1.4 Human Organs & Systems digest & endocrine

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Transcript 1.4 Human Organs & Systems digest & endocrine

p. 62 – 63
Mechanically &
chemically breaks
down food so the
body can use the
nutrients
 Major organs:

› stomach
› liver
› pancreas
› intestines
Mouth
 Teeth break down food into smaller pieces
(mechanical digestion)
 Swallowed food passes through the throat
(pharynx) to the esophagus
Esophagus (food pipe)
 Muscular tube that
& relaxes to push
chunks of food down
to the stomach
› waves of muscle
contraction is called
peristalsis
contracts

Contains liquids called gastric juices that
chemically break down the food more
› juices are highly acidic

Stomach muscles contract
to mix the contents, which
continues the mechanical
breakdown of food
› churning action of stomach
& gastric juices cause food
to break down into a liquid

Food is pushed into the
small intestine
duodenum, ileum, jejunum

Divided into 3 sections
› where the rest of
digestion takes place
› where nutrients are
absorbed
Pancreas, liver, and gall bladder release
digestive chemicals called enzymes into the
duodenum via small tubes called ducts
 Walls of the small intestine are covered with
little projections called villi

› they increase the surface area so that more
nutrients and water can be absorbed into the
bloodstream
Includes the colon, rectum & anus (oh geez)
 Absorbs water, vitamins
& salts from digested
food

› achieved by bacteria in
the gut like E. coli

Remaining (undigested)
food is eliminated as
feces (poo)

The path of a meal from
start to finish:
› mouth  throat (pharynx)
 esophagus  stomach
 small intestine
 large intestine

Weird facts:
› it takes 24 to 33 hrs for a
meal to go from beginning
to end of this system
› the small intestine is
between 6 – 10 m in an
adult
1.
2.
3.
4.
Identify the structures A. – E.
Name 3 organs that help
digest any food that enters
the small intestine.
Name 4 organs in the
digestive system that
chemically break down
food.
Which part(s) of the digestive
systems mechanically breaks
down food?
Human Growth
Hormone
Makes chemicals
called hormones that
allow organs in the
body to function
 Many organs make
up this system, ex:

› glands (adrenal, thyroid,
pituitary, etc.)
› pancreas
› kidneys
› ovaries / testes
Food arriving to your stomach causes the
endocrine system to release hormones
called gastrin, pepsin and secretin that
help break down the food
 Pancreas releases
insulin and glucagon
when sugars in the
blood are high

(e.g., when you eat
sugary foods)
candy or