Download L3 Small Intestine File

L3 Outline
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Job of the small intestine digestion and absorption
Parts of the small intestine
Chemical digestion in the small intestine
Absorption in the small intestine
Diagram work
Do Not Copy
L2 Quiz Upper Digestion
55
1. What is this?
Stomach
56
2. How long to empty the stomach?
2-6 hours
57
3. What enzyme is secreted by the stomach?
n
Pepsin
58
4. What is the pH of the stomach? 2, 7, 10?
2
L3 The SMALL INTENSTINE - Digestion
Mechanical digestion in this location involves
peristalsis.
Chemical digestion involves
¤ Intestinal enzymes secreted by the wall of the intestine
break down starches. Lipase secreted here
¤ The pancreas secretes enzymes to further break down
fats, proteins and starches. Trypsin is produced here
¤ The liver secretes bile via the gall bladder to emulsify
fats.
L3 The Digestive Process - Absorption
How does the body process food?
The small intestine is a thin tube
of up to 7 meters long. Has a large
surface area.
L3: The SMALL INTENSTINE
The small intestine
extends from the pyloric
sphincter to the ileocecal
sphincter.
The small intestine is
divided into the
duodenum, jejunum,
and ileum.
L3 The SMALL INTENSTINE - Absorption
Absorption of the broken down starch, protein and
fat occurs in the ileum into the blood or lymph.
Absorption occurs by diffusion, facilitated diffusion,
osmosis, and active transport; most (90%) occurs in the
small intestine.
L3 The SMALL INTENSTINE - Villi
To help absorb nutrients the
wall of the small intestine
appears like velvet. It’s
surface is covered by villi,
microvilli, and folds.
Just under the surface is
blood vessels (lacteals) that
take the nutrients away.
L3: The SMALL INTENSTINE Assignment
1. Draw a cross section of a villi from a slide and label
the (pg 269) Summary #3
• villi
• lacteal
• arteries and veins
• 2. Draw and label the small intestine. With the
duodenum, jejunum and ileum (pg 266 or internet)
Summary #4
3. Work on the digestive system worksheet with
enzymes and pH (pg 266, 267 and 274)