
 
Living cells require energy for performing metabolic activities. This energy is provided by the oxidation of food materials present within the cells. In oxidation, Oxygen is consumed and produces carbon dioxide and water. Carbon dioxide is harmful to the protoplasm. Hence to keep the oxidation continuously, there is a constant need for the supply of oxygen to the cells and removal of carbon dioxide from them. Oxygen is obtained from the environment (water or air) and in return carbon dioxide is added to the environment. The exchange of oxygen of the environment with the carbon dioxide of the body is known as 'respiration'. In all vertebrates, some organs of. The body are specialised for the exchange of gases. These are called respiratory or breathing organs. The surface of these organs at which the exchange takes place is called as 'respiratory surface'.
 
frog breathing respiration1 thumb14
RESPIRATORY ORGANS OF FROG
 
Vertebrate respiratory organs include gills and lungs. Both of these organs develop from the pharynx. Aquatic fishes perform respiration with the help of gills. These may be internal gills and that to the exterior as external gill slits. Five pairs of gills are present in shark. The type of respiration performed by the gills is called bronchial respiration. Lungs arise in the embryo as an endodermal diverticulum from the ventral wall of the pharynx. The diverticulum soon divides into two parts, which form right and left kings. A wind pipe or trachea connects the lungs with the pharynx. Anterior part of the trachea is modified into the larynx. The larynx communicates with the pharynx by a slit-like aperture the glottis. The larynx functions as sound producing organ in tetrapods except in birds. So the larynx contains a pair of elastic membranes known as the vocal cords. The respiration performed by lungs is called pulmonary respiration.
 
Scoliodon (Shark) Rana (Frog)
1. Scoliodon performs branchial respiration. 1. Rana is adapted for branchial (Tadpole) as well as pulmonary respiration.
2. Respiration is performed by the gills. Skin, and bucco-pharyngeal lining are not respiratory. Lungs are absent. 2. Respiration is performed by the skin,bucco-pharyngeal lining and lungs.There are no gills in the adult.
3. It possess five pairs of internal gills located in the pleural walk of the pharynx. The external gills are absent. But gills are exposedoutside as external gill-slits. 3. Tadpole larva possesses three pairs of external gills in the early stages which are present at the junction of head and trunk. Later these are replaced by three pairs of internal gills.The adult possess the lungs.
4. Respiratory tract consists of mouth, buccal cavity, pharynx, internal branchial apertures, branchial pouches and external branchial apertures. 4. Respiratory tract consists of external nostrils, nasal chambers, internal nostrils, bucco-pharyngeal cavity, glottis and laryngo tracheal chamber. Which open into the lungs.
5. External nostrils, nasal chambers are not used in respiration. Internal nostrils glottis, and laryngo tracheal are absent. 5. Mouth is not used in respiration. Branchial apertures and pouches are absent.
6. The gills have cartilagenous gill arches to support the gill-axes. 6. Such type of organs are absent.
7. The gills are endodermal in origin and are formed by the outpushing of hypoblast. 7. Lungs are also endodermal in origin.
##################################### 8. Such an arrangement is absent in the adult frog.
9. Generally these are pairs of gill pouches one pair of hemi branches on the posterior side of the hy-oid arch and four pairs of holo branches on the 1st, 2nd, 3rd and 4th branchial arches. The 5th branchial arch is abranch. 9. Absent in the adult frog.
10. The gills-remain in well within the gill pouches. 10. Absent in the adult frog.
11. Absent in shark. 11. The larynx and trachea united and form into laryngo tracheal chamber which is supported by three cartilages a cricoid and a pair of lateralary tenoids.
12. Lungs are absent in shark. 12. Paired lungs are simple, thin-walled elastic sacs having on the inner surface low ridges the septa enclosing the alveoli.
13. No such arrangement is present. 13. The septa and alveoli increase the area coming in contact with air. Exchange of gases takes place all over the inner surface of the lungs.
14. During breathing, the buccal flow is lowered by coracohyal and coracobrachial muscles and raised by constrictor muscles. 14. During breathing, the bucco-pha-ryngeal flow is lowered by the sternohyal muscles and raised by the petrohyal muscles.
15. Water enters the respiratory tract through the mouth and leaves through the external branchial apertures. During this water flow, the dissolved oxygen in the water is absorbed and supplied to the blood in the gills. 15. Air enters the respiratory tract through the external nostrils and leaves also through the external nostrils after providing oxygen to the blood in the buccopharyngeal lining and lungs.
16. The blood is transported to the gills by five pairs of afferent branchial vessels. 16. The blood is transported to the lungs, skin and bucco pharyngeal cavity by the respective arteries.
17. Oxygenated blood from the gills is supplied to the body by nine pairs of efferent branchial vessels. 17. Oxygenated blood from the lungs, skin, and buccopharyngeal cavity is transported to the heart by the respective veins.
Digestive System Of Bird: Eg: Pegion Digestive System (Columba)

Digestive System Of Mammal: Eg: Rabbit Digestive System (Oryctolagus)

Digestive System Of Reptile: Eg: Lizard Digestive System (Calotes)

In previous topic we discussed about the comparative anatomy of digestive system of frog and shark. In this topic we discussed about the comparative anatomy of digestive system of Bird, Mammal and Reptiles.
 
Calotes is a poikilothermic and terrestrial lizard. Columba and Oryctolagus are warm blooded animals. Columba is adapted for mode of life-bird. Oryctolagus (Rabbit) is a mammal. The digestive system consists of alimentary canal and its associated digestive glands. The living of the alimentary canal is mostly endodermal in origin being derived from the wall of the archenteron. Distinc' salivary glands secreting enzymes are present only in mammals. In reptiles, the oral glands are present in various positions termed labial, parotid, lingual & sublingual etc. The secretions of which serve primarily to keep the mouth moist and secondarily to facilitate the movements of the tongue. The other connected with the midgut and arising as out growth are the liver and pancreas.
 
DIGESTIVE SYSTEM OF BIRD
digestive system bird thumb23
 
 
Calotes (Lizard) Columba (Pigeon) Oryctoiagus (Rabbit)
1. Mouth is a wide, slit present at the anterior end of head. 1. Mouth is terminal, slitlike aperture bounded by horny Jaws. 1. Mouth is sub-terminal, cleft bounded bv mobile, fleshy lips.
2. Buccal cavity is a narrow gap. Labial glands are present on lips.They secrete mucous. 2. Buccal cavity is narrow and some what and dorsoventrally flattened. 2. Buccal cavity is a spacious chamber andits space between lips and the teeth is called vestibule. This receives the mouth opening.
3. On both jaws teet are present, polyphyodont homodont teeth arranged in a single row on each jaw. Teeth are not useful for mastication. Pleurodont dentition is present. 3. Jaws are modified into tooth less beak. 3. Dentition in mammals:Teeth are diphyodont, heterodont and thecodont. These are arranged in a single row on each Jaw.Teeth are modified cutting (Incissors) and chewing (Premolars & molars) canines are absent in rabbit.
4. Tongue is attached posteriorly  to the floor of buccal cavity and is free anteriorly. Sensory papillae are present. 4. Tongue is narrow triangular and fleshy. Its surface is covered with horny material and bears thorn-like projections which carry taste buds and mucous glands. 4. Tongue is highly specialized, fleshy and muscular and can be moved in different directions. It can be protruded out. Its surface is rugose being covered with numerous papillae along with taste buds.
5. A pair of internal nostrils open into the roof of the buccal cavity anteriorly. Hard palate is present. 5. A bony palate is wanting in birds but a pair of palatal folds and palatal groove between the two folds are present. Internal nostrils are located dorsal to the palatal folds. 5. The nasal passages are separated from the buccal cavity by a bony palate. The internal nostrils open into the pharynx nearer to glottis.
6. A bony palate is present covering the roof of the buccal cavity. 6. A bony palate is absent. But soft palate is formed of two membranous folds. 6. The palate is differentiated into anterior bony hard palate and a soft palate is formed of connective tissue. The soft palate is produced behind into a process – velum palati hanging down from the roof, which prevents the entry of food into nasal passage.
7. Unicellular mucous glands are present and keep the buccal cavity always wet. 7. Unicellular mucous glands are absent in the epithelium of bucco-pharyngeal region. 7. Unicellular mucous glands are absent. But multi cellular serous glands are present.
8. Salivary glands are absent. But labial glands are open at the lips which do not play any role in digestion. 8. Salivary glands which open into the buccal cavity are lingual, mandibular, maxillary, cricoary tenoid, palatinal and sphenopalatinal glands. 8. The multi cellular salaivary glands are four pairs. They are Infra orbital, parotid, sublingual and sub-maxillary glands. Palatine, tonsillar, superior & inferior labial glands are also associated.
9. Pharynx is marked off. On the roof of pharynx near the junction of two jaws a pair of openings is called Eustachian apertures. The floor of pharynx has the glottis. 9. Pharynx is marked off from the buccal cavity but it receives, internal nostrils through which nasal passages open into its cavity, the gullet & glottis. 9. Pharynx is not sharply demarcated from the buccal cavity. It receives the openings of esophagus and the glottis.
10. Esophagus is a narrow tube and straight extends through the neck. Mucous glands are present. 10. Oesophagus is a bng and narrow tube. It has thick walls. Mucous glands are absent. 10. Oesophagus is a long thin walled tube. It is clearly marked off from the pharynx as well as stomach. Mucous glands are present.
11. Crop is absent. 11. The oesophagus is dilated into a thin-walled sac the crop. It secrete pigeon milk in both sexes and used to feed the young birds. 11. Crop is absent. The wall of oesophagus is produced into the cardiac stomach to form cardiac valve.
12. Stomach is a sac- like structure. Its anterior part is cardiac stomach and posterior part is pyloric stomach. At the end of pyloric stomach a small constriction is present. It possesses a pyloric sphincter. 12. Stomach is divided into a glandular proventriculus and posterior muscular gizzard. Gizzard acts like grinding apparatus. Pyloric valve absent. 12. Stomach is divisible into cardiac, fundic and pyloric parts. Pyloric stomach contains pyloric valve.
  13. Intestine is differentiated into duodenum and ileum. Intestine very long and very much coiled because is a herbivorous animal 13. Same structures are present. But the bile duct and pancreatic ducts open separately into the proximal and distal ends of the duodenum respectively.
 14. A single rectal caecum is present. 14. At the junction of ileum & colon, two divertulae are present. These are called Rectaicaeca. 14. An ilio-colic valve is present at the junction of the small intestine and large intestine or colon. At the junction of these portions, a spiral shaped vermi form appendix is present. At the regular intervals of the colon shows pocket-like pouches - 'Haustra'.Colon shows longitudinal muscle folds taeniae'. Cellulose enzyme is produced.
15. Cloaca is common opening for digestive'and urinogenital ducts. It is divided into coprodaeum, urodaeum, and proctodaeum. 15. Cloaca is large and divided into the same parts. On the dorsal side of the proctodaeum a thick walled blindsa "Bursa fabricii" is present. It becomes degenerated in the adult and is known as cloacal thymus. 15. Cloaca is absent. Anus is present.
16. Liver is bilobed gland. The right lobe has a gall bladder. It secretes bile (alkaline& no enzymes). 16. Liver is bilobed dark red gland. Gall Bladder is absent. Separate bile ducts are formed.Liver secretes bile. 16. Liver is very large and consists of five lobes. Kupffer's cells are present in the liver. Liver secretes bile. Gall Bladder is present.
17. Pancreas is a whitish gland present between stomach duodenum. 17. Pancreas is a pink coloured gland present the loop of duodenum. Three pancre catic ducts open into the duodenum. 17. pancreas is a diffused gland of pink colour. Pancreatic duct opens into the duodenum.
18. Gastric, intestinal glands are also present. 18. Same are present. 18. Same are present.
 
 
digestivesystemrabbitmammal thumb17
DIGESTIVE SYSTEM OF RABBIT
Comparison Of Integument Derivatives In Calottes (Reptile), Columba (Bird) And Oryctolagus (Mammal)

Calotes is a terrestrial Reptile (lizard). Columba is flying bird. Oryctolagus is a herbivorous mammal. All these animals are grouped under Amniota and columba & oryctolagus are warm blooded animals. The integument forms the outermost covering of the body in all these animals. It is multilayered in structure and is distinguished into epidermis and dermis. The epidermis consists of several rows of flattened stratified epithelial cells stratum corneum. Below this layer stratum Malpighi is formed with living columnar cells. The dermis is formed of connective tissue traversed with collagen and elastin fibres, muscles, nerves, blood capillaries and lymph vessels etc. It possesses an upper stratum spongiosum and a lower stratum compactum layers. The epidermis and dermis are formed from ectoderm & mesoderm layers.
 
CALOTES SKIN (REPTILE INTEGUMENT) COLUMBA SKIN (BIRD INTEGUMENT) ORYCTOLAGUS SKIN (MAMMAL INTEGUMENT)
1. In Calotes (Reptile) the skin is rough, thick, dry and scaly. Skin is suited to the terrestrial environment which prevents any loss of water. 1. In birds the Skin is thin, loose and dry. 1. In Mammals Skin is thick, elastic and water proof.
2. Epidermis has a heavily cornified stratum, corneum which produce into hormy epidermal scales. 2. The epidermis is thin and delicate all over the body except on sharks and feet where it is thick and produce epidermal scales. 2. The epidermal cells form into four layers - Stratum corneum, S. lucidum, S. granulo sum  & stratum.
3. The exoskeleton of scales is periodical­ly cast off either in fragments or as a sin' gle piece. In turtles & tortoises the epidermal bony plates are formed. In others the scales are modified into shields, scutes, spines etc. 3. The exo Keleton is in the form leathers which are formed from structure corneum & stratum malpighii. The feathers are keratinised. 3. The epidermis also forms Sebaceous and sweat glands. The mu­cous glands are ab­sent. The sweat glands help in excretion and maintain constant body temperature. Sebaceous glands se­crete 'sebum' which lu­bricates the skin and hairs. Hairs are present.
4. The glands are practically absent. The only glands present are 'scent glands'. 4. The epidermis is devoid of glands except the single "uropygial gland" present at the base of the tail. The oily secre¬tion of the glard is used for preening the leathers. 4. Presence of mammary glands is the charac­teristic of mammals (Rifled sebaceous glands.)
5. Dermis is thick having stratum spongiosum & stratum com pactum. 5. Two layers are present in the dermis which is thin. Vascular layer is present in between the two layers. 5. Dermis is very thick. It has intricate system of connective tissue fibres extending in all direc­tions.
6. Stratum spongiosum has numerous chromatophores. They exhibit   wide colour patterns. 6. Chromatophoresare absent. But the pigment is found in the feathers and scales. 6. Chromatophores are absent large dendritic melanophores are present.
7. Sensory corpuscles are absent. 7. Cutaneous receptors are present in the dermis. 7. Numerous tactile corpuscles are highly developed.
8. Fat cells are not present in the dermis. Femoral glands are present. 8. Fat cells are present in the dermis. 8. Subcutaneous layer is formed of adipose tissue (Fat cells).
9. Distal ends of the digits have nails or claws which formed from the homy epidermis. These grow  parallel to the surface of skin and formed of a dorsal plate 'unguis' (nailplate) and a ventral plate sub unguis (sole plate). 9. Similar claws are with unguis in the form of a long plate of keratin sharply curved and subunguis lies between its two edges. 9. Nails & hoofs are found. At the base of the nail, the epidermis is invaginated to form nailgroove and its part covering the nail root-eponychium.
10. Horny teeth are present which are acrodont or pleurodont Similar claws are with unguis in the form of a long plate of keratin. 10. Beaks are formed of enlarged epidermal scales which form hard keratinized covering over the jaw bones. 10. Hairs are keratin derivatives and exclusively present in mammals. These are strictly epidermal structures developed from stratum malpighii.
Bird Skin - Cross Section
Bird Skin - Cross Section
COMPARATIVE ACCOUNT OF THE INTEGUMENT (SKIN) IN THE SCOLIODON (SHARK FISH) AND RANA (FROG)

Scoliodon and Rana are poikilothermic animals. Scoliodon is an aquatic cartilage fish. Rana lives in water and on land-amphibian. In both the vertebrates the skin (integument) is the outermost covering of the body. It is multicellular and multilayered structure typically formed of an outer layer of 'epidermis' and an inner layer of 'dermis'. The integument provides a characteristic form to the body. It also protects the enclosed organs.

The epidermis is derived from the ectoderm and dermis from mesoderm of the embryo. The epidermis is multilayered and differentiated into stratified epithelium and cornification is not complete. The cells of stratum corneum are nucleated. The lowermost layer of the epidermis formed of living columnar cells and is called 'stratum malpighii'or stratlim germinativum.
 
Scoliodon (Fish) - Skin Rana (Frog) - Skin
1. Skin is rough & tough. It is firmly attached to the underlying muscles. 1. Skin is soft, smooth and loose. It is separated from the underlying muscles by lymph sacs.
2. The skin is divided into epidermis and dermis. 2. Same.
3. The epidermis is composed of many layers of similar epithelial cells. Stratum corneum is absent. 3. The epidermis is distinguished into stratum corneum and stratum malpighii.
4. Unicellular mucous glands are present in the dermis. 4. Mucous glands or cutaneous glands are multicellular and are present in the dermis.
5. Dermis is less vascularised. 5. Dermis is richly vascularised.
6. The skin is protective and sensory in function. 6. Skin is protective, sensory and respiratory (Cutaneous respiration) in function.
7. Placoid scales are present. 7. Scales are absent.
8. Dermis has no layers. 8. Dermis has stratum spongiosum & stratum compactum.
9. In the dermis chromatophore and iridocytes are present. 9. Chromatophores are found in the upper part of dermis. These help in changing the colour of integument.
10. In some deep-sea fishes light emiting photophores are present. 10. In some frogs (Bufo) poison glands are present near the tympanum.
FROG SKIN (AMPHIBIAN SKIN) V.S. IMAGE
FROG SKIN (AMPHIBIAN SKIN) V.S. IMAGE

GONADS OF HERDMANIA

Written by Saturday, 08 July 2017 00:17
Herdmania is a bisexual animal. It is a protogynous animal. Ovary matures’ first. Hence cross fertilization takes place.
 
Herdmania contains a pair of gonads. The left gonad lies in the intestinal loop above the heart. Each gonad shows 10 to 25 lobes arranged in two rows. The median lobe is single and large. Other lobes are oval in shape.
 
Each lobe shows outer large testicular part and inner small ovarian part. The testicular part is brick red in colour and produces sperms. The ovarian part is pink in colour and produce ova. From each testicular part sperm ductule will arise. They open into spermduct. From each ovarian part ovarian ductule will come. They open into the oviduct. Each gonad has an oviduct and spermduct. They run parallelly and open separately into cloaca behind anus.
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