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Daily Food for Thought

• List the Basic Trace of Food through the Digestive System

Basic OrganizationMouthEsophagusStomachSmall intestineLarge intestineAnus

Learning Target:I can list the parts of the monogastric digestive system and describe the functions of each.

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Digestion is the process by which large, complex nutrient molecules are broken down into simpler molecules capable of being used by the organism for food.

Different Digestive SystemsThe three different types of digestive systems

are: Monogastric

Pseudo-Ruminant or Modified Monogastric

Ruminant

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Humans, swine, and dogs all have a simple stomach, which is also known as a

monogastric digestive system.

MonogastricCarnivores and

omnivores have monogastric digestive systems.

Monogastric systems have a simple stomach structure and only one compartment.

Some animals with monogastric digestive systems are pigs and dogs. Humans also have monogastric digestive systems.

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Structures in MouthLipsTeethTongueSalivary glands

Monogastric TeethFunction:

Mechanically reduce particle size

Increase surface area

Four types:Incisors are used for

cutting Canine (fangs, eye teeth, tusks)

are tearing teeth Premolars and molars (cheek

teeth) grind the food

Monogastric TongueFunction:

Comprised of three muscles Maneuvers food in the mouth

Moves feed to teeth for grinding and to the back of the mouth for swallowing

Can distinguish between feed and toxins by papillae or taste buds

Monogastric Salivary GlandsTypes of Glands:

Parotid

Sublingual

Mandibular

Zygomatic

Functions of SalivaMoisten feed (salt and water)Lubrication (aids swallowing)Starch and(or) lipid digestion (amylase

and(or) lipase)Volume of saliva

1 - 1.5 L/d man and pig7 - 10 L/d horse

Deglutition (Swallowing)Reflex initiated by presence of food in

pharnyxPropulsion of food to stomach by esophageal

peristalsis

Digestive SystemMouth: “Prehension” tool (grasps food)

Salivary glands secrete juices containing enzymes (digest food)

Chewing food breaks down Esophagus: muscular tube that connects

mouth to stomachPeristaltic Movement: sequential contraction

of ringlike musclesReverse Peristalsis = vomiting

Gastric Digestion• Functions

– Reservoir for controlled release of digesta to small intestine

– Mixing food– Mechanical breakdown of feed– Hydrolytic digestion by acid and enzymes

• Mainly protein– Kill bacteria

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Parts and functions of the monogastric mammal digestive

system continued…•Small Intestine

-enzymatic digestion and absorption -Functions of the small intestine: digestion of proteins, carbohydrates, and fats; absorption

of the end products of digestion 1. duodenum - most digestion occurs

here 2. jejunum - some digestion and some

absorption occur 3. ileum - mostly absorption

-Bile - made in liver, stored in gall bladder, active in the small intestine, emulsifies fat to aid in digestion

Intestinal villi

Digestive SystemAccessory organs:Pancreas secretes enzymes to break down fatLiver (largest internal organ) and gall

bladder which secretes bile, which digests fatsalso stores iron

Large Intestine• Composed of three segments

– Cecum– Colon– Rectum

• Function– Fermentative digestion

• No enzyme secretion• Relies on microbes or secretions washed out of the SI

– Absorption of remaining water, volatile fatty acids (VFAs) from microbial fermentation and minerals

– Digesta storageDegree of development is species dependent

Monogastric Large IntestineFunction:

Absorption of liquidMass movements move fecal matter to anusUsually only a few times a day

Associated with defecation

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Different Digestive SystemsThe three different types of digestive systems

are:

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Digestion is the process by which large, ________________ molecules are broken down into simpler molecules capable of being used by the organism for food.

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Humans,________, rabbits, _________and horses all have a simple stomach, which is also

known as a _______________digestive system.

Monogastric_________and

omnivores have monogastric digestive systems.

Monogastric systems have a simple stomach structure and only ______ compartment.

Some animals with monogastric digestive systems are pigs and dogs. _______ also have monogastric digestive systems.

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Parts and functions of the monogastric mammal digestive

system continued…•Small Intestine

-enzymatic digestion and absorption -Functions of the small intestine: digestion of ____________, carbohydrates, and_______;

absorption of the end products of digestion 1. duodenum -______________________2. ________- some digestion and some

absorption occur 3. ileum -_________________________

-Bile - made in liver, stored in gall bladder, active in the small intestine, ___________________to aid in digestion.

Large Intestine• Composed of three segments

– ______________– ______________– ______________

• Function– ________________ digestion

• No enzyme secretion• Relies on microbes or secretions washed out of the SI

– ______________ of remaining water, volatile fatty acids (VFAs) from microbial fermentation and minerals

– Digesta storage