Download Digestive System Packet

Name: ____________________________________ Date: ____________ Class: ______5/7/17
2009-2010 KEY TERMS AND OBJECTIVES FOR
the Human Digestive System
OBJECTIVES: By the end of this unit, you should be able to…
1. Match each of the key terms below to its correct definition
The Human Digestive System:
2. Identify the major parts of the human digestive system on a diagram
3. Explain functions of the following parts of the digestive system: esophagus, stomach, small
intestine, large intestine, villi, liver, pancreas, gallbladder, rectum, anus
4. *In essay form, explain, in detail how the food you eat moves from the mouth through the
digestive system and ultimately, how nutrients get to all cells throughout the body. During
your explanation, make sure to answer the following questions and also use these words in
your explanation: circulatory system, diffusion, small intestine, villi,
a. List the path that food takes in the digestive system (the order of organs that food
actually passes through)
b. List two organs responsible for mechanical digestion
c. List three organs responsible for chemical digestion
SECTIONS IN BOOK:
Biology: Exploring Life 29.1 – Nutrition depends on digestion and absorption
Biology: Exploring Life 29.2 – Each region of the digestive tube is specialized
KEY TERMS:
The Process of Digestion:
Absorption: the stage of digestion in which certain cells take up small molecules
Chemical change: when food changes into a form the body can use. It is not the same
substance after it is broken down. . (Also known as chemical digestion)
Digestion: the process of breaking food down into molecules small enough for the body to
absorb
Digestive System: a group of organs that take in food and change it into a form the body
can use
Elimination: the stage of digestion in which undigested material passes out of the body as
waste
Ingestion: the act of eating or drinking
Nutrition: the process of how your body obtains raw material from food
Physical change: when large food particles are broken down into smaller pieces of the
same substance. (Also known as mechanical digestion)
The Human Digestive System:
Alimentary Canal: digestive tube that extends from the mouth to the anus
Pharynx: upper portion of the throat
Esophagus: connects the pharynx to the stomach
Stomach: elastic, muscular sac where some chemical and mechanical digestion occur
Small intestine: long narrow tube where digestion is completed and absorption of most
nutrients takes place
Liver: produces bile (a digestive liquid)
Gallbladder: stores bile
Pancreas: produces and secretes digestive juices
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Villi: small, finger-like projections in the small intestine that absorb nutrients
Large intestine: wide, short tube from which water is absorbed into the body
Feces: undigested food material and other waste products
Rectum: stores feces until they are expelled from the body
Anus: passageway for feces to exit the body
Match the following parts to
their correct structure on the
digestive system diagram:
_____ Anus
_____ Appendix
_____ Esophagus
__F__ Gallbladder
_____ Large Intestine
_____ Liver
__J__ Pancreas
__A__ Pharynx
_____ Rectum
_____ Salivary Gland
_____ Small Intestine
_____ Stomach
_____ Tongue
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Name: _________________________________ Date: __________________ Class: _______
NOTES: The Human Digestive System (Concepts 29.1
and 29.2)
This is the note document to go along with the PowerPoint (instead of handing out the slides)
Biology: Exploring Life 29.1 – Nutrition depends on digestion and absorption
Biology: Exploring Life 29.2 – Each region of the digestive tube is specialized
The Digestive Tract
The digestive tract is the tube through which food is processed in the body. It extends from the mouth
through the anus
Mouth
• Food is taken in here, and mixed with saliva.
• Contains:
– Teeth: which begin physical digestion
– Tongue: helps mix food with saliva, aids in swallowing
– Salivary glands: produce saliva
• Enzymes in saliva begin chemical digestion of starch
Types of human teeth
Location of taste buds on the tongue:
Esophagus (Pharynx)
• Tube that squeezes food from the mouth to the stomach
Stomach
• Begins digestion of protein
• Produces pepsin and acid
• Stores food temporarily
• Made of smooth muscle
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Stomach Facts!
• Food usually takes around 24 hours to be fully
digested, although spicy or fatty foods can
sometimes take up to 72 hours.
• Glands in the stomach produce hydrochloric acid.
The hydrochloric acid of the stomach is so strong
will easily eat through a cotton handkerchief. In
one case in California, a penny swallowed four
days earlier by a two-year-old was found riddled
with holes
• Your stomach has to produce a new layer of
mucus every two weeks otherwise it will digest
itself
• Cows have four stomachs
• A frog throws up by dragging its stomach outside
body and cleaning it. Then it stuffs its stomach
back in its body!
it
its
Small Intestine
• Finishes digesting fats, carbohydrates and
proteins
• Villi in the small intestine!
• The small intestine sends nutrients into the
blood after they are absorbed by tiny villi
(finger-like protrusions from the small
intestine).
• This picture was taken with a camera hooked
up to a special type of microscope that allows
us to see the small villi on the surface of a
small intestine.
• You could not see the villi without a
microscope.
Diagram of villi in the small intestine
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Pancreas
• Produces pancreatic juice, which has many digestive enzymes that get sent to the small intestine
Liver
• Large organ that makes bile
• Important in removing toxins and processing digested food
Bile Facts!
• Bile acts as a detergent, and emulsifies (breaks down into small pieces) the fat in food so it can be
absorbed by the small intestine. (This is a physical change)
• The human liver produces about 1 L of bile per day.
• 95% of bile is reabsorbed and re-used
Liver Facts!
• The liver regulates blood sugar levels
• The liver is the largest internal organ
• Because your liver has so many vital functions, you would die within 24 hours if it stopped working.
• A common sign of a damaged liver is jaundice, a yellowness of your eyes and skin. This happens
when bilirubin, a yellow breakdown product of
your red blood cells, builds up in your blood.
Gallbladder
• Stores bile and empties it into the small
intestine
Appendix
• Finger-like projection attached at the junction
between the small and large intestine
• Has no function in humans
Appendix Information / Facts!
• Evidence suggests that our evolutionary
ancestors used their appendices to digest
tough food like tree bark, but we don't use
ours in digestion now.
• Some scientists believe that the appendix will disappear from the human body because we don’t use
it
• In animals that eat grasses, tree bark and bushes, the appendix holds bacteria that help to digest
cellulose.
Large Intestine
• Also called the colon
• Absorbs water from waste material
• Forms feces
Rectum and Anus
• The rectum stores feces until they are
excreted
• Feces exit the body through the anus
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