It is a short branch supplying the skin and muscles of the dorsal side of the trunk. However, in early tadpole, gills are the organs for exchange of gases. Urgency. It does not have direct connection with ureters urinogenital ducts. Frogs are generally known as natural indicators or environmental indicators. Welcome to BiologyDiscussion! The optic nerve is connected with the brain. The rods and cones are followed by a layer of bipolar neurons. There are some glands present on the skin of the frog which secrete poison mostly as defense mechanism. The ears are hearing and balancing organs, which are situated just behind the eyes. Autonomic nervous system is ultimately controlled by diencephalon (hypothala­mus) of the brain. In this essay we will discuss about the Common Indian Frog (Rana trgina). The arterioles divide to form blood capillaries which unite to form venules. The wall of the alveoli is richly supplied with blood cap­illaries. Frogs are classified as amphibians. Before sharing your knowledge on this site, please read the following pages: 1. The latter carries the sperms to the seminal vesicle where they are stored temporarily. The sperms produced by the germinal epithelium of seminiferous tubules are passed into Bidder’s canal via vasa efferentia and thence carried to the transverse collecting tubules and then to the urinogenital duct via longitudinal collecting tubule. This phenomenon, known as ecdysis, is affected by the secretions (hormones) of two ductless glands, the pituitary and thyroid. The pigment cells are responsible for the colour of the animal. In between the two layers, a space, the pericardial cavity is present, which is filled with a pericardial fluid. The anterior, vertical and horizontal canals bear the ampullae at their anterior ends while the posterior vertical canal contains an ampulla each at its posterior end. These elevations get fixed into the sub-rostral fossae and help in closing the mouth firmly during exchange of gases. It only allows the blood to flow towards the right auricle. A club shaped rod like structure, partly formed of bone and partly of cartilage, the columella auris extends from the cen­tre of the tympanic membrane and attaches with a plug of cartilage, the stapes. The first toe is called hallux. Nerve endings are also present in the viscera (soft internal organs). The digital formula for the hind limb of frog is 22343. The opening of the urinary bladder into the cloaca has a sphincter to regulate its passage. Where the optic nerve arises, that point is called blind spot; no image is formed at this spot because sensitive cells of retina are absent at this point. It stores blood hence it is called “blood bank”. The latter consists of a proximal muscular part, the pylangium and the distal part, the synangium. In frog, it is short, somewhat flattened structure which widens anteriorly and tapers towards the posterior end into the urostyle, where it is called filum terminate. Thin walled expanded cup shaped blind end of each tubule, is called ‘Bowman’s capsule. So, it is sensory in nature. The nerves arising from the sympathetic ganglia supply the respective visceral organs, such as heart, liver, stomach, intestine, kidneys, gonads, blood vessels, urinary bladder, etc. Out of these eyes and ears are well organised. There are two sets of muscles which operate the mechanism of buccopharyngeal respiration. The first spinal nerve is also known as hypoglossal Nerve. The stratum germinativum rests on basement membrane. In the stomach the food is stored for quite a long time. The cavities of the brain are known as ventricles. The venules join to form veins. Are any Conservative Measures Implemented. Infact, the two tissues gather in a com­paratively small area and come to lie on the ventral side of the kidneys as irregular yellowish streaks. The body of frog is divisible into two parts only: the head and the trunk. A small opening of the pulmocutaneous arch is present in the cavum pulmocutaneum just behind the anterior row of semilunar valves. How are Frogs different from other Animals? Whenever this nerve is present, it emerges from the urostyle through an aperture and joins the sciatic plexus. The blood is a mobile connective tissue, composed of a fluid, the plasma and the cells, the blood corpuscles. The renal portal system collects the blood from the hind parts on the body from which the urea and uric acid present in the blood are first got filtered in the kidneys before the blood goes into postcaval and then to the heart. The islets of Langerhans secrete a hor­mone known as insulin which converts glucose into glycogen in the liver. But in frog the adrenal glands consist of two types of tissue closely intermixed. Is the Poison Secreted by the Frog Fatal? Circulatory System 8. The latter passes into the duodenum through pyloric sphincter at regular intervals. Anteriorly, each sympathetic cord enters the skull along the vagus cranial nerve (10th) and joins with the vagus ganglion and ends in the gassenan ganglion of the trigeminal cranial nerve (5th). and genotypic (genetic i.e. It consists of the alimentary canal and the associated digestive glands. Increase in carbon dioxide and temperature also affects the sinus venosus and thereby it increases the rate of heart beat. Frogs can live in cold, humid as well as extreme hot regions also (except Antarctica). Pages. I was pleased with the message of the play and the overall performance of actors. Vagus is mixed in nature because it carries both motor and sensory fibres. The pancreas is made up of lobules, connective tissue and inner core of islets of Langerhans. This nerve caries the impulse from brain to these muscles for controlling the movements of the eye ball and is motor in nature. In telolecithal eggs the yolk is concentrated in the vegetal half. The number of cranial nerves is definite in a particular group of animals. The lower eye lid is vestigial and immovable. This is a humorous story about a frog that could jump higher than any other story in the county. The upper eye-lid is prominent, thick and slightly movable, while the lower eye­lid is vestigial and immovable. The act of taking the food material into the buccopharyngeal cavity is called ingestion. In some cases, frog poison is fatal to humans but in most of the cases’ presence of poison on the skin of the frog is just to protect itself from larger carnivorous animals. She is an avid reader of various topics of scientific interest in Chemistry and Biology. The vocal sacs increase the pitch of the sound, while the nuptial pads help in grasping the female during amplexus. Each uriniferous tubule is the structural and functional unit of the kidney. The opening is not guarded by any valve. The lymph capillaries of the intestine are known as lacteals. Testis is composed of a large number of small tubes, the seminiferous tubules, which look rounded in section. The nervous system of frog is divisible into three parts: The nerves arising from the central nervous system constitute the peripheral nervous system. The poisons produced by the frogs can be a mild toxin which might paralyze the predator giving the frog enough time to sneak away from under the predator’s nose. They are small, numerous and spindle shaped nucleated cells. Frog-lets (very small frogs) are used as fish bait. Type of assignment Academic level. Some cells of islets of langerhans secrete insulin hormone which converts glucose into glycogen in the liver. Lipase changes fat into fatty acid and glycerol. Just beneath the stratum germinativum there are present many scattered pigment cells (chromatophores) in the stratum spongiosum. On the ventral side, the brain is thickened to form two fibrous strands of nervous tissue, the crura cerebri (sing, crus cerebrum), which carry the stimuli between the cerebral hemispheres and medulla oblongata.
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