5. The Large Intestine/Colon - These substances pass into appendix, a small saclike organ Clogged and inflamed = appendicitis. Removal needed. Large Intestine.

• 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

• 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.

How much fat??

• 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 disordersFound in: Meats, eggs, dairy products

include

include

such as such as

are made of include

5 Nutrients

includeare made using

Section 38-1

Nutrients

Carbohydrates Fats MineralsProteins Vitamins

Simple ComplexAmino acids

Calcium Iron

Fatty Acids Glycerol

Sugars Starches Fat-solubleWater-soluble

• Q: What is the 6th type of nutrient missing from this chart?• A: Water!

•

• 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!

FatsSugars

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.

Meat, Poultry, Fish, Dry Beans, Eggs, and Nut Group(2-3 servings)These foods are high in protein. They also supply vitamins and minerals.

Vegetable Group(3-5 servings)Vegetables are a low-fat source of carbohydrates,fiber, vitamins, and minerals.

Fruit Group(2-4 servings)Fruits are good sources of carbohydrates, fiber, vitaminsand water.

Bread, Cereal, Riceand 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.

 Food Guide PyramidSection 38-1

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

Kidney (Cross Section)

Cortex

Medulla

Vein Artery

Kidney

Ureter

Urinary bladder

Urethra

The Urinary System

Section 38-3

• 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.

Click to enlarge

Close-up: The Kidney

• 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.

Kidney Nephron

Cortex

Medulla Renal artery

Renal vein

Ureter

To the bladder

Bowman’s capsule

Glomerulus

Capillaries

Collecting duct

To the ureter

Loop of Henle

Artery

Vein

Section 38-3The Kidney and Nephron

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.

Reabsorption

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 NephronSection 38-3

•Q: Should glucose be in the urine? •A: No. It could be a sign of diabetes.

The nephron - a summary

• 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 transplantDialysis

Vein

Artery

Shunt

Air detector Dialysis machine

Blood pump

Blood in tubing flows through dialysis fluid

Used dialysis fluid

Compressed air

Fresh dialysis

fluid

 Kidney DialysisSectio 38-3