View
218
Download
1
Category
Tags:
Preview:
Citation preview
The Digestive System
Functions:
Ingestion Mechanical &
chemical digestion Absorption Elimination of
solid wastes
The Digestive System 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 Esophagus Muscular
passageway that connects the throat to the stomach
Peristalsis Wavelike
contractions for moving food through the digestive tract
The Digestive System 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
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
The Digestive System Liver (I)
Large organ that produces bile, which breaks down fats
Gall bladder (H) Small organ storing bile
from liver Pancreas (D)
Soft gland that secretes both digestive enzymes & hormones
The Digestive System
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
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 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
The Endocrine System
Ductless glands that secrete hormones into the bloodstream
Hormones Chemical messengers
relaying information to other, target, organs
The Endocrine System 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
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
Thyroid gland Has a major role in regulating the body’s
metabolism
Ex: Calcitonin regulates calcium levels in the blood
The Endocrine System
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
Recommended