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i ain't the one who made this but hope it helps (credits to my classmates in SLSU Lucban) *hi
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2006-2007
Animal andHuman
Digestion
Digestive System – Objectives
Describe and understand the basic functions of the primary components of the digestive system.
Compare the functions and locations of the digestive organs in man and animals.
Differentiate between and identify digestive systems of man and animals.
Digestion Digestion is the breakdown
of large, complex organic molecules into smaller components that can be used by the body.
Molecules need to be small enough to diffuse across plasma membranes.
HUMAN DIGESTION
Four Components of Digestion Ingestion – this is the consumption of
or taking in of nutrients. Digestion – the chemical breakdown of
large organic molecules into smaller components by enzymes.
Absorption – the transport or delivery of digested nutrients to body tissues.
Egestion – the elimination of food waste materials from the body.
Ingestion
Food enters the human digestive tract through the mouth or oral cavity.
Humans are considered chunk feeders because they consume chunks of food that are then mechanically broken down.
Mouth Teeth
mechanically break down food into small pieces. Tongue mixes food with saliva (contains amylase, which helps break down starch).
Epiglottis is a flap-like structure at the back of the throat that closes over the trachea preventing food from entering it.
Mouth
Esophagus Approximately 10” long Functions include:1. Secrete mucus
2. Moves food from the throat to the stomach using muscle movement called peristalsis
If acid from the stomach gets in here that’s heartburn.
Esophagus: muscular tube that connects mouth to stomach–Peristaltic waves send feed down the
esophagus, (muscle contractions).–Reverse Peristalsis = blowing chunks–The cardia, located at the end of the
esophagus prevents feed in the stomach from coming back into the esophagus. ( non-ruminants only)
Stomach J-shaped muscular bag that
stores the food you eat, breaks it down into tiny pieces.
Mixes food with digestive juices that contain enzymes to break down proteins and lipids.
Acid in the stomach kills bacteria.
Food found in the stomach is called chyme.
12
Small Intestine Small intestines are roughly
7 meters long
Lining of intestine walls has finger-like projections called villi, to increase surface area.
The villi are covered in microvilli which further increases surface area for absorption.
13
Small Intestine Nutrients from the food pass
into the bloodstream through the small intestine walls.
Absorbs:– 80% ingested water– Vitamins– Minerals– Carbohydrates– Proteins– Lipids
* Secretes digestive enzymes14
Large Intestine
About 5 feet long Accepts what small
intestines don’t absorb
Rectum (short term storage which holds feces before it is expelled).
Large Intestine
Functions– Bacterial
digestion• Ferment
carbohydrates
• Protein breakdown
– Absorbs more water
– Concentrate wastes
Accessory Organs
Not part of the path of food, but play a critical role.
Include: Liver, gall bladder, and pancreas
Liver
Directly affects digestion by producing bile–Bile helps digest fat
• filters out toxins and waste including drugs and alcohol
18
Gall Bladder
Stores bile from the liver, releases it into the small intestine.
Fatty diets can cause gallstones
Pancreas
Produces digestive enzymes to digest fats, carbohydrates and proteins
Regulates blood sugar by producing insulin
Understanding the Digestive Systems
Ruminants Non-ruminants
A RUMINANT ANIMAL
Has four distinctive compartments in
its stomach, which swallows its food
essentially unchewed, regurgitates, and
chews it thoroughly and reswallows it
again.
Examples include cattle, sheep, goats,
deer, rhinos, and elk.
Rumination (regurgitation) After rumen if full, it lies down to ruminate
(chew its cud)
Cattle spend from 5-7 hours ruminating, broken up into 6-8 periods
Regurgitation is the process of forcing the feed back into the mouth for chewing
Done through a series of muscular contractions and pressure in the rumen and reticulum
A NONRUMINANT ANIMAL
Has a single compartment in its
stomach, which swallows its
food after chewing and does not
regurgitate its food.
Examples include pigs,
humans, bears, and dogs.
Nonruminant Digestion
food is
swallowed
directly into
the single
stomach
compartment
it is mixed
with digestive
juices
What do animals need to live? Animals make energy
using:– food– oxygen
Animals build bodies using:– food for raw materials
• amino acids, sugars, fats, nucleotides
– ATP energy for synthesis
O2
food
ATP
mitochondria
How do animals get their food?
filter feeding living in your food
fluid feeding bulk feeding
Getting & Using Food Ingest
– taking in food Digest
– mechanical digestion• breaking up food into smaller pieces
– chemical digestion• breaking down food into molecules
small enough to be absorbed into cells
• enzymes Absorb
– absorb nutrients across cell membranes• diffusion• active transport
Eliminate – undigested material passes out of body
intracellulardigestion
extracellulardigestion
Different diets; different bodies Adaptations of herbivore vs. carnivore
– teeth– length of digestive system– number & size of stomachs
Teeth Carnivore
– sharp ripping teeth
– “canines” Herbivore
– wide grinding teeth
– molars Omnivore
– both kinds of teeth
Length of digestive system
Herbivores & omnivores– long digestive
systems– harder to digest
cellulose (cell walls)• bacteria in
intestines help Carnivores
– short digestive systems
– protein easier to digest than cellulose
appendix
Fun Facts
• HOW LONG ARE YOUR INTESTINES? At least 25 feet in an adult. Be glad you're not a full-grown horse -- their coiled-up intestines are 89 feet long!
• Food drying up and hanging out in the large intestine can last 18 hours to 2 days!
• In your lifetime, your digestive system may handle about 50 tons!!
Write the name of each colored organ:
Green: Red: Pink: Brown: Purple: Green: Yellow:
How’d you do? Green: Esophagus Red: Stomach Pink: Small
Intestine Brown: Large
Intestine Purple: Liver Green: Gall Bladder Yellow: Pancreas
Great Job!