Uploaded by Julie Tak 탁효서

digestive system

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HUMAN BODY
SYSTEM
14 APRIL 2019
WHAT IS DIGESTIVE
SYSTEM?
1.
Take in food (ingestion)
2. Digest food into smaller molecules
and absorb nutrients
3.
Remove undigestable food from
body (feces)
WHAT IS CIRCULATORY
SYSTEM?
• Transport materials to and from cells
WHAT IS NERVOUS
SYSTEM?
1.
Gathers and interprets information
2.
Responds to information
3.
Helps maintain homeostasis
WHAT IS EXCRETORY
SYSTEM?
1.
Removes waste products from
cellular metabolism (urea, water,
CO2)
2.
Filters blood
WHAT IS
RESPIRATORY SYSTEM?
Takes in oxygen and removes carbon dioxide
and water
Respiration:
Respiration refers to a person’s breathing and
the movement of air into and out of the lungs.
The respiratory system provides oxygen to
body tissues for cellular respiration and
removes the waste product carbon dioxide.
WHAT IS SKELETAL
SYSTEM?
1.
Protects organs
2.
Provides shape, support
3.
Stores materials (fats, minerals)
4.
Produces blood cells
5.
Allows movement
WHAT IS MUSCULAR
SYSTEM?
Allows for movement by contracting
and relaxing
WHAT IS
REPRODUCTIVE SYSTEM?
Allows organisms to reproduce which
prevents their species from becoming
extinct.
HUMAN
DIGESTIVE
SYSTEM
Recall:
WHAT IS DIGESTIVE
SYSTEM?
1.
Take in food (ingestion)
2. Digest food into smaller molecules
and absorb nutrients
3.
Remove undigestable food from
body (feces)
3 TYPES OF FOOD
• Carbohydrate
• Protein
• Fats
MOUTH
• The mouth is where the digestive
tract begins. Enzymes released into
the mouth start the process of
digestion.
WHAT ARE ENZYMES? (RECAP)
TEETH/TOOTH
• Teeth are the organs of chewing,
which is also known as mastication.
• Break down into smaller substances,
leading to an increase of surface area.
• By age 7, 32 permanent or secondary
teeth are developed & are divided into 4
types: incisors (for cutting) , Canines
(for tearing) , Premolars (for crushing),
and Molars (for grinding). these teeth
follow the human dental formula of 2-12-3.
TONGUE AND
SALIVA
The tongue , made of skeletal muscle,
manipulates the food during mastication.
It also contains taste buds to detect
taste sensations (intrinsic).
Food particles are mixed with saliva
during mastication , resulting in a moist
lump called bolus for easier passage
into or pharynx .
GULLET OR
OESOPHAGUS
It carries swallowed masses of chewed
food along its length, from mouth to
stomach.
How can we swallow while lying down
and without the help or gravity?
- Peristalsis!
PERISTALSIS
The involuntary constriction and
relaxation of the muscles of the
intestine or another canal, creating
wave-like movements that push the
contents of the canal forward.
STOMACH
• A pouch-like organ primarily designed
for food storage (for 2-4 hours), some
physical/ mechanical and chemical
digestion also occur
• Churns, mixes and stores food
• Digestion takes 2 forms– Physical and
Chemical digestion
• Stomach contributes to both forms of
digestions
SMALL INTESTINE
• A long tube, with a small diameter
(about 1 inch), extending from stomach
to large intestine
• The small intestine is the part of the
intestines where 90% of
the digestion and absorption of food
occurs, the other 10% taking place in
the stomach and large intestine.
• The main function of the small intestine
is absorption of nutrients and
minerals from food.
LARGE INTESTINE
• The last segment of the GI tract , with
a large diameter (2-3 inches)
• Water is absorbed here and the
remaining waste material is stored as
feces before being removed by
defecation
• Make your feces compact
RECTUM AND
ANUS
• The rectum is a chamber that begins
at the end of the large intestine, and
ends at the anus