Transcript Food and Nutrition

• 5. The Large Intestine/Colon • These substances pass into appendix, a
small saclike organ
• Clogged and inflamed = appendicitis.
Removal needed.
• Large Intestine -11.5 long x 5 cm wide
- removes water from undigested
material
• Bacteria in colon produce needed
compounds, including Vitamin K.
• Antibiotics can destroy these beneficial
bacteria. (Eat yogurt!)
• Next - eliminate wastes. Go out rectum
and anus = feces
• Disorders:
• Diarrhea - not enough water is absorbed.
• Constipation - too much water is
absorbed - stays in colon too long.(Eat
fiber!)
• Colon polyps or cancer
Food and Nutrition - Some basic facts
• Food gives you energy (fuel)
• When you eat, you break
down the food into sugar
glucose (+ others), then
convert it into ATP
• When you burn your food
using ATP (respiration), the
energy is converted to heat
which is measured in calories
• calorie = the amount of heat
needed to raise the
temperature of 1 gram of
water by 1 degree Celsius
• We use kilocalorie (= 1000
calories) or Calorie
• Ex: Lab: Calorimetry
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How much fat??
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Nutrients - substances in food which supply energy and
materials your body uses for growth, repair, and
maintenance
6 types: Water, carbohydrates, fats, proteins, vitamins,
minerals.
1. Water - all body’s processes and chemical reactions
take place in water
2. Carbohydrates - energy source:
Ex: fruits, vegetables, grains.
Get broken down into glucose, fructose, galactose.
Monosaccharides, Disaccharides, Polysaccharides
3. Fats (Lipids) - store energy, make cell membranes,
hormones
Ex: Butter & animal fats = (saturated/solid/single bonds
between the C atoms.)
Ex: Vegetable oils = (unsaturated/liquids/at least 1
double bond, or many = polyunsaturated).
Get broken down into fatty acids & glycerol.
Fat Rec: Max. of 30% Calories from fat, only 10% from
saturated fats. Risks: high blood pressure, heart disease,
obesity, diabetes.
• 4. Proteins - growth, repair,
regulatory.
• Get broken down into amino acids.
• Ex: Meat, fish, eggs, milk.
• 5. Vitamins-regulate body
processes, work with enzymes.
• Ex: Fat soluble (stored) = A,D,E,K.
Water soluble (not stored)= C,B.
• 6. Minerals - inorganic nutrients
needed in small amounts.
• Ex: Calcium, iron, sodium,
potassium.
• See next slide for an overview of
nutrients.
Ex: Vitamin B-12:
Deficiency = anemia, nervous system disorders
Found in: Meats, eggs, dairy products
Section 38-1
5 Nutrients
Nutrients
include
Carbohydrates
Fats
include
are made of
Simple
Complex
such as
such as
Starches
are made using
Vitamins
Minerals
include
include
Amino
acids
Fatty Acids
Sugars
Proteins
Calcium
Glycerol
Fat-soluble
• Q: What is the 6th type of nutrient missing from this chart?
• A: Water!
Watersoluble
Iron
• Q: What balance of these nutrients should we eat?
• A: Scientists made a Food Pyramid that classifies foods
into 6 groups, & shows how many servings from each
group should be eaten every day. See next slide!
Section 38-1
Food Guide Pyramid
Fats, Oils, and Sweets (use sparingly)
Soft drinks, candy, ice cream, mayonnaise, and
other foods in this group have relatively few
valuable nutrients.
Milk, Yogurt, and Cheese Group
(2-3 Servings)
Milk and other dairy products are rich in
proteins, carbohydrates, vitamins, and
minerals.
Vegetable Group
(3-5 servings)
Vegetables are a low-fat
source of carbohydrates,
fiber, vitamins, and minerals.
Fats
Sugars
Meat, Poultry, Fish, Dry Beans, Eggs,
and Nut Group
(2-3 servings)
These foods are high in protein.
They also supply vitamins and minerals.
Fruit Group
(2-4 servings)
Fruits are good sources of
carbohydrates, fiber, vitamins
and water.
Bread, Cereal, Rice
and Pasta Group
(6-11 servings)
The foods at the base of the
pyramid are rich in complex
carbohydrates and also
provide proteins, fiber,
vitamins, and some
minerals.
Q: How do you know what is in the food that you eat?
A: Read the Nutritional Food Labels- see below:
Q: What is the best way for an average person to lose weight?
A: No liquid or crash diets; lose weight slowly over time.
•Cut down Calories including carbohydrates and fats, get exercise.
•If you lose weight too fast, it may be water weight, and you will gain it all back. (Ex:
Yo-yo dieting.)
Teen problems - losing too much weight can stunt your growth, even permanently! Need
to eat a balanced diet. Problems: anorexia and bulimia
The Excretory
System
How Do We Excrete Our Liquid
Wastes?
• Every cell in the body produces
metabolic wastes: excess salts,
CO2, urea
• Urea - toxic compound produced
when AA. are used for energy.
• Excretion - eliminating metabolic
wastes. Organs involved:
• a.skin (water, salts, urea (sweat)
b.lungs (CO2 gas)
c. liver -converts poisonous
nitrogenous wastes into urea
d. kidneys - principal organs of
excretion. Remove urea from the
bloodstream; maintain blood pH;
regulate water content of blood,
maintain homeostasis.
• Kidneys - 2,located near lower
back. Unfiltered blood enters
kidney through renal artery.
Kidney removes urea, excess
water, waste products, passes
them to ureter.
• Ureter- tube which leaves each
kidney. Carries urine to bladder.
• Urinary bladder - saclike organ
where urine is stored before being
excreted
• Clean, filtered blood leaves
kidney through renal vein, returns
to circulation.
• This system is also called “The
Urinary System” or tract
Section 38-3
The Urinary
System
Vein
Kidney (Cross Section)
Kidney
Cortex
Medulla
Ureter
Urinary bladder
Urethra
Artery
Click to enlarge
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Kidney Structure - cross section (cut kidney in half)
Inner part = Renal medulla
Outer part = Renal cortex
Functional units = nephrons, located in renal cortex, except for loops of
Henle.
• Microscopic, 1,000,000 per kidney. Each has its own blood supply:
arteriole, venule, capillaries.
• Blood enters nephron through arteriole, impurities are filtered out and are
emptied into collecting duct.
• Purified blood exits nephron through venule.
Close-up: The Kidney
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2 Processes of blood purification:
1. Filtration - takes place in glomerulus, a
network of capillaries at beginning of nephron.
Encased by a hollow, cup-shaped structure called
Bowman’s capsule. Filtration slide
Going into nephron, blood is under pressure;
much of fluid from blood flows into Bowman’s
capsule = filtrate. Filtrate contains water, urea,
glucose, salts, amino acids,some vitamins.
Too large particles do not go into capsule, thus
remain in blood: proteins, cells, platelets.
Kidneys filter all body’s blood every 45 minutes
2. Reabsorption - Not all of filtrate is excreted;
most gets back into blood. When liquid is taken
back into a vessel = reabsorption.
Ex: amino acids, fats, glucose, water
Urine = material that remains (urea, excess salts
& water), concentrated in loop of Henle.
Purified blood is returned to circulation.
Urine is collected in urinary bladder, then
released through urethra = Excretion.
The Kidney and Nephron
Section 38-3
Kidney
Nephron
Bowman’s
capsule
Cortex
Capillaries
Glomerulus
Medulla
Renal
artery
Renal vein
Ureter
Collecting
duct
Vein
To the bladder
Artery
Loop of Henle
To the ureter
The Nephron
Section 38-3
Reabsorption
Filtration
Most filtration occurs in the
glomerulus. Blood pressure forces
water, salt, glucose, amino acids,
and urea into Bowman’s capsule.
Proteins and blood cells are too
large to cross the membrane; they
remain in the blood. The fluid that
enters the renal tubules is called
the filtrate.
•Q: Should glucose be in the urine?
•A: No. It could be a sign of diabetes.
As the filtrate flows through the
renal tubule, most of the water
and nutrients are reabsorbed into
the blood. The concentrated fluid
that remains is called urine.
The nephron - a summary
Dialysis
• Q: Can you live with your kidneys?
Without 1 kidney?
• Q: Why do athletes get urine tests?
• A: Drugs generally remain in filtrate
and are eliminated in urine.Urine
testing is now done routinely to check
for presence of prohibited drugs. Also
used to screen job applicants.
• Q: What are kidney stones?
• A: Calcium, magnesium, uric acid
salts crystallize and form kidney
stones. Block ureter, cause pain.
Treatment: ultrasound waves.
• Q: What is dialysis?
• A:Blood is removed from body
pumped through tubing that acts like
nephrons, wastes are removed,
purified blood returns to body.
• Option: Kidney transplant
Kidney Dialysis
Sectio 38-3
Blood in tubing flows
through dialysis fluid
Blood pump
Vein
Artery
Used dialysis fluid
Shunt
Air detector
Dialysis
machine
Fresh
dialysis
fluid
Compressed
air