, ANIMAL NUTRITION
All animals are heterotrophic organisms that depend on other organisms for their organic nutrients. They usually
obtain their organic food in a complex, insoluble form although it is then broken down into simpler, soluble nutrients.
There are 5 main processes in nutrition:
1. Ingestion —> food is take and enters alimentary canal
2. Digestion —> food is exposed to mechanical and chemical processes that change it into simple and soluble
substances
3. Absorption —> end products of digestion are absorbed into the bloodstream
4. Assimilation —> the cells absorb the nutrients from the blood and use it to build new cell structures and
compositions
5. Egestion —> process through which indigestion remains are removed from the body in the form of faeces
Food is important because:
• Provides energy through the ingestion of carbohydrates and fats
• Growth and repair of damaged tissues due to the ingestion of proteins
• Regulation of body processes such as cellular respiration and excretion
Modes of Nutrition in Animals
Herbivores: Carnivores: Omnivores:
• Feed on plant material • Feed on animal material • Eat both plant and animal
• Large volumes are ingested as • Ingest less food as proteins and fats material
they have a low energy value in meat have higher energy value • The amount of food consume
• Teeth are adapted as: then plants depends in the energy value of
- Incisors: sharp to cut off • Teeth are adapted in following ways: the food they eat
plant material - Incisors: sharp ends to bite off • Omnivores teeth are similar to
- Canines / Fangs: absent food carnivores except that their
- Premolars and Molar: large - Canine / Fangs; long and strong molars don’t have cut dominant
and fat to grind plant material to pierce, kill and tear protrusions and the fangs are
- Premolars and Molar: have rather used for self defense
protrusions hit sharp edges to cut and social display
off the food
Human Nutrition
The human digestive systems consist of the alimentary canal and the accessory organs
Colon / Large Intestine :
Consists of 3 parts:
• Caecum —> sac like structure where joins small intestine and has appendix attached to it
• Colon —> ascending, transverse and descending and is largest part
• Rectum —> last muscular portion and is opening to the anus
• Function: secrets large amount of mucus to aid with egestion, water and useful substances are absorbed
and undigested waste ( faeces ) is temporarily stored before egested
,Teeth: Mouth/Mouth Cavity: ⑤ Stomach: &
• Humans have 4 types of teeth: • Upper opening of alimentary canal surrounded by 2 • Sickle-shaped, sac like organ located just below
• Incisors —> bites and cut off food fleshy lips • The oesophagus opening at the top is closed b
• Canine —> holds food in place and tear it • Cavity inside —> mouth cavity which is lined with a by the pyloric sphincter
off mucous membrane • Function: causes churning movements that ass
• Premolars and Molars —> chew and grind • Roof of cavity consist of hard, rigid plate at front and juices ( glands in stomach secrete these juices
the food soft palate at back • Food leaves stomach in semi-solid state known
• Human dental formula: 2.1.2..1.2.3 • Soft palate ends with uvula ( closes opening to nasal
• This means one half of the upper jaw has cavity ) Tongue:
2 incisors, 1 canine, 2 premolars and 3 • Cavity also has tongue, teeth and opening to 3 pairs of • Muscular organ attached to the mouth floor
molars salivary glands • The taste buds occur on the Papillae which are
• Complete set of teeth is 32 ( 16 on each • Function: breaks down larger food particles into smaller projections
jaw ) pieces and mixes it with saliva ( mechanical digestion ) • Functions: serves as a taste organ and helps i
process by pressing food against the hard pala
Salivary Glands: - Pharynx: the teeth
5g • Ensures the food is mixed with saliva and rolls
• Opens into mouth and has 3 pairs: • Back of the mouth and is
3
I
• Parotid Salivary Glands —> below the ears opening to the oesophagus • Helps with swallowing process as it pushes the
• Submandibular Salivary Glands —> in lower jaw and trachea the opening of the throat
• Sublingual Salivary Glands —> under the tongue • Function: common passage
• Function: produce and secrete saliva ( exocrine for food and air from Pancreas: -
glands hit release their secretions in ducts ) mouth z • Tongue-shaped gland located belo
·
epiglotris prevents wrong rube • Normal Pancreatic cells —> secret
Small Intestine: • The Islets of Langerhans —> secr
chrome
• Long, muscular tube of 5m-6m in length that consists of 3 parts ~ final place for • The pancreatic juice is transport
• - Duodenum —> first and shortest part as its the common bile duct from the gall which both of them opens into th
bladder and the pancreatic duct from the pancreas open as a joint tube to the • The pancreas is both an exocrine
duodenum Lacidic Food enters) Pancreas chelps) acid
+
+ bile (gallbladder/liver) helps wILk their secretions directly into the
• ↑ Jejunum —> middle part main focus
>
-
absorption
Far
• The exocrine function is when th
,
regulte nutriention
• - Ileum —> lasts longest part as it joins the first part of the large intestine absorption pancreatic duct that opens into t
E
( caecum ), which is closed by a ring muscles known as the ileo-caecal sphincter • The endocrine function is when t
• Function: layer of muscles in walls cause peristaltic movements which moves the
⑳ bloodstream
w
chyme forward ensuring that it becomes mixed with the digestive juices • Remember that glucagon increas
• Glands in duodenal walls ( Liberkuhn and Brunner ) secrete digestive juices the opposite function to insulin
( intestinal juices ) • Function: It secret pancreatic ju
• The villi increase the surface area for the aborption of digested nutrients • It secretes insulin and glucagon w
adaptions
:
, Liver: &
• It’s the largest gland in the body located just below the diaphragm and its the second largest organ in the
body
• It consists of 2 lobes, a large right lobe and smaller left lobe and each lobe is made of tiny lobules that
consists of liver cells
• The liver cells produce bile that is transported away from away from the liver via the common hepatic duct,
which forms a branch, the cystic duct, which transports bile to the gall bladder for storage
• The common hepatic duct and cystic ducts join and form the common bile duct which, then joins the
pancreatic duct to open into duodenum
• These ducts have some power of regeneration
• Functions: the liver produces bile ( emulsifies the fat which is a physical process is which bile salts break
down large fat globules and this include salicylic acid ), which is then stored in the gall bladder
• It converts glucose into glycogen for storage in liver and any excess glucose is converted into fat and is stored
( gain weight - too many carbs )
• Excess amino acids are broken down to form urea ( urine acid-toxic which is nitrogenous waste excreted from
the body ) and glucose i the liver by a process called deaminating
• The liver is a detoxifying organ that absorbs and neutralizes certain toxins such as alcohol
• Vitamins A, D, E, K and B12 ( fat soluble ) are stored in the liver
• The liver synthesize heparin which prevents blood clotting
• Helps process food
Liver
·
Gall Bladder -
• Muscular Sac located between
liver lobes and contracts to
release bile when it is Stomach
stimulated
Gall Bladder
• The bile moves along the Common Hepatic Duct
cystic duct, common bile duct Cystic Duct
and pancreatic duct into the
·
duodenum
Common Bile Duct
• Function: stores and releases
Pancreas
bile that is produced in the
liver
Duodenum l Pancreatic Duct
Digestion
Nutrients must be in a simple, soluble form to be absorbed by the blood and transported to the body cells.
Complex, insoluble food particles are broken down by digestion into simple, soluble nutrients and there are 2 types
of digestion: Mechanical or Physical Digestion and Chemical Digestion
Mechanical / Physical Digestion
This is when food is broken down into smaller particles as smaller particles have a larger surface area for
digestive enzymes to break them down further. This digestion can include:
• Chewing Process ( mastication ) —> food broken down by teeth and tongue
• Bolus formation —> chewed food is mixed with saliva and rolled into a food ball using the tongue and the
swallowing process starts with the tongue pushing the bolus through the pharynx, from where it enters the
oesophagus
• Churning movements —> takes place by contraction and relaxation of the muscles of the stomach wall. food
particles are broken down further for effective enzyme action and throughly mixed with gastric juice
All animals are heterotrophic organisms that depend on other organisms for their organic nutrients. They usually
obtain their organic food in a complex, insoluble form although it is then broken down into simpler, soluble nutrients.
There are 5 main processes in nutrition:
1. Ingestion —> food is take and enters alimentary canal
2. Digestion —> food is exposed to mechanical and chemical processes that change it into simple and soluble
substances
3. Absorption —> end products of digestion are absorbed into the bloodstream
4. Assimilation —> the cells absorb the nutrients from the blood and use it to build new cell structures and
compositions
5. Egestion —> process through which indigestion remains are removed from the body in the form of faeces
Food is important because:
• Provides energy through the ingestion of carbohydrates and fats
• Growth and repair of damaged tissues due to the ingestion of proteins
• Regulation of body processes such as cellular respiration and excretion
Modes of Nutrition in Animals
Herbivores: Carnivores: Omnivores:
• Feed on plant material • Feed on animal material • Eat both plant and animal
• Large volumes are ingested as • Ingest less food as proteins and fats material
they have a low energy value in meat have higher energy value • The amount of food consume
• Teeth are adapted as: then plants depends in the energy value of
- Incisors: sharp to cut off • Teeth are adapted in following ways: the food they eat
plant material - Incisors: sharp ends to bite off • Omnivores teeth are similar to
- Canines / Fangs: absent food carnivores except that their
- Premolars and Molar: large - Canine / Fangs; long and strong molars don’t have cut dominant
and fat to grind plant material to pierce, kill and tear protrusions and the fangs are
- Premolars and Molar: have rather used for self defense
protrusions hit sharp edges to cut and social display
off the food
Human Nutrition
The human digestive systems consist of the alimentary canal and the accessory organs
Colon / Large Intestine :
Consists of 3 parts:
• Caecum —> sac like structure where joins small intestine and has appendix attached to it
• Colon —> ascending, transverse and descending and is largest part
• Rectum —> last muscular portion and is opening to the anus
• Function: secrets large amount of mucus to aid with egestion, water and useful substances are absorbed
and undigested waste ( faeces ) is temporarily stored before egested
,Teeth: Mouth/Mouth Cavity: ⑤ Stomach: &
• Humans have 4 types of teeth: • Upper opening of alimentary canal surrounded by 2 • Sickle-shaped, sac like organ located just below
• Incisors —> bites and cut off food fleshy lips • The oesophagus opening at the top is closed b
• Canine —> holds food in place and tear it • Cavity inside —> mouth cavity which is lined with a by the pyloric sphincter
off mucous membrane • Function: causes churning movements that ass
• Premolars and Molars —> chew and grind • Roof of cavity consist of hard, rigid plate at front and juices ( glands in stomach secrete these juices
the food soft palate at back • Food leaves stomach in semi-solid state known
• Human dental formula: 2.1.2..1.2.3 • Soft palate ends with uvula ( closes opening to nasal
• This means one half of the upper jaw has cavity ) Tongue:
2 incisors, 1 canine, 2 premolars and 3 • Cavity also has tongue, teeth and opening to 3 pairs of • Muscular organ attached to the mouth floor
molars salivary glands • The taste buds occur on the Papillae which are
• Complete set of teeth is 32 ( 16 on each • Function: breaks down larger food particles into smaller projections
jaw ) pieces and mixes it with saliva ( mechanical digestion ) • Functions: serves as a taste organ and helps i
process by pressing food against the hard pala
Salivary Glands: - Pharynx: the teeth
5g • Ensures the food is mixed with saliva and rolls
• Opens into mouth and has 3 pairs: • Back of the mouth and is
3
I
• Parotid Salivary Glands —> below the ears opening to the oesophagus • Helps with swallowing process as it pushes the
• Submandibular Salivary Glands —> in lower jaw and trachea the opening of the throat
• Sublingual Salivary Glands —> under the tongue • Function: common passage
• Function: produce and secrete saliva ( exocrine for food and air from Pancreas: -
glands hit release their secretions in ducts ) mouth z • Tongue-shaped gland located belo
·
epiglotris prevents wrong rube • Normal Pancreatic cells —> secret
Small Intestine: • The Islets of Langerhans —> secr
chrome
• Long, muscular tube of 5m-6m in length that consists of 3 parts ~ final place for • The pancreatic juice is transport
• - Duodenum —> first and shortest part as its the common bile duct from the gall which both of them opens into th
bladder and the pancreatic duct from the pancreas open as a joint tube to the • The pancreas is both an exocrine
duodenum Lacidic Food enters) Pancreas chelps) acid
+
+ bile (gallbladder/liver) helps wILk their secretions directly into the
• ↑ Jejunum —> middle part main focus
>
-
absorption
Far
• The exocrine function is when th
,
regulte nutriention
• - Ileum —> lasts longest part as it joins the first part of the large intestine absorption pancreatic duct that opens into t
E
( caecum ), which is closed by a ring muscles known as the ileo-caecal sphincter • The endocrine function is when t
• Function: layer of muscles in walls cause peristaltic movements which moves the
⑳ bloodstream
w
chyme forward ensuring that it becomes mixed with the digestive juices • Remember that glucagon increas
• Glands in duodenal walls ( Liberkuhn and Brunner ) secrete digestive juices the opposite function to insulin
( intestinal juices ) • Function: It secret pancreatic ju
• The villi increase the surface area for the aborption of digested nutrients • It secretes insulin and glucagon w
adaptions
:
, Liver: &
• It’s the largest gland in the body located just below the diaphragm and its the second largest organ in the
body
• It consists of 2 lobes, a large right lobe and smaller left lobe and each lobe is made of tiny lobules that
consists of liver cells
• The liver cells produce bile that is transported away from away from the liver via the common hepatic duct,
which forms a branch, the cystic duct, which transports bile to the gall bladder for storage
• The common hepatic duct and cystic ducts join and form the common bile duct which, then joins the
pancreatic duct to open into duodenum
• These ducts have some power of regeneration
• Functions: the liver produces bile ( emulsifies the fat which is a physical process is which bile salts break
down large fat globules and this include salicylic acid ), which is then stored in the gall bladder
• It converts glucose into glycogen for storage in liver and any excess glucose is converted into fat and is stored
( gain weight - too many carbs )
• Excess amino acids are broken down to form urea ( urine acid-toxic which is nitrogenous waste excreted from
the body ) and glucose i the liver by a process called deaminating
• The liver is a detoxifying organ that absorbs and neutralizes certain toxins such as alcohol
• Vitamins A, D, E, K and B12 ( fat soluble ) are stored in the liver
• The liver synthesize heparin which prevents blood clotting
• Helps process food
Liver
·
Gall Bladder -
• Muscular Sac located between
liver lobes and contracts to
release bile when it is Stomach
stimulated
Gall Bladder
• The bile moves along the Common Hepatic Duct
cystic duct, common bile duct Cystic Duct
and pancreatic duct into the
·
duodenum
Common Bile Duct
• Function: stores and releases
Pancreas
bile that is produced in the
liver
Duodenum l Pancreatic Duct
Digestion
Nutrients must be in a simple, soluble form to be absorbed by the blood and transported to the body cells.
Complex, insoluble food particles are broken down by digestion into simple, soluble nutrients and there are 2 types
of digestion: Mechanical or Physical Digestion and Chemical Digestion
Mechanical / Physical Digestion
This is when food is broken down into smaller particles as smaller particles have a larger surface area for
digestive enzymes to break them down further. This digestion can include:
• Chewing Process ( mastication ) —> food broken down by teeth and tongue
• Bolus formation —> chewed food is mixed with saliva and rolled into a food ball using the tongue and the
swallowing process starts with the tongue pushing the bolus through the pharynx, from where it enters the
oesophagus
• Churning movements —> takes place by contraction and relaxation of the muscles of the stomach wall. food
particles are broken down further for effective enzyme action and throughly mixed with gastric juice
