Transcript Unit 10 Chapter 35 The Digestive and Endocrine Systems

Unit 10
Chapter 35
The Digestive
and
Endocrine
Systems
The Digestive System
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Functions:
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Ingestion
Mechanical &
chemical digestion
Absorption
Elimination of
solid wastes
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The Digestive System
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Mouth:
Teeth
Adapted for tearing &
grinding food
Tongue
Adapted for tasting, &
swallowing food, speech
Salivary glands
Secretes enzymes for
digestion of starch
The Digestive System
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Esophagus
Muscular
passageway that
connects the throat
to the stomach
Peristalsis
Wavelike
contractions for
moving food through
the digestive tract
The Digestive System
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Stomach
Muscular, pouch-like enlargement of the
digestive tract
Mechanical digestion,
muscular churning
Chemical digestion,
gastric fluids begin
the digestion of protein
The Digestive System
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Small intestine
Muscular tube connecting
the stomach and large
intestine
Completion of digestion by
chemicals added from
pancreas & liver
Absorption of food by villi
Fingerlike projections that
increase the surface area
Cross-section of Small Intestine showing villi
The Digestive System
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Liver (I)
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Gall bladder (H)
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Large organ that
produces bile, which
breaks down fats
Small organ storing bile
from liver
Pancreas (D)
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Soft gland that secretes
both digestive enzymes
& hormones
The Digestive System
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Large intestine
Muscular tube leading from the small
intestine to the rectum
Absorption of
water & minerals
Synthesis of vitamins
by symbiotic bacteria
Elimination of
indigestible wastes
Nutrition
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Carbohydrates
(sugars & starches)
The body’s main source for energy
Lipids (fats, oils & waxes)
Stores energy for the body and used as
building materials for cell membrane
Proteins
Provides cell structure & function, i.e.
enzymes, hormones, antibodies, etc
Nutrition
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Minerals & vitamins
For normal growth and chemical
reactions
Minerals are inorganic, such as
iron, iodine, & sodium
Vitamins are organic, such as
riboflavin, niacin, & ascorbic acid
Water
Facilitates chemical reactions,
universal solvent, maintains body
temperature
Calories measure energy content of food in units of heat
The Endocrine System
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Ductless glands that
secrete hormones into
the bloodstream
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Hormones
Chemical messengers
relaying information to
other, target, organs
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The Endocrine System
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Negative feedback
Increasing one hormone
inhibits another to reduce
the production of the
second hormone
Ex: insulin decreases
sugar while glucagon
increases sugar, together
maintaining blood sugar
levels
The Endocrine System
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Hypothalamus
Portion of the brain that connects the
nervous and endocrine system (pituitary g.)
Pituitary gland
Secretes 9 hormones that directly regulate
the actions of several other endocrine
glands
Ex: Growth hormone is essential for
normal growth & development
The Endocrine System
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Thyroid gland
Has a major role in regulating the body’s
metabolism
Ex: Calcitonin
regulates calcium
levels in the blood
The Endocrine System
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Adrenal gland
Plays a major role in preparing the body
for stressful situations
Ex: Epinephrine
(adrenalin)
is associated with
the body’s fight
or flight reactions