ruminants and rodents

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Biology Form 4 :Nutrition Azneezal Ar-Rashid Ruminants and rodents

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Page 1: Ruminants and Rodents

BiologyForm 4 :Nutrition

Azneezal Ar-Rashid

Ruminants and rodents

Page 2: Ruminants and Rodents

Today lesson

1. Digestive system in ruminants2. Digestive system in rodents3. Similiarities & differences of humans,

ruminants & rodents4. Problems related food digestion5. Absorbtion & assimilation of digested

food6. Defecation7. Eating habits8. The importance of healthy digestive

system

Page 3: Ruminants and Rodents

Digestion system in ruminants

• Ruminants are group of herbivorous mammals– Cows, goats, & camels

• Have UNUSUAL eating habit• Why unusual?

– Ruminants chew their food, swallow, and after some time regurgitate (throw up) the food from their stomach. The food is chewed for a second time and then swallowed again

• Have four-chambered stomach

Page 4: Ruminants and Rodents

Digestion system in ruminants

• Have four-chambered stomach– Rumen, reticulum, omasum & abomasum

• Being herbivores, ruminants eat plant matter. Plant matter contains a lot of cellulose

• Cellulose can be digested into glucose by cellulase enzyme. However, cellulase is not produce by ruminnts themselves

• There are microorganisms such as bacteria & protozoa which produce cellulase in the ruminants digestive system (rumen)

Page 5: Ruminants and Rodents

The process

• After grinding up grass in the oral cavity, the grass is swallowed into the rumen.

• In the rumen, cellulose in the grass is acted upon by microorganisms and broken down into glucose

• Food then enters the reticulum where the digestion of cellulose continues

• Food is then regurgitated into the oral cavity to be ground again.

Page 6: Ruminants and Rodents

The process

• When reswallowed, food enters the omasum. Here the product of digestion of cellulose is absorb

• Next, food enters abomasum.

• Abomasum is the true stomach in the sense that it produces gastric juice.

• Digestion of other nutriens such as protiens accurs here

Page 7: Ruminants and Rodents

Today lesson

1. Digestive system in ruminants √2. Digestive system in rodents3. Similiarities & differences of humans,

ruminants & rodents4. Problems related food digestion5. Absorbtion & assimilation of digested

food6. Defecation7. Eating habits8. The importance of healthy digestive

system

Page 8: Ruminants and Rodents

Digestive system in rodents

• Rodents refer to a group of mammals that comprise rabbits, rats, hamsters & squirrels

• Rodents have pair of long incisors, in each of upper and lower jaw

• Most rodents are herbivores• In rodents, digestion of cellulose occurs in the

caecum• Caecum is the first part of large intestine. There

are many bacteria and protozoa in the ceacum which can secrete cellulase to digest cellulose.

• Rodents have a big and well-developed caecum.

Page 9: Ruminants and Rodents

Today lesson

1. Digestive system in ruminants √2. Digestive system in rodents √3. Similiarities & differences of humans,

ruminants & rodents4. Problems related food digestion5. Absorbtion & assimilation of digested

food6. Defecation7. Eating habits8. The importance of healthy digestive

system

Page 10: Ruminants and Rodents

Similiarities & differences of humans, ruminants & rodents

Similiarities- All of them have a digestive system which

includes stomach, small intestine & large intestine

- All of the consume plant matter- All of them are able to digest starch, protiens &

fats- All of them have long small intestine

Page 11: Ruminants and Rodents

Differences of humans, ruminants & rodentsHumans Ruminants Rodents

Omnivores Herbivores Mostly herbivores

Single stomach chamber

Stomach of four chamber

Single stomach chamber

Caecum about the same size as the other part of colon

Caecum about the same size as the other part of colon

Big and well developed caecum

Bacteria present throughout the large intestine

Bacteria and protozoa present in the stomach

Bacteria and protozoa present in the caecum

Unable to digest cellulose

Able to digest cellulose

Able to digest cellulose

Do not regurgitate food

Regurgitate food Do not regurgitate food

Page 12: Ruminants and Rodents

Today lesson

1. Digestive system in ruminants √2. Digestive system in rodents √3. Similiarities & differences of humans,

ruminants & rodents4. Problems related food digestion5. Absorbtion & assimilation of digested

food6. Defecation7. Eating habits8. Healthy eating habits

Page 13: Ruminants and Rodents

Problems related to food digestion

• Incomplete digestion of food

• Bile stones preventing the flow of bile

• Reduced production of specific digestive enzymes

Page 14: Ruminants and Rodents

Today lesson

1. Digestive system in ruminants √2. Digestive system in rodents √3. Similiarities & differences of humans, ruminants &

rodents √4. Problems related food digestion5. Absorption & assimilation of digested food6. Defecation7. Eating habits8. The importance of healthy digestive system

Page 15: Ruminants and Rodents

Absorption & assimilation of digested food

• The small intestine has the following adaptations to increase the surface area for absorption food:– Very long ( 6m in length)– There are folds in the small intestine– Entire inner surface has finger-like projections

called villi (singular villus)– On the epithelium of each villi, there are fine

rojections called microvilli

Page 16: Ruminants and Rodents

Absorption & assimilation of digested food

• Each villus contains a network of blood capillaries

• In the middle of the vilus there is a lacteal which appears milky. The lacteal is continuous with lymphatic vessels

• The absorption occurs by diffusion initially, and then by active transport

• Simple sugars, amino acids, mineral salts, water soluble vitamins (Vit B and C) and 95% of water are absorped into the blood capilaries

Page 17: Ruminants and Rodents

• Blood cappilaries from all villi join up to form hepatic portal vein

• The hepatic portal vein carries blood containing digested food to the liver

• Fatty acid & glycerol diffuse into the epithelial cells of villus. In the epithelial cells, fatty acids combine with glycerol to form fat droplets that give the lacteal a milky appearance

• Fat-soluble vitamins (Vit A,D,E,K) are also absorbed into the lacteal.

Page 18: Ruminants and Rodents

• The fat droplets are transported out from the lacteal by lymphatic ducts. These lymphatic ducts finally open into the left subclavia vein in the region between the neck and the shoulder

Page 19: Ruminants and Rodents

Assimilation of digested food

• Assimilitaion = the process of incorporating digested food into our body cells & tissues, so that they become part of body tissues. An example is the building of cytoplasm by using amino acids from the digestion of protiens

• If a person has eating an excessive amount of carbohydrates, the excess glucose is produced from digestion will be converted by liver cells into glycogen. Glycogen is the stored in the liver cells. It has now become a part of the liver cells.

Page 20: Ruminants and Rodents

• The liver also uses the aino acids that arrive there to synthesise enzymes and plasma proteins. Two example of plasma proteins are prothrombin and fibrinogen. Both of them are needed for the clotting of blood at wounds

• Besides functioning in assimilation, liver also functions in detoxification, for example breaking down toxic substances and poisons in food

Page 21: Ruminants and Rodents

• Excess amino acid are toxic and cannot be stored in the body. Because of that, the liver converts excess amino acids into urea.

• Urea is then transported by blood to the kidneys to be excreted through urine

• Poisons and drugs such as alcohol are broken down by the liver and the products excreted through urine

• Excess fats are built into fatty tissue and are stored under the skin abd around the organs.

Page 22: Ruminants and Rodents

Assimilation of water and minerals in the colon

• 95 % of water is absorbed in the small intestine

• The colon (the main part of the large intestine) will absorb most of the remaining water

• Most of minerals are actively absorbed in the small intestine except for sodium and chlorine. These minerals are absobed in the large intestine.

Page 23: Ruminants and Rodents

Today lesson

1. Digestive system in ruminants √2. Digestive system in rodents √3. Similiarities & differences of humans, ruminants &

rodents √4. Problems related food digestion5. Absorption & assimilation of digested food6. Defecation7. Eating habits8. The importance of healthy digestive system

Page 24: Ruminants and Rodents

Defaecation

• Undigested food that consist of mainly fibres and excretory products, such as bile pigments, dead cells and dead bacteria is not absorbed in the small intestine. It is channeled to the large intestine by peristalsis

• In the colon, absorption of water occurs. As a result of water absorption, undigested food residues harden to become faeces. Faeces is stored in the rectum tompararily.

Page 25: Ruminants and Rodents

• When the rectum is full, its muscular wall will contract to excrete the faeces through anus. This process called defeaction

• There are some friendly bacteria that live in our colon. These bacteria can act on undigested food residues to produce vitamins B12 and K. These vitamins are absorbed into the blood for use by body cells.

Page 26: Ruminants and Rodents

• Some bacteria such as Salmonella can disturb the normal function of the colon, causing the diarrhoea.

• Consuming antibiotics can kill the bad bacteria in the colon. However the friendly bacteria are also killed. Vitamin B12 and K cannot be produced. Hence we need to consume natural sources of both vitamins.

Page 27: Ruminants and Rodents

Today lesson

1. Digestive system in ruminants √2. Digestive system in rodents √3. Similiarities & differences of humans, ruminants &

rodents √4. Problems related food digestion5. Absorption & assimilation of digested food6. Defecation7. Eating habits8. The importance of healthy digestive system

Page 28: Ruminants and Rodents

Eating habits

• Gastritis– Inflammation of the lining of stomach

• Obesity– Weight exceeds the right weight 20 % or more

• Anorexia nervosa– Obsessed maintaing slim figure– Adolescent female (emotional disturbance)

• Bulimia– Eating disorder– Binge-purge syndrome– Eats excessively then feel guilty--vomit

Page 29: Ruminants and Rodents

Today lesson

1. Digestive system in ruminants √2. Digestive system in rodents √3. Similiarities & differences of humans, ruminants &

rodents √4. Problems related food digestion5. Absorption & assimilation of digested food6. Defecation7. Eating habits8. The importance of healthy digestive system

Page 30: Ruminants and Rodents

Healthy eating habits

• Eating balanced diets• Eating at fixed time everyday• Eating moderately• Eating only nutritious food• Avoiding snacks which are tasty but lacking in

nutrients• Avoiding drinking much water just before, during

or after a meal. This is because water will dilute the digestive juices and slow down digestion