1. KEY CONCEPT Cells require many different nutrients.

2. Carbohydrates are the main source of energy for the body.
simple and complex carbohydrates supply glucose
fiber from plant foods helps elimination
Simple and Complex Carbohydrates

3. Proteins are necessary for growth and repair of the body’s cells.
body makes 12 out of 20 amino acids
other eight essential amino acids come from food
Fats provide energy and key building components.
fats are saturated and unsaturated
essential fatty acids come from food
Proteins and Fats

4. Minerals are inorganic materials.
help to build or repair tissues
replenished by eating variety of foods

5. Vitamins are organic molecules that work with enzymes.
vitamins are fat-soluble and water-soluble
regulate cell functions, growth, development
replenished by eating variety of foods

6. KEY CONCEPT The digestive system breaks down food into simpler molecules.

7. Several digestive organs work together to break down food.
The digestive system breaks down food into energy cells can use.
After digestion is complete, nutrients are absorbed and transported to all cells.
Undigested materials are eliminated as liquid and solid wastes.
mouth
esophagus
liver
gallbladder
large intestine
small intestine
rectum/anus

8. Digestion begins in the mouth and continues in the stomach.
Mechanical and chemical digestion break down food.
Peristalsis moves food through the organs.
esophagus
muscles contract
muscles relax
food
stomach

9. Digestion of carbohydrates begins in the mouth.
Digestion of proteins occurs in the stomach.
Digestion of fats and sugars occur in the small intestine.

10. Digestion is completed in part of the small intestine.
Most digestion takes place in the duodenum.
The pancreas, liver, and gallbladder aid in digestion.
pancreas helps digest fat and protein
bile from the liver/gallbladder helps digest fats
liver
stomach
bile
chyme
bile
enzymes
gallbladder
pancreas
duodenum

12. Saliva contains an enzyme (amylase)
Amylase breaks down starches into maltose (disaccaride)

13. Stomach contains pepsin, an enzyme activated HCl
Pepsin breaks down proteins to form amino acids

14. Small intestine is 6m long!
The pancreas secretes many enzymes to break down nutrients in food
Gallbladder secretes bile for fat digestion
Bile is a mechanical digestion; emulsification; bile and lecithin form droplets of fat called micelles; then the fats are broken down by lipase
Pancreas also releases hormones to tell the body it is full

15. Diarrhea occurs when the muscles are contracting too quickly  not enough time for water to be removed from bolus  watery stool
Diarrhea occurs when the muscles are contracting too quickly  not enough time for water to be removed from bolus  watery stool
Constipation is opposite

16. This is defection.

17. Most absorption of nutrients occurs in the small intestine.
Three structures in the small intestine help absorb nutrients.
folded lining: adds surface area, slows food
villi: absorb nutrients
microvilli: cover villi, absorb nutrients

18. Duodenum- simple sugars, amino acids, and minerals are absorbed and go to liver
Jejunum- glucose, amino acids, vitamins and water are absorbed and go to body parts
Ileum- absorb fat soluble vitamins, vitamin B12,, fatty acids, cholesterol

19. Nutrients enter the circulatory or lymphatic systems.
Liver stores excess glucose for future use.
liver
small intestine

20. The colon helps to maintain the body’s fluid balance.
Water is absorbed and solid wastes are eliminated from the large intestine.
The colon helps to maintain the body’s fluid balance.
Undigested material forms the solid feces.
stored in rectum
eliminated through anus
large intestine
rectum/anus

21. KEY CONCEPT The excretory system removes wastes and helps maintain homeostasis.

22. Kidney
filters blood
salt and water absorption
located behind the intestines
Ureter
carries urine from kidney to bladder
Bladder
holds urine
Urethra
carries urine from bladder out of body

23. The excretory system eliminates nonsolid wastes from the body.
Nonsolid wastes are eliminated through lungs, skin, and kidneys.
Lungs exhale carbon dioxide and water vapor.
Sweat glands in skin release excess water and salts.
Kidneys filter and clean the blood to produce urine.
skin
lungs
kidneys
ureters
urinary bladder
urethra

24. The kidneys help to maintain homeostasis by filtering the blood.
cortex
medulla
renal artery
renal vein
ureter
(to bladder)
Kidneys are a pair of bean-shaped organs.
two layers: medulla and cortex
filtering units called nephrons
renal artery and renal vein

25. Kidneys have three basic functions in maintaining homeostasis.
remove waste from blood
help to maintain electrolyte, pH, and fluid balances
release key hormones

26. Nephrons clean the blood and produce urine.
Nephrons are the filtering units in the kidneys.
They clean and rebalance the blood to produce urine.

27. Nephrons clean the blood in a three-step process.
The first step is filtration of the blood.
FILTRATION
Water,electrolytes,aminoacids,glucose,urea, and other small molecules diffuse out of the blood,creating the filtrate. 1
Glomerulus
Bowman’s capsule

28. The first step is filtration of the blood.
The second step is reabsorption of materials.
The third step is excretion of materials.
REABSORPTION
As the filtrate enters the rest of the tubule ,most of the materials are reabsorbed into the blood.Materials not reabsorbed make up the urine,which flows into the loop of Henle. 2
from body
collecting duct
EXCRETION
In the loop of Henle,water can be reabsorbed one final time to reduce the volume of urine.The remaining urine flows into a collecting duct that leads to the ureter. 3
to body
from other nephrons
loop of Henle

29. Dialysis can be used to filter and clean the blood.