Transcript Human Digestive System

Human Digestive System
Chapter 5 / 11
I. Heterotrophic Nutrition

A.

Organisms obtain own
food
Ingest
Taking in of food
B.


Digestion
Breaking down food
Large food molecules are
broken down into usable
form
C. Absorption

Small molecules move into cells
•D. Egestion
•Removal of undigested (unused) foods
(solid)
Nutrition
 Activities
by which
organisms obtain and
process nutrients needed
for growth, repair, energy,
and regulation
 Maintain Metabolism
A. 6 Nutrients

No Digestion
required



1 – Vitamins
2 – Minerals
3 - Water

Digestion required



1 – carbohydrates
2 – Proteins
3 - Lipids
B. Roughage (Fiber)
•Human diet must contain fiber
•Fiber is indigestible and contains
cellulose
•Ex: Fruits, Vegetables, Whole Grains

YouTube - Digestion 2
Digestive system animation

YouTube - The Digestive System
animation
V. Human Digestive
System
 One
way tract
 GI Tract or Alimentary Canal
 Oral CavityPharynx
Esophagus Stomach
Small Intestine Large
Intestine RectumAnus
Human digestive
system
II. Digestive Organs
1.Oral Cavity - Mouth
 Teeth mechanical digestion
 Salivary GlandsChemical
Digestion

Carbohydrates salivary amylase
mouth
break up food
digest starch
kill germs
moisten food
stomach
kills germs
break up food
digest proteins
store food
sphincter
sphincter
Pharynx
(throat)
 Where oral
cavity and nasal
cavity meet
2.
Epiglottis
 Flap of cartilage
 Closes trachea
(windpipe) to
lungs when you
swallow
 Allows food to
go down
esophogus
 “Down the
wrong pipe”
3.
4.Esophagus
 Connects
mouth to
stomach
 Peristalsis Muscular
Contraction
 No
digestion
here
3. Stomach
Gastric juices and Hydrochloric
Acid
 Proteins  gastric protease and
pepsin
 HCl provides proper pH level for
protease

mouth
break up food
digest starch
kill germs
moisten food
stomach
kills germs
break up food
digest proteins
store food
sphincter
sphincter
4. Small Intestine
 18-23ft
long
 Long thin more surface area
absorption
 Villi:
small finger like
projections – line small
intestine – absorb nutrients
Villi – Small Intestine
 All
Digestion finishes in
the Small Intestine
 Lipids start and finish
here (bile and enzyme)
 Lipids enzyme lipase
 Carbohydrates and
proteins finish here
III. Accessory Organs
Food
does not pass
through
Secrete substances
into the Small
intestine!
Accessory Organs
small
intestine
pancreas
A. Liver
- Secretes bile (not an enzyme)
 Emulsifies fat (squishes) 
Mechanical digestion
B. Gall bladder
Stores
bile
C. Pancreas
 Pancreatic
enzymes
(juices)  protease,
lipase, amylase
 Chemical Digestion
mouth
break up food
digest starch
kill germs
moisten food
liver
produces bile
- stored in gall
bladder
break up fats
pancreas
produces enzymes to
digest proteins &
starch
stomach
kills germs
break up food
digest proteins
store food
small intestines
breakdown food
- proteins
- starch
- fats
absorb nutrients
6. Large Intestine
 Undigested
and Unabsorbed
materials pass here
 Short and thick
 No digestion
 Water absorption from food
mass
mouth
break up food
digest starch
kill germs
moisten food
liver
produces bile
- stored in gall
bladder
break up fats
pancreas
produces enzymes to
digest proteins &
carbs
stomach
kills germs
break up food
digest proteins
store food
small intestines
breakdown food
- proteins
- starch
- fats
absorb nutrients
large intestines
absorb water
IV. Malfunctions of the
Digestive System
A. Ulcer
Open sores in the interior wall of
the digestive tract – stomach
 Treatments antacids, surgery,
diet
 Caused (supposedly) due to stress
or nervousness – also hereditary

B. Constipation
 Large
intestine absorbs too
much water
 Treatment:
Eat fruits and
veggies, Laxative, Fiber
C. Diarrhea

Decreased water absorption in the
large intestine

Watery Feces

Result severe dehydration

Treatment: Pepto Bismol,
Kaopectate
D. Appendicitis
 Inflammation
appendix
 Treatment:
of the
Surgery
Appendix
Vestigial organ

YouTube - Treatment appendicitis
E. Gallstones
Accumulation of hardened
cholesterol deposits in the
gallbladder
 Cause: bad diet, hereditary

 Treatment:
Medication,
Surgery, Better Diet

YouTube - Gall bladder-stones
In the Lab:
Indicators:
Indicate if a substance is
present in a mixture

1.

Blue Benedict’s Solution:
Tests for MONOSACCHARIDE
 Blue  Orange/Red
Lugol’s Iodine:
 Tests for polysaccharides  starch
 Turns from amber blue/black
2.
Unglazed Paper:
 Tests for Lipids
Paper will become translucent
if fats are present
3.

Human Nutrition
 Needs
vary with
 Age
 Gender
 Activity Level
 Energy
content of food is expressed
in calories