Digestive System of Frog
The digestive system of frogs is made up of an alimentary canal and accessory glands, which together carry out ingestion, digestion, absorption, and excretion. Being carnivorous, frogs use their sticky, protrusible tongue to capture prey, which is then processed through specialized organs for efficient digestion. This is an important topic in NEET and Class 11 Biology, linking structure with function in amphibians.
This Story also Contains
- What is the Digestive System of Frog?
- Anatomy of Frog Digestive System
- Accessory Organs of Digestion
- Digestive Process in Frogs
- Common Disorders of Frog Digestive System
- Digestive System of Frog NEET MCQs (With Answers & Explanations)
- Recommended video on "Digestive System of Frog"
What is the Digestive System of Frog?
Frogs are among the most studied amphibians because they are adapted and highly important to various ecosystems. The digestive system consists of alimentary canal and digestive glands. The alimentary canal is short because frogs are carnivores and hence the length of the intestine is reduced but complete i.e from mouth to cloaca.
The digestive system of frogs is essential for study as it illustrates how such animals process their food for their energy requirements, which shows a wider principle of vertebrate physiology.
Anatomy of Frog Digestive System
The anatomy of the frog's digestive system is explained below:
Digestive Tract Components
The frog's digestive system is made up of alimentary canal and digestive glands. The alimentary canal includes the mouth, pharynx, oesophagus, stomach, small intestine, large intestine, and cloaca. Digestive glands include liver, pancreas and gall bladder. Each organ plays an important role in the digestion process.
Mouth and Teeth (Sticky Tongue, Vomerine Teeth)
The mouth is provided with a sticky tongue which helps in catching prey and maxillary and vomerine teeth to hold the food. The digestion process is also initiated in the mouth, which secretes the saliva.
Pharynx and Oesophagus
Pharynx serves as a passage through which food moves from the mouth to the oesophagus. It also plays a part in the respiration because it connects the mouth to the lungs through the glottis.
The oesophagus is a short muscular tube through which food travels from the pharynx to the stomach. The muscle contraction, peristalsis, helps in propelling food by forcing it into the parts below.
Stomach (Mechanical & Chemical Digestion)
The stomach is an organ that looks like a sac, believed to provide a conducive environment for the mechanical and chemical churning of food. The digestive enzymes work on food to make it into chyme—a semi-liquid form digestible by the small intestines.
Small Intestine (Duodenum, Jejunum, Ileum)
The small intestine is the main area by which food is absorbed. The small intestine is divided into three parts: the duodenum, jejunum, and the ileum. Here, digestive products that come from the pancreas mix with the bile acids from the liver and get absorbed by the body wall of the intestine.
Large Intestine
The large intestine absorbs the water and electrolytes from the remaining indigestible food and forms solid waste or faeces. It is shorter compared to the small intestine and it leads to the cloaca.
Cloaca
Cloaca is a common cavity running at the end of the digestive tract that receives wastes from the intestines, urine from kidneys, and reproductive cells. It participates in excretion.
Accessory Organs of Digestion
The accessory organs are:
Liver
The liver, which is the biggest organ and responsible for the production of bile, used to digest fats. Besides storing food substances, the liver also eliminates poisons in the blood.
Gall bladder
Gall bladder is a small pouch-like organ used for storing bile produced by the liver, which is then released to the small intestines where it functions in the digestion of especially fats.
Pancreas
Pancreas produces and secretes the digestive enzyme into the small intestines, it helps to break down the major nutrients, including carbohydrates, proteins, and fats and produces insulin, a blood sugar-regulating hormone.
Digestive Process in Frogs
The frog's digestive process is explained below:
Ingestion
Ingestion is the process through which frogs bring their food into their bodies. Frogs capture food items on their sticky tongue and then swallow the food item whole. Most prey, including insects, are captured employing their sticky tongue.
Digestion
Digestion begins in the stomach. The gastric juices work on breaking down the food. The process ensues in the small intestine with the assistance of bile and pancreatic enzymes, which advance further in the breaking down of food into easily absorbable nutrients.
Absorption
Absorption mostly occurs in the small intestine. In this step, nutrients from the digested food will then pass through the walls of the intestine to the bloodstream and then used for energy and building materials.
Excretion
Excretion is the process of eliminating indigestible substances and waste products. These are passed from the large intestine into the cloaca and then expelled from the body.
Common Disorders of Frog Digestive System
The common disorders of the Frog's digestive system are explained below:
Parasitic Infections
Frogs are susceptible to various parasitic infections, which are primarily also due to nematodes, trematodes, and protozoa. The parasites could potentially find an entryway to the gastrointestinal tract, and this would lead to malabsorption, weight loss, and other issues.
Bacterial Infections and Blockages
The other digestive disorders to which frogs are prone are bacterial infections that cause inflammation of the stomach or the intestines and blockages in the digestive tract, conditions that will become life-threatening if not treated.
Environmental Causes
Pollution and other environmental factors can also lead to problems in the digestive system of a frog.
Digestive System of Frog NEET MCQs (With Answers & Explanations)
This topic carries a significant weightage in NEET exam. Important topics to be covered are:
Components of Digestive System
Mechanism of Digestion
Practice Questions for NEET
Q1. Frogs have
Salivary glands, mucous glands, and parotid glands
Parotid glands, warty skin, and semicircular snout
Slippery skin, blue pigment, and abundant mucous glands
Bifid tongue, slippery skin, and mucous glands
Correct answer: 4) Bifid tongue, slippery skin, and mucous glands
Explanation:
1. Bifid Tongue: Frogs are equipped with a bifurcated tongue which is a distinctive feature aiding in their predatory behavior. It is muscular and sticky, anchored to the anterior part of the buccal cavity. This allows them to rapidly project their tongue to capture prey items such as insects with remarkable accuracy.
2. Slippery Skin: Frogs exhibit a smooth, mucus-covered epidermis due to mucus production by glands. This serves dual purposes: it provides a protective mechanism against predators by reducing their ability to grasp the frog, and it maintains skin hydration necessary for cutaneous respiration.
3. Mucous Glands: These glands are dispersed throughout frog skin and release a moisturizing mucus. Their key functions are:
- Moisture preservation for effective gas exchange via skin.
- Barrier formation against pathogens and water loss.
- In certain species, the mucus acts as a chemical deterrent with toxic or unpleasant properties to ward off predators.
Hence, the correct answer is option 4) Bifid tongue, slippery skin, and mucous glands.
Q2. Which type of teeth is found in frogs?
Acrodont
Homodont
Polyphyodont
All of these
Correct answer: 4) All of these
Explanation:
Acrodont, polyphyodont, and homodont teeth are all seen in frogs. This indicates that all of their teeth are of the same kind—small, pointed, and not designed for chewing. Rather, they are made to aid in retaining prey. Unlike human teeth, the teeth are acrodont which means they are affixed to the jaw directly and do not have sockets. As polyphyodonts, frogs can have many tooth replacements during their lifetime. Typically pointing backwards, the teeth aid in keeping prey from escaping. Instead of chewing their meal frogs grasp their prey with their teeth and then swallow it whole.
Hence, the correct answer is option 4)All of these.
Q3. Which of the following is mainly used in capturing the prey in frog
Lips
Teeth
Tongue
hand
Correct answer: 3) Tongue
Explanation:
The digestive system of a frog comprises the alimentary canal and associated digestive glands. It begins with food being caught by the large, muscular, bilobed tongue. Once this is captured, food will pass down through the oesophagus into the stomach, where it is mixed with gastric juices to break it down for digestion. The partially digested food now called chyme enters the duodenum and receives further digestion, this time from bile and pancreatic juices. Nutrients get absorbed in the small intestine by villi and microvilli, whilst waste to be excreted goes out the cloaca.
Hence, the correct answer is option 3) Tongue.
Also Read:
Recommended video on "Digestive System of Frog"
Frequently Asked Questions (FAQs)
In the small intestine, the maximum absorption of nutrients takes place.
The frogs are a much simpler model to understand the basic digestive processes and, in some ways similar to the human digestive system.
Sometimes parasitic infections and other gastrointestinal disorders may affect the frogs, thus impairing their health and digestion too.
Bile is secreted by the liver. It emulsifies the fats and fat-soluble vitamins. This is significant as it helps in the digestion and absorption processes of fats and vitamins.
Frogs have a cloaca as they do not have specific openings for their digestive, urinary and reproductive systems.