Nutrition in Animals

1. Life Processes in Animals – 5.1 Life processes in animals-nutrition NUTRlTlON  Subject  : Biology Done By : Jinsi Hirpara,7CM 1B By JinsiHirpara,VII CM 1B

2. CONTENT  OF THIS CHAPTER 1.Introduction 2.Nutrition 3.Nutrition in Animals 4.Steps Of Nutrition 5.Feeding And Digestion 6.Adaptations of Herbivores 7.Human Digestive System 8.Working of the digestive system 9.The Buccal Cavity 10.Disorders of digestive system

3. 1.INTRODUCTION • Life processes are the series of actions or functions that are essential for a living being to sustain . Example:Nutrition,Respiration,Excretion,Reproduction,etc... • The main thing required to carry out most of the processes is ENERGY 5 MAIN TYPES OF LIFE PROCESSES IN ANIMALS

4. 2.NUTRITION • NUTRlTlON is a method in which the food is consumed by the organisms into the body and utilizing the nutrients from the food •  Nutrients are energy source for the human body and are listed as fibers, carbohydrates, minerals, vitamins, fats, water and proteins. • There are basically 2 modes of nutrition based on the method of food procurement namely- AUTOTROPHlCNUTRlTlON : Autotrophic nutrition is a process in which the organism produces their food from the simple inorganic materials such as water, carbon dioxide and mineral salts in the presence of sunlight. All the green plants have an autotrophic mode of nutrition.                                                                    AND HETEROTROPHlCNUTRlTlON : Heterotrophic nutrition is a type of nutrition in which organisms depend upon other organisms for food to survive. Heterotrophic organisms have to take in all the organic substances they need to survive.

5. 3.NUTRITION IN ANIMALS • Heterotrophs(animals)undergo HOLOZOlC NUTRlTlON • Holozoic nutrition (Greek: holo-whole ; zoikos-of animals) is a type of heterotrophic nutrition that is characterized by the internalization (ingestion) and internal processing of gaseous, liquids or solid food particles. • And based on the type of food they eat they are mainly divided into three categories, HERBlVORES,CARNlVORES AND OMNlVORES

6. 4.STEPS OF NUTRITION • There are five steps in the process of Nutrition in animals. These are: Ingestion, Digestion, Absorption, Assimilation and Egestion. • Ingestion: Is the process of taking food in to the body or ‘eating of food’ by the animal. When we put food in to our mouth with hands, we are ingesting it. • Digestion: Is the process in which the food containing large, insoluble molecules is broken down in to small, water soluble molecules which can be absorbed by the body or digestion is the dissolving of the solid food. Most of the animals include both physical and chemical methods for digesting the food. Physical method includes chewing and grinding the food in mouth and chemical method include the addition of digestive juices (enzymes) to food by the body itself. • Absorption: Is the process in which the digested food passes through the intestinal wall in to blood stream. As, after the digestion, food molecules become small and soluble. This food passes through the walls of our intestine and goes in to the blood. • Assimilation: Is the process in which the absorbed food is taken in by the body cells and used for energy, growth and repair. Blood carries the absorbed food to all the parts of the body. • Egestion: Is the process in which the undigested food is removed from the body. The whole food which we eat is not digested by our body, a part of the food remains undigested which cannot be used by the body and so it is removed from the body in the form of faeces

8. 5.FEEDING AND DIGESTION • There are different methods of different animals and insects in the ways of taking food. For example:

9. Feeding and Digestion in AMOEBA • Amoeba is a simple, unicellular organism which is found at the bottom of fresh water, It contains jelly-like cytoplasm with a clear nucleus, many food vacuoles, and contractile vacuoles. Because amoeba is unicellular, It means a single cell performs all the function like digestion, respiration, reproduction etc. • Digestion Process in Amoeba : Digestion in amoeba is intracellular taking place within the cell.The food taken in remains in a food vacuole or gastric vacuole formed by the cell membrane and small part of the cytoplasm. The vacuoles are transported deeper into the cells by cytoplasmic movements. Here they fuse with lysosomes that contain enzymes. Two enzymes amylase and proteinase have been reported. Thus, amoeba can digest sugars, cellulose and proteins. Fats, however, remain undigested. The contents of the vacuole become lighter and the outline of the vacuole becomes indefinite indicating that the digestion is complete.

11. 6.ADAPTATIONS IN HERBIVORES RUMINANTS : COW • Ruminants are mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The process typically requires the fermented ingesta (known as cud) to be regurgitated and chewed again. The process of rechewing the cud to further break down plant matter and stimulate digestion is called rumination. The word “ruminant” comes from the Latin RUMINARE which means “to chew over again”.There are roughly 150 species of ruminants that include both domestic and wild species. • Ruminants undergo reverse peristalsis which means the oesophagus of the digestive system allows the food to come into the mouth again for complete digestion. • Humans undergo reverse peristalsis very rare times.The often go under peristalsis.

12. DIGESTION : • Grass-eating animals swallow the food quickly and store it in the rumen. Rumen also inhabits cellulose digesting bacteria which establish a symbiotic relationship with the animal stomach. • Digestion in ruminants is a good example of symbiosis. Microorganisms present in the stomach of ruminants help in digesting cellulose and in turn obtain shelter and nourishment form the animal. A symbiotic relationship exists between microorganisms and the ruminants. • As rumen is full, the food is taken into second part of the stomach, the reticulum. • Digestive juices of the reticulum partially digest the food. The partially digested food in the reticulum is called as cud. • While resting, cow brings back the cud into the mouth for regurgitation. • Food is chewed completely and swallowed into omasum for further digestion. • Then the food moves into abomasum for digestion brought about by digestive juices. • A large sac-like structure called the caecum lies between the small and large intestines. • The symbiotic bacteria present in the caecum help in the complete digestion of cellulose. Digestion of food is completed in the intestine. • As the symbiotic bacteria are not present in the human digestive system, humans cannot digest cellulose. Click to add text

14. Rabbit Food travels from the stomach to the small intestine, where it encounters enzymes which aid in digestion and absorption of nutrients from proteins, sugars and starches. From there it travels to the cecum, where the microbial breakdown of fiber occurs. It then enters the large intestine, where there is significant water resorption, followed by excretion of the faeces or pellets.The rabbit eats those pellets andpass through the digestive system for the second time.This type of feeding is called caprophagy.The digestion of cellulose in rabbit occurs in large intestine and appendix.

16. 7.Human Digestive system • The basic need for the digestive system is to provide the human body with the energy to perform human functions. This energy is needed for life processes such as growth, movement, reproduction etc.The food consumed by the human body is the source of all this energy.The word digestion is derived from the Latin word, DIGERERE, which means “to arrange”. This is what digestive system does, it breaks down food and arranges its different components into molecules your body can use. • The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body

17. Organs of the digestive system: Mouth : Buccal Cavity Oesophagus Stomach Duodenum : Liver and Pancreas Small Intestine Large Intestine Rectum Anus

18. 8.WORKING OF THE DIGESTIVE SYSTEM • MOUTH  Food starts its journey from the mouth or the oral cavity. There are many other organs that contribute to the digestion process, including teeth, salivary glands, and tongue. • BUCCAL CAVITY The buccal cavity is the first cavity of the alimentary canal which includes teeth, tongue, and palate (Palate is the roof of the mouth. It separates the mouth and the nose.). The buccal cavity helps to take the food inside by the process of ingestion (ingestion is the process of taking food into the body). Mastication (chewing), in which food is crushed and mixed with saliva to form a bolus for swallowing, is a complex mechanism involving opening and closing of the jaw, secretion of saliva, and mixing of food with the tongue.

19. OESOPHAGUS This is a muscular tube that connects the pharynx, which is a part of an upper section of the gastrointestinal tract. It supplies swallowed food along with its length. • STOMACH It serves as a muscular bag which is situated towards the left side of the abdominal cavity, beneath the diaphragm. This vital organ acts as a storage for the food and provides enough time to digest meals. The stomach also produces digestive enzymes and hydrochloric acid that maintains the process of digestion. • Mucous: It is an aqueous secretion produced by the mucous membranes. It functions by protecting the stomach lining and gastric pits from the acid, which is produced by the glands to destroy the bacteria that entered along with the food particles. • Digestive enzymes: They are the group of enzymes which functions by breaking down polymeric macromolecules like biopolymers into their smaller and simpler substances. • Hydrochloric acid: It is the digestive fluid formed by the stomach during the process of digestion. It functions by destroying harmful microorganisms present in the food particles.

20. DUODENUM The duodenum is the first part of the small intestine. It is located between the stomach and the middle part of the small intestine, or jejunum. After foods mix with stomach acid, they move into the duodenum, where they mix with bile from the gallbladder and digestive juices from the pancreas. • SMALL INTESTINE The small intestine is a thin, long tube of about 10 feet long and a part of the lower gastrointestinal tract. It is present just behind the stomach and acquires a maximum area of the abdominal cavity. The complete small intestine is coiled and the inner surface consists of folds and ridges. • LARGE INTESTINE This is a thick, long tube measuring around 5 feet in length. It is present just beneath the stomach and wraps over the superior and lateral edges of the small intestine. It absorbs water and consists of bacteria (symbiotic) that support the breakdown of wastes to fetch small nutrients.

21. RECTUM AND ANUS Waste products are passed into the end of the large intestine called the rectum and eliminated out of the body as a solid matter called stool. It is stored in the rectum as semi-solid faeces which later exits from the body through the anal canal through the process of defecation.The anus is the opening at the far end of the digestive tract through which stool leaves the body. The anus is formed partly from the surface layers of the body, including the skin, and partly from the intestine. The anus is lined with a continuation of the external skin. • Mouth : Ingestion. • The partly digested,smooth slippery food is called bolus. • The stomach churns the food into milky paste called chyme. • Duodenum receives pancreatic juice from pancreas and bile juice from liver. • Salivary glands secrete saliva and intestinal walls secrete intsestinal juice • Small Intestine : Absorption,Assimillation • Rectum and Anus : Egestion or Defecation

23. 9.BUCCAL CAVITY • TEETH : The teeth are the hardest substances in the human body. Besides being essential for chewing, the teeth play an important role in speech. Parts of the teeth include: Enamel: The hardest, white outer part of the tooth. Enamel is mostly made of calcium phosphate, a rock-hard mineral. Dentin: A layer underlying the enamel. It is a hard tissue that contains microscopic tubes. When the enamel is damaged, heat  or cold can enter the tooth through these paths and cause sensitivity or pain. Pulp: The softer, living inner structure of teeth. Blood vessels and nerves run through the pulp of the teeth. Cementum: A layer of connective tissue that binds the roots of the teeth firmly to the gums and jawbone.

24. A normal adult mouth has 32 teeth, and age below 18 have 28 teeth.  • Incisors (8 total): The middlemost four teeth on the upper and lower jaws. • Canines (4 total): The pointed teeth just outside the incisors. • Premolars (8 total): Teeth between the canines and molars. • Molars (8 total): Flat teeth in the rear of the mouth, best at grinding food. • Wisdom teeth or third molars (4 total): These teeth erupt at around age 18, but are often surgically removed to prevent displacement of other teeth.

26. DENTALCARIES • Tooth decay (dental caries) is damage to a tooth that can happen when decay-causing bacteria in your mouth make acids that attack the tooth's surface, or enamel. Dental plaque is a sticky, colorless or pale yellow film that is constantly forming on your teeth. When saliva, food and fluids combine, plaque - which contains bacteria - forms between your teeth and along the gum line.This can lead to a small hole in a tooth, called a cavity. If tooth decay is not treated, it can cause pain, infection, and even tooth loss.

28. 10.Disorders Of DIGESTIVE SYSTEM • Worm Infestations : Worm infestations happen when worms affect the intestines and other parts of the body. Examples of the different worms are roundworms, whipworms, hookworms, tapeworms and flukes. A patient with a mild infestation might not show any symptoms. • Indigestion : A pain or discomfort in the stomach which is caused when food is not digested properly, resulting in the feeling of fullness.  Indigestion is mainly caused due to inadequate enzyme secretion, food poisoning, anxiety, overeating and eating spicy foods. • Constipation : A condition in which the faeces are clutched within the rectum due to an irregular bowel movement. • Diarrhoea : It is the abnormal watery bowel movement. Prolonged diarrhoea eventually leads to dehydration. • Peptic Ulcer : Peptic ulcers are open sores that develop on the inside lining of your stomach and the upper portion of your small intestine. The most common symptom of a peptic ulcer is stomach pain. Peptic ulcers include: Gastric ulcers that occur on the inside of the stomach.