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Morphology and Anatomy of Frog

  • Zoology

In this morphology and anatomy of frog post we have briefly explained about external morphology and anatomy of frogs.

Frogs are carnivorous, tailless amphibians, frogs can be found all over the world in a wide diversity of species. They belong to the Amphibia class of vertebrates (phylum Chordata). 

Frogs are cold-blooded animals (poikilotherms) whose body temperature varies depending on their surroundings; as a result, they must shield themselves from extreme heat and cold in order to maintain a healthy body temperature. 

During the summer and winter seasons, they go into aestivation and hibernation, respectively. Frogs also have the ability to camouflage, which means they can change their skin colour to blend in with their surroundings.

Morphology and Anatomy of Frog

External Morphology of Frog

Adult frogs do not have tails, despite the fact that their larvae have. The body of an adult frog is sturdy, with a distinct head and trunk. A pair of nostrils, projecting eyes, a membrane tympanum (ear), slippery/warty damp skin, and webbed limbs are some of the other outward traits.

Frogs have a slippery, wet, and permeable skin that allows them to absorb water and breathe. In frogs, the moist skin serves as a respiratory organ. In addition, the skin is glandular in nature, producing mucus and poisonous compounds to alert them to predators. The colour of the skin can range from brown to green to bright colours, depending on the secretions.

Frogs move with the help of their forelimbs and hind limbs. Frogs are unisexual, which means that they have no sexual dimorphism. The presence of vocal sacs and a copulatory pad on the forelimbs distinguishes a male frog from a female frog. These characteristics are absent in female frogs.

Morphology and Anatomy of Frogs

External Morphology of Frog

Internal Anatomy of Frog

Internal anatomy of frog have well-developed systems in their bodies that aid them in their physiological operations. All of the organ systems, such as the digestive, respiratory, circulatory, excretory, nervous, and reproductive systems, are housed in the body cavity and perform tasks that are nearly identical to those of human body systems. Internal anatomy of frog are discussed below,

Morphology and Anatomy of Frogs

Internal Anatomy of Frog

Digestive system

Internal anatomy of frog digestive system, because frogs are carnivores, their alimentary canal is short. Buccal cavity, pharynx, oesophagus, stomach, intestine, and rectum make up the alimentary canal. The rectum is opened by the cloaca. Bile is produced by the liver, whereas pancreatic juice is produced by the pancreas. The pancreatic juice contains digestive enzymes. The bilobed tongue aids in prey capture.

Digestion: Gastric juices and HCl are secreted in the stomach, which is where food is partially digested. The duodenum receives bile and pancreatic juice. Fat is emulsified by bile. Carbohydrates and protein are digested by pancreatic secretions. The intestine is where the final digesting takes place.

Absorption: The inner wall of the intestine has many finger-like folds that aid in absorption. These are called villi and microvilli, and they help with food absorption. Undigested food travels to the rectum and is ejected through the cloaca.

Circulatory System

Internal anatomy of frog heart of a frog is well-developed, having three chambers: two atria and one ventricle. Food, air, and other chemicals are transported throughout the body via the network of blood vessels by blood and lymph. Plasma and blood cells make up the blood (RBC, WBC, and platelets).

Heart: The heart is found in the upper portion of the bodily cavity. In the heart of a frog, there are three chambers. Two atria and one ventricle make up the heart. The pericardium is a membrane that surrounds the heart. The right atrium is joined by a triangular structure known as the sinus venosus. The sinus venosus receives blood from the vena cava. On the ventral side of the heart, the ventricle opens into a sac-like conus arteriosus.

Arteries and Veins: Blood is transported from the heart to all regions of the body via arteries. The veins transport blood to the heart from all regions of the body. Frogs have a hepatic portal system and a renal portal system. The hepatic portal system is a venous system that connects the liver with the gut. The renal portal system connects the kidneys to the rest of the body via a unique venous connection.

Blood: Plasma and cells make up the substance that makes up blood. The blood of frogs contains RBCs, WBCs, and platelets. RBCs contain haemoglobin and are nucleated. Lymph differs from blood since it lacks a few proteins and RBCs.

Excretory system

Internal anatomy of frog excretory system, The frog is a ureotelic animal, meaning it excretes urea as its primary excretory product. A pair of kidneys, ureters, cloaca, and urine bladder make up their distinct excretory system. The nephron is a structural unit in the kidneys that filters the blood and excretes waste in internal anatomy of frog.

Coordination system

Internal anatomy of frog coordination system. In frogs, the neurological and endocrine systems work together to control and coordinate their movements. Endocrine glands such as the pituitary, thyroid, parathyroid, thymus, pineal body, pancreatic islets, adrenals, and gonads make up the endocrine system. Hormones, which are secreted by these glands, are responsible for metamorphism and other regulatory activities.

CNS and PNS are the two parts of the nervous system. The forebrain, midbrain, and hindbrain are three sections of the brain that control different portions of the body. The brain is protected by the cranium, while the spinal cord is protected by the vertebral column.

Reproductive system

Internal anatomy of frog reproductive system, Male and female frogs each have their own reproductive system, which produces gametes for reproduction. The testes of a male frog create sperm, which are then ejected through the cloaca. A pair of ovaries in a female frog generate ovum and transmit it to the oviduct, which opens into the cloaca. The cloaca is a frequent excretion and reproductive channel. 2500 to 3000 eggs are laid at a time, and they are externally fertilised.

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